bool GrPorterDuffXPFactory::SrcOverWillNeedDstTexture(const GrCaps& caps,
const GrPipelineOptimizations& optimizations) {
if (caps.shaderCaps()->dstReadInShaderSupport() ||
caps.shaderCaps()->dualSourceBlendingSupport()) {
return false;
}
// When we have four channel coverage we always need to read the dst in order to correctly
// blend. The one exception is when we are using srcover mode and we know the input color
// into the XP.
if (optimizations.fCoveragePOI.isFourChannelOutput()) {
if (kRGBA_GrColorComponentFlags == optimizations.fColorPOI.validFlags() &&
!caps.shaderCaps()->dstReadInShaderSupport()) {
return false;
}
return get_lcd_blend_formula(optimizations.fCoveragePOI,
SkBlendMode::kSrcOver).hasSecondaryOutput();
}
// We fallback on the shader XP when the blend formula would use dual source blending but we
// don't have support for it.
static const bool kHasMixedSamples = false;
SkASSERT(!caps.usesMixedSamples()); // We never use mixed samples without dual source blending.
return get_blend_formula(optimizations.fColorPOI, optimizations.fCoveragePOI,
kHasMixedSamples, SkBlendMode::kSrcOver).hasSecondaryOutput();
}
GrXferProcessor*
GrPorterDuffXPFactory::onCreateXferProcessor(const GrCaps& caps,
const GrPipelineOptimizations& optimizations,
bool hasMixedSamples,
const DstTexture* dstTexture) const {
if (optimizations.fOverrides.fUsePLSDstRead) {
return new ShaderPDXferProcessor(dstTexture, hasMixedSamples, fXfermode);
}
BlendFormula blendFormula;
if (optimizations.fCoveragePOI.isFourChannelOutput()) {
if (SkBlendMode::kSrcOver == fXfermode &&
kRGBA_GrColorComponentFlags == optimizations.fColorPOI.validFlags() &&
!caps.shaderCaps()->dualSourceBlendingSupport() &&
!caps.shaderCaps()->dstReadInShaderSupport()) {
// If we don't have dual source blending or in shader dst reads, we fall back to this
// trick for rendering SrcOver LCD text instead of doing a dst copy.
SkASSERT(!dstTexture || !dstTexture->texture());
return PDLCDXferProcessor::Create(fXfermode, optimizations.fColorPOI);
}
blendFormula = get_lcd_blend_formula(optimizations.fCoveragePOI, fXfermode);
} else {
blendFormula = get_blend_formula(optimizations.fColorPOI, optimizations.fCoveragePOI,
hasMixedSamples, fXfermode);
}
if (blendFormula.hasSecondaryOutput() && !caps.shaderCaps()->dualSourceBlendingSupport()) {
return new ShaderPDXferProcessor(dstTexture, hasMixedSamples, fXfermode);
}
SkASSERT(!dstTexture || !dstTexture->texture());
return new PorterDuffXferProcessor(blendFormula);
}
GrXferProcessor*
GrPorterDuffXPFactory::onCreateXferProcessor(const GrCaps& caps,
const GrProcOptInfo& colorPOI,
const GrProcOptInfo& covPOI,
bool hasMixedSamples,
const DstTexture* dstTexture) const {
BlendFormula blendFormula;
if (covPOI.isFourChannelOutput()) {
if (SkXfermode::kSrcOver_Mode == fXfermode &&
kRGBA_GrColorComponentFlags == colorPOI.validFlags()) {
SkASSERT(!dstTexture || !dstTexture->texture());
return PDLCDXferProcessor::Create(fXfermode, colorPOI);
}
blendFormula = get_lcd_blend_formula(covPOI, fXfermode);
} else {
blendFormula = get_blend_formula(colorPOI, covPOI, hasMixedSamples, fXfermode);
}
if (blendFormula.hasSecondaryOutput() && !caps.shaderCaps()->dualSourceBlendingSupport()) {
return new ShaderPDXferProcessor(dstTexture, hasMixedSamples, fXfermode);
}
SkASSERT(!dstTexture || !dstTexture->texture());
return new PorterDuffXferProcessor(blendFormula);
}
GrXferProcessor* GrPorterDuffXPFactory::CreateSrcOverXferProcessor(
const GrCaps& caps,
const GrPipelineOptimizations& optimizations,
bool hasMixedSamples,
const GrXferProcessor::DstTexture* dstTexture) {
if (optimizations.fOverrides.fUsePLSDstRead) {
return new ShaderPDXferProcessor(dstTexture, hasMixedSamples, SkBlendMode::kSrcOver);
}
// We want to not make an xfer processor if possible. Thus for the simple case where we are not
// doing lcd blending we will just use our global SimpleSrcOverXP. This slightly differs from
// the general case where we convert a src-over blend that has solid coverage and an opaque
// color to src-mode, which allows disabling of blending.
if (!optimizations.fCoveragePOI.isFourChannelOutput()) {
// We return nullptr here, which our caller interprets as meaning "use SimpleSrcOverXP".
// We don't simply return the address of that XP here because our caller would have to unref
// it and since it is a global object and GrProgramElement's ref-cnting system is not thread
// safe.
return nullptr;
}
if (kRGBA_GrColorComponentFlags == optimizations.fColorPOI.validFlags() &&
!caps.shaderCaps()->dualSourceBlendingSupport() &&
!caps.shaderCaps()->dstReadInShaderSupport()) {
// If we don't have dual source blending or in shader dst reads, we fall
// back to this trick for rendering SrcOver LCD text instead of doing a
// dst copy.
SkASSERT(!dstTexture || !dstTexture->texture());
return PDLCDXferProcessor::Create(SkBlendMode::kSrcOver, optimizations.fColorPOI);
}
BlendFormula blendFormula;
blendFormula = get_lcd_blend_formula(optimizations.fCoveragePOI, SkBlendMode::kSrcOver);
if (blendFormula.hasSecondaryOutput() && !caps.shaderCaps()->dualSourceBlendingSupport()) {
return new ShaderPDXferProcessor(dstTexture, hasMixedSamples, SkBlendMode::kSrcOver);
}
SkASSERT(!dstTexture || !dstTexture->texture());
return new PorterDuffXferProcessor(blendFormula);
}
bool GrPorterDuffXPFactory::willReadDstColor(const GrCaps& caps,
const GrProcOptInfo& colorPOI,
const GrProcOptInfo& covPOI,
bool hasMixedSamples) const {
if (caps.shaderCaps()->dualSourceBlendingSupport()) {
return false;
}
// When we have four channel coverage we always need to read the dst in order to correctly
// blend. The one exception is when we are using srcover mode and we know the input color into
// the XP.
if (covPOI.isFourChannelOutput()) {
if (SkXfermode::kSrcOver_Mode == fXfermode &&
kRGBA_GrColorComponentFlags == colorPOI.validFlags()) {
return false;
}
return get_lcd_blend_formula(covPOI, fXfermode).hasSecondaryOutput();
}
// We fallback on the shader XP when the blend formula would use dual source blending but we
// don't have support for it.
return get_blend_formula(colorPOI, covPOI, hasMixedSamples, fXfermode).hasSecondaryOutput();
}
