diff options
| author |  reed@google.com <reed@google.com@2bbb7eff-a529-9590-31e7-b0007b416f81> | 2013-02-04 20:06:00 +0000 |
|---|---|---|
| committer | reed@google.com <reed@google.com@2bbb7eff-a529-9590-31e7-b0007b416f81> | 2013-02-04 20:06:00 +0000 |
| commit | 25cfa693420b6da4182bda42ba15970999b840dd (patch) | |
| tree | 53a9fffdad072fab9239130ef3302b426e72104d /src/core/SkXfermode.cpp | |
| parent | 4e5a89570b4ae40e716ab66a139b1d05e0406066 (diff) | |
land https://codereview.appspot.com/7221086/ -- add Multiply xfermode matching CSS spec
git-svn-id: http://skia.googlecode.com/svn/trunk@7553 2bbb7eff-a529-9590-31e7-b0007b416f81
Diffstat (limited to 'src/core/SkXfermode.cpp')
| -rw-r--r-- | src/core/SkXfermode.cpp | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/src/core/SkXfermode.cpp b/src/core/SkXfermode.cpp index 520ab876a6..c0a825cde0 100644 --- a/src/core/SkXfermode.cpp +++ b/src/core/SkXfermode.cpp @@ -191,10 +191,28 @@ static SkPMColor modulate_modeproc(SkPMColor src, SkPMColor dst) { return SkPackARGB32(a, r, g, b); } -// kScreen_Mode static inline int srcover_byte(int a, int b) { return a + b - SkAlphaMulAlpha(a, b); } + +// kMultiply_Mode +// B(Cb, Cs) = Cb x Cs +// multiply uses its own version of blendfunc_byte because sa and da are not needed +static int blendfunc_multiply_byte(int sc, int dc, int sa, int da) { + return clamp_div255round(sc * (255 - da) + dc * (255 - sa) + sc * dc); +} + +static SkPMColor multiply_modeproc(SkPMColor src, SkPMColor dst) { + int sa = SkGetPackedA32(src); + int da = SkGetPackedA32(dst); + int a = srcover_byte(sa, da); + int r = blendfunc_multiply_byte(SkGetPackedR32(src), SkGetPackedR32(dst), sa, da); + int g = blendfunc_multiply_byte(SkGetPackedG32(src), SkGetPackedG32(dst), sa, da); + int b = blendfunc_multiply_byte(SkGetPackedB32(src), SkGetPackedB32(dst), sa, da); + return SkPackARGB32(a, r, g, b); +} + +// kScreen_Mode static SkPMColor screen_modeproc(SkPMColor src, SkPMColor dst) { int a = srcover_byte(SkGetPackedA32(src), SkGetPackedA32(dst)); int r = srcover_byte(SkGetPackedR32(src), SkGetPackedR32(dst)); @@ -447,6 +465,7 @@ static const ProcCoeff gProcCoeffs[] = { { softlight_modeproc, CANNOT_USE_COEFF, CANNOT_USE_COEFF }, { difference_modeproc, CANNOT_USE_COEFF, CANNOT_USE_COEFF }, { exclusion_modeproc, CANNOT_USE_COEFF, CANNOT_USE_COEFF }, + { multiply_modeproc, CANNOT_USE_COEFF, CANNOT_USE_COEFF }, }; /////////////////////////////////////////////////////////////////////////////// |