APNG support

ZDoom · Sep 14, 2023 · 3b5cd6e · 3b5cd6e
1 parent bafaf13
commit 3b5cd6e
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Showing 5 changed files with 774 additions and 35 deletions.
diff --git a/src/common/textures/bitmap.cpp b/src/common/textures/bitmap.cpp
@@ -226,7 +226,8 @@ static const CopyFunc copyfuncs[][12]={
 	COPY_FUNCS(bCopyAlpha),
 	COPY_FUNCS(bCopyNewAlpha),
 	COPY_FUNCS(bOverlay),
-	COPY_FUNCS(bOverwrite)
+	COPY_FUNCS(bOverwrite),
+	COPY_FUNCS(bComposeAlpha)
 };
 #undef COPY_FUNCS
 
@@ -257,21 +258,21 @@ bool ClipCopyPixelRect(const FClipRect *cr, int &originx, int &originy,
 		step_y = pstep_y;
 		break;
 
-	case 1: // rotate 90° right
+	case 1: // rotate 90� right
 		pixxoffset = 0;
 		pixyoffset = srcheight - 1;
 		step_x = -pstep_y;
 		step_y = pstep_x;
 		break;
 
-	case 2:	// rotate 180°
+	case 2:	// rotate 180�
 		pixxoffset = srcwidth - 1;
 		pixyoffset = srcheight - 1;
 		step_x = -pstep_x;
 		step_y = -pstep_y;
 		break;
 
-	case 3: // rotate 90° left
+	case 3: // rotate 90� left
 		pixxoffset = srcwidth - 1;
 		pixyoffset = 0;
 		step_x = pstep_y;
@@ -285,7 +286,7 @@ bool ClipCopyPixelRect(const FClipRect *cr, int &originx, int &originy,
 		step_y = pstep_y;
 		break;
 
-	case 5:	// flip horizontally and rotate 90° right
+	case 5:	// flip horizontally and rotate 90� right
 		pixxoffset = srcwidth - 1;
 		pixyoffset = srcheight - 1;
 		step_x = -pstep_y;
@@ -299,7 +300,7 @@ bool ClipCopyPixelRect(const FClipRect *cr, int &originx, int &originy,
 		step_y = -pstep_y;
 		break;
 
-	case 7:	// flip horizontally and rotate 90° left
+	case 7:	// flip horizontally and rotate 90� left
 		pixxoffset = 0;
 		pixyoffset = 0;
 		step_x = pstep_y;
@@ -443,7 +444,8 @@ static const CopyPalettedFunc copypalettedfuncs[]=
 	iCopyPaletted<cBGRA, bCopyAlpha>,
 	iCopyPaletted<cBGRA, bCopyNewAlpha>,
 	iCopyPaletted<cBGRA, bOverlay>,
-	iCopyPaletted<cBGRA, bOverwrite>
+	iCopyPaletted<cBGRA, bOverwrite>,
+	iCopyPaletted<cBGRA, bComposeAlpha>
 };
 
 //===========================================================================

diff --git a/src/common/textures/bitmap.h b/src/common/textures/bitmap.h
@@ -424,7 +424,8 @@ enum ECopyOp
 	OP_COPYALPHA,
 	OP_COPYNEWALPHA,
 	OP_OVERLAY,
-	OP_OVERWRITE
+	OP_OVERWRITE,
+	OP_COMPOSEALPHA		// Only intended for internal use.
 };
 
 struct FCopyInfo
@@ -507,5 +508,11 @@ struct bModulate
 	static __forceinline bool ProcessAlpha0() { return false; }
 };
 
+struct bComposeAlpha
+{
+	static __forceinline void OpC(uint8_t &d, uint8_t s, uint8_t a, FCopyInfo *i) { d = (s*a + d*(255-a))/255; }
+	static __forceinline void OpA(uint8_t &d, uint8_t s, FCopyInfo *i) { d = (s*255 + d*(255-s))/255; }
+	static __forceinline bool ProcessAlpha0() { return false; }
+};
 
 #endif