Fix clang-tidy check readability-implicit-bool-cast.

94 files changed, 609 insertions, 600 deletions

diff --git a/src/resources/action.cpp b/src/resources/action.cpp
index feb991684..c059624c5 100644
--- a/src/resources/action.cpp
+++ b/src/resources/action.cpp
@@ -80,7 +80,7 @@ void Action::setLastFrameDelay(const int delay) noexcept2
     FOR_EACH (AnimationIter, it, mAnimations)
     {
         Animation *const animation = (*it).second;
-        if (!animation)
+        if (animation == nullptr)
             continue;
         animation->setLastFrameDelay(delay);
     }
diff --git a/src/resources/ambientlayer.cpp b/src/resources/ambientlayer.cpp
index 50397ab6a..fe702ccde 100644
--- a/src/resources/ambientlayer.cpp
+++ b/src/resources/ambientlayer.cpp
@@ -55,7 +55,7 @@ AmbientLayer::AmbientLayer(const std::string &name,
     mMask(mask),
     mKeepRatio(keepRatio)
 {
-    if (!mImage)
+    if (mImage == nullptr)
         return;
 
     if (keepRatio &&
@@ -74,7 +74,7 @@ AmbientLayer::AmbientLayer(const std::string &name,
                 CAST_S32(mImage->mBounds.h) /
                 defaultScreenHeight * height);
 
-            if (rescaledOverlay)
+            if (rescaledOverlay != nullptr)
                 mImage = rescaledOverlay;
             else
                 mImage->incRef();
@@ -86,7 +86,7 @@ AmbientLayer::AmbientLayer(const std::string &name,
 
 AmbientLayer::~AmbientLayer()
 {
-    if (mImage)
+    if (mImage != nullptr)
     {
         mImage->decRef();
         mImage = nullptr;
@@ -95,7 +95,7 @@ AmbientLayer::~AmbientLayer()
 
 void AmbientLayer::update(const int timePassed, const float dx, const float dy)
 {
-    if (!mImage)
+    if (mImage == nullptr)
         return;
 
     const float time = static_cast<float>(timePassed) / 10;
@@ -126,7 +126,7 @@ void AmbientLayer::update(const int timePassed, const float dx, const float dy)
 void AmbientLayer::draw(Graphics *const graphics, const int x,
                         const int y) const
 {
-    if (!mImage)
+    if (mImage == nullptr)
         return;
 
     if (imageHelper->useOpenGL() == RENDER_SOFTWARE ||
diff --git a/src/resources/animation/animation.cpp b/src/resources/animation/animation.cpp
index ff3883c0d..4f83161de 100644
--- a/src/resources/animation/animation.cpp
+++ b/src/resources/animation/animation.cpp
@@ -84,7 +84,7 @@ void Animation::setLastFrameDelay(const int delay) noexcept2
     for (FramesRevIter it = mFrames.rbegin(), it_end = mFrames.rend();
          it != it_end; ++ it)
     {
-        if ((*it).type == FrameType::ANIMATION && (*it).image)
+        if ((*it).type == FrameType::ANIMATION && ((*it).image != nullptr))
         {
             (*it).delay = delay;
             break;
diff --git a/src/resources/animation/simpleanimation.cpp b/src/resources/animation/simpleanimation.cpp
index 7f20b5eef..ed92d2b50 100644
--- a/src/resources/animation/simpleanimation.cpp
+++ b/src/resources/animation/simpleanimation.cpp
@@ -43,7 +43,7 @@ SimpleAnimation::SimpleAnimation(Animation *const animation) :
     mAnimation(animation),
     mAnimationTime(0),
     mAnimationPhase(0),
-    mCurrentFrame(mAnimation ? &mAnimation->mFrames[0] : nullptr),
+    mCurrentFrame(mAnimation != nullptr ? &mAnimation->mFrames[0] : nullptr),
     mInitialized(true),
     mImageSet(nullptr)
 {
@@ -59,7 +59,7 @@ SimpleAnimation::SimpleAnimation(XmlNodeConstPtr animationNode,
     mImageSet(nullptr)
 {
     initializeAnimation(animationNode, dyePalettes);
-    if (mAnimation)
+    if (mAnimation != nullptr)
         mCurrentFrame = &mAnimation->mFrames[0];
     else
         mCurrentFrame = nullptr;
@@ -68,7 +68,7 @@ SimpleAnimation::SimpleAnimation(XmlNodeConstPtr animationNode,
 SimpleAnimation::~SimpleAnimation()
 {
     delete2(mAnimation);
-    if (mImageSet)
+    if (mImageSet != nullptr)
     {
         mImageSet->decRef();
         mImageSet = nullptr;
@@ -79,7 +79,7 @@ void SimpleAnimation::draw(Graphics *const graphics,
                            const int posX, const int posY) const
 {
     FUNC_BLOCK("SimpleAnimation::draw", 1)
-    if (!mCurrentFrame || !mCurrentFrame->image)
+    if ((mCurrentFrame == nullptr) || (mCurrentFrame->image == nullptr))
         return;
 
     graphics->drawImage(mCurrentFrame->image,
@@ -95,7 +95,7 @@ void SimpleAnimation::reset()
 
 void SimpleAnimation::setFrame(int frame)
 {
-    if (!mAnimation)
+    if (mAnimation == nullptr)
         return;
 
     if (frame < 0)
@@ -109,7 +109,7 @@ void SimpleAnimation::setFrame(int frame)
 
 bool SimpleAnimation::update(const int timePassed)
 {
-    if (!mCurrentFrame || !mAnimation || !mInitialized)
+    if ((mCurrentFrame == nullptr) || (mAnimation == nullptr) || !mInitialized)
         return false;
 
     bool updated(false);
@@ -131,7 +131,7 @@ bool SimpleAnimation::update(const int timePassed)
 
 int SimpleAnimation::getLength() const
 {
-    if (!mAnimation)
+    if (mAnimation == nullptr)
         return 0;
 
     return CAST_S32(mAnimation->getLength());
@@ -139,7 +139,7 @@ int SimpleAnimation::getLength() const
 
 Image *SimpleAnimation::getCurrentImage() const
 {
-    if (mCurrentFrame)
+    if (mCurrentFrame != nullptr)
         return mCurrentFrame->image;
     else
         return nullptr;
@@ -150,7 +150,7 @@ void SimpleAnimation::initializeAnimation(XmlNodeConstPtr animationNode,
 {
     mInitialized = false;
 
-    if (!animationNode)
+    if (animationNode == nullptr)
         return;
 
     std::string imagePath = XML::getProperty(
@@ -165,7 +165,7 @@ void SimpleAnimation::initializeAnimation(XmlNodeConstPtr animationNode,
         XML::getProperty(animationNode, "width", 0),
         XML::getProperty(animationNode, "height", 0));
 
-    if (!imageset)
+    if (imageset == nullptr)
         return;
 
     const int x1 = imageset->getWidth() / 2 - mapTileSize / 2;
@@ -192,13 +192,13 @@ void SimpleAnimation::initializeAnimation(XmlNodeConstPtr animationNode,
 
             Image *const img = imageset->get(index);
 
-            if (!img)
+            if (img == nullptr)
             {
                 reportAlways("No image at index %d", index);
                 continue;
             }
 
-            if (mAnimation)
+            if (mAnimation != nullptr)
                 mAnimation->addFrame(img, delay, offsetX, offsetY, rand);
         }
         else if (xmlNameEqual(frameNode, "sequence"))
@@ -216,20 +216,20 @@ void SimpleAnimation::initializeAnimation(XmlNodeConstPtr animationNode,
             {
                 Image *const img = imageset->get(start);
 
-                if (!img)
+                if (img == nullptr)
                 {
                     reportAlways("No image at index %d", start);
                     continue;
                 }
 
-                if (mAnimation)
+                if (mAnimation != nullptr)
                     mAnimation->addFrame(img, delay, offsetX, offsetY, rand);
                 start++;
             }
         }
         else if (xmlNameEqual(frameNode, "end"))
         {
-            if (mAnimation)
+            if (mAnimation != nullptr)
                 mAnimation->addTerminator(rand);
         }
     }
diff --git a/src/resources/atlas/atlasitem.h b/src/resources/atlas/atlasitem.h
index 5d2762fb5..4da78af6e 100644
--- a/src/resources/atlas/atlasitem.h
+++ b/src/resources/atlas/atlasitem.h
@@ -33,8 +33,8 @@ struct AtlasItem final : public MemoryCounter
         name(),
         x(0),
         y(0),
-        width(image0 ? image0->mBounds.w : 0),
-        height(image0 ? image0->mBounds.h : 0)
+        width(image0 != nullptr ? image0->mBounds.w : 0),
+        height(image0 != nullptr ? image0->mBounds.h : 0)
     {
     }
 
diff --git a/src/resources/atlas/atlasmanager.cpp b/src/resources/atlas/atlasmanager.cpp
index 8a9991714..c2da00732 100644
--- a/src/resources/atlas/atlasmanager.cpp
+++ b/src/resources/atlas/atlasmanager.cpp
@@ -76,7 +76,7 @@ AtlasResource *AtlasManager::loadTextureAtlas(const std::string &name,
     FOR_EACH (std::vector<TextureAtlas*>::iterator, it, atlases)
     {
         TextureAtlas *const atlas = *it;
-        if (!atlas)
+        if (atlas == nullptr)
             continue;
 
         createSDLAtlas(atlas);
@@ -105,7 +105,7 @@ AtlasResource *AtlasManager::loadEmptyAtlas(const std::string &name,
     FOR_EACH (std::vector<TextureAtlas*>::iterator, it, atlases)
     {
         TextureAtlas *const atlas = *it;
-        if (!atlas)
+        if (atlas == nullptr)
             continue;
 
         atlas->atlasImage = new Image(0,
@@ -132,7 +132,7 @@ void AtlasManager::loadImages(const StringVect &files,
         // check is image with same name already in cache
         // and if yes, move it to deleted set
         Resource *const res = ResourceManager::getTempResource(str);
-        if (res)
+        if (res != nullptr)
         {
             // increase counter because in moveToDeleted it will be decreased.
             res->incRef();
@@ -149,12 +149,13 @@ void AtlasManager::loadImages(const StringVect &files,
         }
 
         SDL_RWops *const rw = VirtFs::rwopsOpenRead(path);
-        if (rw)
+        if (rw != nullptr)
         {
-            Image *const image = d ? surfaceImageHelper->load(rw, *d)
-                : surfaceImageHelper->load(rw);
+            Image *const image = d != nullptr ?
+                surfaceImageHelper->load(rw, *d) :
+                surfaceImageHelper->load(rw);
 
-            if (image)
+            if (image != nullptr)
             {
                 image->mIdPath = str;
 #ifdef DEBUG_IMAGES
@@ -181,7 +182,7 @@ void AtlasManager::loadEmptyImages(const StringVect &files,
         // check is image with same name already in cache
         // and if yes, move it to deleted set
         Resource *const res = ResourceManager::getTempResource(str);
-        if (res)
+        if (res != nullptr)
         {
             // increase counter because in moveToDeleted it will be decreased.
             res->incRef();
@@ -212,7 +213,7 @@ void AtlasManager::simpleSort(const std::string &restrict name,
     for (it = images.begin(); it != it_end; ++ it)
     {
         const Image *const img = *it;
-        if (img)
+        if (img != nullptr)
         {
             atlas->name = std::string("atlas_").append(name).append(
                 "_").append(img->mIdPath);
@@ -223,7 +224,7 @@ void AtlasManager::simpleSort(const std::string &restrict name,
     for (it = images.begin(); it != it_end; ++ it)
     {
         Image *const img = *it;
-        if (img)
+        if (img != nullptr)
         {
             AtlasItem *const item = new AtlasItem(img);
             item->name = img->mIdPath;
@@ -279,7 +280,7 @@ void AtlasManager::emptySort(const std::string &restrict name,
     for (it = images.begin(); it != it_end; ++ it)
     {
         const Image *const img = *it;
-        if (img)
+        if (img != nullptr)
         {
             atlas->name = std::string("atlas_").append(name).append(
                 "_").append(img->mIdPath);
@@ -290,7 +291,7 @@ void AtlasManager::emptySort(const std::string &restrict name,
     for (it = images.begin(); it != it_end; ++ it)
     {
         Image *const img = *it;
-        if (img)
+        if (img != nullptr)
         {
             AtlasItem *const item = new AtlasItem(img);
             item->name = img->mIdPath;
@@ -340,7 +341,7 @@ void AtlasManager::createSDLAtlas(TextureAtlas *const atlas)
     // temp SDL surface for atlas
     SDL_Surface *const surface = MSDL_CreateRGBSurface(SDL_SWSURFACE,
         width, height, 32U, rmask, gmask, bmask, amask);
-    if (!surface)
+    if (surface == nullptr)
     {
         reportAlways("Error creating surface for atlas. Size: %dx%d",
             width,
@@ -401,7 +402,7 @@ void AtlasManager::convertEmptyAtlas(TextureAtlas *const atlas)
     // convert surface to OpemGL image
     Image *const oldImage = atlas->atlasImage;
 
-    if (oldImage->mSDLSurface)
+    if (oldImage->mSDLSurface != nullptr)
     {
         atlas->atlasImage = imageHelper->loadSurface(
             atlas->atlasImage->mSDLSurface);
@@ -409,7 +410,7 @@ void AtlasManager::convertEmptyAtlas(TextureAtlas *const atlas)
     }
 
     Image *const image = atlas->atlasImage;
-    if (!image)
+    if (image == nullptr)
         return;
 
     image->mIdPath = atlas->name;
@@ -429,7 +430,7 @@ void AtlasManager::convertEmptyAtlas(TextureAtlas *const atlas)
         item->image = image->getSubImage(item->x, item->y,
             item->width, item->height);
         Image *const image2 = item->image;
-        if (image2)
+        if (image2 != nullptr)
         {
             image2->mIdPath = item->name;
 #ifdef DEBUG_IMAGES
@@ -448,7 +449,7 @@ void AtlasManager::convertAtlas(TextureAtlas *const atlas)
     // convert surface to OpemGL image
     Image *const oldImage = atlas->atlasImage;
 
-    if (oldImage->mSDLSurface)
+    if (oldImage->mSDLSurface != nullptr)
     {
         atlas->atlasImage = imageHelper->loadSurface(
             atlas->atlasImage->mSDLSurface);
@@ -456,7 +457,7 @@ void AtlasManager::convertAtlas(TextureAtlas *const atlas)
     }
 
     Image *const image = atlas->atlasImage;
-    if (!image)
+    if (image == nullptr)
         return;
 
     image->mIdPath = atlas->name;
@@ -476,7 +477,7 @@ void AtlasManager::convertAtlas(TextureAtlas *const atlas)
         item->image = image->getSubImage(item->x, item->y,
             item->width, item->height);
         Image *const image2 = item->image;
-        if (image2)
+        if (image2 != nullptr)
         {
             image2->mIdPath = item->name;
 #ifdef DEBUG_IMAGES
@@ -491,22 +492,22 @@ void AtlasManager::convertAtlas(TextureAtlas *const atlas)
 
 void AtlasManager::injectToResources(const AtlasResource *const resource)
 {
-    if (!resource)
+    if (resource == nullptr)
         return;
     FOR_EACH (std::vector<TextureAtlas*>::const_iterator,
               it, resource->atlases)
     {
         // add each atlas image to resources
         TextureAtlas *const atlas = *it;
-        if (atlas)
+        if (atlas != nullptr)
         {
             Image *const image = atlas->atlasImage;
-            if (image)
+            if (image != nullptr)
                 ResourceManager::addResource(atlas->name, image);
             FOR_EACH (std::vector<AtlasItem*>::iterator, it2, atlas->items)
             {
                 AtlasItem *const item = *it2;
-                if (!item)
+                if (item == nullptr)
                     continue;
                 // add each atlas sub image to resources
                 ResourceManager::addResource(item->name, item->image);
@@ -517,16 +518,16 @@ void AtlasManager::injectToResources(const AtlasResource *const resource)
 
 void AtlasManager::moveToDeleted(AtlasResource *const resource)
 {
-    if (!resource)
+    if (resource == nullptr)
         return;
     FOR_EACH (std::vector<TextureAtlas*>::iterator, it, resource->atlases)
     {
         // move each atlas image to deleted
         TextureAtlas *const atlas = *it;
-        if (atlas)
+        if (atlas != nullptr)
         {
             Image *const image = atlas->atlasImage;
-            if (image)
+            if (image != nullptr)
             {
                 // move each atlas image to deleted
                 ResourceManager::moveToDeleted(image);
@@ -534,10 +535,10 @@ void AtlasManager::moveToDeleted(AtlasResource *const resource)
             FOR_EACH (std::vector<AtlasItem*>::iterator, it2, atlas->items)
             {
                 AtlasItem *const item = *it2;
-                if (item)
+                if (item != nullptr)
                 {
                     Image *const image2 = item->image;
-                    if (image2)
+                    if (image2 != nullptr)
                     {
                         // move each atlas sub image to deleted
                         ResourceManager::moveToDeleted(image2);
diff --git a/src/resources/atlas/atlasresource.cpp b/src/resources/atlas/atlasresource.cpp
index eab7c660e..51a807975 100644
--- a/src/resources/atlas/atlasresource.cpp
+++ b/src/resources/atlas/atlasresource.cpp
@@ -34,21 +34,21 @@ AtlasResource::~AtlasResource()
     FOR_EACH (std::vector<TextureAtlas*>::iterator, it, atlases)
     {
         TextureAtlas *const atlas = *it;
-        if (atlas)
+        if (atlas != nullptr)
         {
             FOR_EACH (std::vector<AtlasItem*>::iterator, it2, atlas->items)
             {
                 AtlasItem *const item = *it2;
-                if (item)
+                if (item != nullptr)
                 {
                     Image *const image2 = item->image;
-                    if (image2)
+                    if (image2 != nullptr)
                         image2->decRef();
                     delete item;
                 }
             }
             Image *const image = atlas->atlasImage;
-            if (image)
+            if (image != nullptr)
                 image->decRef();
             delete atlas;
         }
@@ -58,7 +58,7 @@ AtlasResource::~AtlasResource()
 
 void AtlasResource::incRef()
 {
-    if (!mRefCount)
+    if (mRefCount == 0u)
         AtlasManager::injectToResources(this);
     Resource::incRef();
 }
@@ -66,7 +66,7 @@ void AtlasResource::incRef()
 void AtlasResource::decRef()
 {
     Resource::decRef();
-    if (!mRefCount)
+    if (mRefCount == 0u)
         AtlasManager::moveToDeleted(this);
 }
 
diff --git a/src/resources/beinginfo.cpp b/src/resources/beinginfo.cpp
index 466a5832d..e4fe5c851 100644
--- a/src/resources/beinginfo.cpp
+++ b/src/resources/beinginfo.cpp
@@ -148,7 +148,7 @@ void BeingInfo::addSound(const ItemSoundEvent::Type event,
     if (mSounds.find(event) == mSounds.end())
         mSounds[event] = new SoundInfoVect;
 
-    if (mSounds[event])
+    if (mSounds[event] != nullptr)
         mSounds[event]->push_back(SoundInfo("sfx/" + filename, delay));
 }
 
@@ -162,7 +162,7 @@ const SoundInfo &BeingInfo::getSound(const ItemSoundEvent::Type event) const
         return emptySound;
 
     const SoundInfoVect *const vect = i->second;
-    if (!vect || vect->empty())
+    if ((vect == nullptr) || vect->empty())
         return emptySound;
     else
         return vect->at(CAST_SIZE(rand()) % vect->size());
@@ -205,7 +205,7 @@ void BeingInfo::clear()
 
 void BeingInfo::init()
 {
-    if (empty)
+    if (empty != nullptr)
     {
         empty->mEffectId = paths.getIntValue("effectId");
         empty->mHitEffectId = paths.getIntValue("hitEffectId");
@@ -224,7 +224,7 @@ void BeingInfo::setColorsList(const std::string &name)
 
 std::string BeingInfo::getColor(const ItemColor idx) const
 {
-    if (!mColors)
+    if (mColors == nullptr)
         return std::string();
 
     const std::map <ItemColor, ColorDB::ItemColorData>::const_iterator
diff --git a/src/resources/beinginfo.h b/src/resources/beinginfo.h
index a68e7ca7b..0b1b0e7b4 100644
--- a/src/resources/beinginfo.h
+++ b/src/resources/beinginfo.h
@@ -317,7 +317,7 @@ class BeingInfo final
         { mAllowDelete = b; }
 
         int getAllowDelete() const noexcept2 A_WARN_UNUSED
-        { return mAllowDelete; }
+        { return static_cast<int>(mAllowDelete); }
 
         void setQuickActionEffectId(const int n)
         { mQuickActionEffectId = n; }
diff --git a/src/resources/db/avatardb.cpp b/src/resources/db/avatardb.cpp
index eddf08b29..86c2ff5aa 100644
--- a/src/resources/db/avatardb.cpp
+++ b/src/resources/db/avatardb.cpp
@@ -59,7 +59,7 @@ void AvatarDB::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "avatars"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "avatars"))
     {
         logger->log("Avatars Database: Error while loading %s!",
             fileName.c_str());
@@ -85,7 +85,7 @@ void AvatarDB::loadXmlFile(const std::string &fileName,
         BeingInfo *currentInfo = nullptr;
         if (mAvatarInfos.find(id) != mAvatarInfos.end())
             currentInfo = mAvatarInfos[id];
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new BeingInfo;
 
         currentInfo->setName(XML::langProperty(
diff --git a/src/resources/db/chardb.cpp b/src/resources/db/chardb.cpp
index b0984a56f..fe87ea157 100644
--- a/src/resources/db/chardb.cpp
+++ b/src/resources/db/chardb.cpp
@@ -54,7 +54,7 @@ void CharDB::load()
         SkipError_false);
     XmlNodeConstPtrConst root = doc->rootNode();
 
-    if (!root || !xmlNameEqual(root, "chars"))
+    if ((root == nullptr) || !xmlNameEqual(root, "chars"))
     {
         logger->log("CharDB: Failed to parse %s.",
             paths.getStringValue("charCreationFile").c_str());
@@ -113,9 +113,9 @@ void CharDB::loadMinMax(XmlNodeConstPtr node,
                         unsigned *restrict const min,
                         unsigned *restrict const max)
 {
-    if (min)
+    if (min != nullptr)
         *min = XML::getProperty(node, "min", 1);
-    if (max)
+    if (max != nullptr)
         *max = XML::getProperty(node, "max", 10);
 }
 
diff --git a/src/resources/db/colordb.cpp b/src/resources/db/colordb.cpp
index cf377eca1..15e66bb5b 100644
--- a/src/resources/db/colordb.cpp
+++ b/src/resources/db/colordb.cpp
@@ -83,7 +83,7 @@ void ColorDB::loadHair(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst root = doc->rootNode();
 
-    if (!root || !xmlNameEqual(root, "colors"))
+    if ((root == nullptr) || !xmlNameEqual(root, "colors"))
     {
         logger->log("ColorDB: Failed to find hair colors file.");
         if (colors.find(ItemColor_zero) == colors.end())
@@ -128,7 +128,7 @@ void ColorDB::loadColorLists(const std::string &fileName,
         UseVirtFs_true,
         skipError);
     XmlNodeConstPtrConst root = doc->rootNode();
-    if (!root)
+    if (root == nullptr)
     {
         delete doc;
         return;
diff --git a/src/resources/db/commandsdb.cpp b/src/resources/db/commandsdb.cpp
index 115046b1d..eec3eb7ce 100644
--- a/src/resources/db/commandsdb.cpp
+++ b/src/resources/db/commandsdb.cpp
@@ -64,7 +64,7 @@ void CommandsDB::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "commands"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "commands"))
     {
         logger->log("Commands Database: Error while loading %s!",
             fileName.c_str());
@@ -121,7 +121,7 @@ void CommandsDB::loadXmlFile(const std::string &fileName,
 
         TextCommand *cmd = nullptr;
 #ifdef TMWA_SUPPORT
-        if (skill1)
+        if (skill1 != 0)
         {
             cmd = new TextCommand(id,
                 name,
diff --git a/src/resources/db/deaddb.cpp b/src/resources/db/deaddb.cpp
index 53a0f6e0f..bcca023eb 100644
--- a/src/resources/db/deaddb.cpp
+++ b/src/resources/db/deaddb.cpp
@@ -54,7 +54,7 @@ void DeadDB::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst root = doc->rootNode();
 
