// TODO Processors cannot output zeros because an empty string is all 1s
// the fix is to allow effects to take the GrGLSLExpr4 directly
void GrGLProgramBuilder::emitAndInstallProc(const GrFragmentProcessor& fp,
int index,
const GrGLSLExpr4& input,
GrGLSLExpr4* output) {
// Program builders have a bit of state we need to clear with each effect
AutoStageAdvance adv(this);
this->nameExpression(output, "output");
// Enclose custom code in a block to avoid namespace conflicts
SkString openBrace;
openBrace.printf("{ // Stage %d, %s\n", fStageIndex, fp.name());
fFS.codeAppend(openBrace.c_str());
this->emitAndInstallProc(fp, index, output->c_str(), input.isOnes() ? nullptr : input.c_str());
fFS.codeAppend("}");
}
void GrGLShaderBuilder::createAndEmitEffects(GrGLProgramEffectsBuilder* programEffectsBuilder,
const GrEffectStage* effectStages[],
int effectCnt,
const GrGLProgramDesc::EffectKeyProvider& keyProvider,
GrGLSLExpr4* fsInOutColor) {
bool effectEmitted = false;
GrGLSLExpr4 inColor = *fsInOutColor;
GrGLSLExpr4 outColor;
for (int e = 0; e < effectCnt; ++e) {
SkASSERT(NULL != effectStages[e] && NULL != effectStages[e]->getEffect());
const GrEffectStage& stage = *effectStages[e];
CodeStage::AutoStageRestore csar(&fCodeStage, &stage);
if (inColor.isZeros()) {
SkString inColorName;
// Effects have no way to communicate zeros, they treat an empty string as ones.
this->nameVariable(&inColorName, '\0', "input");
this->fsCodeAppendf("\tvec4 %s = %s;\n", inColorName.c_str(), inColor.c_str());
inColor = inColorName;
}
// create var to hold stage result
SkString outColorName;
this->nameVariable(&outColorName, '\0', "output");
this->fsCodeAppendf("\tvec4 %s;\n", outColorName.c_str());
outColor = outColorName;
programEffectsBuilder->emitEffect(stage,
keyProvider.get(e),
outColor.c_str(),
inColor.isOnes() ? NULL : inColor.c_str(),
fCodeStage.stageIndex());
inColor = outColor;
effectEmitted = true;
}
if (effectEmitted) {
*fsInOutColor = outColor;
}
}
