--- a/hedgewars/SDLh.pas Tue Apr 13 22:45:46 2010 +0000
+++ b/hedgewars/SDLh.pas Thu Apr 15 14:24:26 2010 +0000
@@ -617,6 +617,7 @@
function SDL_Flip(Screen: PSDL_Surface): LongInt; cdecl; external SDLLibName;
procedure SDL_GetRGB(pixel: Longword; fmt: PSDL_PixelFormat; r, g, b: PByte); cdecl; external SDLLibName;
+procedure SDL_GetRGBA(pixel: Longword; fmt: PSDL_PixelFormat; r, g, b, a: PByte); cdecl; external SDLLibName;
function SDL_MapRGB(format: PSDL_PixelFormat; r, g, b: Byte): Longword; cdecl; external SDLLibName;
function SDL_MapRGBA(format: PSDL_PixelFormat; r, g, b, a: Byte): Longword; cdecl; external SDLLibName;
--- a/hedgewars/uStore.pas Tue Apr 13 22:45:46 2010 +0000
+++ b/hedgewars/uStore.pas Thu Apr 15 14:24:26 2010 +0000
@@ -1310,6 +1310,7 @@
procedure copyToXY(src, dest: PSDL_Surface; destX, destY: LongInt);
var srcX, srcY, i, j, maxDest: LongInt;
srcPixels, destPixels: PLongWordArray;
+ r0, g0, b0, a0, r1, g1, b1, a1: Byte;
begin
maxDest:= (dest^.pitch div 4) * dest^.h;
srcPixels:= src^.pixels;
@@ -1320,8 +1321,12 @@
begin
i:= (destY + srcY) * (dest^.pitch div 4) + destX + srcX;
j:= srcY * (src^.pitch div 4) + srcX;
- // basic skip of transparent pixels - cleverness would be to do true alpha
- if (i < maxDest) and (AMask and srcPixels^[j] <> 0) then destPixels^[i]:= srcPixels^[j];
+ if (i < maxDest) and (srcPixels^[j] and AMask <> 0) then
+ begin
+ SDL_GetRGBA(destPixels^[i], dest^.format, @r0, @g0, @b0, @a0);
+ SDL_GetRGBA(srcPixels^[j], src^.format, @r1, @g1, @b1, @a1);
+ destPixels^[i]:= SDL_MapRGBA(dest^.format, (r0 * (255 - a1) + r1 * a1) div 255, (g0 * (255 - a1) + g1 * a1) div 255, (b0 * (255 - a1) + b1 * a1) div 255, (a0 * (255 - a1) + a1 * a1) div 255);
+ end;
end;
end;