Improve perfomance in creation SDL font surfaces.

3 files changed, 92 insertions, 8 deletions

diff --git a/src/gui/sdlfont.cpp b/src/gui/sdlfont.cpp
index 9cbee4e89..a0f8699f8 100644
--- a/src/gui/sdlfont.cpp
+++ b/src/gui/sdlfont.cpp
@@ -64,7 +64,7 @@ class SDLTextChunk
             return (chunk.text == text && chunk.color == color);
         }
 
-        void generate(TTF_Font *font)
+        void generate(TTF_Font *font, float alpha)
         {
             SDL_Color sdlCol;
             sdlCol.b = static_cast<Uint8>(color.b);
@@ -83,7 +83,8 @@ class SDLTextChunk
                 return;
             }
 
-            img = Image::load(surface);
+            img = Image::createTextSurface(surface, alpha);
+//            img = Image::load(surface);
 
             SDL_FreeSurface(surface);
         }
@@ -243,7 +244,7 @@ void SDLFont::drawString(gcn::Graphics *graphics,
         mCreateCounter ++;
 #endif
         cache->push_front(chunk);
-        cache->front().generate(mFont);
+        cache->front().generate(mFont, alpha);
 
         if (!mCleanTime)
         {
@@ -254,9 +255,13 @@ void SDLFont::drawString(gcn::Graphics *graphics,
             doClean();
             mCleanTime = cur_time + CLEAN_TIME;
         }
+        if (cache->front().img)
+        {
+//            cache->front().img->setAlpha(alpha);
+            g->drawImage(cache->front().img, x, y);
+        }
     }
-
-    if (cache->front().img)
+    else if (cache->front().img)
     {
         cache->front().img->setAlpha(alpha);
         g->drawImage(cache->front().img, x, y);
@@ -271,9 +276,9 @@ void SDLFont::createSDLTextChunk(SDLTextChunk *chunk)
 
     const float alpha = static_cast<float>(chunk->color.a) / 255.0f;
     chunk->color.a = 255;
-    chunk->generate(mFont);
-    if (chunk->img)
-        chunk->img->setAlpha(alpha);
+    chunk->generate(mFont, alpha);
+//    if (chunk->img)
+//        chunk->img->setAlpha(alpha);
 }
 
 int SDLFont::getWidth(const std::string &text) const
diff --git a/src/resources/image.cpp b/src/resources/image.cpp
index 29e89d26e..583cf7343 100644
--- a/src/resources/image.cpp
+++ b/src/resources/image.cpp
@@ -189,6 +189,83 @@ Image *Image::load(SDL_Surface *tmpImage)
     return _SDLload(tmpImage);
 }
 
+Image *Image::createTextSurface(SDL_Surface *tmpImage, float alpha)
+{
+    if (!tmpImage)
+        return NULL;
+
+    Image *img;
+#ifdef USE_OPENGL
+    if (mUseOpenGL)
+    {
+        img = _GLload(tmpImage);
+        img->setAlpha(alpha);
+        return img;
+    }
+#endif
+
+    bool hasAlpha = false;
+    bool converted = false;
+
+    // The alpha channel to be filled with alpha values
+    Uint8 *alphaChannel = new Uint8[tmpImage->w * tmpImage->h];
+
+    const int sz = tmpImage->w * tmpImage->h;
+    const SDL_PixelFormat * const fmt = tmpImage->format;
+    if (fmt->Amask)
+    {
+        for (int i = 0; i < sz; ++ i)
+        {
+            unsigned v = ((static_cast<Uint32*>(tmpImage->pixels))[i]
+                & fmt->Amask) >> fmt->Ashift;
+            Uint8 a = (v << fmt->Aloss) + (v >> (8 - (fmt->Aloss << 1)));
+
+            Uint8 a2 = static_cast<Uint8>(static_cast<float>(a) * alpha);
+
+            (static_cast<Uint32*>(tmpImage->pixels))[i] &= ~fmt->Amask;
+            (static_cast<Uint32*>(tmpImage->pixels))[i] |=
+                ((a2 >> fmt->Aloss) << fmt->Ashift & fmt->Amask);
+
+            if (a != 255)
+                hasAlpha = true;
+
+            alphaChannel[i] = a;
+
+        }
+    }
+
+    SDL_Surface *image;
+
+    // Convert the surface to the current display format
+    if (hasAlpha)
+    {
+        image = SDL_DisplayFormatAlpha(tmpImage);
+    }
+    else
+    {
+        image = SDL_DisplayFormat(tmpImage);
+
+        // We also delete the alpha channel since
+        // it's not used.
+        delete[] alphaChannel;
+        alphaChannel = 0;
+    }
+
+    if (!image)
+    {
+        logger->log1("Error: Image convert failed.");
+        delete[] alphaChannel;
+        return 0;
+    }
+
+    if (converted)
+        SDL_FreeSurface(tmpImage);
+
+    img = new Image(image, hasAlpha, alphaChannel);
+    img->mAlpha = alpha;
+    return img;
+}
+
 void Image::SDLCleanCache()
 {
     ResourceManager *resman = ResourceManager::getInstance();
diff --git a/src/resources/image.h b/src/resources/image.h
index 718301f81..9ac2b163e 100644
--- a/src/resources/image.h
+++ b/src/resources/image.h
@@ -95,6 +95,8 @@ class Image : public Resource
 
         static SDL_Surface* convertTo32Bit(SDL_Surface* tmpImage);
 
+        static Image *createTextSurface(SDL_Surface *tmpImage, float alpha);
+
         /**
          * Frees the resources created by SDL.
          */