-    if (!root || !xmlNameEqual(root, "messages"))
+    if ((root == nullptr) || !xmlNameEqual(root, "messages"))
     {
         logger->log("DeadDB: Failed to parse %s.",
             paths.getStringValue("deadMessagesFile").c_str());
@@ -75,9 +75,9 @@ void DeadDB::loadXmlFile(const std::string &fileName,
         {
             XmlChar *const data = reinterpret_cast<XmlChar*>(
                 XmlNodeGetContent(node));
-            if (!data)
+            if (data == nullptr)
                 continue;
-            if (!*data)
+            if (*data == 0)
             {
                 XmlFree(data);
                 continue;
@@ -99,7 +99,7 @@ void DeadDB::unload()
 std::string DeadDB::getRandomString()
 {
     const size_t sz = mMessages.size();
-    if (!sz)
+    if (sz == 0u)
         return std::string();
     return translator->getStr(mMessages[rand() % sz]);
 }
diff --git a/src/resources/db/elementaldb.cpp b/src/resources/db/elementaldb.cpp
index 2a626a10e..8701081a3 100644
--- a/src/resources/db/elementaldb.cpp
+++ b/src/resources/db/elementaldb.cpp
@@ -57,7 +57,7 @@ void ElementalDb::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodeConstPtr rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "elementals"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "elementals"))
     {
         logger->log("Elemental Database: Error while loading %s!",
             paths.getStringValue("elementalsFile").c_str());
@@ -89,7 +89,7 @@ void ElementalDb::loadXmlFile(const std::string &fileName,
             logger->log("ElementalDb: Redefinition of elemental ID %d", id);
             currentInfo = mElementalInfos[fromInt(id + offset, BeingTypeId)];
         }
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new BeingInfo;
 
         currentInfo->setBlockType(BlockType::NONE);
@@ -107,7 +107,7 @@ void ElementalDb::loadXmlFile(const std::string &fileName,
         currentInfo->setColorsList(XML::getProperty(elementalNode,
             "colors", ""));
 
-        if (currentInfo->getMaxHP())
+        if (currentInfo->getMaxHP() != 0)
             currentInfo->setStaticMaxHP(true);
 
         SpriteDisplay display;
diff --git a/src/resources/db/emotedb.cpp b/src/resources/db/emotedb.cpp
index 7d9e47e8b..085f81abe 100644
--- a/src/resources/db/emotedb.cpp
+++ b/src/resources/db/emotedb.cpp
@@ -75,7 +75,7 @@ void EmoteDB::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodePtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "emotes"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "emotes"))
     {
         logger->log("Emote Database: Error while loading %s!",
             fileName.c_str());
@@ -113,7 +113,7 @@ void EmoteDB::loadXmlFile(const std::string &fileName,
             currentInfo = mEmoteInfos[id];
         else
             currentInfo = new EmoteInfo;
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             continue;
         currentInfo->time = XML::getProperty(emoteNode, "time", 500);
         currentInfo->effectId = XML::getProperty(emoteNode, "effect", -1);
@@ -152,7 +152,7 @@ void EmoteDB::loadSpecialXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodePtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "emotes"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "emotes"))
     {
         logger->log1("Emote Database: Error while loading"
                      " manaplus_emotes.xml!");
@@ -186,7 +186,7 @@ void EmoteDB::loadSpecialXmlFile(const std::string &fileName,
         EmoteInfo *currentInfo = nullptr;
         if (mEmoteInfos.find(id) != mEmoteInfos.end())
             currentInfo = mEmoteInfos[id];
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new EmoteInfo;
         currentInfo->time = XML::getProperty(emoteNode, "time", 500);
         currentInfo->effectId = XML::getProperty(emoteNode, "effect", -1);
@@ -226,7 +226,7 @@ void EmoteDB::unload()
 {
     FOR_EACH (EmoteInfos::const_iterator, i, mEmoteInfos)
     {
-        if (i->second)
+        if (i->second != nullptr)
         {
             std::list<EmoteSprite*> &sprites = i->second->sprites;
             while (!sprites.empty())
@@ -295,7 +295,7 @@ const EmoteInfo *EmoteDB::get2(int id, const bool allowNull)
 const EmoteSprite *EmoteDB::getSprite(const int id, const bool allowNull)
 {
     const EmoteInfo *const info = get(id, allowNull);
-    if (!info)
+    if (info == nullptr)
         return nullptr;
 
     return info->sprites.front();
diff --git a/src/resources/db/homunculusdb.cpp b/src/resources/db/homunculusdb.cpp
index cf627dc01..3fdced887 100644
--- a/src/resources/db/homunculusdb.cpp
+++ b/src/resources/db/homunculusdb.cpp
@@ -58,7 +58,7 @@ void HomunculusDB::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodeConstPtr rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "homunculuses"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "homunculuses"))
     {
         logger->log("Homunculus Database: Error while loading %s!",
             paths.getStringValue("homunculusesFile").c_str());
@@ -90,7 +90,7 @@ void HomunculusDB::loadXmlFile(const std::string &fileName,
             logger->log("HomunculusDB: Redefinition of homunculus ID %d", id);
             currentInfo = mHomunculusInfos[fromInt(id + offset, BeingTypeId)];
         }
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new BeingInfo;
 
         currentInfo->setBlockType(BlockType::NONE);
@@ -114,7 +114,7 @@ void HomunculusDB::loadXmlFile(const std::string &fileName,
         currentInfo->setColorsList(XML::getProperty(homunculusNode,
             "colors", ""));
 
-        if (currentInfo->getMaxHP())
+        if (currentInfo->getMaxHP() != 0)
             currentInfo->setStaticMaxHP(true);
 
         SpriteDisplay display;
diff --git a/src/resources/db/horsedb.cpp b/src/resources/db/horsedb.cpp
index a6b395d3f..961fbca32 100644
--- a/src/resources/db/horsedb.cpp
+++ b/src/resources/db/horsedb.cpp
@@ -153,7 +153,7 @@ void HorseDB::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodePtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "horses"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "horses"))
     {
         logger->log("Horse Database: Error while loading %s!",
             fileName.c_str());
@@ -189,7 +189,7 @@ void HorseDB::loadXmlFile(const std::string &fileName,
         else
             currentInfo = new HorseInfo;
 
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             continue;
         for_each_xml_child_node(spriteNode, horseNode)
         {
diff --git a/src/resources/db/itemdb.cpp b/src/resources/db/itemdb.cpp
index 4bd68c42e..6efe6086f 100644
--- a/src/resources/db/itemdb.cpp
+++ b/src/resources/db/itemdb.cpp
@@ -129,7 +129,7 @@ static void readFields(std::string &effect,
                        XmlNodeConstPtr node,
                        const ItemFieldDb::FieldInfos &fields)
 {
-    if (!translator)
+    if (translator == nullptr)
         return;
 
     FOR_EACH (ItemFieldDb::FieldInfos::const_iterator, it, fields)
@@ -249,7 +249,7 @@ void ItemDB::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "items"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "items"))
     {
         logger->log("ItemDB: Error while loading %s!", fileName.c_str());
         mLoaded = true;
@@ -287,7 +287,7 @@ void ItemDB::loadXmlFile(const std::string &fileName,
             logger->log("ItemDB: Redefinition of item ID %d", id);
             itemInfo = mItemInfos[id];
         }
-        if (!itemInfo)
+        if (itemInfo == nullptr)
             itemInfo = new ItemInfo;
 
         const std::string typeStr = XML::getProperty(node, "type", "");
@@ -375,7 +375,7 @@ void ItemDB::loadXmlFile(const std::string &fileName,
         }
 
         itemInfo->setId(id);
-        if (name.empty() && inheritItemInfo)
+        if (name.empty() && (inheritItemInfo != nullptr))
             name = inheritItemInfo->getName();
         // TRANSLATORS: item info name
         itemInfo->setName(name.empty() ? _("unnamed") : name);
@@ -389,12 +389,12 @@ void ItemDB::loadXmlFile(const std::string &fileName,
             itemInfo->setNameEn(nameEn);
         }
 
-        if (description.empty() && inheritItemInfo)
+        if (description.empty() && (inheritItemInfo != nullptr))
             description = inheritItemInfo->getDescription();
         itemInfo->setDescription(description);
         if (typeStr.empty())
         {
-            if (inheritItemInfo)
+            if (inheritItemInfo != nullptr)
                 itemInfo->setType(inheritItemInfo->getType());
             else
                 itemInfo->setType(itemTypeFromString("other"));
@@ -404,12 +404,12 @@ void ItemDB::loadXmlFile(const std::string &fileName,
             itemInfo->setType(itemTypeFromString(typeStr));
         }
         itemInfo->setType(itemTypeFromString(typeStr));
-        if (useButton.empty() && inheritItemInfo)
+        if (useButton.empty() && (inheritItemInfo != nullptr))
             useButton = inheritItemInfo->getUseButton();
         if (useButton.empty())
             useButton = useButtonFromItemType(itemInfo->getType());
         itemInfo->setUseButton(useButton);
-        if (useButton2.empty() && inheritItemInfo)
+        if (useButton2.empty() && (inheritItemInfo != nullptr))
             useButton2 = inheritItemInfo->getUseButton();
         if (useButton2.empty())
             useButton2 = useButton2FromItemType(itemInfo->getType());
@@ -419,7 +419,7 @@ void ItemDB::loadXmlFile(const std::string &fileName,
             node, "sellProtected", false));
         if (cardColor != -1)
             itemInfo->setCardColor(fromInt(cardColor, ItemColor));
-        else if (inheritItemInfo)
+        else if (inheritItemInfo != nullptr)
             itemInfo->setCardColor(inheritItemInfo->getCardColor());
 
         switch (itemInfo->getType())
@@ -462,46 +462,46 @@ void ItemDB::loadXmlFile(const std::string &fileName,
             }
         }
 
-        if (!view && inheritItemInfo)
+        if ((view == 0) && (inheritItemInfo != nullptr))
             view = inheritItemInfo->getView();
         itemInfo->setView(view);
-        if (!weight && inheritItemInfo)
+        if ((weight == 0) && (inheritItemInfo != nullptr))
             weight = inheritItemInfo->getWeight();
         itemInfo->setWeight(weight);
-        if (attackAction.empty() && inheritItemInfo)
+        if (attackAction.empty() && (inheritItemInfo != nullptr))
             attackAction = inheritItemInfo->getAttackAction();
         itemInfo->setAttackAction(attackAction);
-        if (skyAttackAction.empty() && inheritItemInfo)
+        if (skyAttackAction.empty() && (inheritItemInfo != nullptr))
             skyAttackAction = inheritItemInfo->getSkyAttackAction();
         itemInfo->setSkyAttackAction(skyAttackAction);
-        if (waterAttackAction.empty() && inheritItemInfo)
+        if (waterAttackAction.empty() && (inheritItemInfo != nullptr))
             waterAttackAction = inheritItemInfo->getWaterAttackAction();
         itemInfo->setWaterAttackAction(waterAttackAction);
-        if (rideAttackAction.empty() && inheritItemInfo)
+        if (rideAttackAction.empty() && (inheritItemInfo != nullptr))
             rideAttackAction = inheritItemInfo->getRideAttackAction();
         itemInfo->setRideAttackAction(rideAttackAction);
-        if (!attackRange && inheritItemInfo)
+        if ((attackRange == 0) && (inheritItemInfo != nullptr))
             attackRange = inheritItemInfo->getAttackRange();
         itemInfo->setAttackRange(attackRange);
-        if (missileParticle.empty() && inheritItemInfo)
+        if (missileParticle.empty() && (inheritItemInfo != nullptr))
             missileParticle = inheritItemInfo->getMissileParticleFile();
         itemInfo->setMissileParticleFile(missileParticle);
-        if (!hitEffectId && inheritItemInfo)
+        if ((hitEffectId == 0) && (inheritItemInfo != nullptr))
             hitEffectId = inheritItemInfo->getHitEffectId();
         itemInfo->setHitEffectId(hitEffectId);
-        if (!criticalEffectId && inheritItemInfo)
+        if ((criticalEffectId == 0) && (inheritItemInfo != nullptr))
             criticalEffectId = inheritItemInfo->getCriticalHitEffectId();
         itemInfo->setCriticalHitEffectId(criticalEffectId);
-        if (!missEffectId && inheritItemInfo)
+        if ((missEffectId == 0) && (inheritItemInfo != nullptr))
             missEffectId = inheritItemInfo->getMissEffectId();
         itemInfo->setMissEffectId(missEffectId);
         itemInfo->setDrawBefore(-1, parseSpriteName(drawBefore));
         itemInfo->setDrawAfter(-1, parseSpriteName(drawAfter));
         itemInfo->setDrawPriority(-1, drawPriority);
-        if (colors.empty() && inheritItemInfo)
+        if (colors.empty() && (inheritItemInfo != nullptr))
             colors = inheritItemInfo->getColorsListName();
         itemInfo->setColorsList(colors);
-        if (iconColors.empty() && inheritItemInfo)
+        if (iconColors.empty() && (inheritItemInfo != nullptr))
             iconColors = inheritItemInfo->getIconColorsListName();
         itemInfo->setIconColorsList(iconColors);
         itemInfo->setMaxFloorOffsetX(maxFloorOffsetX);
@@ -516,7 +516,7 @@ void ItemDB::loadXmlFile(const std::string &fileName,
         if (!effect.empty() && !temp.empty())
             effect.append(" / ");
         effect.append(temp);
-        if (effect.empty() && inheritItemInfo)
+        if (effect.empty() && (inheritItemInfo != nullptr))
             effect = inheritItemInfo->getEffect();
         itemInfo->setEffect(effect);
 
@@ -840,7 +840,7 @@ static int parseDirectionName(const std::string &name)
 static void loadSpriteRef(ItemInfo *const itemInfo, XmlNodeConstPtr node)
 {
     const std::string gender = XML::getProperty(node, "gender", "unisex");
-    if (!node || !XmlHaveChildContent(node))
+    if ((node == nullptr) || !XmlHaveChildContent(node))
         return;
 
     const std::string filename = XmlChildContent(node);
@@ -856,7 +856,7 @@ static void loadSpriteRef(ItemInfo *const itemInfo, XmlNodeConstPtr node)
 
 static void loadSoundRef(ItemInfo *const itemInfo, XmlNodeConstPtr node)
 {
-    if (!node || !XmlHaveChildContent(node))
+    if ((node == nullptr) || !XmlHaveChildContent(node))
         return;
     const std::string event = XML::getProperty(node, "event", "");
     const std::string filename = XmlChildContent(node);
@@ -878,7 +878,7 @@ static void loadSoundRef(ItemInfo *const itemInfo, XmlNodeConstPtr node)
 static void loadFloorSprite(SpriteDisplay &display,
                             XmlNodeConstPtrConst floorNode)
 {
-    if (!floorNode)
+    if (floorNode == nullptr)
         return;
     for_each_xml_child_node(spriteNode, floorNode)
     {
@@ -902,7 +902,7 @@ static void loadFloorSprite(SpriteDisplay &display,
 static void loadReplaceSprite(ItemInfo *const itemInfo,
                               XmlNodeConstPtr replaceNode)
 {
-    if (!replaceNode)
+    if (replaceNode == nullptr)
         return;
     const std::string removeSprite = XML::getProperty(
         replaceNode, "sprite", "");
@@ -929,7 +929,7 @@ static void loadReplaceSprite(ItemInfo *const itemInfo,
                 {
                     IntMap *const mapList = itemInfo->addReplaceSprite(
                         parseSpriteName(removeSprite), f);
-                    if (!mapList)
+                    if (mapList == nullptr)
                         continue;
                     for_each_xml_child_node(itemNode, replaceNode)
                     {
@@ -963,17 +963,17 @@ static void loadReplaceSprite(ItemInfo *const itemInfo,
                     const int to = XML::getProperty(itemNode, "to", 1);
                     IntMap *mapList = itemInfo->addReplaceSprite(
                         parseSpriteName(removeSprite), SpriteDirection::DOWN);
-                    if (mapList)
+                    if (mapList != nullptr)
                         (*mapList)[from] = to;
 
                     mapList = itemInfo->addReplaceSprite(parseSpriteName(
                         removeSprite), SpriteDirection::DOWNLEFT);
-                    if (mapList)
+                    if (mapList != nullptr)
                         (*mapList)[from] = to;
 
                     mapList = itemInfo->addReplaceSprite(parseSpriteName(
                         removeSprite), SpriteDirection::DOWNRIGHT);
-                    if (mapList)
+                    if (mapList != nullptr)
                         (*mapList)[from] = to;
                 }
             }
@@ -996,17 +996,17 @@ static void loadReplaceSprite(ItemInfo *const itemInfo,
                     const int to = XML::getProperty(itemNode, "to", 1);
                     IntMap *mapList = itemInfo->addReplaceSprite(
                         parseSpriteName(removeSprite), SpriteDirection::UP);
-                    if (mapList)
+                    if (mapList != nullptr)
                         (*mapList)[from] = to;
 
                     mapList = itemInfo->addReplaceSprite(parseSpriteName(
                         removeSprite), SpriteDirection::UPLEFT);
-                    if (mapList)
+                    if (mapList != nullptr)
                         (*mapList)[from] = to;
 
                     mapList = itemInfo->addReplaceSprite(parseSpriteName(
                         removeSprite), SpriteDirection::UPRIGHT);
-                    if (mapList)
+                    if (mapList != nullptr)
                         (*mapList)[from] = to;
                 }
             }
@@ -1016,7 +1016,7 @@ static void loadReplaceSprite(ItemInfo *const itemInfo,
         {
             IntMap *const mapList = itemInfo->addReplaceSprite(
                 parseSpriteName(removeSprite), direction);
-            if (!mapList)
+            if (mapList == nullptr)
                 return;
             for_each_xml_child_node(itemNode, replaceNode)
             {
diff --git a/src/resources/db/itemfielddb.cpp b/src/resources/db/itemfielddb.cpp
index 65020e824..8a32ccc02 100644
--- a/src/resources/db/itemfielddb.cpp
+++ b/src/resources/db/itemfielddb.cpp
@@ -107,7 +107,7 @@ void ItemFieldDb::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "itemfields"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "itemfields"))
     {
         logger->log("ItemFieldDb: Error while loading %s!",
             fileName.c_str());
diff --git a/src/resources/db/itemoptiondb.cpp b/src/resources/db/itemoptiondb.cpp
index 1199e07f7..bd78f95c5 100644
--- a/src/resources/db/itemoptiondb.cpp
+++ b/src/resources/db/itemoptiondb.cpp
@@ -88,7 +88,7 @@ void ItemOptionDb::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "itemoptions"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "itemoptions"))
     {
         if (skipError == SkipError_true)
         {
diff --git a/src/resources/db/languagedb.cpp b/src/resources/db/languagedb.cpp
index b7e3ebc0e..a5443824e 100644
--- a/src/resources/db/languagedb.cpp
+++ b/src/resources/db/languagedb.cpp
@@ -52,7 +52,7 @@ void LanguageDb::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst root = doc->rootNode();
 
-    if (!root || !xmlNameEqual(root, "languages"))
+    if ((root == nullptr) || !xmlNameEqual(root, "languages"))
     {
         delete doc;
         return;
diff --git a/src/resources/db/mapdb.cpp b/src/resources/db/mapdb.cpp
index d991e8273..e96f31e52 100644
--- a/src/resources/db/mapdb.cpp
+++ b/src/resources/db/mapdb.cpp
@@ -67,7 +67,7 @@ void MapDB::loadRemapXmlFile(const std::string &fileName,
         skipError);
 
     XmlNodeConstPtrConst root = doc->rootNode();
-    if (!root)
+    if (root == nullptr)
     {
         delete doc;
         return;
@@ -101,7 +101,7 @@ void MapDB::loadRemapXmlFile(const std::string &fileName,
 
 void MapDB::readMap(XmlNodePtrConst node)
 {
-    if (!node)
+    if (node == nullptr)
         return;
     const std::string map = XML::getProperty(node, "name", "");
     if (map.empty())
@@ -121,7 +121,7 @@ void MapDB::readMap(XmlNodePtrConst node)
 
 void MapDB::readAtlas(XmlNodePtrConst node)
 {
-    if (!node)
+    if (node == nullptr)
         return;
     const std::string atlas = XML::getProperty(node, "name", "");
     if (atlas.empty())
@@ -154,7 +154,7 @@ void MapDB::loadInfo(const std::string &fileName,
         UseVirtFs_true,
         skipError);
     XmlNodeConstPtrConst root = doc->rootNode();
-    if (!root)
+    if (root == nullptr)
     {
         delete doc;
         return;
diff --git a/src/resources/db/mercenarydb.cpp b/src/resources/db/mercenarydb.cpp
index bc1b20840..a528c7def 100644
--- a/src/resources/db/mercenarydb.cpp
+++ b/src/resources/db/mercenarydb.cpp
@@ -60,7 +60,7 @@ void MercenaryDB::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtr rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "mercenaries"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "mercenaries"))
     {
         logger->log("MercenaryDB: Error while loading %s!",
             paths.getStringValue("mercenariesFile").c_str());
@@ -92,7 +92,7 @@ void MercenaryDB::loadXmlFile(const std::string &fileName,
             logger->log("MercenaryDB: Redefinition of mercenary ID %d", id);
             currentInfo = mMercenaryInfos[fromInt(id + offset, BeingTypeId)];
         }
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new BeingInfo;
 
         currentInfo->setBlockType(BlockType::NONE);
@@ -111,7 +111,7 @@ void MercenaryDB::loadXmlFile(const std::string &fileName,
         currentInfo->setColorsList(XML::getProperty(mercenaryNode,
             "colors", ""));
 
-        if (currentInfo->getMaxHP())
+        if (currentInfo->getMaxHP() != 0)
             currentInfo->setStaticMaxHP(true);
 
         SpriteDisplay display;
diff --git a/src/resources/db/moddb.cpp b/src/resources/db/moddb.cpp
index 7a23e255f..5932d9b19 100644
--- a/src/resources/db/moddb.cpp
+++ b/src/resources/db/moddb.cpp
@@ -54,7 +54,7 @@ void ModDB::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "mods"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "mods"))
     {
         logger->log("Mods Database: Error while loading %s!",
             fileName.c_str());
@@ -80,7 +80,7 @@ void ModDB::loadXmlFile(const std::string &fileName,
         ModInfo *currentInfo = nullptr;
         if (mModInfos.find(name) != mModInfos.end())
             currentInfo = mModInfos[name];
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new ModInfo;
 
         currentInfo->setName(name);
diff --git a/src/resources/db/monsterdb.cpp b/src/resources/db/monsterdb.cpp
index 1ed0caa27..44b430144 100644
--- a/src/resources/db/monsterdb.cpp
+++ b/src/resources/db/monsterdb.cpp
@@ -62,7 +62,7 @@ void MonsterDB::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodeConstPtr rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "monsters"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "monsters"))
     {
         logger->log("Monster Database: Error while loading %s!",
             paths.getStringValue("monstersFile").c_str());
@@ -94,7 +94,7 @@ void MonsterDB::loadXmlFile(const std::string &fileName,
             logger->log("MonsterDB: Redefinition of monster ID %d", id);
             currentInfo = mMonsterInfos[fromInt(id + offset, BeingTypeId)];
         }
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new BeingInfo;
 
         currentInfo->setBlockType(BlockType::NONE);
@@ -114,7 +114,7 @@ void MonsterDB::loadXmlFile(const std::string &fileName,
         currentInfo->setColorsList(XML::getProperty(monsterNode,
             "colors", ""));
 
-        if (currentInfo->getMaxHP())
+        if (currentInfo->getMaxHP() != 0)
             currentInfo->setStaticMaxHP(true);
 
         SpriteDisplay display;
diff --git a/src/resources/db/npcdb.cpp b/src/resources/db/npcdb.cpp
index 9be217819..44a0bc747 100644
--- a/src/resources/db/npcdb.cpp
+++ b/src/resources/db/npcdb.cpp
@@ -63,7 +63,7 @@ void NPCDB::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "npcs"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "npcs"))
     {
         logger->log("NPC Database: Error while loading %s!",
             paths.getStringValue("npcsFile").c_str());
@@ -99,7 +99,7 @@ void NPCDB::loadXmlFile(const std::string &fileName,
             logger->log("NpcDB: Redefinition of npc ID %d", toInt(id, int));
             currentInfo = mNPCInfos[id];
         }
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new BeingInfo;
 
         currentInfo->setTargetSelection(XML::getBoolProperty(npcNode,
@@ -198,7 +198,7 @@ BeingInfo *NPCDB::get(const BeingTypeId id)
 BeingTypeId NPCDB::getAvatarFor(const BeingTypeId id)
 {
     const BeingInfo *const info = get(id);
-    if (!info)
+    if (info == nullptr)
         return BeingTypeId_zero;
     return info->getAvatarId();
 }
diff --git a/src/resources/db/npcdialogdb.cpp b/src/resources/db/npcdialogdb.cpp
index 76eaea7c5..7411faca9 100644
--- a/src/resources/db/npcdialogdb.cpp
+++ b/src/resources/db/npcdialogdb.cpp
@@ -155,7 +155,7 @@ void NpcDialogDB::loadXmlFile(const std::string &fileName,
         skipError);
 
