Buffer layered sprites under SDL

This improves framerate and allows transparent overlay for complex
sprites. Two copies of the buffer are kept, one at full opacity,
one with variable opactiy, to reduce calls to setAlpha.

Reviewed-by: Bertram

1 files changed, 12 insertions, 0 deletions

diff --git a/src/graphics.h b/src/graphics.h
index 211fb901..344c31c3 100644
--- a/src/graphics.h
+++ b/src/graphics.h
@@ -73,6 +73,11 @@ struct ImageRect
 class Graphics : public gcn::SDLGraphics
 {
     public:
+        enum BlitMode {
+            BLIT_NORMAL = 0,
+            BLIT_GFX
+        };
+
         /**
          * Constructor.
          */
@@ -182,6 +187,12 @@ class Graphics : public gcn::SDLGraphics
             drawImageRect(area.x, area.y, area.width, area.height, imgRect);
         }
 
+        void setBlitMode(BlitMode mode)
+        { mBlitMode = mode; }
+
+        BlitMode getBlitMode()
+        { return mBlitMode; }
+
         /**
          * Updates the screen. This is done by either copying the buffer to the
          * screen or swapping pages.
@@ -211,6 +222,7 @@ class Graphics : public gcn::SDLGraphics
         int mBpp;
         bool mFullscreen;
         bool mHWAccel;
+        BlitMode mBlitMode;
 };
 
 extern Graphics *graphics;