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/*
* Copyright 2014 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrProcessorAnalysis_DEFINED
#define GrProcessorAnalysis_DEFINED
#include "SkColorData.h"
class GrDrawOp;
class GrFragmentProcessor;
class GrProcessorAnalysisColor {
public:
enum class Opaque {
kNo,
kYes,
};
constexpr GrProcessorAnalysisColor(Opaque opaque = Opaque::kNo)
: fFlags(opaque == Opaque::kYes ? kIsOpaque_Flag : 0)
, fColor(SK_PMColor4fTRANSPARENT) {}
GrProcessorAnalysisColor(const SkPMColor4f& color) { this->setToConstant(color); }
void setToConstant(const SkPMColor4f& color) {
fColor = color;
if (color.isOpaque()) {
fFlags = kColorIsKnown_Flag | kIsOpaque_Flag;
} else {
fFlags = kColorIsKnown_Flag;
}
}
void setToUnknown() { fFlags = 0; }
void setToUnknownOpaque() { fFlags = kIsOpaque_Flag; }
bool isUnknown() const { return SkToBool(fFlags == 0); }
bool isOpaque() const { return SkToBool(kIsOpaque_Flag & fFlags); }
bool isConstant(SkPMColor4f* color = nullptr) const {
if (kColorIsKnown_Flag & fFlags) {
if (color) {
*color = fColor;
}
return true;
}
return false;
}
bool operator==(const GrProcessorAnalysisColor& that) const {
if (fFlags != that.fFlags) {
return false;
}
return (kColorIsKnown_Flag & fFlags) ? fColor == that.fColor : true;
}
/** The returned value reflects the common properties of the two inputs. */
static GrProcessorAnalysisColor Combine(const GrProcessorAnalysisColor& a,
const GrProcessorAnalysisColor& b) {
GrProcessorAnalysisColor result;
uint32_t commonFlags = a.fFlags & b.fFlags;
if ((kColorIsKnown_Flag & commonFlags) && a.fColor == b.fColor) {
result.fColor = a.fColor;
result.fFlags = a.fFlags;
} else if (kIsOpaque_Flag & commonFlags) {
result.fFlags = kIsOpaque_Flag;
}
return result;
}
private:
enum Flags {
kColorIsKnown_Flag = 0x1,
kIsOpaque_Flag = 0x2,
};
uint32_t fFlags;
SkPMColor4f fColor;
};
enum class GrProcessorAnalysisCoverage { kNone, kSingleChannel, kLCD };
/**
* GrColorFragmentProcessorAnalysis gathers invariant data from a set of color fragment processor.
* It is used to recognize optimizations that can simplify the generated shader or make blending
* more effecient.
*/
class GrColorFragmentProcessorAnalysis {
public:
GrColorFragmentProcessorAnalysis() = delete;
GrColorFragmentProcessorAnalysis(const GrProcessorAnalysisColor& input,
const GrFragmentProcessor* const* processors,
int cnt);
bool isOpaque() const { return fIsOpaque; }
/**
* Are all the fragment processors compatible with conflating coverage with color prior to the
* the first fragment processor. This result assumes that processors that should be eliminated
* as indicated by initialProcessorsToEliminate() are in fact eliminated.
*/
bool allProcessorsCompatibleWithCoverageAsAlpha() const {
return fCompatibleWithCoverageAsAlpha;
}
/**
* Do any of the fragment processors require local coords. This result assumes that
* processors that should be eliminated as indicated by initialProcessorsToEliminate() are in
* fact eliminated.
*/
bool usesLocalCoords() const { return fUsesLocalCoords; }
/**
* If we detected that the result after the first N processors is a known color then we
* eliminate those N processors and replace the GrDrawOp's color input to the GrPipeline with
* the known output of the Nth processor, so that the Nth+1 fragment processor (or the XP if
* there are only N processors) sees its expected input. If this returns 0 then there are no
* processors to eliminate.
*/
int initialProcessorsToEliminate(SkPMColor4f* newPipelineInputColor) const {
if (fProcessorsToEliminate > 0) {
*newPipelineInputColor = fLastKnownOutputColor;
}
return fProcessorsToEliminate;
}
/**
* Provides known information about the last processor's output color.
*/
GrProcessorAnalysisColor outputColor() const {
if (fKnowOutputColor) {
return fLastKnownOutputColor;
}
return fIsOpaque ? GrProcessorAnalysisColor::Opaque::kYes
: GrProcessorAnalysisColor::Opaque::kNo;
}
private:
bool fIsOpaque;
bool fCompatibleWithCoverageAsAlpha;
bool fUsesLocalCoords;
bool fKnowOutputColor;
int fProcessorsToEliminate;
SkPMColor4f fLastKnownOutputColor;
};
#endif