     XmlNodeConstPtrConst root = doc->rootNode();
-    if (!root)
+    if (root == nullptr)
     {
         delete doc;
         return;
diff --git a/src/resources/db/petdb.cpp b/src/resources/db/petdb.cpp
index 5dca543a0..a47956e7f 100644
--- a/src/resources/db/petdb.cpp
+++ b/src/resources/db/petdb.cpp
@@ -61,7 +61,7 @@ void PETDB::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "pets"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "pets"))
     {
         logger->log("PET Database: Error while loading %s!",
             fileName.c_str());
@@ -95,7 +95,7 @@ void PETDB::loadXmlFile(const std::string &fileName,
         BeingInfo *currentInfo = nullptr;
         if (mPETInfos.find(id) != mPETInfos.end())
             currentInfo = mPETInfos[id];
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new BeingInfo;
 
         currentInfo->setName(XML::langProperty(petNode,
diff --git a/src/resources/db/questdb.cpp b/src/resources/db/questdb.cpp
index 41b3b0062..db67e5138 100644
--- a/src/resources/db/questdb.cpp
+++ b/src/resources/db/questdb.cpp
@@ -54,7 +54,7 @@ void QuestDb::load()
 static void loadQuest(const int var,
                       XmlNodeConstPtr node)
 {
-    if (!node)
+    if (node == nullptr)
         return;
     QuestItem *const quest = new QuestItem;
     // TRANSLATORS: quests window quest name
@@ -85,7 +85,7 @@ static void loadQuest(const int var,
             continue;
         XmlChar *const data = reinterpret_cast<XmlChar*>(
             XmlNodeGetContent(dataNode));
-        if (!data)
+        if (data == nullptr)
             continue;
         std::string str = translator->getStr(data);
         XmlFree(data);
@@ -181,7 +181,7 @@ void QuestDb::loadXmlFile(const std::string &fileName,
         UseVirtFs_true,
         skipError);
     XmlNodeConstPtrConst root = doc.rootNode();
-    if (!root)
+    if (root == nullptr)
         return;
 
     for_each_xml_child_node(varNode, root)
diff --git a/src/resources/db/skillunitdb.cpp b/src/resources/db/skillunitdb.cpp
index cec48a4a1..b5c4592ad 100644
--- a/src/resources/db/skillunitdb.cpp
+++ b/src/resources/db/skillunitdb.cpp
@@ -59,7 +59,7 @@ void SkillUnitDb::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "skillunits"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "skillunits"))
     {
         logger->log("SkillUnitDb: Error while loading %s!",
             fileName.c_str());
@@ -94,7 +94,7 @@ void SkillUnitDb::loadXmlFile(const std::string &fileName,
         BeingInfo *currentInfo = nullptr;
         if (mSkillUnitInfos.find(id) != mSkillUnitInfos.end())
             currentInfo = mSkillUnitInfos[id];
-        if (!currentInfo)
+        if (currentInfo == nullptr)
             currentInfo = new BeingInfo;
 
         currentInfo->setName(XML::langProperty(skillUnitNode,
diff --git a/src/resources/db/sounddb.cpp b/src/resources/db/sounddb.cpp
index d58a585ee..47eb99232 100644
--- a/src/resources/db/sounddb.cpp
+++ b/src/resources/db/sounddb.cpp
@@ -51,7 +51,7 @@ void SoundDB::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst root = doc->rootNode();
 
-    if (!root || !xmlNameEqual(root, "sounds"))
+    if ((root == nullptr) || !xmlNameEqual(root, "sounds"))
     {
         delete doc;
         return;
@@ -70,7 +70,7 @@ void SoundDB::loadXmlFile(const std::string &fileName,
         {
             const std::string name = XML::getProperty(node, "name", "");
             const int id = NotifyManager::getIndexBySound(name);
-            if (id)
+            if (id != 0)
             {
                 const std::string value = XML::getProperty(node, "value", "");
                 mSounds[id] = value;
diff --git a/src/resources/db/statdb.cpp b/src/resources/db/statdb.cpp
index 12126f36a..7911009a3 100644
--- a/src/resources/db/statdb.cpp
+++ b/src/resources/db/statdb.cpp
@@ -175,7 +175,7 @@ void StatDb::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "stats"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "stats"))
     {
         logger->log("StatDb: Error while loading %s!",
             fileName.c_str());
diff --git a/src/resources/db/statuseffectdb.cpp b/src/resources/db/statuseffectdb.cpp
index 58c5cf30d..d5fc96849 100644
--- a/src/resources/db/statuseffectdb.cpp
+++ b/src/resources/db/statuseffectdb.cpp
@@ -90,7 +90,7 @@ void StatusEffectDB::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodeConstPtrConst rootNode = doc.rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "status-effects"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "status-effects"))
     {
         logger->log("Error loading status effects file: " + fileName);
         return;
@@ -151,9 +151,9 @@ void StatusEffectDB::loadXmlFile(const std::string &fileName,
         StatusEffect *endEffect = statusEffects[0][id];
         const std::string name = XML::getProperty(node, "name", "");
         const std::string name2 = XML::langProperty(node, "name", "");
-        if (!startEffect)
+        if (startEffect == nullptr)
             startEffect = new StatusEffect;
-        if (!endEffect)
+        if (endEffect == nullptr)
             endEffect = new StatusEffect;
 
         startEffect->mName = name2;
diff --git a/src/resources/db/textdb.cpp b/src/resources/db/textdb.cpp
index 24a5f2a38..e4d0b9b65 100644
--- a/src/resources/db/textdb.cpp
+++ b/src/resources/db/textdb.cpp
@@ -49,7 +49,7 @@ void TextDb::loadXmlFile(const std::string &fileName,
         skipError);
     XmlNodeConstPtrConst root = doc->rootNode();
 
-    if (!root || !xmlNameEqual(root, "texts"))
+    if ((root == nullptr) || !xmlNameEqual(root, "texts"))
     {
         delete doc;
         return;
diff --git a/src/resources/db/unitsdb.cpp b/src/resources/db/unitsdb.cpp
index 0437c81e4..9481406c4 100644
--- a/src/resources/db/unitsdb.cpp
+++ b/src/resources/db/unitsdb.cpp
@@ -193,7 +193,7 @@ void UnitsDb::loadXmlFile(const std::string &fileName,
     XML::Document doc(fileName, UseVirtFs_true, skipError);
     XmlNodeConstPtrConst root = doc.rootNode();
 
-    if (!root || !xmlNameEqual(root, "units"))
+    if ((root == nullptr) || !xmlNameEqual(root, "units"))
     {
         logger->log("Error loading unit definition file: "
             + paths.getStringValue("unitsFile"));
@@ -259,7 +259,7 @@ static std::string formatUnit(const int value,
             int levelAmount = CAST_S32(amount);
             int nextAmount = 0;
 
-            if (ul.count)
+            if (ul.count != 0)
                 levelAmount /= ul.count;
 
             amount -= static_cast<double>(levelAmount * ul.count);
@@ -275,7 +275,7 @@ static std::string formatUnit(const int value,
                 pl = ul;
                 ul = ud.levels[i];
 
-                if (ul.count)
+                if (ul.count != 0)
                 {
                     nextAmount = levelAmount / ul.count;
                     levelAmount %= ul.count;
@@ -287,7 +287,7 @@ static std::string formatUnit(const int value,
                         pl.separator).append(pl.symbol).append(output);
                 }
 
-                if (!nextAmount)
+                if (nextAmount == 0)
                     break;
                 levelAmount = nextAmount;
             }
@@ -305,7 +305,7 @@ static std::string formatUnit(const int value,
                     ul = ud.levels[i - 1];
                     break;
                 }
-                if (ul.count)
+                if (ul.count != 0)
                     amount /= ul.count;
             }
 
diff --git a/src/resources/dye/dye.cpp b/src/resources/dye/dye.cpp
index b9c9e4cd8..70d2a21b1 100644
--- a/src/resources/dye/dye.cpp
+++ b/src/resources/dye/dye.cpp
@@ -143,9 +143,9 @@ void Dye::instantiate(std::string &restrict target,
 
 int Dye::getType() const restrict2 noexcept2
 {
-    if (mDyePalettes[sPaleteIndex])
+    if (mDyePalettes[sPaleteIndex] != nullptr)
         return 1;
-    if (mDyePalettes[aPaleteIndex])
+    if (mDyePalettes[aPaleteIndex] != nullptr)
         return 2;
     return 0;
 }
@@ -153,7 +153,7 @@ int Dye::getType() const restrict2 noexcept2
 void Dye::normalDye(uint32_t *restrict pixels,
                     const int bufSize) const restrict2
 {
-    if (!pixels)
+    if (pixels == nullptr)
         return;
 
 #ifdef ENABLE_CILKPLUS
@@ -230,7 +230,7 @@ endlabel:{}
         const int alpha = p & 0xff;
 #endif  // SDL_BYTEORDER == SDL_BIG_ENDIAN
 
-        if (!alpha)
+        if (alpha == 0)
             continue;
         unsigned int color[3];
 #if SDL_BYTEORDER == SDL_BIG_ENDIAN
@@ -260,10 +260,11 @@ endlabel:{}
             continue;
         }
 
-        const unsigned int i = (color[0] != 0) | ((color[1] != 0) << 1)
-            | ((color[2] != 0) << 2);
+        const unsigned int i = static_cast<int>(color[0] != 0) |
+            (static_cast<int>(color[1] != 0) << 1) |
+            (static_cast<int>(color[2] != 0) << 2);
 
-        if (mDyePalettes[i - 1])
+        if (mDyePalettes[i - 1] != nullptr)
             mDyePalettes[i - 1]->getColor(cmax, color);
 
 #if SDL_BYTEORDER == SDL_BIG_ENDIAN
@@ -281,7 +282,7 @@ endlabel:{}
 void Dye::normalOGLDye(uint32_t *restrict pixels,
                        const int bufSize) const restrict2
 {
-    if (!pixels)
+    if (pixels == nullptr)
         return;
 
 #ifdef ENABLE_CILKPLUS
@@ -357,7 +358,7 @@ endlabel:{}
         const int alpha = p & 0xff000000;
 #endif  // SDL_BYTEORDER == SDL_BIG_ENDIAN
 
-        if (!alpha)
+        if (alpha == 0)
             continue;
         unsigned int color[3];
 #if SDL_BYTEORDER == SDL_BIG_ENDIAN
@@ -387,10 +388,11 @@ endlabel:{}
             continue;
         }
 
-        const unsigned int i = (color[0] != 0) | ((color[1] != 0) << 1)
-            | ((color[2] != 0) << 2);
+        const unsigned int i = static_cast<int>(color[0] != 0) |
+            (static_cast<int>(color[1] != 0) << 1) |
+            (static_cast<int>(color[2] != 0) << 2);
 
-        if (mDyePalettes[i - 1])
+        if (mDyePalettes[i - 1] != nullptr)
             mDyePalettes[i - 1]->getColor(cmax, color);
 
 #if SDL_BYTEORDER == SDL_BIG_ENDIAN
diff --git a/src/resources/dye/dyepalette.cpp b/src/resources/dye/dyepalette.cpp
index 65063959b..cf1d7c205 100644
--- a/src/resources/dye/dyepalette.cpp
+++ b/src/resources/dye/dyepalette.cpp
@@ -97,7 +97,7 @@ DyePalette::DyePalette(const std::string &restrict description,
                 continue;
             }
             const DyeColor *const color = PaletteDB::getColor(str);
-            if (color)
+            if (color != nullptr)
             {
                 DyeColor color2 = *color;
                 color2.value[3] = alpha;
@@ -249,7 +249,7 @@ void DyePalette::initFunctions()
 {
 #ifdef SIMD_SUPPORTED
     const uint32_t flags = Cpu::getFlags();
-    if (flags & Cpu::FEATURE_AVX2)
+    if ((flags & Cpu::FEATURE_AVX2) != 0u)
     {
         funcReplaceSColor = &DyePalette::replaceSColorAvx2;
         funcReplaceSColorAvx2 = &DyePalette::replaceSColorAvx2;
@@ -267,7 +267,7 @@ void DyePalette::initFunctions()
         funcReplaceAOGLColorSse2 = &DyePalette::replaceAOGLColorSse2;
 #endif  // USE_OPENGL
     }
-    else if (flags & Cpu::FEATURE_SSE2)
+    else if ((flags & Cpu::FEATURE_SSE2) != 0u)
     {
         funcReplaceSColor = &DyePalette::replaceSColorSse2;
         funcReplaceSColorAvx2 = &DyePalette::replaceSColorSse2;
diff --git a/src/resources/dye/dyepalette_replaceacolor.cpp b/src/resources/dye/dyepalette_replaceacolor.cpp
index 718a85853..21cd0b0c5 100644
--- a/src/resources/dye/dyepalette_replaceacolor.cpp
+++ b/src/resources/dye/dyepalette_replaceacolor.cpp
@@ -38,9 +38,9 @@ void DyePalette::replaceAColorDefault(uint32_t *restrict pixels,
 {
     std::vector<DyeColor>::const_iterator it_end = mColors.end();
     const size_t sz = mColors.size();
-    if (!sz || !pixels)
+    if ((sz == 0u) || (pixels == nullptr))
         return;
-    if (sz % 2)
+    if ((sz % 2) != 0u)
         -- it_end;
 
 #ifdef ENABLE_CILKPLUS
@@ -140,9 +140,9 @@ void DyePalette::replaceAColorSse2(uint32_t *restrict pixels,
 {
     std::vector<DyeColor>::const_iterator it_end = mColors.end();
     const size_t sz = mColors.size();
-    if (!sz || !pixels)
+    if ((sz == 0u) || (pixels == nullptr))
         return;
-    if (sz % 2)
+    if ((sz % 2) != 0u)
         -- it_end;
     const int mod = bufSize % 4;
     const int bufEnd = bufSize - mod;
@@ -211,9 +211,9 @@ void DyePalette::replaceAColorAvx2(uint32_t *restrict pixels,
 {
     std::vector<DyeColor>::const_iterator it_end = mColors.end();
     const size_t sz = mColors.size();
-    if (!sz || !pixels)
+    if ((sz == 0u) || (pixels == nullptr))
         return;
-    if (sz % 2)
+    if ((sz % 2) != 0u)
         -- it_end;
     const int mod = bufSize % 8;
     const int bufEnd = bufSize - mod;
diff --git a/src/resources/dye/dyepalette_replaceaoglcolor.cpp b/src/resources/dye/dyepalette_replaceaoglcolor.cpp
index 19f74d4c7..c0225df65 100644
--- a/src/resources/dye/dyepalette_replaceaoglcolor.cpp
+++ b/src/resources/dye/dyepalette_replaceaoglcolor.cpp
@@ -40,9 +40,9 @@ void DyePalette::replaceAOGLColorDefault(uint32_t *restrict pixels,
 {
     std::vector<DyeColor>::const_iterator it_end = mColors.end();
     const size_t sz = mColors.size();
-    if (!sz || !pixels)
+    if (sz == 0u || pixels == nullptr)
         return;
-    if (sz % 2)
+    if ((sz % 2) != 0u)
         -- it_end;
 
 #ifdef ENABLE_CILKPLUS
@@ -143,9 +143,9 @@ void DyePalette::replaceAOGLColorSse2(uint32_t *restrict pixels,
 {
     std::vector<DyeColor>::const_iterator it_end = mColors.end();
     const size_t sz = mColors.size();
-    if (!sz || !pixels)
+    if (sz == 0u || pixels == nullptr)
         return;
-    if (sz % 2)
+    if ((sz % 2) != 0u)
         -- it_end;
 
     if (bufSize >= 8)
@@ -269,9 +269,9 @@ void DyePalette::replaceAOGLColorAvx2(uint32_t *restrict pixels,
 {
     std::vector<DyeColor>::const_iterator it_end = mColors.end();
     const size_t sz = mColors.size();
-    if (!sz || !pixels)
+    if (sz == 0u || pixels == nullptr)
         return;
-    if (sz % 2)
+    if ((sz % 2) != 0u)
         -- it_end;
 
     if (bufSize >= 8)
diff --git a/src/resources/dye/dyepalette_replacescolor.cpp b/src/resources/dye/dyepalette_replacescolor.cpp
index 3f14adb74..0a4206e83 100644
--- a/src/resources/dye/dyepalette_replacescolor.cpp
+++ b/src/resources/dye/dyepalette_replacescolor.cpp
@@ -38,9 +38,9 @@ void DyePalette::replaceSColorDefault(uint32_t *restrict pixels,
 {
     std::vector<DyeColor>::const_iterator it_end = mColors.end();
     const size_t sz = mColors.size();
-    if (!sz || !pixels)
+    if (sz == 0u || pixels == nullptr)
         return;
-    if (sz % 2)
+    if ((sz % 2) != 0u)
         -- it_end;
 
 #ifdef ENABLE_CILKPLUS
@@ -138,9 +138,9 @@ void DyePalette::replaceSColorSse2(uint32_t *restrict pixels,
 {
     std::vector<DyeColor>::const_iterator it_end = mColors.end();
     const size_t sz = mColors.size();
-    if (!sz || !pixels)
+    if (sz == 0u || pixels == nullptr)
         return;
-    if (sz % 2)
+    if ((sz % 2) != 0u)
         -- it_end;
     const int mod = bufSize % 8;
     const int bufEnd = bufSize - mod;
@@ -219,9 +219,9 @@ void DyePalette::replaceSColorAvx2(uint32_t *restrict pixels,
 {
     std::vector<DyeColor>::const_iterator it_end = mColors.end();
     const size_t sz = mColors.size();
-    if (!sz || !pixels)
+    if (sz == 0u || pixels == nullptr)
         return;
-    if (sz % 2)
+    if ((sz % 2) != 0u)
         -- it_end;
     const int mod = bufSize % 8;
     const int bufEnd = bufSize - mod;
diff --git a/src/resources/dye/dyepalette_replacesoglcolor.cpp b/src/resources/dye/dyepalette_replacesoglcolor.cpp
index da7cd0519..cde7fac8e 100644
--- a/src/resources/dye/dyepalette_replacesoglcolor.cpp
+++ b/src/resources/dye/dyepalette_replacesoglcolor.cpp
@@ -40,9 +40,9 @@ void DyePalette::replaceSOGLColorDefault(uint32_t *restrict pixels,
 {
     std::vector<DyeColor>::const_iterator it_end = mColors.end();
     const size_t sz = mColors.size();
-    if (!sz || !pixels)
+    if ((sz == 0u) || (pixels == nullptr))
         return;
-    if (sz % 2)
+    if ((sz % 2) != 0u)
         -- it_end;
 
 #ifdef ENABLE_CILKPLUS
@@ -143,9 +143,9 @@ void DyePalette::replaceSOGLColorSse2(uint32_t *restrict pixels,
 {
     std::vector<DyeColor>::const_iterator it_end = mColors.end();
     const size_t sz = mColors.size();
-    if (!sz || !pixels)
+    if ((sz == 0u) || (pixels == nullptr))
         return;
-    if (sz % 2)
+    if ((sz % 2) != 0u)
         -- it_end;
 
     if (bufSize >= 8)
@@ -271,9 +271,9 @@ void DyePalette::replaceSOGLColorAvx2(uint32_t *restrict pixels,
 {
     std::vector<DyeColor>::const_iterator it_end = mColors.end();
     const size_t sz = mColors.size();
-    if (!sz || !pixels)
+    if ((sz == 0u) || (pixels == nullptr))
         return;
-    if (sz % 2)
+    if ((sz % 2) != 0u)
         -- it_end;
 
     if (bufSize >= 8)
diff --git a/src/resources/image/image.cpp b/src/resources/image/image.cpp
index 7d96cb0af..b1b23ce13 100644
--- a/src/resources/image/image.cpp
+++ b/src/resources/image/image.cpp
@@ -147,7 +147,7 @@ Image::Image(SDL_Surface *restrict const image, const bool hasAlphaChannel0,
     mBounds.x = 0;
     mBounds.y = 0;
 
-    if (mSDLSurface)
+    if (mSDLSurface != nullptr)
     {
         mBounds.w = CAST_U16(mSDLSurface->w);
         mBounds.h = CAST_U16(mSDLSurface->h);
@@ -191,7 +191,7 @@ Image::Image(const GLuint glimage, const int width, const int height,
     mBounds.w = CAST_U16(width);
     mBounds.h = CAST_U16(height);
 
-    if (mGLImage)
+    if (mGLImage != 0u)
     {
         mLoaded = true;
     }
@@ -225,7 +225,7 @@ void Image::unload()
 {
     mLoaded = false;
 
-    if (mSDLSurface)
+    if (mSDLSurface != nullptr)
     {
         SDLCleanCache();
         // Free the image surface.
@@ -244,7 +244,7 @@ void Image::unload()
 #endif  // USE_SDL2
 
 #ifdef USE_OPENGL
-    if (mGLImage)
+    if (mGLImage != 0u)
     {
         glDeleteTextures(1, &mGLImage);
         mGLImage = 0;
@@ -286,12 +286,12 @@ void Image::setAlpha(const float alpha)
     if (alpha < 0.0F || alpha > 1.0F)
         return;
 
-    if (mSDLSurface)
+    if (mSDLSurface != nullptr)
     {
         if (mUseAlphaCache)
         {
             SDL_Surface *surface = getByAlpha(mAlpha);
-            if (!surface)
+            if (surface == nullptr)
             {
                 if (mAlphaCache.size() > 100)
                 {
@@ -308,7 +308,7 @@ void Image::setAlpha(const float alpha)
                     SDLCleanCache();
                 }
                 surface = mSDLSurface;
-                if (surface)
+                if (surface != nullptr)
                     mAlphaCache[mAlpha] = surface;
             }
             else
@@ -317,7 +317,7 @@ void Image::setAlpha(const float alpha)
             }
 
             surface = getByAlpha(alpha);
-            if (surface)
+            if (surface != nullptr)
             {
                 if (mSDLSurface == surface)
                     logger->log("bug");
@@ -329,7 +329,7 @@ void Image::setAlpha(const float alpha)
             else
             {
                 mSDLSurface = SDLImageHelper::SDLDuplicateSurface(mSDLSurface);
-                if (!mSDLSurface)
+                if (mSDLSurface == nullptr)
                     return;
             }
         }
@@ -368,7 +368,7 @@ void Image::setAlpha(const float alpha)
             const uint8_t aloss = fmt->Aloss;
             const uint8_t ashift = fmt->Ashift;
 
-            if (!bx && bxw == sw)
+            if ((bx == 0) && bxw == sw)
             {
                 const int i2 = (maxHeight - 1) * sw + maxWidth - 1;
                 for (int i = i1; i <= i2; i++)
@@ -443,7 +443,7 @@ Image* Image::SDLgetScaledImage(const int width, const int height) const
 
     Image* scaledImage = nullptr;
 
-    if (mSDLSurface)
+    if (mSDLSurface != nullptr)
     {
         SDL_Surface *const scaledSurface = zoomSurface(mSDLSurface,
                     static_cast<double>(width) / mBounds.w,
@@ -452,7 +452,7 @@ Image* Image::SDLgetScaledImage(const int width, const int height) const
 
         // The load function takes care of the SDL<->OpenGL implementation
         // and about freeing the given SDL_surface*.
-        if (scaledSurface)
+        if (scaledSurface != nullptr)
         {
             scaledImage = imageHelper->loadSurface(scaledSurface);
             MSDL_FreeSurface(scaledSurface);
@@ -508,7 +508,7 @@ int Image::calcMemoryLocal() const
     int sz = static_cast<int>(sizeof(Image) +
         sizeof(std::map<float, SDL_Surface*>)) +
         Resource::calcMemoryLocal();
-    if (mSDLSurface)
+    if (mSDLSurface != nullptr)
     {
         sz += CAST_S32(mAlphaCache.size()) *
             memoryManager.getSurfaceSize(mSDLSurface);
@@ -519,7 +519,7 @@ int Image::calcMemoryLocal() const
 #ifdef USE_OPENGL
 void Image::decRef()
 {
-    if (mGLImage && mRefCount <= 1)
+    if ((mGLImage != 0u) && mRefCount <= 1)
         OpenGLImageHelper::invalidate(mGLImage);
     Resource::decRef();
 }
diff --git a/src/resources/image/subimage.cpp b/src/resources/image/subimage.cpp
index 7d936ecbf..77d0eb889 100644
--- a/src/resources/image/subimage.cpp
+++ b/src/resources/image/subimage.cpp
@@ -90,7 +90,7 @@ SubImage::SubImage(Image *const parent,
     mInternalBounds(),
     mParent(parent)
 {
-    if (mParent)
+    if (mParent != nullptr)
     {
         mParent->incRef();
         mParent->SDLTerminateAlphaCache();
@@ -118,7 +118,7 @@ SubImage::SubImage(Image *const parent,
     mBounds.y = CAST_S16(y);
     mBounds.w = CAST_U16(width);
     mBounds.h = CAST_U16(height);
-    if (mParent)
+    if (mParent != nullptr)
     {
         mInternalBounds.x = mParent->mBounds.x;
         mInternalBounds.y = mParent->mBounds.y;
@@ -145,7 +145,7 @@ SubImage::SubImage(Image *const parent,
     mInternalBounds(),
     mParent(parent)
 {
-    if (mParent)
+    if (mParent != nullptr)
         mParent->incRef();
 
