[YAROTOWS] Reintegrate the branch. For a brighter future.
[reactos.git] / reactos / subsystems / win32 / win32k / dib / alphablend.c
1 /*
2 * PROJECT: Win32 subsystem
3 * LICENSE: See COPYING in the top level directory
4 * FILE: subsystems/win32/win32k/dib/stretchblt.c
5 * PURPOSE: AlphaBlend implementation suitable for all bit depths
6 * PROGRAMMERS: Jérôme Gardou
7 */
8
9 #include <win32k.h>
10
11 #define NDEBUG
12 #include <debug.h>
13
14 typedef union
15 {
16 ULONG ul;
17 struct
18 {
19 UCHAR red;
20 UCHAR green;
21 UCHAR blue;
22 UCHAR alpha;
23 } col;
24 } NICEPIXEL32;
25
26 static __inline UCHAR
27 Clamp8(ULONG val)
28 {
29 return (val > 255) ? 255 : val;
30 }
31
32 BOOLEAN
33 DIB_XXBPP_AlphaBlend(SURFOBJ* Dest, SURFOBJ* Source, RECTL* DestRect,
34 RECTL* SourceRect, CLIPOBJ* ClipRegion,
35 XLATEOBJ* ColorTranslation, BLENDOBJ* BlendObj)
36 {
37 INT DstX, DstY, SrcX, SrcY;
38 BLENDFUNCTION BlendFunc;
39 register NICEPIXEL32 DstPixel32;
40 register NICEPIXEL32 SrcPixel32;
41 UCHAR Alpha, SrcBpp = BitsPerFormat(Source->iBitmapFormat);
42 EXLATEOBJ* pexlo;
43 EXLATEOBJ exloSrcRGB, exloDstRGB, exloRGBSrc;
44 PFN_DIB_PutPixel pfnDibPutPixel = DibFunctionsForBitmapFormat[Dest->iBitmapFormat].DIB_PutPixel;
45
46 DPRINT("DIB_16BPP_AlphaBlend: srcRect: (%d,%d)-(%d,%d), dstRect: (%d,%d)-(%d,%d)\n",
47 SourceRect->left, SourceRect->top, SourceRect->right, SourceRect->bottom,
48 DestRect->left, DestRect->top, DestRect->right, DestRect->bottom);
49
50 BlendFunc = BlendObj->BlendFunction;
51 if (BlendFunc.BlendOp != AC_SRC_OVER)
52 {
53 DPRINT1("BlendOp != AC_SRC_OVER\n");
54 return FALSE;
55 }
56 if (BlendFunc.BlendFlags != 0)
57 {
58 DPRINT1("BlendFlags != 0\n");
59 return FALSE;
60 }
61 if ((BlendFunc.AlphaFormat & ~AC_SRC_ALPHA) != 0)
62 {
63 DPRINT1("Unsupported AlphaFormat (0x%x)\n", BlendFunc.AlphaFormat);
64 return FALSE;
65 }
66 if ((BlendFunc.AlphaFormat & AC_SRC_ALPHA) != 0 &&
67 SrcBpp != 32)
68 {
69 DPRINT1("Source bitmap must be 32bpp when AC_SRC_ALPHA is set\n");
70 return FALSE;
71 }
72
73 if (!ColorTranslation)
74 {
75 DPRINT1("ColorTranslation must not be NULL!\n");
76 return FALSE;
77 }
78
79 pexlo = CONTAINING_RECORD(ColorTranslation, EXLATEOBJ, xlo);
80 EXLATEOBJ_vInitialize(&exloSrcRGB, pexlo->ppalSrc, &gpalRGB, 0, 0, 0);
81 EXLATEOBJ_vInitialize(&exloDstRGB, pexlo->ppalDst, &gpalRGB, 0, 0, 0);
82 EXLATEOBJ_vInitialize(&exloRGBSrc, &gpalRGB, pexlo->ppalSrc, 0, 0, 0);
83
84 SrcY = SourceRect->top;
85 DstY = DestRect->top;
86 while ( DstY < DestRect->bottom )
87 {
88 SrcX = SourceRect->left;
89 DstX = DestRect->left;
90 while(DstX < DestRect->right)
91 {
92 SrcPixel32.ul = DIB_GetSource(Source, SrcX, SrcY, &exloSrcRGB.xlo);
93 SrcPixel32.col.red = (SrcPixel32.col.red * BlendFunc.SourceConstantAlpha) / 255;
94 SrcPixel32.col.green = (SrcPixel32.col.green * BlendFunc.SourceConstantAlpha) / 255;
95 SrcPixel32.col.blue = (SrcPixel32.col.blue * BlendFunc.SourceConstantAlpha) / 255;
96
97 Alpha = ((BlendFunc.AlphaFormat & AC_SRC_ALPHA) != 0) ?
98 (SrcPixel32.col.alpha * BlendFunc.SourceConstantAlpha) / 255 :
99 BlendFunc.SourceConstantAlpha ;
100
101 DstPixel32.ul = DIB_GetSource(Dest, DstX, DstY, &exloDstRGB.xlo);
102 DstPixel32.col.red = Clamp8((DstPixel32.col.red * (255 - Alpha)) / 255 + SrcPixel32.col.red) ;
103 DstPixel32.col.green = Clamp8((DstPixel32.col.green * (255 - Alpha)) / 255 + SrcPixel32.col.green) ;
104 DstPixel32.col.blue = Clamp8((DstPixel32.col.blue * (255 - Alpha)) / 255 + SrcPixel32.col.blue) ;
105 DstPixel32.ul = XLATEOBJ_iXlate(&exloRGBSrc.xlo, DstPixel32.ul);
106 pfnDibPutPixel(Dest, DstX, DstY, XLATEOBJ_iXlate(ColorTranslation, DstPixel32.ul));
107
108 DstX++;
109 SrcX = SourceRect->left + ((DstX-DestRect->left)*(SourceRect->right - SourceRect->left))
110 /(DestRect->right-DestRect->left);
111 }
112 DstY++;
113 SrcY = SourceRect->top + ((DstY-DestRect->top)*(SourceRect->bottom - SourceRect->top))
114 /(DestRect->bottom-DestRect->top);
115 }
116
117 EXLATEOBJ_vCleanup(&exloDstRGB);
118 EXLATEOBJ_vCleanup(&exloRGBSrc);
119 EXLATEOBJ_vCleanup(&exloSrcRGB);
120
121 return TRUE;
122 }
123