added support for setting alpha value for global animations

[rocksndiamonds.git] / src / libgame / system.c

diff --git a/src/libgame/system.c b/src/libgame/system.c
index a3eae88217bc14c3ee295acea1f721530c7ecec2..2f21541d8e0419b5c938853082051c8075f550fe 100644 (file)
--- a/src/libgame/system.c
+++ b/src/libgame/system.c
@@ -601,7 +601,15 @@ void FreeBitmap(Bitmap *bitmap)
 
 Bitmap *CreateBitmapStruct(void)
 {
-  return checked_calloc(sizeof(Bitmap));
+  Bitmap *new_bitmap = checked_calloc(sizeof(Bitmap));
+
+  new_bitmap->alpha[0][0] = -1;
+  new_bitmap->alpha[0][1] = -1;
+  new_bitmap->alpha[1][0] = -1;
+  new_bitmap->alpha[1][1] = -1;
+  new_bitmap->alpha_next_blit = -1;
+
+  return new_bitmap;
 }
 
 Bitmap *CreateBitmap(int width, int height, int depth)
@@ -772,6 +780,12 @@ static boolean InClippedRectangle(Bitmap *bitmap, int *x, int *y,
   return TRUE;
 }
 
+void SetBitmapAlphaNextBlit(Bitmap *bitmap, int alpha)
+{
+  // set alpha value for next blitting of bitmap
+  bitmap->alpha_next_blit = alpha;
+}
+
 void BlitBitmap(Bitmap *src_bitmap, Bitmap *dst_bitmap,
                int src_x, int src_y, int width, int height,
                int dst_x, int dst_y)