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comparison: gfx/cairo/gdi-RGB24-ARGB32.patch
gfx/cairo/gdi-RGB24-ARGB32.patch
- changeset 0
- 6474c204b198
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| -1:000000000000 | 0:5a4da10a61a4 |
|---|---|
| 1 changeset: 106848:28db6dbdd9ea | |
| 2 tag: gdi-patch | |
| 3 tag: qbase | |
| 4 tag: qtip | |
| 5 tag: tip | |
| 6 user: Jeff Muizelaar <jmuizelaar@mozilla.com> | |
| 7 date: Wed Sep 12 22:52:06 2012 -0400 | |
| 8 summary: Bug 788794. Use BitBlt to do SOURCE and OVER from RGB24 to ARGB32. r=nical | |
| 9 | |
| 10 diff --git a/gfx/cairo/cairo/src/cairo-win32-surface.c b/gfx/cairo/cairo/src/cairo-win32-surface.c | |
| 11 --- a/gfx/cairo/cairo/src/cairo-win32-surface.c | |
| 12 +++ b/gfx/cairo/cairo/src/cairo-win32-surface.c | |
| 13 @@ -884,16 +884,28 @@ static cairo_int_status_t | |
| 14 src_x, src_y, | |
| 15 src_w, src_h, | |
| 16 blend_function)) | |
| 17 return _cairo_win32_print_gdi_error ("_cairo_win32_surface_composite(AlphaBlend)"); | |
| 18 | |
| 19 return CAIRO_STATUS_SUCCESS; | |
| 20 } | |
| 21 | |
| 22 +/* makes the alpha channel in a RGB24 surface 0xff */ | |
| 23 +static void | |
| 24 +make_opaque (cairo_image_surface_t *image, cairo_rectangle_int_t src_r) | |
| 25 +{ | |
| 26 + int x; int y; | |
| 27 + for (y = src_r.y; y < src_r.height; y++) { | |
| 28 + for (x = src_r.x; x < src_r.width; x++) { | |
| 29 + image->data[y * image->stride + x*4 + 3] = 0xff; | |
| 30 + } | |
| 31 + } | |
| 32 +} | |
| 33 + | |
| 34 static cairo_int_status_t | |
| 35 _cairo_win32_surface_composite_inner (cairo_win32_surface_t *src, | |
| 36 cairo_image_surface_t *src_image, | |
| 37 cairo_win32_surface_t *dst, | |
| 38 cairo_rectangle_int_t src_extents, | |
| 39 cairo_rectangle_int_t src_r, | |
| 40 cairo_rectangle_int_t dst_r, | |
| 41 int alpha, | |
| 42 @@ -935,16 +947,24 @@ static cairo_int_status_t | |
| 43 src_r.width, - (int) src_r.height, | |
| 44 src_image->data, | |
| 45 &bi, | |
| 46 DIB_RGB_COLORS, | |
| 47 SRCCOPY)) | |
| 48 return _cairo_win32_print_gdi_error ("_cairo_win32_surface_composite(StretchDIBits)"); | |
| 49 } | |
| 50 } else if (!needs_alpha) { | |
| 51 + if (src->format == CAIRO_FORMAT_RGB24 && dst->format == CAIRO_FORMAT_ARGB32) { | |
| 52 + /* Because we store RGB24 & ARGB32 in the same way GDI has no way | |
| 53 + * to ignore the alpha channel from a RGB24 source. Therefore, we set | |
| 54 + * the alpha channel in our RGB24 source to opaque so that we can treat | |
| 55 + * it like ARGB32. */ | |
| 56 + GdiFlush(); | |
| 57 + make_opaque(src->image, src_r); | |
| 58 + } | |
| 59 /* BitBlt or StretchBlt? */ | |
| 60 if (!needs_scale && (dst->flags & CAIRO_WIN32_SURFACE_CAN_BITBLT)) { | |
| 61 if (!BitBlt (dst->dc, | |
| 62 dst_r.x, dst_r.y, | |
| 63 dst_r.width, dst_r.height, | |
| 64 src->dc, | |
| 65 src_r.x, src_r.y, | |
| 66 SRCCOPY)) | |
| 67 @@ -1184,28 +1204,36 @@ static cairo_int_status_t | |
| 68 } | |
| 69 } else { | |
| 70 needs_repeat = TRUE; | |
| 71 } | |
| 72 | |
| 73 /* | |
| 74 * Operations that we can do: | |
| 75 * | |