     // Set up the rectangle.
@@ -153,7 +153,7 @@ SubImage::SubImage(Image *const parent,
     mBounds.y = CAST_S16(y);
     mBounds.w = CAST_U16(width);
     mBounds.h = CAST_U16(height);
-    if (mParent)
+    if (mParent != nullptr)
     {
         mInternalBounds.x = mParent->mBounds.x;
         mInternalBounds.y = mParent->mBounds.y;
@@ -196,7 +196,7 @@ SubImage::~SubImage()
 #ifdef USE_OPENGL
     mGLImage = 0;
 #endif  // USE_OPENGL
-    if (mParent)
+    if (mParent != nullptr)
     {
 #ifdef DEBUG_IMAGES
         logger->log("decref from subminage: %p, parent: %p",
@@ -211,7 +211,7 @@ SubImage::~SubImage()
 Image *SubImage::getSubImage(const int x, const int y,
                              const int w, const int h)
 {
-    if (mParent)
+    if (mParent != nullptr)
         return mParent->getSubImage(mBounds.x + x, mBounds.y + y, w, h);
     else
         return nullptr;
diff --git a/src/resources/imagehelper.cpp b/src/resources/imagehelper.cpp
index 9495dde4e..1879e9a6a 100644
--- a/src/resources/imagehelper.cpp
+++ b/src/resources/imagehelper.cpp
@@ -46,7 +46,7 @@ RenderType ImageHelper::mUseOpenGL = RENDER_SOFTWARE;
 Image *ImageHelper::load(SDL_RWops *const rw)
 {
     SDL_Surface *const tmpImage = loadPng(rw);
-    if (!tmpImage)
+    if (tmpImage == nullptr)
     {
         logger->log("Error, image load failed: %s", IMG_GetError());
         return nullptr;
@@ -62,7 +62,7 @@ Image *ImageHelper::load(SDL_RWops *const rw, Dye const &dye)
 {
     BLOCK_START("ImageHelper::load")
     SDL_Surface *const tmpImage = loadPng(rw);
-    if (!tmpImage)
+    if (tmpImage == nullptr)
     {
         logger->log("Error, image load failed: %s", IMG_GetError());
         BLOCK_END("ImageHelper::load")
@@ -91,7 +91,7 @@ Image *ImageHelper::load(SDL_RWops *const rw, Dye const &dye)
         tmpImage, &rgba, SDL_SWSURFACE);
     MSDL_FreeSurface(tmpImage);
 
-    if (!surf)
+    if (surf == nullptr)
         return nullptr;
 
     uint32_t *const pixels = static_cast<uint32_t *>(surf->pixels);
@@ -102,14 +102,14 @@ Image *ImageHelper::load(SDL_RWops *const rw, Dye const &dye)
         case 1:
         {
             const DyePalette *const pal = dye.getSPalete();
-            if (pal)
+            if (pal != nullptr)
                 DYEPALETTEP(pal, SColor)(pixels, surf->w * surf->h);
             break;
         }
         case 2:
         {
             const DyePalette *const pal = dye.getAPalete();
-            if (pal)
+            if (pal != nullptr)
                 DYEPALETTEP(pal, AColor)(pixels, surf->w * surf->h);
             break;
         }
@@ -129,7 +129,7 @@ Image *ImageHelper::load(SDL_RWops *const rw, Dye const &dye)
 
 SDL_Surface* ImageHelper::convertTo32Bit(SDL_Surface *const tmpImage)
 {
-    if (!tmpImage)
+    if (tmpImage == nullptr)
         return nullptr;
     SDL_PixelFormat RGBAFormat;
     RGBAFormat.palette = nullptr;
@@ -174,9 +174,9 @@ SDL_Surface* ImageHelper::convertTo32Bit(SDL_Surface *const tmpImage)
 
 void ImageHelper::dumpSurfaceFormat(const SDL_Surface *const image)
 {
-    if (!image)
+    if (image == nullptr)
         return;
-    if (image->format)
+    if (image->format != nullptr)
     {
         const SDL_PixelFormat * const format = image->format;
         logger->log("Bytes per pixel: %d", format->BytesPerPixel);
@@ -201,17 +201,17 @@ void ImageHelper::dumpSurfaceFormat(const SDL_Surface *const image)
 
 SDL_Surface *ImageHelper::loadPng(SDL_RWops *const rw)
 {
-    if (!rw)
+    if (rw == nullptr)
         return nullptr;
 
-    if (IMG_isPNG(rw))
+    if (IMG_isPNG(rw) != 0)
     {
         SDL_Surface *const tmpImage = MIMG_LoadPNG_RW(rw);
         SDL_RWclose(rw);
         return tmpImage;
     }
 
-    if (IMG_isJPG(rw))
+    if (IMG_isJPG(rw) != 0)
     {
         SDL_Surface *const tmpImage = MIMG_LoadJPG_RW(rw);
         SDL_RWclose(rw);
diff --git a/src/resources/imageset.cpp b/src/resources/imageset.cpp
index c2f1e532e..59a44c87f 100644
--- a/src/resources/imageset.cpp
+++ b/src/resources/imageset.cpp
@@ -39,7 +39,7 @@ ImageSet::ImageSet(Image *const img, const int width, const int height,
     mOffsetX(0),
     mOffsetY(0)
 {
-    if (img)
+    if (img != nullptr)
     {
         const int hAdd = height + spacing;
         const int wAdd = width + spacing;
diff --git a/src/resources/imagewriter.cpp b/src/resources/imagewriter.cpp
index b9287cf8a..a797e2496 100644
--- a/src/resources/imagewriter.cpp
+++ b/src/resources/imagewriter.cpp
@@ -32,7 +32,7 @@
 bool ImageWriter::writePNG(SDL_Surface *const surface,
                            const std::string &filename)
 {
-    if (!surface)
+    if (surface == nullptr)
         return false;
 
 
@@ -41,14 +41,14 @@ bool ImageWriter::writePNG(SDL_Surface *const surface,
 
     png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
         nullptr, nullptr, nullptr);
-    if (!png_ptr)
+    if (png_ptr == nullptr)
     {
         reportAlways("Had trouble creating png_structp");
         return false;
     }
 
     png_infop info_ptr = png_create_info_struct(png_ptr);
-    if (!info_ptr)
+    if (info_ptr == nullptr)
     {
         png_destroy_write_struct(&png_ptr, static_cast<png_infopp>(nullptr));
         reportAlways("Could not create png_info");
@@ -63,7 +63,7 @@ bool ImageWriter::writePNG(SDL_Surface *const surface,
     }
 
     FILE *const fp = fopen(filename.c_str(), "wb");
-    if (!fp)
+    if (fp == nullptr)
     {
         reportAlways("could not open file %s for writing",
             filename.c_str());
diff --git a/src/resources/inventory/complexinventory.cpp b/src/resources/inventory/complexinventory.cpp
index 82490ac8b..065b77e49 100644
--- a/src/resources/inventory/complexinventory.cpp
+++ b/src/resources/inventory/complexinventory.cpp
@@ -44,7 +44,7 @@ bool ComplexInventory::addVirtualItem(const Item *const item,
                                       int index,
                                       const int amount)
 {
-    if (!item || PlayerInfo::isItemProtected(item->getId()))
+    if ((item == nullptr) || PlayerInfo::isItemProtected(item->getId()))
         return false;
 
     if (index >= 0 && index < CAST_S32(mSize))
@@ -59,7 +59,7 @@ bool ComplexInventory::addVirtualItem(const Item *const item,
                 return false;
             }
             citem = dynamic_cast<ComplexItem*>(mItems[index]);
-            if (!citem)
+            if (citem == nullptr)
             {   // if in inventory not complex item, converting it to complex
                 citem = new ComplexItem(item2->getId(),
                     item2->getType(),
@@ -109,7 +109,7 @@ bool ComplexInventory::addVirtualItem(const Item *const item,
         return false;
 
     Item *const item2 = getItem(index);
-    if (item2)
+    if (item2 != nullptr)
         item2->setTag(item->getInvIndex());
     return true;
 }
@@ -133,7 +133,7 @@ void ComplexInventory::setItem(const int index,
     }
 
     const Item *const item1 = mItems[index];
-    if (!item1 && id > 0)
+    if ((item1 == nullptr) && id > 0)
     {
         ComplexItem *const item = new ComplexItem(id,
             type,
diff --git a/src/resources/inventory/inventory.cpp b/src/resources/inventory/inventory.cpp
index 92f35715a..97bb255fe 100644
--- a/src/resources/inventory/inventory.cpp
+++ b/src/resources/inventory/inventory.cpp
@@ -49,7 +49,7 @@ namespace
 
         bool operator()(const Item *const item) const
         {
-            return item && item->mId >= 0 && item->mQuantity > 0;
+            return (item != nullptr) && item->mId >= 0 && item->mQuantity > 0;
         }
         typedef Item *argument_type;
     };
@@ -80,7 +80,7 @@ Inventory::~Inventory()
 
 Item *Inventory::getItem(const int index) const
 {
-    if (index < 0 || index >= CAST_S32(mSize) || !mItems[index]
+    if (index < 0 || index >= CAST_S32(mSize) || (mItems[index] == nullptr)
         || mItems[index]->mQuantity <= 0)
     {
         return nullptr;
@@ -95,7 +95,7 @@ Item *Inventory::findItem(const int itemId,
     for (unsigned i = 0; i < mSize; i++)
     {
         Item *const item = mItems[i];
-        if (item && item->mId == itemId)
+        if ((item != nullptr) && item->mId == itemId)
         {
             if (color == ItemColor_zero ||
                 item->mColor == color ||
@@ -156,7 +156,7 @@ void Inventory::setItem(const int index,
     }
 
     Item *const item1 = mItems[index];
-    if (!item1 && id > 0)
+    if ((item1 == nullptr) && id > 0)
     {
         Item *const item = new Item(id,
             type,
@@ -173,7 +173,7 @@ void Inventory::setItem(const int index,
         mUsed++;
         distributeSlotsChangedEvent();
     }
-    else if (id > 0 && item1)
+    else if (id > 0 && (item1 != nullptr))
     {
         item1->setId(id, color);
         item1->setQuantity(quantity);
@@ -183,7 +183,7 @@ void Inventory::setItem(const int index,
         item1->setDamaged(damaged);
         item1->setFavorite(favorite);
     }
-    else if (item1)
+    else if (item1 != nullptr)
     {
         removeItemAt(index);
     }
@@ -201,7 +201,7 @@ void Inventory::setCards(const int index,
     }
 
     Item *const item1 = mItems[index];
-    if (item1)
+    if (item1 != nullptr)
         item1->setCards(cards, size);
 }
 
@@ -215,7 +215,7 @@ void Inventory::setOptions(const int index,
         return;
     }
     Item *const item1 = mItems[index];
-    if (item1)
+    if (item1 != nullptr)
         item1->setOptions(options);
 }
 
@@ -230,14 +230,14 @@ void Inventory::removeItem(const int id)
     for (unsigned i = 0; i < mSize; i++)
     {
         const Item *const item = mItems[i];
-        if (item && item->mId == id)
+        if ((item != nullptr) && item->mId == id)
             removeItemAt(i);
     }
 }
 
 void Inventory::removeItemAt(const int index)
 {
-    if (!mItems[index])
+    if (mItems[index] == nullptr)
         return;
     delete2(mItems[index]);
     mUsed--;
@@ -249,14 +249,14 @@ void Inventory::removeItemAt(const int index)
 
 bool Inventory::contains(const Item *const item) const
 {
-    if (!item)
+    if (item == nullptr)
         return false;
 
     const int id = item->mId;
     for (unsigned i = 0; i < mSize; i++)
     {
         const Item *const item1 = mItems[i];
-        if (item1 && item1->mId == id)
+        if ((item1 != nullptr) && item1->mId == id)
             return true;
     }
 
@@ -311,7 +311,7 @@ const Item *Inventory::findItemBySprite(std::string spritePath,
     for (unsigned i = 0; i < mSize; i++)
     {
         const Item *const item = mItems[i];
-        if (item)
+        if (item != nullptr)
         {
             std::string path = item->getInfo().getSprite(gender, race);
             if (!path.empty())
@@ -397,7 +397,7 @@ int Inventory::findIndexByTag(const int tag) const
     for (unsigned i = 0; i < mSize; i++)
     {
         const Item *const item = mItems[i];
-        if (item && item->mTag == tag)
+        if ((item != nullptr) && item->mTag == tag)
             return i;
     }
 
@@ -408,7 +408,7 @@ bool Inventory::addVirtualItem(const Item *const item,
                                int index,
                                const int amount)
 {
-    if (item && !PlayerInfo::isItemProtected(item->getId()))
+    if ((item != nullptr) && !PlayerInfo::isItemProtected(item->getId()))
     {
         if (index >= 0 && index < CAST_S32(mSize))
         {
@@ -443,7 +443,7 @@ bool Inventory::addVirtualItem(const Item *const item,
             return false;
 
         Item *const item2 = getItem(index);
-        if (item2)
+        if (item2 != nullptr)
             item2->setTag(item->getInvIndex());
         return true;
     }
@@ -453,7 +453,7 @@ bool Inventory::addVirtualItem(const Item *const item,
 void Inventory::virtualRemove(Item *const item,
                               const int amount)
 {
-    if (!item || item->mQuantity < amount)
+    if ((item == nullptr) || item->mQuantity < amount)
         return;
 
     const int index = item->getInvIndex();
@@ -475,7 +475,7 @@ void Inventory::restoreVirtuals()
         if (index < 0 || index >= sz)
             continue;
         Item *const item = mItems[index];
-        if (!item)
+        if (item == nullptr)
             continue;
         item->mQuantity += (*it).second;
     }
@@ -492,7 +492,7 @@ void Inventory::virtualRestore(const Item *const item,
         mVirtualRemove[index] -= amount;
         if (mVirtualRemove[index] < 0)
             mVirtualRemove.erase(index);
-        if (index < 0 || index >= CAST_S32(mSize) || !mItems[index])
+        if (index < 0 || index >= CAST_S32(mSize) || (mItems[index] == nullptr))
             return;
         mItems[index]->mQuantity += amount;
     }
@@ -511,9 +511,9 @@ void Inventory::moveItem(const int index1,
 
     Item *const item1 = mItems[index1];
     Item *const item2 = mItems[index2];
-    if (item1)
+    if (item1 != nullptr)
         item1->setInvIndex(index2);
-    if (item2)
+    if (item2 != nullptr)
         item2->setInvIndex(index1);
     mItems[index1] = item2;
     mItems[index2] = item1;
diff --git a/src/resources/item/cardslist.h b/src/resources/item/cardslist.h
index f4c488404..6bc1f5e22 100644
--- a/src/resources/item/cardslist.h
+++ b/src/resources/item/cardslist.h
@@ -42,7 +42,7 @@ struct CardsList final
 
     explicit CardsList(const int *const cards0)
     {
-        if (cards0)
+        if (cards0 != nullptr)
         {
             for (int f = 0; f < maxCards; f ++)
                 cards[f] = cards0[f];
diff --git a/src/resources/item/complexitem.cpp b/src/resources/item/complexitem.cpp
index 08901a90e..047c50614 100644
--- a/src/resources/item/complexitem.cpp
+++ b/src/resources/item/complexitem.cpp
@@ -57,7 +57,7 @@ ComplexItem::~ComplexItem()
 void ComplexItem::addChild(const Item *const item,
                            const int amount)
 {
-    if (!item)
+    if (item == nullptr)
         return;
     increaseQuantity(amount);
     Item *child = nullptr;
@@ -72,7 +72,7 @@ void ComplexItem::addChild(const Item *const item,
             break;
         }
     }
-    if (child)
+    if (child != nullptr)
     {
         child->increaseQuantity(amount);
     }
diff --git a/src/resources/item/item.cpp b/src/resources/item/item.cpp
index c2c25a78c..897340732 100644
--- a/src/resources/item/item.cpp
+++ b/src/resources/item/item.cpp
@@ -78,7 +78,7 @@ Item::Item(const int id,
 
 Item::~Item()
 {
-    if (mImage)
+    if (mImage != nullptr)
     {
         mImage->decRef();
         mImage = nullptr;
@@ -97,7 +97,7 @@ void Item::setId(const int id,
     mEquipment = fromBool(id && CAST_S32(getInfo().getType())
         >= 2, Equipm);
 
-    if (mImage)
+    if (mImage != nullptr)
         mImage->decRef();
 
     const ItemInfo &info = getInfo();
@@ -108,7 +108,7 @@ void Item::setId(const int id,
         info.getDyeIconColorsString(color));
     mImage = Loader::getImage(dye);
 
-    if (!mImage)
+    if (mImage == nullptr)
     {
         mImage = Theme::getImageFromTheme(paths.getValue("unknownItemFile",
             "unknown-item.png"));
@@ -131,7 +131,7 @@ Image *Item::getImage(const int id,
         "itemIcons"), info.getDisplay().image),
         info.getDyeIconColorsString(color)));
 
-    if (!image)
+    if (image == nullptr)
         image = Theme::getImageFromTheme("unknown-item.png");
     return image;
 }
@@ -167,7 +167,7 @@ int Item::getCard(const int index) const
 
 void Item::setCards(const int *const cards, const int size)
 {
-    if (size < 0 || !cards)
+    if (size < 0 || (cards == nullptr))
         return;
     int sz = size;
     if (sz > maxCards)
@@ -180,7 +180,7 @@ void Item::addCard(const int card)
 {
     for (int f = 0; f < maxCards; f ++)
     {
-        if (!mCards[f])
+        if (mCards[f] == 0)
         {
             mCards[f] = card;
             return;
diff --git a/src/resources/item/shopitem.cpp b/src/resources/item/shopitem.cpp
index 0c013ee89..99e0c43dd 100644
--- a/src/resources/item/shopitem.cpp
+++ b/src/resources/item/shopitem.cpp
@@ -102,7 +102,7 @@ void ShopItem::updateDisplayName(const int quantity)
     else
 #endif  // TMWA_SUPPORT
         mDisplayName = std::string(getInfo().getName(mColor));
-    if (mPrice)
+    if (mPrice != 0)
     {
         mDisplayName.append(" (").append(
             UnitsDb::formatCurrency(mCurrency, mPrice)).append(") ");
@@ -138,7 +138,7 @@ void ShopItem::addDuplicate()
 int ShopItem::sellCurrentDuplicate(const int quantity)
 {
     DuplicateItem* dupl = mDuplicates.top();
-    if (!dupl)
+    if (dupl == nullptr)
         return 0;
 
     const int sellCount = quantity <= dupl->quantity
@@ -155,7 +155,7 @@ int ShopItem::sellCurrentDuplicate(const int quantity)
 
 void ShopItem::increaseUsedQuantity(const int amount)
 {
-    if (mShowQuantity && mQuantity)
+    if (mShowQuantity && (mQuantity != 0))
     {
         if (mQuantity < mUsedQuantity + amount ||
             mUsedQuantity + amount < 0)
diff --git a/src/resources/iteminfo.cpp b/src/resources/iteminfo.cpp
index 75e166a0d..7a88a63ca 100644
--- a/src/resources/iteminfo.cpp
+++ b/src/resources/iteminfo.cpp
@@ -95,7 +95,7 @@ ItemInfo::~ItemInfo()
 const std::string &ItemInfo::getSprite(const GenderT gender,
                                        const BeingTypeId race) const
 {
-    if (mView)
+    if (mView != 0)
     {
         // Forward the request to the item defining how to view this item
         return ItemDB::get(mView).getSprite(gender, race);
@@ -177,7 +177,7 @@ IntMap *ItemInfo::addReplaceSprite(const int sprite,
 
     SpriteToItemMap *spMap = mSpriteToItemReplaceMap[direction];
 
-    if (!spMap)
+    if (spMap == nullptr)
     {
         spMap = new SpriteToItemMap;
         mSpriteToItemReplaceMap[direction] = spMap;
@@ -224,7 +224,7 @@ void ItemInfo::setIconColorsList(const std::string &name)
 
 std::string ItemInfo::getDyeColorsString(const ItemColor color) const
 {
-    if (!mColorsList || mColorsListName.empty())
+    if ((mColorsList == nullptr) || mColorsListName.empty())
         return "";
 
     const std::map <ItemColor, ColorDB::ItemColorData>::const_iterator
@@ -237,7 +237,7 @@ std::string ItemInfo::getDyeColorsString(const ItemColor color) const
 
 std::string ItemInfo::getDyeIconColorsString(const ItemColor color) const
 {
-    if (!mIconColorsList || mIconColorsListName.empty())
+    if ((mIconColorsList == nullptr) || mIconColorsListName.empty())
         return "";
 
     const std::map <ItemColor, ColorDB::ItemColorData>::const_iterator
@@ -267,7 +267,7 @@ const std::string ItemInfo::replaceColors(std::string str,
                                           const ItemColor color) const
 {
     std::string name;
-    if (mColorsList && !mColorsListName.empty())
+    if ((mColorsList != nullptr) && !mColorsListName.empty())
     {
         const std::map <ItemColor, ColorDB::ItemColorData>::const_iterator
             it = mColorsList->find(color);
@@ -295,7 +295,7 @@ const SpriteToItemMap *ItemInfo::getSpriteToItemReplaceMap(const int direction)
         return nullptr;
 
     const SpriteToItemMap *const spMap = mSpriteToItemReplaceMap[direction];
-    if (spMap)
+    if (spMap != nullptr)
         return spMap;
     if (direction == SpriteDirection::UPLEFT
         || direction == SpriteDirection::UPRIGHT)
@@ -410,7 +410,7 @@ void ItemInfo::setSprite(const std::string &animationFile,
 
 std::string ItemInfo::getColorName(const ItemColor idx) const
 {
-    if (!mColorsList)
+    if (mColorsList == nullptr)
         return std::string();
 
     const std::map <ItemColor, ColorDB::ItemColorData>::const_iterator
@@ -427,7 +427,7 @@ std::string ItemInfo::getColorName(const ItemColor idx) const
 
 std::string ItemInfo::getColor(const ItemColor idx) const
 {
-    if (!mColorsList)
+    if (mColorsList == nullptr)
         return std::string();
 
     const std::map <ItemColor, ColorDB::ItemColorData>::const_iterator
@@ -444,7 +444,7 @@ std::string ItemInfo::getColor(const ItemColor idx) const
 
 std::string ItemInfo::getIconColorName(const ItemColor idx) const
 {
-    if (!mIconColorsList)
+    if (mIconColorsList == nullptr)
         return std::string();
 
     const std::map <ItemColor, ColorDB::ItemColorData>::const_iterator
@@ -461,7 +461,7 @@ std::string ItemInfo::getIconColorName(const ItemColor idx) const
 
 std::string ItemInfo::getIconColor(const ItemColor idx) const
 {
-    if (!mIconColorsList)
+    if (mIconColorsList == nullptr)
         return std::string();
 
     const std::map <ItemColor, ColorDB::ItemColorData>::const_iterator
diff --git a/src/resources/iteminfo.h b/src/resources/iteminfo.h
index 722db5c15..502fbfbf7 100644
--- a/src/resources/iteminfo.h
+++ b/src/resources/iteminfo.h
@@ -303,12 +303,12 @@ class ItemInfo final
         { return mProtected; }
 
         int getColorsSize() const noexcept2 A_WARN_UNUSED
-        { return mColorsList ? CAST_S32(mColorsList->size()) : 0; }
+        { return mColorsList != nullptr ? CAST_S32(mColorsList->size()) : 0; }
 
         int getIconColorsSize() const noexcept2 A_WARN_UNUSED
         {
-            return mIconColorsList ? CAST_S32(mIconColorsList->size())
-                : 0;
+            return mIconColorsList != nullptr ?
+                CAST_S32(mIconColorsList->size()) : 0;
         }
 
         std::string getColorName(const ItemColor idx) const;
diff --git a/src/resources/loaders/atlasloader.cpp b/src/resources/loaders/atlasloader.cpp
index d3e2e276f..9f7b4ab09 100644
--- a/src/resources/loaders/atlasloader.cpp
+++ b/src/resources/loaders/atlasloader.cpp
@@ -40,13 +40,13 @@ struct AtlasLoader final
 
     static Resource *load(const void *const v)
     {
-        if (!v)
+        if (v == nullptr)
             return nullptr;
 
         const AtlasLoader *const rl = static_cast<const AtlasLoader *>(v);
         AtlasResource *const resource = AtlasManager::loadTextureAtlas(
             rl->name, *rl->files);
-        if (!resource)
+        if (resource == nullptr)
             reportAlways("Atlas creation error: %s", rl->name.c_str());
         return resource;
     }
diff --git a/src/resources/loaders/emptyatlasloader.cpp b/src/resources/loaders/emptyatlasloader.cpp
index 24c73ac21..3138c821b 100644
--- a/src/resources/loaders/emptyatlasloader.cpp
+++ b/src/resources/loaders/emptyatlasloader.cpp
@@ -40,14 +40,14 @@ struct EmptyAtlasLoader final
 
     static Resource *load(const void *const v)
     {
-        if (!v)
+        if (v == nullptr)
             return nullptr;
 
         const EmptyAtlasLoader *const rl =
             static_cast<const EmptyAtlasLoader *>(v);
         AtlasResource *const resource = AtlasManager::loadEmptyAtlas(
             rl->name, *rl->files);
-        if (!resource)
+        if (resource == nullptr)
             reportAlways("Empty atlas creation error: %s", rl->name.c_str());
         return resource;
     }
diff --git a/src/resources/loaders/imageloader.cpp b/src/resources/loaders/imageloader.cpp
index 5a1830e15..c5635ef14 100644
--- a/src/resources/loaders/imageloader.cpp
+++ b/src/resources/loaders/imageloader.cpp
@@ -46,7 +46,7 @@ namespace
         static Resource *load(const void *const v)
         {
             BLOCK_START("DyedImageLoader::load")
-            if (!v)
+            if (v == nullptr)
             {
                 BLOCK_END("DyedImageLoader::load")
                 return nullptr;
@@ -64,17 +64,17 @@ namespace
                 path1 = path1.substr(0, p);
             }
             SDL_RWops *const rw = VirtFs::rwopsOpenRead(path1);
-            if (!rw)
+            if (rw == nullptr)
             {
                 delete d;
                 reportAlways("Image loading error: %s", path1.c_str());
                 BLOCK_END("DyedImageLoader::load")
                 return nullptr;
             }
-            Resource *const res = d ? imageHelper->load(rw, *d)
+            Resource *const res = d != nullptr ? imageHelper->load(rw, *d)
                 : imageHelper->load(rw);
             delete d;
-            if (!res)
+            if (res == nullptr)
                 reportAlways("Image loading error: %s", path1.c_str());
             BLOCK_END("DyedImageLoader::load")
             return res;
diff --git a/src/resources/loaders/imagesetloader.cpp b/src/resources/loaders/imagesetloader.cpp
index 342b26d9a..63b56d1fe 100644
--- a/src/resources/loaders/imagesetloader.cpp
+++ b/src/resources/loaders/imagesetloader.cpp
@@ -44,14 +44,14 @@ struct ImageSetLoader final
 
     static Resource *load(const void *const v)
     {
-        if (!v)
+        if (v == nullptr)
             return nullptr;
 
         const ImageSetLoader *const
             rl = static_cast<const ImageSetLoader *>(v);
 
