Added an image merge feature loosely based on a merge function found in

the open source project Wormux. To improve SDL performance, the number
of layers that are pushed out to the hardware or software buffers should
be reduced, which is where this function comes into play, as it combines
two surfaces together so that the number of blit operations is reduced.

This function is currently not used, but will be used once a good way to
link each of the target systems is determined so that it only initiates
when SDL is enabled, as well as making sure that each hook that uses
this function is benefiting from it sufficiently. At the moment, it's
suspected that the particle engine will likely be the most likely to
benefit from this function, followed by tile drawing, then sprite drawing.

Signed-off-by: Ira Rice <irarice@gmail.com>

1 files changed, 24 insertions, 20 deletions

diff --git a/src/particle.cpp b/src/particle.cpp
index e56435ed..0e412ada 100644
--- a/src/particle.cpp
+++ b/src/particle.cpp
@@ -177,7 +177,8 @@ bool Particle::update()
                 mVelocity *= mBounce;
                 mVelocity.z = -mVelocity.z;
             }
-            else {
+            else
+            {
                 mAlive = false;
             }
         }
@@ -185,16 +186,12 @@ bool Particle::update()
         // Update child emitters
         if ((mLifetimePast-1)%Particle::emitterSkip == 0)
         {
-            for (   EmitterIterator e = mChildEmitters.begin();
-                    e != mChildEmitters.end();
-                    e++
-                )
+            for (EmitterIterator e = mChildEmitters.begin();
+                 e != mChildEmitters.end(); e++)
             {
                 Particles newParticles = (*e)->createParticles(mLifetimePast);
-                for (   ParticleIterator p = newParticles.begin();
-                        p != newParticles.end();
-                        p++
-                    )
+                for (ParticleIterator p = newParticles.begin();
+                     p != newParticles.end(); p++)
                 {
                     (*p)->moveBy(mPos);
                     mChildParticles.push_back (*p);
@@ -219,7 +216,9 @@ bool Particle::update()
         if ((*p)->update())
         {
             p++;
-        } else {
+        }
+        else
+        {
             delete (*p);
             p = mChildParticles.erase(p);
         }
@@ -237,8 +236,7 @@ void Particle::moveBy(const Vector &change)
 {
     mPos += change;
     for (ParticleIterator p = mChildParticles.begin();
-         p != mChildParticles.end();
-         p++)
+         p != mChildParticles.end(); p++)
     {
         if ((*p)->doesFollow())
         {
@@ -279,20 +277,21 @@ Particle* Particle::addEffect(const std::string &particleEffectFile,
         xmlNodePtr node;
 
         // Animation
-        if ((node = XML::findFirstChildByName(
-                        effectChildNode, "animation"))) {
+        if ((node = XML::findFirstChildByName(effectChildNode, "animation")))
+        {
             newParticle = new AnimationParticle(mMap, node);
         }
         // Image
-        else if ((node = XML::findFirstChildByName(
-                        effectChildNode, "image"))) {
+        else if ((node = XML::findFirstChildByName(effectChildNode, "image")))
+        {
             Image *img= resman->getImage((const char*)
                     node->xmlChildrenNode->content);
 
             newParticle = new ImageParticle(mMap, img);
         }
         // Other
-        else {
+        else
+        {
             newParticle = new Particle(mMap);
         }
 
@@ -315,7 +314,8 @@ Particle* Particle::addEffect(const std::string &particleEffectFile,
                 continue;
 
             ParticleEmitter *newEmitter;
-            newEmitter = new ParticleEmitter(emitterNode, newParticle, mMap, rotation);
+            newEmitter = new ParticleEmitter(emitterNode, newParticle, mMap,
+                                             rotation);
             newParticle->addEmitter(newEmitter);
         }
 
@@ -326,7 +326,8 @@ Particle* Particle::addEffect(const std::string &particleEffectFile,
 }
 
 Particle *Particle::addTextSplashEffect(const std::string &text, int x, int y,
-        const gcn::Color *color, gcn::Font *font, bool outline)
+                                        const gcn::Color *color,
+                                        gcn::Font *font, bool outline)
 {
     Particle *newParticle = new TextParticle(mMap, text, color, font, outline);
     newParticle->moveTo(x, y);
@@ -344,7 +345,10 @@ Particle *Particle::addTextSplashEffect(const std::string &text, int x, int y,
 }
 
 Particle *Particle::addTextRiseFadeOutEffect(const std::string &text,
-        int x, int y, const gcn::Color *color, gcn::Font *font, bool outline){
+                                             int x, int y,
+                                             const gcn::Color *color,
+                                             gcn::Font *font, bool outline)
+{
     Particle *newParticle = new TextParticle(mMap, text, color, font, outline);
     newParticle->moveTo(x, y);
     newParticle->setVelocity(0.0f, 0.0f, 0.5f);