static MaskedColor get_term(GrBlendCoeff coeff, const MaskedColor& src, const MaskedColor& dst,
const MaskedColor& value) {
switch (coeff) {
case kZero_GrBlendCoeff:
return MaskedColor(0, kRGBA_GrColorComponentFlags);
case kOne_GrBlendCoeff:
return value;
case kDC_GrBlendCoeff:
return MaskedColor::Mul(dst, value);
case kIDC_GrBlendCoeff:
return MaskedColor::Mul(MaskedColor::Invert(dst), value);
case kDA_GrBlendCoeff:
return MaskedColor::Mul(MaskedColor::ExtractAlpha(dst), value);
case kIDA_GrBlendCoeff:
return MaskedColor::Mul(MaskedColor::ExtractInverseAlpha(dst), value);
case kSC_GrBlendCoeff:
return MaskedColor::Mul(src, value);
case kISC_GrBlendCoeff:
return MaskedColor::Mul(MaskedColor::Invert(src), value);
case kSA_GrBlendCoeff:
return MaskedColor::Mul(MaskedColor::ExtractAlpha(src), value);
case kISA_GrBlendCoeff:
return MaskedColor::Mul(MaskedColor::ExtractInverseAlpha(src), value);
default:
SK_ABORT("Illegal coefficient");
return MaskedColor();
}
}
AlphaFont::AlphaFont( const char *alpha_image, const char *font_desc )
:FacedFont( MaskedColor(alpha_image), font_desc ),
_opacity(1.0), _back_opacity(0.0), _back_color(0xFFFFFF)
{
_color = 0xFFFFFF;
}
static MaskedColor ExtractInverseAlpha(const MaskedColor& in) {
GrColorComponentFlags flags = (in.fFlags & kA_GrColorComponentFlag) ?
kRGBA_GrColorComponentFlags : kNone_GrColorComponentFlags;
return MaskedColor(GrColorPackA4(0xFF - GrColorUnpackA(in.fColor)), flags);
}
static MaskedColor SatAdd(const MaskedColor& a, const MaskedColor& b) {
GrColorComponentFlags outFlags = (a.fFlags & b.fFlags) | a.componentsWithValue(0xFF) |
b.componentsWithValue(0xFF);
return MaskedColor(GrColorSatAdd(a.fColor, b.fColor), outFlags);
}
static MaskedColor Invert(const MaskedColor& in) {
return MaskedColor(GrInvertColor(in.fColor), in.fFlags);
}
