const char* GrGLSLFragmentShaderBuilder::dstColor() {
fHasReadDstColor = true;
const char* override = fProgramBuilder->primitiveProcessor().getDestColorOverride();
if (override != nullptr) {
return override;
}
const GrGLSLCaps* glslCaps = fProgramBuilder->glslCaps();
if (glslCaps->fbFetchSupport()) {
this->addFeature(1 << kFramebufferFetch_GLSLPrivateFeature,
glslCaps->fbFetchExtensionString());
// Some versions of this extension string require declaring custom color output on ES 3.0+
const char* fbFetchColorName = glslCaps->fbFetchColorName();
if (glslCaps->fbFetchNeedsCustomOutput()) {
this->enableCustomOutput();
fOutputs[fCustomColorOutputIndex].setTypeModifier(GrShaderVar::kInOut_TypeModifier);
fbFetchColorName = DeclaredColorOutputName();
}
return fbFetchColorName;
} else {
return kDstTextureColorName;
}
}
void GrGLSLFragmentShaderBuilder::enableCustomOutput() {
if (!fHasCustomColorOutput) {
fHasCustomColorOutput = true;
fCustomColorOutputIndex = fOutputs.count();
fOutputs.push_back().set(kVec4f_GrSLType,
GrGLSLShaderVar::kOut_TypeModifier,
DeclaredColorOutputName());
}
}
const char* GrGLSLFragmentShaderBuilder::getPrimaryColorOutputName() const {
return fHasCustomColorOutput ? DeclaredColorOutputName() : "gl_FragColor";
}
