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/*
* Copyright 2006 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkArenaAlloc.h"
#include "SkBlendModePriv.h"
#include "SkComposeShader.h"
#include "SkColorFilter.h"
#include "SkColorData.h"
#include "SkColorShader.h"
#include "SkRasterPipeline.h"
#include "SkReadBuffer.h"
#include "SkWriteBuffer.h"
#include "SkString.h"
#include "../jumper/SkJumper.h"
sk_sp<SkShader> SkShader::MakeCompose(sk_sp<SkShader> dst, sk_sp<SkShader> src, SkBlendMode mode,
float lerpT) {
if (!src || !dst || SkScalarIsNaN(lerpT)) {
return nullptr;
}
lerpT = SkScalarPin(lerpT, 0, 1);
if (lerpT == 0) {
return dst;
} else if (lerpT == 1) {
if (mode == SkBlendMode::kSrc) {
return src;
}
if (mode == SkBlendMode::kDst) {
return dst;
}
}
return sk_sp<SkShader>(new SkComposeShader(std::move(dst), std::move(src), mode, lerpT));
}
///////////////////////////////////////////////////////////////////////////////
sk_sp<SkFlattenable> SkComposeShader::CreateProc(SkReadBuffer& buffer) {
sk_sp<SkShader> dst(buffer.readShader());
sk_sp<SkShader> src(buffer.readShader());
unsigned mode = buffer.read32();
float lerp = buffer.readScalar();
// check for valid mode before we cast to the enum type
if (!buffer.validate(mode <= (unsigned)SkBlendMode::kLastMode)) {
return nullptr;
}
return MakeCompose(std::move(dst), std::move(src), static_cast<SkBlendMode>(mode), lerp);
}
void SkComposeShader::flatten(SkWriteBuffer& buffer) const {
buffer.writeFlattenable(fDst.get());
buffer.writeFlattenable(fSrc.get());
buffer.write32((int)fMode);
buffer.writeScalar(fLerpT);
}
sk_sp<SkShader> SkComposeShader::onMakeColorSpace(SkColorSpaceXformer* xformer) const {
return MakeCompose(xformer->apply(fDst.get()), xformer->apply(fSrc.get()),
fMode, fLerpT);
}
#ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
bool SkComposeShader::asACompose(ComposeRec* rec) const {
if (!this->isJustMode()) {
return false;
}
if (rec) {
rec->fShaderA = fDst.get();
rec->fShaderB = fSrc.get();
rec->fBlendMode = fMode;
}
return true;
}
#endif
bool SkComposeShader::onAppendStages(const StageRec& rec) const {
struct Storage {
float fRGBA[4 * SkJumper_kMaxStride];
float fAlpha;
};
auto storage = rec.fAlloc->make<Storage>();
if (!as_SB(fSrc)->appendStages(rec)) {
return false;
}
// This outputs r,g,b,a, which we'll need later when we apply the mode, but we save it off now
// since fShaderB will overwrite them.
rec.fPipeline->append(SkRasterPipeline::store_rgba, storage->fRGBA);
if (!as_SB(fDst)->appendStages(rec)) {
return false;
}
// We now have our logical 'dst' in r,g,b,a, but we need it in dr,dg,db,da for the mode/lerp
// so we have to shuttle them. If we had a stage the would load_into_dst, then we could
// reverse the two shader invocations, and avoid this move...
rec.fPipeline->append(SkRasterPipeline::move_src_dst);
rec.fPipeline->append(SkRasterPipeline::load_rgba, storage->fRGBA);
if (!this->isJustLerp()) {
SkBlendMode_AppendStages(fMode, rec.fPipeline);
}
if (!this->isJustMode()) {
rec.fPipeline->append(SkRasterPipeline::lerp_1_float, &fLerpT);
}
return true;
}
#if SK_SUPPORT_GPU
#include "effects/GrConstColorProcessor.h"
#include "effects/GrXfermodeFragmentProcessor.h"
/////////////////////////////////////////////////////////////////////
std::unique_ptr<GrFragmentProcessor> SkComposeShader::asFragmentProcessor(
const GrFPArgs& args) const {
if (this->isJustMode()) {
SkASSERT(fMode != SkBlendMode::kSrc && fMode != SkBlendMode::kDst); // caught in factory
if (fMode == SkBlendMode::kClear) {
return GrConstColorProcessor::Make(GrColor4f::TransparentBlack(),
GrConstColorProcessor::InputMode::kIgnore);
}
}
std::unique_ptr<GrFragmentProcessor> fpA(as_SB(fDst)->asFragmentProcessor(args));
if (!fpA) {
return nullptr;
}
std::unique_ptr<GrFragmentProcessor> fpB(as_SB(fSrc)->asFragmentProcessor(args));
if (!fpB) {
return nullptr;
}
// TODO: account for fLerpT when it is < 1
return GrXfermodeFragmentProcessor::MakeFromTwoProcessors(std::move(fpB),
std::move(fpA), fMode);
}
#endif