         Image *const img = Loader::getImage(rl->path);
-        if (!img)
+        if (img == nullptr)
         {
             reportAlways("Image loading error: %s", rl->path.c_str());
             return nullptr;
diff --git a/src/resources/loaders/musicloader.cpp b/src/resources/loaders/musicloader.cpp
index 23a994e1b..f0b67cb67 100644
--- a/src/resources/loaders/musicloader.cpp
+++ b/src/resources/loaders/musicloader.cpp
@@ -42,12 +42,12 @@ namespace
 
         static Resource *load(const void *const v)
         {
-            if (!v)
+            if (v == nullptr)
                 return nullptr;
             const ResourceLoader *const
                 rl = static_cast<const ResourceLoader *>(v);
             SDL_RWops *const rw = VirtFs::rwopsOpenRead(rl->path);
-            if (!rw)
+            if (rw == nullptr)
             {
                 reportAlways("Error loading resource: %s",
                     rl->path.c_str());
diff --git a/src/resources/loaders/rescaledloader.cpp b/src/resources/loaders/rescaledloader.cpp
index c6a70f969..cea73b382 100644
--- a/src/resources/loaders/rescaledloader.cpp
+++ b/src/resources/loaders/rescaledloader.cpp
@@ -42,15 +42,15 @@ namespace
         const int height;
         static Resource *load(const void *const v)
         {
-            if (!v)
+            if (v == nullptr)
                 return nullptr;
             const RescaledLoader *const rl
                 = static_cast<const RescaledLoader *>(v);
-            if (!rl->image)
+            if (rl->image == nullptr)
                 return nullptr;
             Image *const rescaled = rl->image->SDLgetScaledImage(
                 rl->width, rl->height);
-            if (!rescaled)
+            if (rescaled == nullptr)
             {
                 reportAlways("Rescale image failed: %s",
                     rl->image->mIdPath.c_str());
@@ -65,7 +65,7 @@ Image *Loader::getRescaled(const Image *const image,
                            const int width,
                            const int height)
 {
-    if (!image)
+    if (image == nullptr)
         return nullptr;
 
     const std::string idPath = image->mIdPath + strprintf(
diff --git a/src/resources/loaders/shaderloader.cpp b/src/resources/loaders/shaderloader.cpp
index 5d5b70869..550be0a75 100644
--- a/src/resources/loaders/shaderloader.cpp
+++ b/src/resources/loaders/shaderloader.cpp
@@ -44,13 +44,13 @@ namespace
 
         static Resource *load(const void *const v)
         {
-            if (!v)
+            if (v == nullptr)
                 return nullptr;
 
             const ShaderLoader *const rl
                 = static_cast<const ShaderLoader *>(v);
             Shader *const resource = shaders.createShader(rl->type, rl->name);
-            if (!resource)
+            if (resource == nullptr)
                 reportAlways("Shader creation error: %s", rl->name.c_str());
             return resource;
         }
diff --git a/src/resources/loaders/shaderprogramloader.cpp b/src/resources/loaders/shaderprogramloader.cpp
index 2f73cb5a8..fe4a5cf50 100644
--- a/src/resources/loaders/shaderprogramloader.cpp
+++ b/src/resources/loaders/shaderprogramloader.cpp
@@ -45,7 +45,7 @@ namespace
 
         static Resource *load(const void *const v)
         {
-            if (!v)
+            if (v == nullptr)
                 return nullptr;
 
             const ShaderProgramLoader *const rl
@@ -54,7 +54,7 @@ namespace
                 rl->vertex,
                 rl->fragment,
                 rl->isNewShader);
-            if (!resource)
+            if (resource == nullptr)
                 reportAlways("Shader program creation error");
             return resource;
         }
diff --git a/src/resources/loaders/soundloader.cpp b/src/resources/loaders/soundloader.cpp
index f5e7f1058..a84898201 100644
--- a/src/resources/loaders/soundloader.cpp
+++ b/src/resources/loaders/soundloader.cpp
@@ -42,12 +42,12 @@ namespace
 
         static Resource *load(const void *const v)
         {
-            if (!v)
+            if (v == nullptr)
                 return nullptr;
             const ResourceLoader *const
                 rl = static_cast<const ResourceLoader *>(v);
             SDL_RWops *const rw = VirtFs::rwopsOpenRead(rl->path);
-            if (!rw)
+            if (rw == nullptr)
             {
                 reportAlways("Error loading resource: %s",
                     rl->path.c_str());
@@ -56,7 +56,7 @@ namespace
             // Load the music data and free the RWops structure
             Mix_Chunk *const tmpSoundEffect = Mix_LoadWAV_RW(rw, 1);
 
-            if (tmpSoundEffect)
+            if (tmpSoundEffect != nullptr)
             {
                 return new SoundEffect(tmpSoundEffect, rl->path);
             }
diff --git a/src/resources/loaders/spritedefloader.cpp b/src/resources/loaders/spritedefloader.cpp
index 69f182b89..2e91d759b 100644
--- a/src/resources/loaders/spritedefloader.cpp
+++ b/src/resources/loaders/spritedefloader.cpp
@@ -42,7 +42,7 @@ namespace
         const int variant;
         static Resource *load(const void *const v)
         {
-            if (!v)
+            if (v == nullptr)
                 return nullptr;
 
             const SpriteDefLoader *const
diff --git a/src/resources/loaders/subimageloader.cpp b/src/resources/loaders/subimageloader.cpp
index f340f69c9..a4ccc2346 100644
--- a/src/resources/loaders/subimageloader.cpp
+++ b/src/resources/loaders/subimageloader.cpp
@@ -44,17 +44,17 @@ namespace
         const int height;
         static Resource *load(const void *const v)
         {
-            if (!v)
+            if (v == nullptr)
                 return nullptr;
 
             const SubImageLoader *const
                 rl = static_cast<const SubImageLoader *>(v);
-            if (!rl->parent)
+            if (rl->parent == nullptr)
                 return nullptr;
 
             Image *const res = rl->parent->getSubImage(rl->x, rl->y,
                 rl->width, rl->height);
-            if (!res)
+            if (res == nullptr)
             {
                 reportAlways("SubImage loading error: %s",
                     rl->parent->mSource.c_str());
@@ -70,7 +70,7 @@ Image *Loader::getSubImage(Image *const parent,
                            const int width,
                            const int height)
 {
-    if (!parent)
+    if (parent == nullptr)
         return nullptr;
 
     const SubImageLoader rl = { parent, x, y, width, height};
diff --git a/src/resources/loaders/subimagesetloader.cpp b/src/resources/loaders/subimagesetloader.cpp
index 4aefb4c2e..ef47b164d 100644
--- a/src/resources/loaders/subimagesetloader.cpp
+++ b/src/resources/loaders/subimagesetloader.cpp
@@ -43,13 +43,13 @@ namespace
         int height;
         static Resource *load(const void *const v)
         {
-            if (!v)
+            if (v == nullptr)
                 return nullptr;
 
             const SubImageSetLoader *const
                 rl = static_cast<const SubImageSetLoader *>(v);
 
-            if (!rl->parent)
+            if (rl->parent == nullptr)
                 return nullptr;
             ImageSet *const res = new ImageSet(rl->parent,
                 rl->width, rl->height);
@@ -62,7 +62,7 @@ ImageSet *Loader::getSubImageSet(Image *const parent,
                                  const int width,
                                  const int height)
 {
-    if (!parent)
+    if (parent == nullptr)
         return nullptr;
 
     const SubImageSetLoader rl = { parent, width, height };
diff --git a/src/resources/loaders/walklayerloader.cpp b/src/resources/loaders/walklayerloader.cpp
index c5e4569c8..16be1e2ce 100644
--- a/src/resources/loaders/walklayerloader.cpp
+++ b/src/resources/loaders/walklayerloader.cpp
@@ -42,13 +42,13 @@ struct WalkLayerLoader final
 
     static Resource *load(const void *const v)
     {
-        if (!v)
+        if (v == nullptr)
             return nullptr;
 
         const WalkLayerLoader *const rl = static_cast<const
             WalkLayerLoader *>(v);
         Resource *const resource = NavigationManager::loadWalkLayer(rl->map);
-        if (!resource)
+        if (resource == nullptr)
             reportAlways("WalkLayer creation error");
         return resource;
     }
diff --git a/src/resources/loaders/xmlloader.cpp b/src/resources/loaders/xmlloader.cpp
index 9cacd1c41..61618530e 100644
--- a/src/resources/loaders/xmlloader.cpp
+++ b/src/resources/loaders/xmlloader.cpp
@@ -40,7 +40,7 @@ namespace
 
         static Resource *load(const void *const v)
         {
-            if (!v)
+            if (v == nullptr)
                 return nullptr;
             const ResourceLoader *const
                 rl = static_cast<const ResourceLoader *>(v);
diff --git a/src/resources/map/map.cpp b/src/resources/map/map.cpp
index f0092c448..f2c8f4636 100644
--- a/src/resources/map/map.cpp
+++ b/src/resources/map/map.cpp
@@ -83,7 +83,7 @@ class ActorFunctuator final
         bool operator()(const Actor *const a,
                         const Actor *const b) const
         {
-            if (!a || !b)
+            if ((a == nullptr) || (b == nullptr))
                 return false;
             return a->getSortPixelY() < b->getSortPixelY();
         }
@@ -174,7 +174,7 @@ Map::~Map()
     config.removeListeners(this);
     CHECKLISTENERS
 
-    if (mWalkLayer)
+    if (mWalkLayer != nullptr)
     {
         mWalkLayer->decRef();
         mWalkLayer = nullptr;
@@ -189,7 +189,7 @@ Map::~Map()
     delete2(mTempLayer);
     delete2(mObjects);
     delete_all(mMapPortals);
-    if (mAtlas)
+    if (mAtlas != nullptr)
     {
         mAtlas->decRef();
         mAtlas = nullptr;
@@ -244,10 +244,10 @@ void Map::initializeAmbientLayers() restrict2
 
         Image *restrict const img = Loader::getImage(
             getProperty(name + "image"));
-        if (img)
+        if (img != nullptr)
         {
             int mask = atoi(getProperty(name + "mask").c_str());
-            if (!mask)
+            if (mask == 0)
                 mask = 1;
             const float parallax = getFloatProperty(name + "parallax");
             mForegrounds.push_back(new AmbientLayer(
@@ -275,10 +275,10 @@ void Map::initializeAmbientLayers() restrict2
         Image *restrict const img = Loader::getImage(
             getProperty(name + "image"));
 
-        if (img)
+        if (img != nullptr)
         {
             int mask = atoi(getProperty(name + "mask").c_str());
-            if (!mask)
+            if (mask == 0)
                 mask = 1;
 
             const float parallax = getFloatProperty(name + "parallax");
@@ -303,7 +303,7 @@ void Map::initializeAmbientLayers() restrict2
 void Map::addLayer(MapLayer *const layer) restrict2
 {
     mLayers.push_back(layer);
-    if (layer->isFringeLayer() && !mFringeLayer)
+    if (layer->isFringeLayer() && (mFringeLayer == nullptr))
         mFringeLayer = layer;
 }
 
@@ -321,7 +321,7 @@ void Map::update(const int ticks) restrict2
     FOR_EACH (TileAnimationMapCIter, iAni, mTileAnimations)
     {
         TileAnimation *restrict const tileAni = iAni->second;
-        if (tileAni && tileAni->update(ticks))
+        if ((tileAni != nullptr) && tileAni->update(ticks))
             mRedrawMap = true;
     }
 }
@@ -329,7 +329,7 @@ void Map::update(const int ticks) restrict2
 void Map::draw(Graphics *restrict const graphics,
                int scrollX, int scrollY) restrict2
 {
-    if (!localPlayer)
+    if (localPlayer == nullptr)
         return;
 
     BLOCK_START("Map::draw")
@@ -357,7 +357,7 @@ void Map::draw(Graphics *restrict const graphics,
         MapLayerPosition::BACKGROUND_LAYERS,
         mOverlayDetail);
 
-    if (mDrawLayersFlags == MapType::BLACKWHITE && userPalette)
+    if (mDrawLayersFlags == MapType::BLACKWHITE && (userPalette != nullptr))
     {
         graphics->setColor(userPalette->getColorWithAlpha(
             UserColorId::WALKABLE_HIGHLIGHT));
@@ -395,7 +395,7 @@ void Map::draw(Graphics *restrict const graphics,
 
     if (mDrawOnlyFringe)
     {
-        if (mFringeLayer)
+        if (mFringeLayer != nullptr)
         {
             mFringeLayer->setSpecialLayer(mSpecialLayer);
             mFringeLayer->setTempLayer(mTempLayer);
@@ -411,7 +411,7 @@ void Map::draw(Graphics *restrict const graphics,
 #ifdef USE_OPENGL
         if (mCachedDraw)
         {
-            if (updateFlag)
+            if (updateFlag != 0)
             {
                 FOR_EACH (Layers::iterator, it, mDrawUnderLayers)
                 {
@@ -432,7 +432,7 @@ void Map::draw(Graphics *restrict const graphics,
             FOR_EACH (Layers::iterator, it, mDrawUnderLayers)
                 (*it)->drawOGL(graphics);
 
-            if (mFringeLayer)
+            if (mFringeLayer != nullptr)
             {
                 mFringeLayer->setSpecialLayer(mSpecialLayer);
                 mFringeLayer->setTempLayer(mTempLayer);
@@ -457,7 +457,7 @@ void Map::draw(Graphics *restrict const graphics,
                     scrollX, scrollY);
             }
 
-            if (mFringeLayer)
+            if (mFringeLayer != nullptr)
             {
                 mFringeLayer->setSpecialLayer(mSpecialLayer);
                 mFringeLayer->setTempLayer(mTempLayer);
@@ -626,14 +626,14 @@ void Map::updateAmbientLayers(const float scrollX,
     FOR_EACH (AmbientLayerVectorIter, i, mBackgrounds)
     {
         AmbientLayer *const layer = *i;
-        if (layer && (layer->mMask & mMask))
+        if ((layer != nullptr) && ((layer->mMask & mMask) != 0))
             layer->update(timePassed, dx, dy);
     }
 
     FOR_EACH (AmbientLayerVectorIter, i, mForegrounds)
     {
         AmbientLayer *const layer = *i;
-        if (layer && (layer->mMask & mMask))
+        if ((layer != nullptr) && ((layer->mMask & mMask) != 0))
             layer->update(timePassed, dx, dy);
     }
 
@@ -674,7 +674,7 @@ void Map::drawAmbientLayers(Graphics *restrict const graphics,
     {
         const AmbientLayer *restrict const layer = *i;
         // need check mask to draw or not to draw
-        if (layer && (layer->mMask & mMask))
+        if ((layer != nullptr) && ((layer->mMask & mMask) != 0))
             (layer)->draw(graphics, graphics->mWidth, graphics->mHeight);
 
         // Detail 1: only one overlay, higher: all overlays
@@ -778,7 +778,7 @@ bool Map::getWalk(const int x, const int y,
         return false;
 
     // Check if the tile is walkable
-    return !(mMetaTiles[x + y * mWidth].blockmask & blockWalkMask);
+    return (mMetaTiles[x + y * mWidth].blockmask & blockWalkMask) == 0;
 }
 
 unsigned char Map::getBlockMask(const int x,
@@ -877,7 +877,7 @@ Path Map::findPath(const int startX, const int startY,
 
     // Reset starting tile's G cost to 0
     MetaTile *const startTile = &mMetaTiles[startX + startY * mWidth];
-    if (!startTile)
+    if (startTile == nullptr)
     {
         BLOCK_END("Map::findPath")
         return path;
@@ -941,9 +941,9 @@ Path Map::findPath(const int startX, const int startY,
                 // can be removed. It left here only for protect from
                 // walk on wall in any case
                 if (newTile->whichList == mOnClosedList ||
-                    ((newTile->blockmask & blockWalkMask)
+                    (((newTile->blockmask & blockWalkMask) != 0)
                     && !(x == destX && y == destY))
-                    || (newTile->blockmask & BlockMask::WALL))
+                    || ((newTile->blockmask & BlockMask::WALL) != 0))
                 {
                     continue;
                 }
@@ -958,7 +958,7 @@ Path Map::findPath(const int startX, const int startY,
                         dx + curWidth];
 
                     // on player abilities.
-                    if (((t1->blockmask | t2->blockmask) & blockWalkMask))
+                    if (((t1->blockmask | t2->blockmask) & blockWalkMask) != 0)
                         continue;
                 }
 
@@ -1096,7 +1096,7 @@ void Map::addParticleEffect(const std::string &effectFile,
 void Map::initializeParticleEffects() const restrict2
 {
     BLOCK_START("Map::initializeParticleEffects")
-    if (!particleEngine)
+    if (particleEngine == nullptr)
     {
         BLOCK_END("Map::initializeParticleEffects")
         return;
@@ -1113,7 +1113,7 @@ void Map::initializeParticleEffects() const restrict2
                 i->file,
                 i->x,
                 i->y);
-            if (p &&
+            if ((p != nullptr) &&
                 i->w > 0 &&
                 i->h > 0)
             {
@@ -1127,7 +1127,7 @@ void Map::initializeParticleEffects() const restrict2
 void Map::addExtraLayer() restrict2
 {
     BLOCK_START("Map::addExtraLayer")
-    if (!mSpecialLayer)
+    if (mSpecialLayer == nullptr)
     {
         logger->log1("No special layer");
         BLOCK_END("Map::addExtraLayer")
@@ -1137,7 +1137,8 @@ void Map::addExtraLayer() restrict2
         "extralayer.txt");
     logger->log("loading extra layer: " + mapFileName);
     struct stat statbuf;
-    if (!stat(mapFileName.c_str(), &statbuf) && S_ISREG(statbuf.st_mode))
+    if (stat(mapFileName.c_str(), &statbuf) == 0 &&
+        S_ISREG(statbuf.st_mode))
     {
         std::ifstream mapFile;
         mapFile.open(mapFileName.c_str(), std::ios::in);
@@ -1201,7 +1202,7 @@ void Map::addExtraLayer() restrict2
 
 void Map::saveExtraLayer() const restrict2
 {
-    if (!mSpecialLayer)
+    if (mSpecialLayer == nullptr)
     {
         logger->log1("No special layer");
         return;
@@ -1210,7 +1211,7 @@ void Map::saveExtraLayer() const restrict2
         "extralayer.txt");
     logger->log("saving extra layer: " + mapFileName);
 
-    if (mkdir_r(getUserMapDirectory().c_str()))
+    if (mkdir_r(getUserMapDirectory().c_str()) != 0)
     {
         logger->log(strprintf("%s doesn't exist and can't be created! "
                               "Exiting.", getUserMapDirectory().c_str()));
@@ -1234,7 +1235,7 @@ void Map::saveExtraLayer() const restrict2
         for (int y = 0; y < height; y ++)
         {
             const MapItem *restrict const item = mSpecialLayer->getTile(x, y);
-            if (item && item->mType != MapItemType::EMPTY
+            if ((item != nullptr) && item->mType != MapItemType::EMPTY
                 && item->mType != MapItemType::HOME)
             {
                 mapFile << x << " " << y << " "
@@ -1257,7 +1258,7 @@ void Map::addRange(const std::string &restrict name,
                    const int x, const int y,
                    const int dx, const int dy) restrict2
 {
-    if (!mObjects)
+    if (mObjects == nullptr)
         return;
 
     mObjects->addObject(name, type, x / mapTileSize, y / mapTileSize,
@@ -1277,7 +1278,7 @@ void Map::addPortalTile(const std::string &restrict name,
                         const int type,
                         const int x, const int y) restrict2
 {
-    if (mSpecialLayer)
+    if (mSpecialLayer != nullptr)
     {
         mSpecialLayer->setTile(x, y, new MapItem(type, name, x, y));
         mSpecialLayer->updateCache();
@@ -1292,13 +1293,13 @@ void Map::updatePortalTile(const std::string &restrict name,
                            const bool addNew) restrict2
 {
     MapItem *restrict item = findPortalXY(x, y);
-    if (item)
+    if (item != nullptr)
     {
         item->mComment = name;
         item->setType(type);
         item->mX = x;
         item->mY = y;
-        if (mSpecialLayer)
+        if (mSpecialLayer != nullptr)
         {
             item = new MapItem(type, name, x, y);
             mSpecialLayer->setTile(x, y, item);
@@ -1315,7 +1316,7 @@ MapItem *Map::findPortalXY(const int x, const int y) const restrict2
 {
     FOR_EACH (std::vector<MapItem*>::const_iterator, it, mMapPortals)
     {
-        if (!*it)
+        if (*it == nullptr)
             continue;
 
         MapItem *restrict const item = *it;
@@ -1338,12 +1339,12 @@ void Map::setPvpMode(const int mode) restrict2
 {
     const int oldMode = mPvp;
 
-    if (!mode)
+    if (mode == 0)
         mPvp = 0;
     else
         mPvp |= mode;
 
-    if (mPvp != oldMode && localPlayer)
+    if (mPvp != oldMode && (localPlayer != nullptr))
     {
         switch (mPvp)
         {
@@ -1369,11 +1370,11 @@ void Map::setPvpMode(const int mode) restrict2
 std::string Map::getObjectData(const unsigned x, const unsigned y,
                                const int type) const restrict2
 {
-    if (!mObjects)
+    if (mObjects == nullptr)
         return "";
 
     MapObjectList *restrict const list = mObjects->getAt(x, y);
-    if (!list)
+    if (list == nullptr)
         return "";
 
     std::vector<MapObject>::const_iterator it = list->objects.begin();
@@ -1400,14 +1401,14 @@ void Map::indexTilesets() restrict2
     FOR_EACH (Tilesets::const_iterator, it, mTilesets)
     {
         const size_t sz = (*it)->size();
-        if (!s || CAST_SIZE(s->getFirstGid()) + sSz
+        if ((s == nullptr) || CAST_SIZE(s->getFirstGid()) + sSz
             < CAST_SIZE((*it)->getFirstGid()) + sz)
         {
             s = *it;
             sSz = sz;
         }
     }
-    if (!s)
+    if (s == nullptr)
     {
         mIndexedTilesetsSize = 0;
         mIndexedTilesets = nullptr;
@@ -1423,7 +1424,7 @@ void Map::indexTilesets() restrict2
     FOR_EACH (Tilesets::const_iterator, it, mTilesets)
     {
         Tileset *restrict const s2 = *it;
-        if (s2)
+        if (s2 != nullptr)
         {
             const int start = s2->getFirstGid();
             const int end = start + CAST_S32(s2->size());
@@ -1452,7 +1453,7 @@ void Map::reduce() restrict2
     return;
 #else  // USE_SDL2
 
-    if (!mFringeLayer ||
+    if ((mFringeLayer == nullptr) ||
         mOpenGL != RENDER_SOFTWARE ||
         !config.getBoolValue("enableMapReduce"))
     {
@@ -1479,7 +1480,7 @@ void Map::reduce() restrict2
 
                 Image *restrict const img =
                     layer->mTiles[x + y * layer->mWidth].image;
-                if (img)
+                if (img != nullptr)
                 {
                     if (img->hasAlphaChannel() && img->isAlphaCalculated())
                     {
@@ -1505,7 +1506,7 @@ void Map::reduce() restrict2
                     {
                         const uint8_t *restrict const arr =
                             img->SDLgetAlphaChannel();
-                        if (!arr)
+                        if (arr == nullptr)
                             continue;
 
