blob: 1771f9edef923a14b3938b22f8366eb301fc64f4 [file] [log] [blame]
* Copyright 2014 Google Inc.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
#include "src/gpu/ganesh/effects/GrDisableColorXP.h"
#include "src/gpu/ganesh/GrPipeline.h"
#include "src/gpu/ganesh/GrProcessor.h"
#include "src/gpu/ganesh/GrShaderCaps.h"
#include "src/gpu/ganesh/GrXferProcessor.h"
#include "src/gpu/ganesh/glsl/GrGLSLFragmentShaderBuilder.h"
#include "src/gpu/ganesh/glsl/GrGLSLProgramDataManager.h"
* This xfer processor disables color writing. Thus color and coverage and ignored and no blending
* occurs. This XP is usful for things like stenciling.
class DisableColorXP : public GrXferProcessor {
DisableColorXP() : INHERITED(kDisableColorXP_ClassID) {}
const char* name() const override { return "Disable Color"; }
bool onIsEqual(const GrXferProcessor& xpBase) const override { return true; }
void onAddToKey(const GrShaderCaps&, skgpu::KeyBuilder*) const override {}
void onGetBlendInfo(skgpu::BlendInfo* blendInfo) const override {
blendInfo->fWritesColor = false;
std::unique_ptr<ProgramImpl> makeProgramImpl() const override;
using INHERITED = GrXferProcessor;
std::unique_ptr<GrXferProcessor::ProgramImpl> DisableColorXP::makeProgramImpl() const {
class Impl : public ProgramImpl {
void emitOutputsForBlendState(const EmitArgs& args) override {
if (args.fShaderCaps->fMustWriteToFragColor) {
// This emit code should be empty. However, on the nexus 6 there is a driver bug
// where if you do not give gl_FragColor a value, the gl context is lost and we end
// up drawing nothing. So this fix just sets the gl_FragColor arbitrarily to 0.
GrGLSLXPFragmentBuilder* fragBuilder = args.fXPFragBuilder;
fragBuilder->codeAppendf("%s = half4(0);", args.fOutputPrimary);
void emitWriteSwizzle(GrGLSLXPFragmentBuilder*,
const skgpu::Swizzle&,
const char*,
const char*) const override {
// Don't write any swizzling. This makes sure the final shader does not output a color.
return std::make_unique<Impl>();
sk_sp<const GrXferProcessor> GrDisableColorXPFactory::MakeXferProcessor() {
return sk_make_sp<DisableColorXP>();
const GrXPFactory* GrDisableColorXPFactory::TestGet(GrProcessorTestData*) {
return GrDisableColorXPFactory::Get();