std::unique_ptr<GrFragmentProcessor> SkColor4Shader::asFragmentProcessor(
const GrFPArgs& args) const {
// Construct an xform assuming float inputs. The color space can have a transfer function on
// it, which will be applied below.
auto colorSpaceXform = GrColorSpaceXform::Make(fColorSpace.get(), kRGBA_float_GrPixelConfig,
args.fDstColorSpaceInfo->colorSpace());
GrColor4f color = GrColor4f::FromSkColor4f(fColor4);
if (colorSpaceXform) {
color = colorSpaceXform->clampedXform(color);
}
return GrConstColorProcessor::Make(color.premul(),
GrConstColorProcessor::InputMode::kModulateA);
}
static inline bool skpaint_to_grpaint_impl(GrContext* context,
const GrColorSpaceInfo& colorSpaceInfo,
const SkPaint& skPaint,
const SkMatrix& viewM,
std::unique_ptr<GrFragmentProcessor>* shaderProcessor,
SkBlendMode* primColorMode,
GrPaint* grPaint) {
grPaint->setAllowSRGBInputs(colorSpaceInfo.isGammaCorrect());
// Convert SkPaint color to 4f format, including optional linearizing and gamut conversion.
GrColor4f origColor = SkColorToUnpremulGrColor4f(skPaint.getColor(), colorSpaceInfo);
const GrFPArgs fpArgs(context, &viewM, skPaint.getFilterQuality(), &colorSpaceInfo);
// Setup the initial color considering the shader, the SkPaint color, and the presence or not
// of per-vertex colors.
std::unique_ptr<GrFragmentProcessor> shaderFP;
if (!primColorMode || blend_requires_shader(*primColorMode)) {
if (shaderProcessor) {
shaderFP = std::move(*shaderProcessor);
} else if (const auto* shader = as_SB(skPaint.getShader())) {
shaderFP = shader->asFragmentProcessor(fpArgs);
if (!shaderFP) {
return false;
}
}
}
// Set this in below cases if the output of the shader/paint-color/paint-alpha/primXfermode is
// a known constant value. In that case we can simply apply a color filter during this
// conversion without converting the color filter to a GrFragmentProcessor.
bool applyColorFilterToPaintColor = false;
if (shaderFP) {
if (primColorMode) {
// There is a blend between the primitive color and the shader color. The shader sees
// the opaque paint color. The shader's output is blended using the provided mode by
// the primitive color. The blended color is then modulated by the paint's alpha.
// The geometry processor will insert the primitive color to start the color chain, so
// the GrPaint color will be ignored.
GrColor4f shaderInput = origColor.opaque();
shaderFP = GrFragmentProcessor::OverrideInput(std::move(shaderFP), shaderInput);
shaderFP = GrXfermodeFragmentProcessor::MakeFromSrcProcessor(std::move(shaderFP),
*primColorMode);
// The above may return null if compose results in a pass through of the prim color.
if (shaderFP) {
grPaint->addColorFragmentProcessor(std::move(shaderFP));
}
// We can ignore origColor here - alpha is unchanged by gamma
GrColor paintAlpha = SkColorAlphaToGrColor(skPaint.getColor());
if (GrColor_WHITE != paintAlpha) {
// No gamut conversion - paintAlpha is a (linear) alpha value, splatted to all
// color channels. It's value should be treated as the same in ANY color space.
grPaint->addColorFragmentProcessor(GrConstColorProcessor::Make(
GrColor4f::FromGrColor(paintAlpha),
GrConstColorProcessor::InputMode::kModulateRGBA));
}
} else {
// The shader's FP sees the paint unpremul color
grPaint->setColor4f(origColor);
grPaint->addColorFragmentProcessor(std::move(shaderFP));
}
} else {
if (primColorMode) {
// There is a blend between the primitive color and the paint color. The blend considers
// the opaque paint color. The paint's alpha is applied to the post-blended color.
auto processor = GrConstColorProcessor::Make(origColor.opaque(),
GrConstColorProcessor::InputMode::kIgnore);
processor = GrXfermodeFragmentProcessor::MakeFromSrcProcessor(std::move(processor),
*primColorMode);
if (processor) {
grPaint->addColorFragmentProcessor(std::move(processor));
}
grPaint->setColor4f(origColor.opaque());
// We can ignore origColor here - alpha is unchanged by gamma
GrColor paintAlpha = SkColorAlphaToGrColor(skPaint.getColor());
if (GrColor_WHITE != paintAlpha) {
// No gamut conversion - paintAlpha is a (linear) alpha value, splatted to all
// color channels. It's value should be treated as the same in ANY color space.
grPaint->addColorFragmentProcessor(GrConstColorProcessor::Make(
GrColor4f::FromGrColor(paintAlpha),
GrConstColorProcessor::InputMode::kModulateRGBA));
}
} else {
// No shader, no primitive color.
grPaint->setColor4f(origColor.premul());
applyColorFilterToPaintColor = true;
}
}
SkColorFilter* colorFilter = skPaint.getColorFilter();
if (colorFilter) {
if (applyColorFilterToPaintColor) {
// If we're in legacy mode, we *must* avoid using the 4f version of the color filter,
// because that will combine with the linearized version of the stored color.
if (colorSpaceInfo.isGammaCorrect()) {
grPaint->setColor4f(GrColor4f::FromSkColor4f(
colorFilter->filterColor4f(origColor.toSkColor4f())).premul());
} else {
grPaint->setColor4f(SkColorToPremulGrColor4fLegacy(
colorFilter->filterColor(skPaint.getColor())));
}
} else {
auto cfFP = colorFilter->asFragmentProcessor(context, colorSpaceInfo);
if (cfFP) {
grPaint->addColorFragmentProcessor(std::move(cfFP));
} else {
return false;
}
}
}
SkMaskFilterBase* maskFilter = as_MFB(skPaint.getMaskFilter());
if (maskFilter) {
if (auto mfFP = maskFilter->asFragmentProcessor(fpArgs)) {
grPaint->addCoverageFragmentProcessor(std::move(mfFP));
}
}
// When the xfermode is null on the SkPaint (meaning kSrcOver) we need the XPFactory field on
// the GrPaint to also be null (also kSrcOver).
SkASSERT(!grPaint->getXPFactory());
if (!skPaint.isSrcOver()) {
grPaint->setXPFactory(SkBlendMode_AsXPFactory(skPaint.getBlendMode()));
}
#ifndef SK_IGNORE_GPU_DITHER
// Conservative default, in case GrPixelConfigToColorType() fails.
SkColorType ct = SkColorType::kRGB_565_SkColorType;
GrPixelConfigToColorType(colorSpaceInfo.config(), &ct);
if (SkPaintPriv::ShouldDither(skPaint, ct) && grPaint->numColorFragmentProcessors() > 0 &&
!colorSpaceInfo.isGammaCorrect()) {
auto ditherFP = GrDitherEffect::Make(colorSpaceInfo.config());
if (ditherFP) {
grPaint->addColorFragmentProcessor(std::move(ditherFP));
}
}
#endif
return true;
}