                         bool bad(false);
@@ -1513,7 +1514,7 @@ void Map::reduce() restrict2
                         int width;
                         const SubImage *restrict const subImg
                             = dynamic_cast<SubImage*>(img);
-                        if (subImg)
+                        if (subImg != nullptr)
                             width = subImg->mInternalBounds.w;
                         else
                             width = img->mBounds.w;
@@ -1570,7 +1571,7 @@ void Map::reduce() restrict2
 
                 const Image *restrict img =
                     layer->mTiles[x + y * layer->mWidth].image;
-                if (img && !img->isAlphaVisible())
+                if ((img != nullptr) && !img->isAlphaVisible())
                 {   // removing all down tiles
                     ++ ri;
                     while (ri != mLayers.rend())
@@ -1585,7 +1586,7 @@ void Map::reduce() restrict2
                         const size_t pos = CAST_SIZE(
                             x + y * layer2->mWidth);
                         img = layer2->mTiles[pos].image;
-                        if (img)
+                        if (img != nullptr)
                         {
                             layer2->mTiles[pos].image = nullptr;
                             cnt ++;
@@ -1610,7 +1611,7 @@ void Map::addHeights(const MapHeights *restrict const heights) restrict2
 
 uint8_t Map::getHeightOffset(const int x, const int y) const restrict2
 {
-    if (!mHeights)
+    if (mHeights == nullptr)
         return 0;
     return mHeights->getHeight(x, y);
 }
@@ -1628,7 +1629,7 @@ void Map::updateDrawLayersList() restrict2
     for (; layers != layers_end; ++ layers)
     {
         MapLayer *const layer = *layers;
-        if (!(layer->mMask & mMask))
+        if ((layer->mMask & mMask) == 0)
             continue;
 
         if (layer->isFringeLayer())
@@ -1646,7 +1647,7 @@ void Map::updateDrawLayersList() restrict2
     for (; layers != layers_end; ++ layers)
     {
         MapLayer *const layer = *layers;
-        if (!(layer->mMask & mMask))
+        if ((layer->mMask & mMask) == 0)
             continue;
 
         mDrawOverLayers.push_back(layer);
@@ -1705,7 +1706,7 @@ void Map::setActorsFix(const int x, const int y) restrict2
 {
     mActorFixX = x;
     mActorFixY = y;
-    if (mFringeLayer)
+    if (mFringeLayer != nullptr)
         mFringeLayer->setActorsFix(y);
 }
 
@@ -1716,7 +1717,7 @@ void Map::updateConditionLayers() restrict2
     FOR_EACH (LayersCIter, it, mLayers)
     {
         MapLayer *restrict const layer = *it;
-        if (!layer || layer->mTileCondition == -1)
+        if ((layer == nullptr) || layer->mTileCondition == -1)
             continue;
         layer->updateConditionTiles(mMetaTiles,
             mWidth, mHeight);
@@ -1728,7 +1729,7 @@ void Map::preCacheLayers() restrict2
     FOR_EACH (LayersCIter, it, mLayers)
     {
         MapLayer *restrict const layer = *it;
-        if (layer)
+        if (layer != nullptr)
             layer->updateCache(mWidth, mHeight);
     }
 }
@@ -1755,7 +1756,7 @@ int Map::calcMemoryChilds(const int level) const
 {
     int sz = 0;
 
-    if (mWalkLayer)
+    if (mWalkLayer != nullptr)
         sz += mWalkLayer->calcMemory(level + 1);
     FOR_EACH (LayersCIter, it, mLayers)
     {
@@ -1773,13 +1774,13 @@ int Map::calcMemoryChilds(const int level) const
     {
         sz += (*it)->calcMemory(level + 1);
     }
-    if (mSpecialLayer)
+    if (mSpecialLayer != nullptr)
         mSpecialLayer->calcMemory(level + 1);
-    if (mTempLayer)
+    if (mTempLayer != nullptr)
         mTempLayer->calcMemory(level + 1);
-    if (mObjects)
+    if (mObjects != nullptr)
         mObjects->calcMemory(level + 1);
-    if (mHeights)
+    if (mHeights != nullptr)
         mHeights->calcMemory(level + 1);
     return sz;
 }
diff --git a/src/resources/map/mapitem.cpp b/src/resources/map/mapitem.cpp
index eeca6cbf5..ce9e38fec 100644
--- a/src/resources/map/mapitem.cpp
+++ b/src/resources/map/mapitem.cpp
@@ -82,7 +82,7 @@ MapItem::MapItem(const int type, std::string comment,
 
 MapItem::~MapItem()
 {
-    if (mImage)
+    if (mImage != nullptr)
     {
         mImage->decRef();
         mImage = nullptr;
@@ -93,7 +93,7 @@ void MapItem::setType(const int type)
 {
     std::string name;
     mType = type;
-    if (mImage)
+    if (mImage != nullptr)
         mImage->decRef();
 
     switch (type)
@@ -130,7 +130,7 @@ void MapItem::draw(Graphics *const graphics, const int x, const int y,
                    const int dx, const int dy) const
 {
     BLOCK_START("MapItem::draw")
-    if (mImage)
+    if (mImage != nullptr)
         graphics->drawImage(mImage, x, y);
 
     switch (mType)
diff --git a/src/resources/map/maplayer.cpp b/src/resources/map/maplayer.cpp
index 4c6fe3a1e..2598b029c 100644
--- a/src/resources/map/maplayer.cpp
+++ b/src/resources/map/maplayer.cpp
@@ -316,7 +316,7 @@ void MapLayer::updateOGL(Graphics *const graphics,
             if (mSpecialFlag ||
                 img->mBounds.h <= mapTileSize)
             {
-                if (!lastImage ||
+                if ((lastImage == nullptr) ||
                     lastImage->mGLImage != imgGlImage)
                 {
                     if (img->mBounds.w > mapTileSize)
@@ -328,7 +328,7 @@ void MapLayer::updateOGL(Graphics *const graphics,
                     }
                     else
                     {
-                        if (lastImage)
+                        if (lastImage != nullptr)
                             imgSet[lastImage->mGLImage] = imgVert;
                         imgVert = new ImageVertexes;
                         imgVert->ogl.init();
@@ -387,7 +387,7 @@ void MapLayer::drawSpecialLayer(Graphics *const graphics,
         endX1 = 0;
     int x0 = startX;
     const MapItem *item0 = mSpecialLayer->mTiles[ptr + startX];
-    if (!item0 || item0->mType == MapItemType::EMPTY)
+    if ((item0 == nullptr) || item0->mType == MapItemType::EMPTY)
     {
         x0 += mSpecialLayer->mCache[ptr + startX] + 1;
     }
@@ -395,7 +395,7 @@ void MapLayer::drawSpecialLayer(Graphics *const graphics,
     {
         const int px1 = x * mapTileSize - scrollX;
         const MapItem *const item = mSpecialLayer->mTiles[ptr + x];
-        if (item)
+        if (item != nullptr)
         {
             item->draw(graphics, px1, py1,
                 mapTileSize, mapTileSize);
@@ -410,7 +410,7 @@ void MapLayer::drawSpecialLayer(Graphics *const graphics,
     if (endX1 > specialWidth)
         endX1 = specialWidth;
     item0 = mTempLayer->mTiles[ptr + startX];
-    if (!item0 || item0->mType == MapItemType::EMPTY)
+    if ((item0 == nullptr) || item0->mType == MapItemType::EMPTY)
     {
         x0 += mTempLayer->mCache[ptr + startX] + 1;
     }
@@ -434,9 +434,9 @@ void MapLayer::drawFringe(Graphics *const graphics,
                           const Actors &actors) const restrict
 {
     BLOCK_START("MapLayer::drawFringe")
-    if (!localPlayer ||
-        !mSpecialLayer ||
-        !mTempLayer)
+    if ((localPlayer == nullptr) ||
+        (mSpecialLayer == nullptr) ||
+        (mTempLayer == nullptr))
     {
         BLOCK_END("MapLayer::drawFringe")
         return;
@@ -684,7 +684,7 @@ void MapLayer::drawFringe(Graphics *const graphics,
                 h += mapTileSize;
             }
 
-            if (userPalette)
+            if (userPalette != nullptr)
             {
                 graphics->setColor(userPalette->getColorWithAlpha(
                     UserColorId::ATTACK_RANGE));
@@ -783,7 +783,7 @@ void MapLayer::updateConditionTiles(const MetaTile *const metaTiles,
         for (int x = mX; x < width1; x ++, metaPtr ++, tilePtr ++)
         {
             if (tilePtr->image != nullptr &&
-                (metaPtr->blockmask & mTileCondition ||
+                (((metaPtr->blockmask & mTileCondition) != 0) ||
                 (metaPtr->blockmask == 0 &&
                 mTileCondition == BlockMask::GROUND)))
             {
@@ -841,9 +841,9 @@ int MapLayer::calcMemoryLocal() const
 int MapLayer::calcMemoryChilds(const int level) const
 {
     int sz = 0;
-    if (mSpecialLayer)
+    if (mSpecialLayer != nullptr)
         sz += mSpecialLayer->calcMemory(level + 1);
-    if (mTempLayer)
+    if (mTempLayer != nullptr)
         sz += mTempLayer->calcMemory(level + 1);
     return sz;
 }
diff --git a/src/resources/map/objectslayer.cpp b/src/resources/map/objectslayer.cpp
index a100b2c7d..3224da0e6 100644
--- a/src/resources/map/objectslayer.cpp
+++ b/src/resources/map/objectslayer.cpp
@@ -48,7 +48,7 @@ void ObjectsLayer::addObject(const std::string &name, const int type,
                              const unsigned x, const unsigned y,
                              unsigned dx, unsigned dy)
 {
-    if (!mTiles)
+    if (mTiles == nullptr)
         return;
 
     if (x + dx > mWidth)
@@ -63,7 +63,7 @@ void ObjectsLayer::addObject(const std::string &name, const int type,
 
         for (unsigned i = idx1; i < idx2; i ++)
         {
-            if (!mTiles[i])
+            if (mTiles[i] == nullptr)
                 mTiles[i] = new MapObjectList;
             mTiles[i]->objects.push_back(MapObject(type, name));
         }
diff --git a/src/resources/map/speciallayer.cpp b/src/resources/map/speciallayer.cpp
index 4e826dc42..75b56be28 100644
--- a/src/resources/map/speciallayer.cpp
+++ b/src/resources/map/speciallayer.cpp
@@ -72,7 +72,7 @@ void SpecialLayer::setTile(const int x, const int y, MapItem *const item)
 
     const int idx = x + y * mWidth;
     delete mTiles[idx];
-    if (item)
+    if (item != nullptr)
         item->setPos(x, y);
     mTiles[idx] = item;
 }
@@ -87,7 +87,7 @@ void SpecialLayer::setTile(const int x, const int y, const int type)
 
     const int idx = x + y * mWidth;
     MapItem *const tile = mTiles[idx];
-    if (tile)
+    if (tile != nullptr)
     {
         tile->setType(type);
         tile->setPos(x, y);
@@ -105,7 +105,7 @@ void SpecialLayer::addRoad(const Path &road)
     {
         const Position &pos = (*i);
         MapItem *const item = getTile(pos.x, pos.y);
-        if (!item)
+        if (item == nullptr)
             setTile(pos.x, pos.y, new MapItem(MapItemType::ROAD));
         else
             item->setType(MapItemType::ROAD);
@@ -115,13 +115,13 @@ void SpecialLayer::addRoad(const Path &road)
 
 void SpecialLayer::clean()
 {
-    if (!mTiles)
+    if (mTiles == nullptr)
         return;
 
     for (int f = 0; f < mWidth * mHeight; f ++)
     {
         MapItem *const item = mTiles[f];
-        if (item)
+        if (item != nullptr)
             item->setType(MapItemType::EMPTY);
     }
     updateCache();
@@ -148,7 +148,7 @@ void SpecialLayer::draw(Graphics *const graphics, int startX, int startY,
         for (int x = startX; x < endX; x ++)
         {
             const MapItem *const item = mTiles[x + y2];
-            if (item)
+            if (item != nullptr)
             {
                 item->draw(graphics, x * mapTileSize - scrollX, py,
                     mapTileSize, mapTileSize);
diff --git a/src/resources/map/tileanimation.cpp b/src/resources/map/tileanimation.cpp
index 03a6ff1f4..c8ce52a70 100644
--- a/src/resources/map/tileanimation.cpp
+++ b/src/resources/map/tileanimation.cpp
@@ -44,7 +44,7 @@ TileAnimation::~TileAnimation()
 
 bool TileAnimation::update(const int ticks)
 {
-    if (!mAnimation)
+    if (mAnimation == nullptr)
         return false;
 
     // update animation
@@ -57,7 +57,7 @@ bool TileAnimation::update(const int ticks)
     {
         FOR_EACH (TilePairVectorCIter, i, mAffected)
         {
-            if (i->first)
+            if (i->first != nullptr)
                 i->first->setTile(i->second, img);
         }
         mLastImage = img;
diff --git a/src/resources/mapreader.cpp b/src/resources/mapreader.cpp
index 3d82d0404..b795b5e0f 100644
--- a/src/resources/mapreader.cpp
+++ b/src/resources/mapreader.cpp
@@ -147,7 +147,7 @@ PRAGMACLANG6GCC(GCC diagnostic pop)
 
     do
     {
-        if (!strm.next_out)
+        if (strm.next_out == nullptr)
         {
             inflateEnd(&strm);
             return Z_MEM_ERROR;
@@ -174,7 +174,7 @@ PRAGMACLANG6GCC(GCC diagnostic pop)
         {
             out = static_cast<unsigned char*>(realloc(out, bufferSize * 2));
 
-            if (!out)
+            if (out == nullptr)
             {
                 inflateEnd(&strm);
                 return Z_MEM_ERROR;
@@ -199,7 +199,7 @@ int inflateMemory(unsigned char *restrict const in,
     unsigned int outLength = 0;
     const int ret = inflateMemory(in, inLength, out, outLength);
 
-    if (ret != Z_OK || !out)
+    if (ret != Z_OK || (out == nullptr))
     {
         if (ret == Z_MEM_ERROR)
         {
@@ -233,7 +233,7 @@ void MapReader::addLayerToList(const std::string &fileName,
         UseVirtFs_true,
         skipError);
     XmlNodePtrConst node = doc->rootNode();
-    if (!node)
+    if (node == nullptr)
     {
         delete doc;
         return;
@@ -253,7 +253,7 @@ void MapReader::addLayerToList(const std::string &fileName,
         mKnownDocs.insert(doc);
         cnt ++;
     }
-    if (!cnt)
+    if (cnt == 0)
         delete doc;
 }
 
@@ -274,7 +274,7 @@ Map *MapReader::readMap(const std::string &restrict filename,
 
     Map *map = nullptr;
     // Parse the inflated map data
-    if (node)
+    if (node != nullptr)
     {
         if (!xmlNameEqual(node, "map"))
             logger->log("Error: Not a map file (%s)!", realFilename.c_str());
@@ -287,7 +287,7 @@ Map *MapReader::readMap(const std::string &restrict filename,
             realFilename.c_str());
     }
 
-    if (map)
+    if (map != nullptr)
     {
         map->setProperty("_filename", realFilename);
         map->setProperty("_realfilename", filename);
@@ -328,7 +328,7 @@ static void loadReplaceLayer(const LayerInfoIterator &it,
 
 Map *MapReader::readMap(XmlNodePtrConst node, const std::string &path)
 {
-    if (!node)
+    if (node == nullptr)
         return nullptr;
 
     BLOCK_START("MapReader::readMap xml")
@@ -368,7 +368,7 @@ Map *MapReader::readMap(XmlNodePtrConst node, const std::string &path)
     if (graphicsManager.getUseAtlases())
     {
         const MapInfo *const info = MapDB::getMapAtlas(fileName);
-        if (info)
+        if (info != nullptr)
         {
             map->setAtlas(Loader::getAtlas(
                 info->atlas,
@@ -388,7 +388,7 @@ Map *MapReader::readMap(XmlNodePtrConst node, const std::string &path)
         if (xmlNameEqual(childNode, "tileset"))
         {
             Tileset *const tileset = readTileset(childNode, pathDir, map);
-            if (tileset)
+            if (tileset != nullptr)
                 map->addTileset(tileset);
         }
         else if (xmlNameEqual(childNode, "layer"))
@@ -519,7 +519,7 @@ void MapReader::readProperties(XmlNodeConstPtrConst node,
                                Properties *const props)
 {
     BLOCK_START("MapReader::readProperties")
-    if (!node)
+    if (node == nullptr)
     {
         BLOCK_END("MapReader::readProperties")
         return;
@@ -564,16 +564,16 @@ inline static void setTile(Map *const map,
     {
         case MapLayerType::TILES:
         {
-            Image *const img = set ? set->get(gid - set->getFirstGid())
+            Image *const img = set != nullptr ? set->get(gid - set->getFirstGid())
                 : nullptr;
-            if (layer)
+            if (layer != nullptr)
                 layer->setTile(x, y, img);
             break;
         }
 
         case MapLayerType::COLLISION:
         {
-            if (set)
+            if (set != nullptr)
             {
                 if (map->getVersion() >= 1)
                 {
@@ -627,9 +627,9 @@ inline static void setTile(Map *const map,
 
         case MapLayerType::HEIGHTS:
         {
-            if (!set || !heights)
+            if ((set == nullptr) || (heights == nullptr))
                 break;
-            if (heights && map->getVersion() >= 2)
+            if ((heights != nullptr) && map->getVersion() >= 2)
             {
                 heights->setHeight(x, y, CAST_U8(
                     gid - set->getFirstGid() + 1));
@@ -637,7 +637,7 @@ inline static void setTile(Map *const map,
             else
             {
                 Image *const img = set->get(gid - set->getFirstGid());
-                if (layer)
+                if (layer != nullptr)
                     layer->setTile(x, y, img);
             }
             break;
@@ -658,7 +658,7 @@ bool MapReader::readBase64Layer(XmlNodeConstPtrConst childNode,
                                 int &restrict x, int &restrict y,
                                 const int w, const int h)
 {
-    if (!childNode)
+    if (childNode == nullptr)
         return false;
 
     if (!compression.empty() && compression != "gzip"
@@ -677,7 +677,7 @@ bool MapReader::readBase64Layer(XmlNodeConstPtrConst childNode,
     unsigned char *charData = new unsigned char[len + 1];
     const char *const xmlChars = XmlChildContent(childNode);
     const char *charStart = reinterpret_cast<const char*>(xmlChars);
-    if (!charStart)
+    if (charStart == nullptr)
     {
         delete [] charData;
         return false;
@@ -685,7 +685,7 @@ bool MapReader::readBase64Layer(XmlNodeConstPtrConst childNode,
 
     unsigned char *charIndex = charData;
 
-    while (*charStart)
+    while (*charStart != 0)
     {
         if (*charStart != ' ' &&
             *charStart != '\t' &&
@@ -706,7 +706,7 @@ bool MapReader::readBase64Layer(XmlNodeConstPtrConst childNode,
     delete [] charData;
 //    XmlFree(const_cast<char*>(xmlChars));
 
-    if (binData)
+    if (binData != nullptr)
     {
         if (compression == "gzip" || compression == "zlib")
         {
@@ -719,7 +719,7 @@ bool MapReader::readBase64Layer(XmlNodeConstPtrConst childNode,
             binData = inflated;
             binLen = inflatedSize;
 
-            if (!inflated)
+            if (inflated == nullptr)
             {
                 reportAlways("Error: Could not decompress layer!");
                 return false;
@@ -744,7 +744,7 @@ bool MapReader::readBase64Layer(XmlNodeConstPtrConst childNode,
                 if (it != tileAnimations.end())
                 {
                     TileAnimation *const ani = it->second;
-                    if (ani)
+                    if (ani != nullptr)
                         ani->addAffectedTile(layer, x + y * w);
                 }
 
@@ -794,7 +794,7 @@ bool MapReader::readCsvLayer(XmlNodeConstPtrConst childNode,
                              int &restrict x, int &restrict y,
                              const int w, const int h)
 {
-    if (!childNode)
+    if (childNode == nullptr)
         return false;
 
     if (!XmlHaveChildContent(childNode))
@@ -802,7 +802,7 @@ bool MapReader::readCsvLayer(XmlNodeConstPtrConst childNode,
 
     const char *const xmlChars = XmlChildContent(childNode);
     const char *const data = reinterpret_cast<const char*>(xmlChars);
-    if (!data)
+    if (data == nullptr)
         return false;
 
     std::string csv(data);
@@ -826,7 +826,7 @@ bool MapReader::readCsvLayer(XmlNodeConstPtrConst childNode,
             if (it != tileAnimations.end())
             {
                 TileAnimation *const ani = it->second;
-                if (ani)
+                if (ani != nullptr)
                     ani->addAffectedTile(layer, x + y * w);
             }
 
@@ -870,7 +870,7 @@ bool MapReader::readCsvLayer(XmlNodeConstPtrConst childNode,
 
 void MapReader::readLayer(XmlNodeConstPtr node, Map *const map)
 {
-    if (!node)
+    if (node == nullptr)
         return;
 
     // Layers are not necessarily the same size as the map
@@ -1035,7 +1035,7 @@ void MapReader::readLayer(XmlNodeConstPtr node, Map *const map)
                     if (it != tileAnimations.end())
                     {
                         TileAnimation *const ani = it->second;
-                        if (ani)
+                        if (ani != nullptr)
                             ani->addAffectedTile(layer, x + y * w);
                     }
                 }
@@ -1052,7 +1052,7 @@ void MapReader::readLayer(XmlNodeConstPtr node, Map *const map)
 
         if (y < h)
             std::cerr << "TOO SMALL!\n";
-        if (x)
+        if (x != 0)
             std::cerr << "TOO SMALL!\n";
 
         // There can be only one data element
@@ -1065,7 +1065,7 @@ Tileset *MapReader::readTileset(XmlNodePtr node,
                                 Map *const map)
 {
     BLOCK_START("MapReader::readTileset")
-    if (!node)
+    if (node == nullptr)
     {
         BLOCK_END("MapReader::readTileset")
         return nullptr;
@@ -1086,7 +1086,7 @@ Tileset *MapReader::readTileset(XmlNodePtr node,
 
         doc = new XML::Document(filename, UseVirtFs_true, SkipError_false);
         node = doc->rootNode();
-        if (!node)
+        if (node == nullptr)
         {
             delete doc;
             BLOCK_END("MapReader::readTileset")
@@ -1105,7 +1105,7 @@ Tileset *MapReader::readTileset(XmlNodePtr node,
         if (xmlNameEqual(childNode, "image"))
         {
             // ignore second other <image> tags in tileset
-            if (set)
+            if (set != nullptr)
                 continue;
 
             const std::string source = XML::getProperty(
@@ -1116,7 +1116,7 @@ Tileset *MapReader::readTileset(XmlNodePtr node,
                 Image *const tilebmp = Loader::getImage(
                     resolveRelativePath(pathDir, source));
 
-                if (tilebmp)
+                if (tilebmp != nullptr)
                 {
                     set = new Tileset(tilebmp,
                         tw, th,
@@ -1192,7 +1192,7 @@ Tileset *MapReader::readTileset(XmlNodePtr node,
                     }
 
                     // create animation
-                    if (!set || !config.getBoolValue("playMapAnimations"))
+                    if ((set == nullptr) || !config.getBoolValue("playMapAnimations"))
                     {
                         delete ani;
                         continue;
@@ -1230,7 +1230,7 @@ Tileset *MapReader::readTileset(XmlNodePtr node,
                         const int duration = XML::getProperty(
                             frameNode, "duration", 0) /  10;
 
-                        if (set)
+                        if (set != nullptr)
                         {
                             ani->addFrame(set->get(tileId),
                                 duration,
@@ -1249,7 +1249,7 @@ Tileset *MapReader::readTileset(XmlNodePtr node,
 
     delete doc;
 
-    if (set)
+    if (set != nullptr)
         set->setProperties(props);
     BLOCK_END("MapReader::readTileset")
     return set;
@@ -1306,7 +1306,7 @@ void MapReader::loadEmptyAtlas()
 
     const MapInfo *const info = MapDB::getAtlas(
         paths.getStringValue("emptyAtlasName"));
-    if (info)
+    if (info != nullptr)
     {
         mEmptyAtlas = Loader::getEmptyAtlas(
             info->atlas,
@@ -1317,7 +1317,7 @@ void MapReader::loadEmptyAtlas()
 
 void MapReader::unloadEmptyAtlas()
 {
-    if (mEmptyAtlas)
+    if (mEmptyAtlas != nullptr)
         mEmptyAtlas->decRef();
 }
 #endif  // USE_OPENGL
diff --git a/src/resources/memorymanager.cpp b/src/resources/memorymanager.cpp
index 55d157c5f..1e4b8b378 100644
--- a/src/resources/memorymanager.cpp
+++ b/src/resources/memorymanager.cpp
@@ -40,7 +40,7 @@ MemoryManager::MemoryManager()
 
 int MemoryManager::getSurfaceSize(const SDL_Surface *const surface)
 {
-    if (!surface)
+    if (surface == nullptr)
         return 0;
     return CAST_S32(sizeof(SDL_Surface)) +
         CAST_S32(sizeof(SDL_PixelFormat)) +
@@ -78,7 +78,7 @@ void MemoryManager::printMemory(const std::string &name,
 
 void MemoryManager::printAllMemory(ChatTab *const tab A_DYECMD_UNUSED)
 {
-    if (!logger)
+    if (logger == nullptr)
         return;
 
