diff options
Diffstat (limited to 'skia/sgl/SkXfermode.cpp')
| -rw-r--r-- | skia/sgl/SkXfermode.cpp | 29 |
1 files changed, 24 insertions, 5 deletions
diff --git a/skia/sgl/SkXfermode.cpp b/skia/sgl/SkXfermode.cpp index e8a202d..1b2479f 100644 --- a/skia/sgl/SkXfermode.cpp +++ b/skia/sgl/SkXfermode.cpp @@ -43,6 +43,16 @@ static U8CPU mulmuldiv255round(U8CPU a, U8CPU b, U8CPU c, U8CPU d) { return result; } +static unsigned saturated_add(unsigned a, unsigned b) { + SkASSERT(a <= 255); + SkASSERT(b <= 255); + unsigned sum = a + b; + if (sum > 255) { + sum = 255; + } + return sum; +} + /////////////////////////////////////////////////////////////////////////////// bool SkXfermode::asCoeff(Coeff* src, Coeff* dst) { @@ -495,6 +505,14 @@ static SkPMColor screen_modeproc(SkPMColor src, SkPMColor dst) { return SkPackARGB32(a, r, g, b); } +static SkPMColor add_modeproc(SkPMColor src, SkPMColor dst) { + unsigned a = saturated_add(SkGetPackedA32(src), SkGetPackedA32(dst)); + unsigned r = saturated_add(SkGetPackedR32(src), SkGetPackedR32(dst)); + unsigned g = saturated_add(SkGetPackedG32(src), SkGetPackedG32(dst)); + unsigned b = saturated_add(SkGetPackedB32(src), SkGetPackedB32(dst)); + return SkPackARGB32(a, r, g, b); +} + /////////////////////////////////////////////////////////////////////////////// class SkClearXfermode : public SkProcCoeffXfermode { @@ -696,6 +714,8 @@ struct ProcCoeff { SkXfermode::Coeff fDC; }; +#define CANNOT_USE_COEFF SkXfermode::Coeff(-1) + static const ProcCoeff gProcCoeffs[] = { { clear_modeproc, SkXfermode::kZero_Coeff, SkXfermode::kZero_Coeff }, { src_modeproc, SkXfermode::kOne_Coeff, SkXfermode::kZero_Coeff }, @@ -709,12 +729,11 @@ static const ProcCoeff gProcCoeffs[] = { { srcatop_modeproc, SkXfermode::kDA_Coeff, SkXfermode::kISA_Coeff }, { dstatop_modeproc, SkXfermode::kIDA_Coeff, SkXfermode::kSA_Coeff }, { xor_modeproc, SkXfermode::kIDA_Coeff, SkXfermode::kISA_Coeff }, - // these two can't be represented as coefficients - { darken_modeproc, SkXfermode::Coeff(-1), SkXfermode::Coeff(-1) }, - { lighten_modeproc, SkXfermode::Coeff(-1), SkXfermode::Coeff(-1) }, - // these can use coefficients + { darken_modeproc, CANNOT_USE_COEFF, CANNOT_USE_COEFF }, + { lighten_modeproc, CANNOT_USE_COEFF, CANNOT_USE_COEFF }, { mult_modeproc, SkXfermode::kZero_Coeff, SkXfermode::kSC_Coeff }, - { screen_modeproc, SkXfermode::kOne_Coeff, SkXfermode::kISC_Coeff } + { screen_modeproc, SkXfermode::kOne_Coeff, SkXfermode::kISC_Coeff }, + { add_modeproc, CANNOT_USE_COEFF, CANNOT_USE_COEFF } }; SkXfermode* SkPorterDuff::CreateXfermode(SkPorterDuff::Mode mode) { |