| 76 + * AlphaBlend uses the following formula for alpha when not use the per-pixel alpha (AlphaFormat = 0) | |
| 77 + * Dst.Alpha = Src.Alpha * (SCA/255.0) + Dst.Alpha * (1.0 - (SCA/255.0)) | |
| 78 + * This turns into Dst.Alpha = Src.Alpha when SCA = 255. | |
| 79 + * (http://msdn.microsoft.com/en-us/library/aa921335.aspx) | |
| 80 + * | |
| 81 * RGB OVER RGB -> BitBlt (same as SOURCE) | |
| 82 - * RGB OVER ARGB -> UNSUPPORTED (AlphaBlend treats this as a BitBlt, even with SCA 255 and no AC_SRC_ALPHA) | |
| 83 + * RGB OVER ARGB -> Partially supported, We convert this operation into a ARGB SOURCE ARGB | |
| 84 + * by setting the alpha values of the source to 255. | |
| 85 * ARGB OVER ARGB -> AlphaBlend, with AC_SRC_ALPHA | |
| 86 * ARGB OVER RGB -> AlphaBlend, with AC_SRC_ALPHA; we'll have junk in the dst A byte | |
| 87 * | |
| 88 * RGB OVER RGB + mask -> AlphaBlend, no AC_SRC_ALPHA | |
| 89 - * RGB OVER ARGB + mask -> UNSUPPORTED | |
| 90 + * RGB OVER ARGB + mask -> Partially supported, We convert this operation into a ARGB OVER ARGB + mask | |
| 91 + * by setting the alpha values of the source to 255. | |
| 92 * ARGB OVER ARGB + mask -> AlphaBlend, with AC_SRC_ALPHA | |
| 93 * ARGB OVER RGB + mask -> AlphaBlend, with AC_SRC_ALPHA; junk in the dst A byte | |
| 94 * | |
| 95 * RGB SOURCE RGB -> BitBlt | |
| 96 - * RGB SOURCE ARGB -> UNSUPPORTED (AlphaBlend treats this as a BitBlt, even with SCA 255 and no AC_SRC_ALPHA) | |
| 97 + * RGB SOURCE ARGB -> Partially supported, We convert this operation into a ARGB SOURCE ARGB | |
| 98 + * by setting the alpha values of the source to 255. | |
| 99 * ARGB SOURCE ARGB -> BitBlt | |
| 100 * ARGB SOURCE RGB -> BitBlt | |
| 101 * | |
| 102 * RGB SOURCE RGB + mask -> unsupported | |
| 103 * RGB SOURCE ARGB + mask -> unsupported | |
| 104 * ARGB SOURCE ARGB + mask -> unsupported | |
| 105 * ARGB SOURCE RGB + mask -> unsupported | |
| 106 */ | |
| 107 @@ -1222,22 +1250,32 @@ static cairo_int_status_t | |
| 108 needs_alpha = FALSE; | |
| 109 } else { | |
| 110 needs_alpha = TRUE; | |
| 111 } | |
| 112 } else if (src_format == CAIRO_FORMAT_ARGB32 && | |
| 113 dst->format == CAIRO_FORMAT_RGB24) | |
| 114 { | |
| 115 needs_alpha = TRUE; | |
| 116 + } else if (src_format == CAIRO_FORMAT_RGB24 && | |
| 117 + dst->format == CAIRO_FORMAT_ARGB32 && | |
| 118 + src->image) | |
| 119 + { | |
| 120 + if (alpha == 255) { | |
| 121 + needs_alpha = FALSE; | |
| 122 + } else { | |
| 123 + needs_alpha = TRUE; | |
| 124 + } | |
| 125 } else { | |
| 126 goto UNSUPPORTED; | |
| 127 } | |
| 128 } else if (alpha == 255 && op == CAIRO_OPERATOR_SOURCE) { | |
| 129 if ((src_format == dst->format) || | |
| 130 - (src_format == CAIRO_FORMAT_ARGB32 && dst->format == CAIRO_FORMAT_RGB24)) | |
| 131 + (src_format == CAIRO_FORMAT_ARGB32 && dst->format == CAIRO_FORMAT_RGB24) || | |
| 132 + (src_format == CAIRO_FORMAT_RGB24 && dst->format == CAIRO_FORMAT_ARGB32 && src->image)) | |
| 133 { | |
| 134 needs_alpha = FALSE; | |
| 135 } else { | |
| 136 goto UNSUPPORTED; | |
| 137 } | |
| 138 } else { | |
| 139 goto UNSUPPORTED; | |
| 140 } | |
| 141 |