 #ifdef DYECMD
@@ -86,7 +86,7 @@ void MemoryManager::printAllMemory(ChatTab *const tab A_DYECMD_UNUSED)
 #else  // DYECMD
 
     int sz = ResourceManager::calcMemory(0);
-    if (tab)
+    if (tab != nullptr)
     {
         // TRANSLATORS: memory usage chat message
         tab->chatLog(strprintf(_("Calculated memory usage: %d"), sz),
diff --git a/src/resources/mobileopenglscreenshothelper.cpp b/src/resources/mobileopenglscreenshothelper.cpp
index 97312f900..3276ea07f 100644
--- a/src/resources/mobileopenglscreenshothelper.cpp
+++ b/src/resources/mobileopenglscreenshothelper.cpp
@@ -64,7 +64,7 @@ SDL_Surface *MobileOpenGLScreenshotHelper::getScreenshot()
         SDL_SWSURFACE, w, h, 32,
         0x00ff0000, 0x0000ff00, 0x000000ff, 0xff000000);
 
-    if (!tmpImage)
+    if (tmpImage == nullptr)
         return nullptr;
 
     // Grap the pixel buffer and write it to the SDL surface
@@ -79,7 +79,7 @@ SDL_Surface *MobileOpenGLScreenshotHelper::getScreenshot()
         SDL_SWSURFACE, w, h, 24,
         0xff0000, 0x00ff00, 0x0000ff, 0x000000);
 
-    if (!screenshot)
+    if (screenshot == nullptr)
     {
         MSDL_FreeSurface(tmpImage);
         delete [] buf;
diff --git a/src/resources/openglimagehelper.cpp b/src/resources/openglimagehelper.cpp
index d854c0666..66c60e039 100644
--- a/src/resources/openglimagehelper.cpp
+++ b/src/resources/openglimagehelper.cpp
@@ -69,7 +69,7 @@ OpenGLImageHelper::~OpenGLImageHelper()
 Image *OpenGLImageHelper::load(SDL_RWops *const rw, Dye const &dye)
 {
     SDL_Surface *const tmpImage = loadPng(rw);
-    if (!tmpImage)
+    if (tmpImage == nullptr)
     {
         reportAlways("Error, image load failed: %s", IMG_GetError());
         return nullptr;
@@ -77,7 +77,7 @@ Image *OpenGLImageHelper::load(SDL_RWops *const rw, Dye const &dye)
 
     SDL_Surface *const surf = convertTo32Bit(tmpImage);
     MSDL_FreeSurface(tmpImage);
-    if (!surf)
+    if (surf == nullptr)
         return nullptr;
 
     uint32_t *pixels = static_cast<uint32_t *>(surf->pixels);
@@ -88,14 +88,14 @@ Image *OpenGLImageHelper::load(SDL_RWops *const rw, Dye const &dye)
         case 1:
         {
             const DyePalette *const pal = dye.getSPalete();
-            if (pal)
+            if (pal != nullptr)
                 DYEPALETTEP(pal, SOGLColor)(pixels, surf->w * surf->h);
             break;
         }
         case 2:
         {
             const DyePalette *const pal = dye.getAPalete();
-            if (pal)
+            if (pal != nullptr)
                 DYEPALETTEP(pal, AOGLColor)(pixels, surf->w * surf->h);
             break;
         }
@@ -121,11 +121,11 @@ Image *OpenGLImageHelper::createTextSurface(SDL_Surface *const tmpImage,
                                             const int width, const int height,
                                             const float alpha)
 {
-    if (!tmpImage)
+    if (tmpImage == nullptr)
         return nullptr;
 
     Image *const img = glLoad(tmpImage, width, height);
-    if (img)
+    if (img != nullptr)
         img->setAlpha(alpha);
     return img;
 }
@@ -141,7 +141,7 @@ int OpenGLImageHelper::powerOfTwo(const int input)
 SDL_Surface *OpenGLImageHelper::convertSurfaceNormalize(SDL_Surface *tmpImage,
                                                         int width, int height)
 {
-    if (!tmpImage)
+    if (tmpImage == nullptr)
         return nullptr;
 
     int realWidth = powerOfTwo(width);
@@ -190,7 +190,7 @@ SDL_Surface *OpenGLImageHelper::convertSurfaceNormalize(SDL_Surface *tmpImage,
         tmpImage = MSDL_CreateRGBSurface(SDL_SWSURFACE, realWidth, realHeight,
             32, rmask, gmask, bmask, amask);
 
-        if (!tmpImage)
+        if (tmpImage == nullptr)
         {
             reportAlways("Error, image convert failed: out of memory");
             return nullptr;
@@ -203,7 +203,7 @@ SDL_Surface *OpenGLImageHelper::convertSurfaceNormalize(SDL_Surface *tmpImage,
 SDL_Surface *OpenGLImageHelper::convertSurface(SDL_Surface *tmpImage,
                                                int width, int height)
 {
-    if (!tmpImage)
+    if (tmpImage == nullptr)
         return nullptr;
 
 #ifdef USE_SDL2
@@ -242,7 +242,7 @@ SDL_Surface *OpenGLImageHelper::convertSurface(SDL_Surface *tmpImage,
         tmpImage = MSDL_CreateRGBSurface(SDL_SWSURFACE, width, height,
             32, rmask, gmask, bmask, amask);
 
-        if (!tmpImage)
+        if (tmpImage == nullptr)
         {
             reportAlways("Error, image convert failed: out of memory");
             return nullptr;
@@ -308,21 +308,21 @@ void OpenGLImageHelper::bindTexture(const GLuint texture)
 Image *OpenGLImageHelper::glLoad(SDL_Surface *tmpImage,
                                  int width, int height)
 {
-    if (!tmpImage)
+    if (tmpImage == nullptr)
         return nullptr;
 
     BLOCK_START("OpenGLImageHelper::glLoad")
     // Flush current error flag.
     graphicsManager.getLastError();
 
-    if (!width)
+    if (width == 0)
         width = tmpImage->w;
-    if (!height)
+    if (height == 0)
         height = tmpImage->h;
 
     SDL_Surface *oldImage = tmpImage;
     tmpImage = convertSurfaceNormalize(tmpImage, width, height);
-    if (!tmpImage)
+    if (tmpImage == nullptr)
         return nullptr;
 
     const int realWidth = tmpImage->w;
@@ -414,7 +414,7 @@ Image *OpenGLImageHelper::glLoad(SDL_Surface *tmpImage,
         MSDL_FreeSurface(tmpImage);
 
     GLenum error = graphicsManager.getLastError();
-    if (error)
+    if (error != 0u)
     {
         std::string errmsg = GraphicsManager::errorToString(error);
         reportAlways("Error: Image GL import failed: %s (%u)",
@@ -493,17 +493,17 @@ void OpenGLImageHelper::copySurfaceToImage(const Image *const image,
                                            const int x, const int y,
                                            SDL_Surface *surface) const
 {
-    if (!surface || !image)
+    if (surface == nullptr || image == nullptr)
         return;
 
     SDL_Surface *const oldSurface = surface;
     surface = convertSurface(surface, surface->w, surface->h);
-    if (!surface)
+    if (surface == nullptr)
         return;
 
     // +++ probably need combine
     // mglTextureSubImage2D and mglTextureSubImage2DEXT
-    if (mglTextureSubImage2D)
+    if (mglTextureSubImage2D != nullptr)
     {
         mglTextureSubImage2D(image->mGLImage,
             0,
diff --git a/src/resources/openglscreenshothelper.cpp b/src/resources/openglscreenshothelper.cpp
index f56009da4..ef77832f6 100644
--- a/src/resources/openglscreenshothelper.cpp
+++ b/src/resources/openglscreenshothelper.cpp
@@ -63,7 +63,7 @@ SDL_Surface *OpenGLScreenshotHelper::getScreenshot()
         SDL_SWSURFACE, w, h, 24,
         0xff0000, 0x00ff00, 0x0000ff, 0x000000);
 
-    if (!screenshot)
+    if (screenshot == nullptr)
         return nullptr;
 
     if (SDL_MUSTLOCK(screenshot))
diff --git a/src/resources/resourcemanager/resourcemanager.cpp b/src/resources/resourcemanager/resourcemanager.cpp
index 0e77cea38..a60fea2a4 100644
--- a/src/resources/resourcemanager/resourcemanager.cpp
+++ b/src/resources/resourcemanager/resourcemanager.cpp
@@ -107,7 +107,7 @@ void deleteResourceManager()
         }
 #endif  // DEBUG_LEAKS
 
-        if (dynamic_cast<SpriteDef*>(iter->second))
+        if (dynamic_cast<SpriteDef*>(iter->second) != nullptr)
         {
             cleanUp(iter->second);
             const ResourceIterator toErase = iter;
@@ -132,7 +132,7 @@ void deleteResourceManager()
         }
 #endif  // DEBUG_LEAKS
 
-        if (dynamic_cast<ImageSet*>(iter->second))
+        if (dynamic_cast<ImageSet*>(iter->second) != nullptr)
         {
             cleanUp(iter->second);
             const ResourceIterator toErase = iter;
@@ -157,7 +157,7 @@ void deleteResourceManager()
         }
 #endif  // DEBUG_LEAKS
 
-        if (iter->second)
+        if (iter->second != nullptr)
         {
             cleanUp(iter->second);
             const ResourceIterator toErase = iter;
@@ -176,7 +176,7 @@ void deleteResourceManager()
 
 void cleanUp(Resource *const res)
 {
-    if (!res)
+    if (res == nullptr)
         return;
 
     const unsigned refCount = res->mRefCount;
@@ -201,7 +201,7 @@ void cleanProtected()
     while (iter != mResources.end())
     {
         Resource *const res = iter->second;
-        if (!res)
+        if (res == nullptr)
         {
             ++ iter;
             continue;
@@ -234,7 +234,7 @@ bool cleanOrphans(const bool always)
     while (iter != mOrphanedResources.end())
     {
         Resource *const res = iter->second;
-        if (!res)
+        if (res == nullptr)
         {
             ++iter;
             continue;
@@ -264,15 +264,15 @@ bool cleanOrphans(const bool always)
 
 void logResource(const Resource *const res)
 {
-    if (!res)
+    if (res == nullptr)
         return;
 #ifdef USE_OPENGL
     const Image *const image = dynamic_cast<const Image *>(res);
-    if (image)
+    if (image != nullptr)
     {
         std::string src = image->mSource;
         const int count = image->mRefCount;
-        if (count)
+        if (count != 0)
             src.append(" ").append(toString(count));
         logger->log("resource(%s, %u) %s", res->mIdPath.c_str(),
             image->getGLImage(), src.c_str());
@@ -322,7 +322,7 @@ void clearDeleted(const bool full)
         std::set<Resource*>::iterator resDelIter = mDeletedResources.begin();
         while (resDelIter != mDeletedResources.end())
         {
-            if (!(*resDelIter)->mRefCount)
+            if ((*resDelIter)->mRefCount == 0u)
             {
                 status = true;
                 Resource *res = *resDelIter;
@@ -354,7 +354,7 @@ void clearDeleted(const bool full)
 bool addResource(const std::string &idPath,
                  Resource *const resource)
 {
-    if (resource)
+    if (resource != nullptr)
     {
         resource->incRef();
         resource->mIdPath = idPath;
@@ -380,7 +380,7 @@ Resource *getFromCache(const std::string &filename,
 bool isInCache(const std::string &idPath)
 {
     const ResourceCIterator &resIter = mResources.find(idPath);
-    return (resIter != mResources.end() && resIter->second);
+    return (resIter != mResources.end() && (resIter->second != nullptr));
 }
 
 Resource *getTempResource(const std::string &idPath)
@@ -389,7 +389,7 @@ Resource *getTempResource(const std::string &idPath)
     if (resIter != mResources.end())
     {
         Resource *const res = resIter->second;
-        if (resIter->second)
+        if (resIter->second != nullptr)
             return res;
     }
     return nullptr;
@@ -401,7 +401,7 @@ Resource *getFromCache(const std::string &idPath)
     ResourceIterator resIter = mResources.find(idPath);
     if (resIter != mResources.end())
     {
-        if (resIter->second)
+        if (resIter->second != nullptr)
             resIter->second->incRef();
         return resIter->second;
     }
@@ -412,7 +412,7 @@ Resource *getFromCache(const std::string &idPath)
         Resource *const res = resIter->second;
         mResources.insert(*resIter);
         mOrphanedResources.erase(resIter);
-        if (res)
+        if (res != nullptr)
             res->incRef();
         return res;
     }
@@ -425,11 +425,11 @@ Resource *get(const std::string &idPath,
 {
 #ifndef DISABLE_RESOURCE_CACHING
     Resource *resource = getFromCache(idPath);
-    if (resource)
+    if (resource != nullptr)
         return resource;
     resource = fun(data);
 
-    if (resource)
+    if (resource != nullptr)
     {
         resource->incRef();
         resource->mIdPath = idPath;
@@ -469,7 +469,7 @@ Resource *get(const std::string &idPath,
 
 void release(Resource *const res)
 {
-    if (!res || mDestruction)
+    if ((res == nullptr) || mDestruction)
         return;
 
 #ifndef DISABLE_RESOURCE_CACHING
@@ -517,7 +517,7 @@ void release(Resource *const res)
 
 void moveToDeleted(Resource *const res)
 {
-    if (!res)
+    if (res == nullptr)
         return;
 
     bool found(false);
@@ -551,7 +551,7 @@ void moveToDeleted(Resource *const res)
 
 void decRefDelete(Resource *const res)
 {
-    if (!res)
+    if (res == nullptr)
         return;
 
     const int count = res->mRefCount;
@@ -596,9 +596,9 @@ void deleteInstance()
     while (iter != ResourceManager::mResources.end())
     {
         const Resource *const res = iter->second;
-        if (res)
+        if (res != nullptr)
         {
-            if (res->mRefCount)
+            if (res->mRefCount != 0u)
             {
                 logger->log(std::string("ResourceLeak: ").append(
                     res->mIdPath).append(" (").append(toString(
diff --git a/src/resources/resourcemanager/resourcemanager_unittest.cc b/src/resources/resourcemanager/resourcemanager_unittest.cc
index 49599e972..801c8ae0d 100644
--- a/src/resources/resourcemanager/resourcemanager_unittest.cc
+++ b/src/resources/resourcemanager/resourcemanager_unittest.cc
@@ -71,7 +71,7 @@ namespace
         static Resource *load(const void *const v)
         {
             BLOCK_START("TestLoader::load")
-            if (!v)
+            if (v == nullptr)
             {
                 BLOCK_END("TestLoader::load")
                 return nullptr;
diff --git a/src/resources/safeopenglimagehelper.cpp b/src/resources/safeopenglimagehelper.cpp
index 676812d12..c1acea2f0 100644
--- a/src/resources/safeopenglimagehelper.cpp
+++ b/src/resources/safeopenglimagehelper.cpp
@@ -66,7 +66,7 @@ Image *SafeOpenGLImageHelper::load(SDL_RWops *const rw,
                                    Dye const &dye)
 {
     SDL_Surface *const tmpImage = loadPng(rw);
-    if (!tmpImage)
+    if (tmpImage == nullptr)
     {
         logger->log("Error, image load failed: %s", IMG_GetError());
         return nullptr;
@@ -74,7 +74,7 @@ Image *SafeOpenGLImageHelper::load(SDL_RWops *const rw,
 
     SDL_Surface *const surf = convertTo32Bit(tmpImage);
     MSDL_FreeSurface(tmpImage);
-    if (!surf)
+    if (surf == nullptr)
         return nullptr;
 
     uint32_t *pixels = static_cast<uint32_t *>(surf->pixels);
@@ -85,14 +85,14 @@ Image *SafeOpenGLImageHelper::load(SDL_RWops *const rw,
         case 1:
         {
             const DyePalette *const pal = dye.getSPalete();
-            if (pal)
+            if (pal != nullptr)
                 DYEPALETTEP(pal, SOGLColor)(pixels, surf->w * surf->h);
             break;
         }
         case 2:
         {
             const DyePalette *const pal = dye.getAPalete();
-            if (pal)
+            if (pal != nullptr)
                 DYEPALETTEP(pal, AOGLColor)(pixels, surf->w * surf->h);
             break;
         }
@@ -119,11 +119,11 @@ Image *SafeOpenGLImageHelper::createTextSurface(SDL_Surface *const tmpImage,
                                                 const int height,
                                                 const float alpha)
 {
-    if (!tmpImage)
+    if (tmpImage == nullptr)
         return nullptr;
 
     Image *const img = glLoad(tmpImage, width, height);
-    if (img)
+    if (img != nullptr)
         img->setAlpha(alpha);
     return img;
 }
@@ -141,7 +141,7 @@ SDL_Surface *SafeOpenGLImageHelper::convertSurfaceNormalize(SDL_Surface
                                                             int width,
                                                             int height)
 {
-    if (!tmpImage)
+    if (tmpImage == nullptr)
         return nullptr;
 
     int realWidth = powerOfTwo(width);
@@ -190,7 +190,7 @@ SDL_Surface *SafeOpenGLImageHelper::convertSurfaceNormalize(SDL_Surface
         tmpImage = MSDL_CreateRGBSurface(SDL_SWSURFACE, realWidth, realHeight,
             32, rmask, gmask, bmask, amask);
 
-        if (!tmpImage)
+        if (tmpImage == nullptr)
         {
             logger->log("Error, image convert failed: out of memory");
             return nullptr;
@@ -204,7 +204,7 @@ SDL_Surface *SafeOpenGLImageHelper::convertSurface(SDL_Surface *tmpImage,
                                                    int width,
                                                    int height)
 {
-    if (!tmpImage)
+    if (tmpImage == nullptr)
         return nullptr;
 
 #ifdef USE_SDL2
@@ -243,7 +243,7 @@ SDL_Surface *SafeOpenGLImageHelper::convertSurface(SDL_Surface *tmpImage,
         tmpImage = MSDL_CreateRGBSurface(SDL_SWSURFACE, width, height,
             32, rmask, gmask, bmask, amask);
 
-        if (!tmpImage)
+        if (tmpImage == nullptr)
         {
             logger->log("Error, image convert failed: out of memory");
             return nullptr;
@@ -308,21 +308,21 @@ Image *SafeOpenGLImageHelper::glLoad(SDL_Surface *tmpImage,
                                      int width,
                                      int height)
 {
-    if (!tmpImage)
+    if (tmpImage == nullptr)
         return nullptr;
 
     BLOCK_START("SafeOpenGLImageHelper::glLoad")
     // Flush current error flag.
     graphicsManager.getLastError();
 
-    if (!width)
+    if (width == 0)
         width = tmpImage->w;
-    if (!height)
+    if (height == 0)
         height = tmpImage->h;
 
     SDL_Surface *oldImage = tmpImage;
     tmpImage = convertSurfaceNormalize(tmpImage, width, height);
-    if (!tmpImage)
+    if (tmpImage == nullptr)
         return nullptr;
 
     const int realWidth = tmpImage->w;
@@ -389,7 +389,7 @@ Image *SafeOpenGLImageHelper::glLoad(SDL_Surface *tmpImage,
         MSDL_FreeSurface(tmpImage);
 
     GLenum error = graphicsManager.getLastError();
-    if (error)
+    if (error != 0u)
     {
         std::string errmsg = GraphicsManager::errorToString(error);
         logger->log("Error: Image GL import failed: %s (%u)",
@@ -469,17 +469,17 @@ void SafeOpenGLImageHelper::copySurfaceToImage(const Image *const image,
                                                const int y,
                                                SDL_Surface *surface) const
 {
-    if (!surface || !image)
+    if (surface == nullptr || image == nullptr)
         return;
 
     SDL_Surface *const oldSurface = surface;
     surface = convertSurface(surface, surface->w, surface->h);
-    if (!surface)
+    if (surface == nullptr)
         return;
 
     // +++ probably need combine
     // mglTextureSubImage2D and mglTextureSubImage2DEXT
-    if (mglTextureSubImage2D)
+    if (mglTextureSubImage2D != nullptr)
     {
         mglTextureSubImage2D(image->mGLImage,
             0,
diff --git a/src/resources/sdlgfxblitfunc.cpp b/src/resources/sdlgfxblitfunc.cpp
index 2be73229c..109ddaa2e 100644
--- a/src/resources/sdlgfxblitfunc.cpp
+++ b/src/resources/sdlgfxblitfunc.cpp
@@ -339,7 +339,7 @@ static void _SDL_gfxBlitBlitterRGBA(SDL_gfxBlitInfo *info)
     const int dstskip = info->d_skip;
     SDL_PixelFormat *srcfmt = info->src;
 
-    while (height--)
+    while ((height--) != 0)
     {
         GFX_DUFFS_LOOP4(
         {
@@ -393,7 +393,7 @@ static int _SDL_gfxBlitRGBACall(SDL_Surface *const src,
     /*
     * Set up source and destination buffer pointers, then blit
     */
-    if (srcrect->w && srcrect->h)
+    if ((srcrect->w != 0u) && (srcrect->h != 0u))
     {
         SDL_gfxBlitInfo info;
 
@@ -444,7 +444,7 @@ int SDLgfxBlitRGBA(SDL_Surface *const src,
     /*
     * Make sure the surfaces aren't locked
     */
-    if (!src || !dst)
+    if ((src == nullptr) || (dst == nullptr))
     {
         reportAlways("SDLgfxBlitRGBA: passed a NULL surface");
         return -1;
@@ -468,7 +468,7 @@ int SDLgfxBlitRGBA(SDL_Surface *const src,
     /*
     * Clip the source rectangle to the source surface
     */
-    if (srcrect)
+    if (srcrect != nullptr)
     {
         int maxw;
         int maxh;
diff --git a/src/resources/sdlimagehelper.cpp b/src/resources/sdlimagehelper.cpp
index afb81d170..72afe3045 100644
--- a/src/resources/sdlimagehelper.cpp
+++ b/src/resources/sdlimagehelper.cpp
@@ -53,7 +53,7 @@ bool SDLImageHelper::mEnableAlphaCache = false;
 Image *SDLImageHelper::load(SDL_RWops *const rw, Dye const &dye)
 {
     SDL_Surface *const tmpImage = loadPng(rw);
-    if (!tmpImage)
+    if (tmpImage == nullptr)
     {
         reportAlways("Error, image load failed: %s",
             IMG_GetError());
@@ -83,7 +83,7 @@ Image *SDLImageHelper::load(SDL_RWops *const rw, Dye const &dye)
     SDL_Surface *const surf = MSDL_ConvertSurface(
         tmpImage, &rgba, SDL_SWSURFACE);
     MSDL_FreeSurface(tmpImage);
-    if (!surf)
+    if (surf == nullptr)
         return nullptr;
 
     uint32_t *pixels = static_cast<uint32_t *>(surf->pixels);
@@ -94,14 +94,14 @@ Image *SDLImageHelper::load(SDL_RWops *const rw, Dye const &dye)
         case 1:
         {
             const DyePalette *const pal = dye.getSPalete();
-            if (pal)
+            if (pal != nullptr)
                 DYEPALETTEP(pal, SColor)(pixels, surf->w * surf->h);
             break;
         }
         case 2:
         {
             const DyePalette *const pal = dye.getAPalete();
-            if (pal)
+            if (pal != nullptr)
                 DYEPALETTEP(pal, AColor)(pixels, surf->w * surf->h);
             break;
         }
@@ -128,7 +128,7 @@ Image *SDLImageHelper::createTextSurface(SDL_Surface *const tmpImage,
                                          const int height A_UNUSED,
                                          const float alpha)
 {
-    if (!tmpImage)
+    if (tmpImage == nullptr)
         return nullptr;
 
     bool hasAlpha = false;
@@ -138,7 +138,7 @@ Image *SDLImageHelper::createTextSurface(SDL_Surface *const tmpImage,
     uint8_t *alphaChannel = new uint8_t[sz];
 
     const SDL_PixelFormat *const fmt = tmpImage->format;
-    if (fmt->Amask)
+    if (fmt->Amask != 0u)
     {
         for (size_t i = 0; i < sz; ++ i)
         {
@@ -179,7 +179,7 @@ Image *SDLImageHelper::createTextSurface(SDL_Surface *const tmpImage,
         alphaChannel = nullptr;
     }
 
-    if (!image)
+    if (image == nullptr)
     {
         reportAlways("Error: Image convert failed.");
         delete [] alphaChannel;
@@ -193,7 +193,7 @@ Image *SDLImageHelper::createTextSurface(SDL_Surface *const tmpImage,
 
 SDL_Surface* SDLImageHelper::SDLDuplicateSurface(SDL_Surface *const tmpImage)
 {
-    if (!tmpImage || !tmpImage->format)
+    if ((tmpImage == nullptr) || (tmpImage->format == nullptr))
         return nullptr;
 
     return MSDL_ConvertSurface(tmpImage, tmpImage->format, SDL_SWSURFACE);
@@ -201,7 +201,7 @@ SDL_Surface* SDLImageHelper::SDLDuplicateSurface(SDL_Surface *const tmpImage)
 
