- Revert 49927 "Update to trunk" as it breaks KsStudio (again)

[reactos.git] / subsystems / win32 / win32k / dib / dib24bpp.c

diff --git a/subsystems/win32/win32k/dib/dib24bpp.c b/subsystems/win32/win32k/dib/dib24bpp.c
index 0642862..3810024 100644 (file)
--- a/subsystems/win32/win32k/dib/dib24bpp.c
+++ b/subsystems/win32/win32k/dib/dib24bpp.c
@@ -37,7 +37,7 @@ DIB_24BPP_VLine(SURFOBJ *SurfObj, LONG x, LONG y1, LONG y2, ULONG c)
   LONG lDelta = SurfObj->lDelta;
 
   c &= 0xFFFFFF;
-  while(y1++ < y2)
+  while(y1++ < y2) 
   {
     *(PUSHORT)(addr) = c & 0xFFFF;
     *(addr + 2) = c >> 16;
@@ -466,6 +466,7 @@ DIB_24BPP_AlphaBlend(SURFOBJ* Dest, SURFOBJ* Source, RECTL* DestRect,
 {
    INT Rows, Cols, SrcX, SrcY;
    register PUCHAR Dst;
+   ULONG DstDelta;
    BLENDFUNCTION BlendFunc;
    register NICEPIXEL32 DstPixel, SrcPixel;
    UCHAR Alpha, SrcBpp;
@@ -474,6 +475,9 @@ DIB_24BPP_AlphaBlend(SURFOBJ* Dest, SURFOBJ* Source, RECTL* DestRect,
           SourceRect->left, SourceRect->top, SourceRect->right, SourceRect->bottom,
           DestRect->left, DestRect->top, DestRect->right, DestRect->bottom);
 
+   ASSERT(DestRect->bottom - DestRect->top == SourceRect->bottom - SourceRect->top &&
+          DestRect->right - DestRect->left == SourceRect->right - SourceRect->left);
+
    BlendFunc = BlendObj->BlendFunction;
    if (BlendFunc.BlendOp != AC_SRC_OVER)
    {
@@ -499,41 +503,39 @@ DIB_24BPP_AlphaBlend(SURFOBJ* Dest, SURFOBJ* Source, RECTL* DestRect,
 
    Dst = (PUCHAR)((ULONG_PTR)Dest->pvScan0 + (DestRect->top * Dest->lDelta) +
                              (DestRect->left * 3));
+   DstDelta = Dest->lDelta - ((DestRect->right - DestRect->left) * 3);
    SrcBpp = BitsPerFormat(Source->iBitmapFormat);
 
-   Rows = 0;
+   Rows = DestRect->bottom - DestRect->top;
    SrcY = SourceRect->top;
-   while (++Rows <= DestRect->bottom - DestRect->top)
-  {
-    Cols = 0;
-    SrcX = SourceRect->left;
-    while (++Cols <= DestRect->right - DestRect->left)
-    {
-      SrcPixel.ul = DIB_GetSource(Source, SrcX, SrcY, ColorTranslation);
-      SrcPixel.col.red = (SrcPixel.col.red * BlendFunc.SourceConstantAlpha) / 255;
-      SrcPixel.col.green = (SrcPixel.col.green * BlendFunc.SourceConstantAlpha) / 255;
-      SrcPixel.col.blue = (SrcPixel.col.blue * BlendFunc.SourceConstantAlpha) / 255;
-      if (!(BlendFunc.AlphaFormat & AC_SRC_ALPHA))
-      {
-          Alpha = BlendFunc.SourceConstantAlpha ;
-      }
-      else
+   while (--Rows >= 0)
+   {
+      Cols = DestRect->right - DestRect->left;
+      SrcX = SourceRect->left;
+      while (--Cols >= 0)
       {
-        Alpha = (SrcPixel.col.alpha * BlendFunc.SourceConstantAlpha) / 255;
+         SrcPixel.ul = DIB_GetSource(Source, SrcX++, SrcY, ColorTranslation);
+         SrcPixel.col.red = SrcPixel.col.red * BlendFunc.SourceConstantAlpha / 255;
+         SrcPixel.col.green = SrcPixel.col.green * BlendFunc.SourceConstantAlpha / 255;
+         SrcPixel.col.blue = SrcPixel.col.blue * BlendFunc.SourceConstantAlpha / 255;
+         SrcPixel.col.alpha = (SrcBpp == 32) ? (SrcPixel.col.alpha * BlendFunc.SourceConstantAlpha / 255) : BlendFunc.SourceConstantAlpha;
+
+         Alpha = ((BlendFunc.AlphaFormat & AC_SRC_ALPHA) != 0) ?
+                 SrcPixel.col.alpha : BlendFunc.SourceConstantAlpha;
+
+         /* copy only 24bits of dst */
+         DstPixel.ul = *(PUSHORT)(Dst) + (*(Dst+2) << 16);
+         DstPixel.col.red = Clamp8(DstPixel.col.red * (255 - Alpha) / 255 + SrcPixel.col.red);
+         DstPixel.col.green = Clamp8(DstPixel.col.green * (255 - Alpha) / 255 + SrcPixel.col.green);
+         DstPixel.col.blue = Clamp8(DstPixel.col.blue * (255 - Alpha) / 255 + SrcPixel.col.blue);
+         /* copy back 24bits of result */
+         *(PUSHORT)(Dst) = (USHORT)(DstPixel.ul & 0xFFFF);
+         *(Dst + 2) = (UCHAR)((DstPixel.ul >> 16) & 0xFF);
+         Dst = (PUCHAR)((ULONG_PTR)Dst + 3);
       }
-
-      DstPixel.col.red = Clamp8((*Dst * (255 - Alpha)) / 255 + SrcPixel.col.red) ;
-      DstPixel.col.green = Clamp8((*(Dst+1) * (255 - Alpha) / 255 + SrcPixel.col.green)) ;
-      DstPixel.col.blue = Clamp8((*(Dst+2) * (255 - Alpha)) / 255 + SrcPixel.col.blue) ;
-      *Dst++ = DstPixel.col.red;
-      *Dst++ = DstPixel.col.green;
-      *Dst++ = DstPixel.col.blue;
-      SrcX = SourceRect->left + (Cols*(SourceRect->right - SourceRect->left))/(DestRect->right - DestRect->left);
-    }
-    Dst = (PUCHAR)((ULONG_PTR)Dest->pvScan0 + ((DestRect->top + Rows) * Dest->lDelta) +
-                (DestRect->left*3));
-    SrcY = SourceRect->top + (Rows*(SourceRect->bottom - SourceRect->top))/(DestRect->bottom - DestRect->top);
-  }
+      Dst = (PUCHAR)((ULONG_PTR)Dst + DstDelta);
+      SrcY++;
+   }
 
    return TRUE;
 }