 Image *SDLImageHelper::_SDLload(SDL_Surface *tmpImage)
 {
-    if (!tmpImage)
+    if (tmpImage == nullptr)
         return nullptr;
 
     bool hasAlpha = false;
@@ -212,7 +212,7 @@ Image *SDLImageHelper::_SDLload(SDL_Surface *tmpImage)
         reportAlways("Non 32 bit image detected");
         tmpImage = convertTo32Bit(tmpImage);
 
-        if (!tmpImage)
+        if (tmpImage == nullptr)
             return nullptr;
         converted = true;
     }
@@ -223,10 +223,10 @@ Image *SDLImageHelper::_SDLload(SDL_Surface *tmpImage)
     uint8_t *alphaChannel = new uint8_t[sz];
 
     // Figure out whether the image uses its alpha layer
-    if (!tmpImage->format->palette)
+    if (tmpImage->format->palette == nullptr)
     {
         const SDL_PixelFormat *const fmt = tmpImage->format;
-        if (fmt->Amask)
+        if (fmt->Amask != 0u)
         {
             const uint32_t amask = fmt->Amask;
             const uint8_t ashift = fmt->Ashift;
@@ -279,7 +279,7 @@ Image *SDLImageHelper::_SDLload(SDL_Surface *tmpImage)
         alphaChannel = nullptr;
     }
 
-    if (!image)
+    if (image == nullptr)
     {
         reportAlways("Error: Image convert failed.");
         delete [] alphaChannel;
@@ -308,7 +308,7 @@ void SDLImageHelper::copySurfaceToImage(const Image *const image,
                                         const int x, const int y,
                                         SDL_Surface *const surface) const
 {
-    if (!image || !surface)
+    if ((image == nullptr) || (surface == nullptr))
         return;
 
     SDL_SetAlpha(surface, 0, SDL_ALPHA_OPAQUE);
diff --git a/src/resources/sdlmusic.cpp b/src/resources/sdlmusic.cpp
index ab0133588..4d604c8cb 100644
--- a/src/resources/sdlmusic.cpp
+++ b/src/resources/sdlmusic.cpp
@@ -48,7 +48,7 @@ SDLMusic::~SDLMusic()
     Mix_FreeMusic(mMusic);
 #ifndef USE_SDL2
 #if SDL_MIXER_VERSION_ATLEAST(1, 2, 12)
-    if (mRw)
+    if (mRw != nullptr)
     {
         SDL_RWclose(mRw);
         mRw = nullptr;
@@ -60,9 +60,9 @@ SDLMusic::~SDLMusic()
 bool SDLMusic::play(const int loops, const int fadeIn)
 {
     if (fadeIn > 0)
-        return Mix_FadeInMusicPos(mMusic, loops, fadeIn, 0.0);
+        return Mix_FadeInMusicPos(mMusic, loops, fadeIn, 0.0) != 0;
     else
-        return Mix_FadeInMusicPos(mMusic, loops, 0, 0.0);
+        return Mix_FadeInMusicPos(mMusic, loops, 0, 0.0) != 0;
 }
 
 int SDLMusic::calcMemoryLocal() const
diff --git a/src/resources/sdlscreenshothelper.cpp b/src/resources/sdlscreenshothelper.cpp
index 12256e902..2fa9f3e2d 100644
--- a/src/resources/sdlscreenshothelper.cpp
+++ b/src/resources/sdlscreenshothelper.cpp
@@ -47,7 +47,7 @@ void SdlScreenshotHelper::prepare()
 
 SDL_Surface *SdlScreenshotHelper::getScreenshot()
 {
-    if (!mainGraphics)
+    if (mainGraphics == nullptr)
         return nullptr;
 
 #if SDL_BYTEORDER == SDL_BIG_ENDIAN
@@ -69,7 +69,7 @@ SDL_Surface *SdlScreenshotHelper::getScreenshot()
         rmask, gmask, bmask, amask);
 
 #ifndef USE_SDL2
-    if (screenshot)
+    if (screenshot != nullptr)
         SDL_BlitSurface(mainGraphics->mWindow, nullptr, screenshot, nullptr);
 #endif  // USE_SDL2
 
diff --git a/src/resources/skill/skilldata.cpp b/src/resources/skill/skilldata.cpp
index 8bebf8ada..d16aefd8b 100644
--- a/src/resources/skill/skilldata.cpp
+++ b/src/resources/skill/skilldata.cpp
@@ -58,7 +58,7 @@ SkillData::SkillData() :
 
 SkillData::~SkillData()
 {
-    if (icon)
+    if (icon != nullptr)
     {
         icon->decRef();
         icon = nullptr;
@@ -70,7 +70,7 @@ void SkillData::setIcon(const std::string &iconPath)
     if (!iconPath.empty())
         icon = Loader::getImage(iconPath);
 
-    if (!icon)
+    if (icon == nullptr)
     {
         icon = Theme::getImageFromTheme(
             paths.getStringValue("unknownItemFile"));
diff --git a/src/resources/skill/skillinfo.cpp b/src/resources/skill/skillinfo.cpp
index 7f0099a5c..8c90fbd72 100644
--- a/src/resources/skill/skillinfo.cpp
+++ b/src/resources/skill/skillinfo.cpp
@@ -86,7 +86,7 @@ void SkillInfo::update()
         if (visible == Visible_true)
         {
             visible = Visible_false;
-            if (model)
+            if (model != nullptr)
                 model->updateVisibilities();
         }
         return;
@@ -101,7 +101,7 @@ void SkillInfo::update()
     }
     else
     {
-        if (!customSelectedLevel)
+        if (customSelectedLevel == 0)
         {
             // TRANSLATORS: skill level
             skillLevel = strprintf(_("Lvl: %d"), baseLevel);
@@ -144,7 +144,7 @@ void SkillInfo::update()
         skillEffect.append(" ").append(toString(CAST_S32(type)));
     }
 
-    if (sp)
+    if (sp != 0)
     {
         // TRANSLATORS: skill mana
         skillEffect.append(strprintf(_(" / Mana: -%d"), sp));
@@ -164,11 +164,11 @@ void SkillInfo::update()
 
     skillLevelWidth = -1;
 
-    if (updateVisibility && model)
+    if (updateVisibility && (model != nullptr))
         model->updateVisibilities();
 
     data = getData(level);
-    if (!data)
+    if (data == nullptr)
         data = dataMap[0];
 }
 
diff --git a/src/resources/sprite/animatedsprite.cpp b/src/resources/sprite/animatedsprite.cpp
index 7b6900510..be620a52c 100644
--- a/src/resources/sprite/animatedsprite.cpp
+++ b/src/resources/sprite/animatedsprite.cpp
@@ -63,7 +63,7 @@ AnimatedSprite::AnimatedSprite(SpriteDef *restrict const sprite) :
     mAlpha = 1.0F;
 
     // Take possession of the sprite
-    if (mSprite)
+    if (mSprite != nullptr)
         mSprite->incRef();
 }
 
@@ -72,7 +72,7 @@ AnimatedSprite *AnimatedSprite::load(const std::string &restrict filename,
 {
     SpriteDef *restrict const s = Loader::getSprite(
         filename, variant);
-    if (!s)
+    if (s == nullptr)
         return nullptr;
     AnimatedSprite *restrict const as = new AnimatedSprite(s);
 #ifdef DEBUG_ANIMATIONS
@@ -92,7 +92,7 @@ AnimatedSprite *AnimatedSprite::delayedLoad(const std::string &restrict
         return load(filename, variant);
     Resource *restrict const res = ResourceManager::getFromCache(
         filename, variant);
-    if (res)
+    if (res != nullptr)
     {
         res->decRef();
         return load(filename, variant);
@@ -111,7 +111,7 @@ AnimatedSprite *AnimatedSprite::delayedLoad(const std::string &restrict
 AnimatedSprite *AnimatedSprite::clone(const AnimatedSprite *restrict const
                                       anim)
 {
-    if (!anim)
+    if (anim == nullptr)
         return nullptr;
     AnimatedSprite *restrict const sprite = new AnimatedSprite(anim->mSprite);
 #ifdef DEBUG_ANIMATIONS
@@ -124,12 +124,12 @@ AnimatedSprite *AnimatedSprite::clone(const AnimatedSprite *restrict const
 
 AnimatedSprite::~AnimatedSprite()
 {
-    if (mSprite)
+    if (mSprite != nullptr)
     {
         mSprite->decRef();
         mSprite = nullptr;
     }
-    if (mDelayLoad)
+    if (mDelayLoad != nullptr)
     {
         mDelayLoad->clearSprite();
         DelayedManager::removeDelayLoad(mDelayLoad);
@@ -147,7 +147,7 @@ bool AnimatedSprite::reset() restrict2
     mFrameTime = 0;
     mLastTime = 0;
 
-    if (mAnimation)
+    if (mAnimation != nullptr)
         mFrame = &mAnimation->mFrames[0];
     else
         mFrame = nullptr;
@@ -156,22 +156,22 @@ bool AnimatedSprite::reset() restrict2
 
 bool AnimatedSprite::play(const std::string &restrict spriteAction) restrict2
 {
-    if (!mSprite)
+    if (mSprite == nullptr)
     {
-        if (!mDelayLoad)
+        if (mDelayLoad == nullptr)
             return false;
         mDelayLoad->setAction(spriteAction);
         return true;
     }
 
     const Action *const action = mSprite->getAction(spriteAction, mNumber);
-    if (!action)
+    if (action == nullptr)
         return false;
 
     mAction = action;
     const Animation *const animation = mAction->getAnimation(mDirection);
 
-    if (animation &&
+    if ((animation != nullptr) &&
         animation != mAnimation &&
         animation->getLength() > 0)
     {
@@ -191,7 +191,7 @@ bool AnimatedSprite::update(const int time) restrict2
         mLastTime = time;
 
     // If not enough time has passed yet, do nothing
-    if (time <= mLastTime || !mAnimation)
+    if (time <= mLastTime || (mAnimation == nullptr))
         return false;
 
     const unsigned int dt = time - mLastTime;
@@ -214,8 +214,9 @@ bool AnimatedSprite::update(const int time) restrict2
 bool AnimatedSprite::updateCurrentAnimation(const unsigned int time) restrict2
 {
     // move code from Animation::isTerminator(*mFrame)
-    if (!mFrame || !mAnimation || (!mFrame->image
-        && mFrame->type == FrameType::ANIMATION))
+    if (mFrame == nullptr ||
+        mAnimation == nullptr ||
+        (mFrame->image == nullptr && mFrame->type == FrameType::ANIMATION))
     {
         return false;
     }
@@ -245,7 +246,7 @@ bool AnimatedSprite::updateCurrentAnimation(const unsigned int time) restrict2
         {
             const int rand = mFrame->rand;
             if (rand == 100 ||
-                (rand && rand >= mrand() % 100))
+                ((rand != 0) && rand >= mrand() % 100))
             {
                 for (size_t i = 0; i < mAnimation->getLength(); i ++)
                 {
@@ -278,19 +279,19 @@ bool AnimatedSprite::updateCurrentAnimation(const unsigned int time) restrict2
         {
             const int rand = mFrame->rand;
             if (rand == 100 ||
-                (rand && rand >= mrand() % 100))
+                ((rand != 0) && rand >= mrand() % 100))
             {
                 play(mFrame->nextAction);
                 return true;
             }
         }
         // copy code from Animation::isTerminator(*mFrame)
-        else if (!mFrame->image &&
+        else if ((mFrame->image == nullptr) &&
                  mFrame->type == FrameType::ANIMATION)
         {
             const int rand = mFrame->rand;
             if (rand == 100 ||
-                (rand && rand >= mrand() % 100))
+                ((rand != 0) && rand >= mrand() % 100))
             {
                 mAnimation = nullptr;
                 mFrame = nullptr;
@@ -307,13 +308,13 @@ bool AnimatedSprite::updateCurrentAnimation(const unsigned int time) restrict2
             }
             else
             {
-                if (rand && mrand() % 100 <= rand)
+                if ((rand != 0) && mrand() % 100 <= rand)
                     fail = false;
             }
         }
         if (fail)
         {
-            if (mFrame)
+            if (mFrame != nullptr)
                 mFrameTime = mFrame->delay + 1;
             else
                 mFrameTime ++;
@@ -327,7 +328,7 @@ void AnimatedSprite::draw(Graphics *restrict const graphics,
                           const int posY) const restrict2
 {
     FUNC_BLOCK("AnimatedSprite::draw", 1)
-    if (!mFrame || !mFrame->image)
+    if ((mFrame == nullptr) || (mFrame->image == nullptr))
         return;
 
     Image *restrict const image = mFrame->image;
@@ -340,7 +341,7 @@ void AnimatedSprite::drawRaw(Graphics *restrict const graphics,
                              const int posX,
                              const int posY) const restrict2
 {
-    if (!mFrame || !mFrame->image)
+    if ((mFrame == nullptr) || (mFrame->image == nullptr))
         return;
 
     Image *restrict const image = mFrame->image;
@@ -357,13 +358,13 @@ bool AnimatedSprite::setSpriteDirection(const SpriteDirection::Type direction)
     {
         mDirection = direction;
 
-        if (!mAction)
+        if (mAction == nullptr)
             return false;
 
         const Animation *restrict const animation =
             mAction->getAnimation(mDirection);
 
-        if (animation &&
+        if ((animation != nullptr) &&
             animation != mAnimation &&
             animation->getLength() > 0)
         {
@@ -379,7 +380,7 @@ bool AnimatedSprite::setSpriteDirection(const SpriteDirection::Type direction)
 
 unsigned int AnimatedSprite::getFrameCount() const restrict2
 {
-    if (mAnimation)
+    if (mAnimation != nullptr)
         return CAST_U32(mAnimation->getLength());
     else
         return 0;
@@ -387,7 +388,7 @@ unsigned int AnimatedSprite::getFrameCount() const restrict2
 
 int AnimatedSprite::getWidth() const restrict2
 {
-    if (mFrame && mFrame->image)
+    if ((mFrame != nullptr) && (mFrame->image != nullptr))
         return mFrame->image->mBounds.w;
     else
         return 0;
@@ -395,7 +396,7 @@ int AnimatedSprite::getWidth() const restrict2
 
 int AnimatedSprite::getHeight() const restrict2
 {
-    if (mFrame && mFrame->image)
+    if ((mFrame != nullptr) && (mFrame->image != nullptr))
         return mFrame->image->mBounds.h;
     else
         return 0;
@@ -403,45 +404,45 @@ int AnimatedSprite::getHeight() const restrict2
 
 std::string AnimatedSprite::getIdPath() const restrict2
 {
-    if (!mSprite)
+    if (mSprite == nullptr)
         return "";
     return mSprite->mIdPath;
 }
 
 const Image* AnimatedSprite::getImage() const restrict2 noexcept2
 {
-    return mFrame ? mFrame->image : nullptr;
+    return mFrame != nullptr ? mFrame->image : nullptr;
 }
 
 void AnimatedSprite::setAlpha(float alpha) restrict2
 {
     mAlpha = alpha;
 
-    if (mFrame)
+    if (mFrame != nullptr)
     {
         Image *restrict const image = mFrame->image;
-        if (image)
+        if (image != nullptr)
             image->setAlpha(mAlpha);
     }
 }
 
 const void *AnimatedSprite::getHash() const restrict2
 {
-    if (mFrame)
+    if (mFrame != nullptr)
         return mFrame;
     return this;
 }
 
 bool AnimatedSprite::updateNumber(const unsigned num) restrict2
 {
-    if (!mSprite)
+    if (mSprite == nullptr)
         return false;
 
     if (mNumber1 != num)
     {
         mNumber1 = num;
         mNumber = mSprite->findNumber(num);
-        if (!mNumber)
+        if (mNumber == 0u)
         {
             mNumber = 100;
             return false;
@@ -454,7 +455,7 @@ bool AnimatedSprite::updateNumber(const unsigned num) restrict2
 void AnimatedSprite::setDelayLoad(const std::string &restrict filename,
                                   const int variant) restrict2
 {
-    if (mDelayLoad)
+    if (mDelayLoad != nullptr)
     {
         mDelayLoad->clearSprite();
         DelayedManager::removeDelayLoad(mDelayLoad);
diff --git a/src/resources/sprite/animationdelayload.cpp b/src/resources/sprite/animationdelayload.cpp
index 440988252..37222d068 100644
--- a/src/resources/sprite/animationdelayload.cpp
+++ b/src/resources/sprite/animationdelayload.cpp
@@ -40,7 +40,7 @@ AnimationDelayLoad::AnimationDelayLoad(const std::string &fileName,
 
 AnimationDelayLoad::~AnimationDelayLoad()
 {
-    if (mSprite)
+    if (mSprite != nullptr)
     {
         mSprite->clearDelayLoad();
         mSprite = nullptr;
@@ -54,10 +54,10 @@ void AnimationDelayLoad::clearSprite()
 
 void AnimationDelayLoad::load()
 {
-    if (mSprite)
+    if (mSprite != nullptr)
     {
         SpriteDef *const s = Loader::getSprite(mFileName, mVariant);
-        if (!s)
+        if (s == nullptr)
             return;
         mSprite->setSprite(s);
         mSprite->play(mAction);
diff --git a/src/resources/sprite/imagesprite.cpp b/src/resources/sprite/imagesprite.cpp
index 6867bbb01..b5aace2e1 100644
--- a/src/resources/sprite/imagesprite.cpp
+++ b/src/resources/sprite/imagesprite.cpp
@@ -28,7 +28,7 @@
 ImageSprite::ImageSprite(Image *const image) :
     mImage(image)
 {
-    if (mImage)
+    if (mImage != nullptr)
     {
         mAlpha = mImage->mAlpha;
         mImage->incRef();
@@ -41,7 +41,7 @@ ImageSprite::ImageSprite(Image *const image) :
 
 ImageSprite::~ImageSprite()
 {
-    if (mImage)
+    if (mImage != nullptr)
     {
         mImage->decRef();
         mImage = nullptr;
@@ -52,7 +52,7 @@ void ImageSprite::draw(Graphics *const graphics,
                        const int posX, const int posY) const
 {
     FUNC_BLOCK("ImageSprite::draw", 1)
-    if (!mImage)
+    if (mImage == nullptr)
         return;
 
     mImage->setAlpha(mAlpha);
diff --git a/src/resources/sprite/imagesprite.h b/src/resources/sprite/imagesprite.h
index 1b731dc00..9576933d1 100644
--- a/src/resources/sprite/imagesprite.h
+++ b/src/resources/sprite/imagesprite.h
@@ -51,10 +51,10 @@ class ImageSprite final : public Sprite
                   const override final A_NONNULL(2);
 
         int getWidth() const override final A_WARN_UNUSED
-        { return mImage ? mImage->getWidth() : 0; }
+        { return mImage != nullptr ? mImage->getWidth() : 0; }
 
         int getHeight() const override final A_WARN_UNUSED
-        { return mImage ? mImage->getHeight() : 0; }
+        { return mImage != nullptr ? mImage->getHeight() : 0; }
 
         const Image* getImage() const override final A_WARN_UNUSED
         { return mImage; }
diff --git a/src/resources/sprite/spritedef.cpp b/src/resources/sprite/spritedef.cpp
index 263caebe2..8824a2ac1 100644
--- a/src/resources/sprite/spritedef.cpp
+++ b/src/resources/sprite/spritedef.cpp
@@ -54,11 +54,11 @@ const Action *SpriteDef::getAction(const std::string &action,
     if (i == mActions.end() && num != 100)
         i = mActions.find(100);
 
-    if (i == mActions.end() || !(*i).second)
+    if (i == mActions.end() || ((*i).second == nullptr))
         return nullptr;
 
     const ActionMap *const actMap = (*i).second;
-    if (!actMap)
+    if (actMap == nullptr)
         return nullptr;
     const ActionMap::const_iterator it = actMap->find(action);
 
@@ -97,11 +97,11 @@ SpriteDef *SpriteDef::load(const std::string &animationFile,
     XML::Document *const doc = Loader::getXml(animationFile.substr(0, pos),
         UseVirtFs_true,
         SkipError_false);
-    if (!doc)
+    if (doc == nullptr)
         return nullptr;
     XmlNodePtrConst rootNode = doc->rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "sprite"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "sprite"))
     {
         reportAlways("Error, failed to parse sprite %s",
             animationFile.c_str());
@@ -137,12 +137,12 @@ void SpriteDef::fixDeadAction()
     FOR_EACH (ActionsIter, it, mActions)
     {
         ActionMap *const d = (*it).second;
-        if (!d)
+        if (d == nullptr)
             continue;
         const ActionMap::iterator i = d->find(SpriteAction::DEAD);
         const ActionMap::iterator i2 = d->find(SpriteAction::STAND);
         // search dead action and check what it not same with stand action
-        if (i != d->end() && i->second && i->second != i2->second)
+        if (i != d->end() && (i->second != nullptr) && i->second != i2->second)
             (i->second)->setLastFrameDelay(0);
     }
 }
@@ -202,7 +202,7 @@ void SpriteDef::loadSprite(XmlNodeConstPtr spriteNode,
                            const std::string &palettes)
 {
     BLOCK_START("SpriteDef::loadSprite")
-    if (!spriteNode)
+    if (spriteNode == nullptr)
     {
         BLOCK_END("SpriteDef::loadSprite")
         return;
@@ -248,7 +248,7 @@ void SpriteDef::loadImageSet(XmlNodeConstPtr node,
     ImageSet *const imageSet = Loader::getImageSet(imageSrc,
         width, height);
 
-    if (!imageSet)
+    if (imageSet == nullptr)
     {
         reportAlways("%s: Couldn't load imageset: %s",
             mSource.c_str(),
@@ -278,7 +278,7 @@ const ImageSet *SpriteDef::getImageSet(const std::string &imageSetName) const
 void SpriteDef::loadAction(XmlNodeConstPtr node,
                            const int variant_offset)
 {
-    if (!node)
+    if (node == nullptr)
         return;
 
     const std::string actionName = XML::getProperty(node, "name", "");
@@ -320,8 +320,12 @@ void SpriteDef::loadAnimation(XmlNodeConstPtr animationNode,
                               const ImageSet *const imageSet0,
                               const int variant_offset) const
 {
-    if (!action || !imageSet0 || !animationNode)
+    if (action == nullptr ||
+        imageSet0 == nullptr ||
+        animationNode == nullptr)
+    {
         return;
+    }
 
     const std::string directionName =
         XML::getProperty(animationNode, "direction", "");
@@ -376,7 +380,7 @@ void SpriteDef::loadAnimation(XmlNodeConstPtr animationNode,
             }
 
             Image *const img = imageSet->get(index + variant_offset);
-            if (!img)
+            if (img == nullptr)
             {
                 reportAlways("%s: No image at index %d at direction '%s'",
                     mSource.c_str(),
@@ -434,7 +438,7 @@ void SpriteDef::loadAnimation(XmlNodeConstPtr animationNode,
                     {
                         Image *const img = imageSet->get(atoi(
                             str.c_str()) + variant_offset);
-                        if (img)
+                        if (img != nullptr)
                         {
                             animation->addFrame(img, delay,
                                 offsetX, offsetY, rand);
@@ -491,11 +495,11 @@ void SpriteDef::includeSprite(XmlNodeConstPtr includeNode, const int variant)
     XML::Document *const doc = Loader::getXml(filename,
         UseVirtFs_true,
         SkipError_false);
-    if (!doc)
+    if (doc == nullptr)
         return;
     XmlNodeConstPtr rootNode = doc->rootNode();
 
-    if (!rootNode || !xmlNameEqual(rootNode, "sprite"))
+    if ((rootNode == nullptr) || !xmlNameEqual(rootNode, "sprite"))
     {
         reportAlways("%s: No sprite root node in %s",
             mSource.c_str(),
@@ -526,7 +530,7 @@ SpriteDef::~SpriteDef()
 
     FOR_EACH (ImageSetIterator, i, mImageSets)
     {
-        if (i->second)
+        if (i->second != nullptr)
         {
             i->second->decRef();
             i->second = nullptr;
@@ -581,7 +585,7 @@ bool SpriteDef::addSequence(const int start,
                             const ImageSet *const imageSet,
                             Animation *const animation) const
 {
-    if (!imageSet || !animation)
+    if ((imageSet == nullptr) || (animation == nullptr))
         return true;
 
     if (start < 0 || end < 0)
@@ -600,7 +604,7 @@ bool SpriteDef::addSequence(const int start,
             {
                 Image *const img = imageSet->get(pos + variant_offset);
 
-                if (!img)
+                if (img == nullptr)
                 {
                     reportAlways("%s: No image at index %d",
                         mSource.c_str(),
@@ -625,7 +629,7 @@ bool SpriteDef::addSequence(const int start,
             {
                 Image *const img = imageSet->get(pos + variant_offset);
 
-                if (!img)
+                if (img == nullptr)
                 {
                     reportAlways("%s: No image at index %d",
                         mSource.c_str(),