blob: f6bb7b1034fe1e336710a8f46199deb3fff9866f [file] [log] [blame]
* Copyright 2012 Google Inc.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
#ifndef GrConfigConversionEffect_DEFINED
#define GrConfigConversionEffect_DEFINED
#include "GrFragmentProcessor.h"
* This class is used to perform config conversions. Clients may want to read/write data that is
* unpremultiplied.
class GrConfigConversionEffect : public GrFragmentProcessor {
* The PM->UPM or UPM->PM conversions to apply.
enum PMConversion {
kToPremul_PMConversion = 0,
* Returns a fragment processor that calls the passed in fragment processor, and then performs
* the requested premul or unpremul conversion.
static sk_sp<GrFragmentProcessor> Make(sk_sp<GrFragmentProcessor>, PMConversion);
const char* name() const override { return "Config Conversion"; }
PMConversion pmConversion() const { return fPMConversion; }
// This function determines whether it is possible to choose PM->UPM and UPM->PM conversions
// for which in any PM->UPM->PM->UPM sequence the two UPM values are the same. This means that
// if pixels are read back to a UPM buffer, written back to PM to the GPU, and read back again
// both reads will produce the same result. This test is quite expensive and should not be run
// multiple times for a given context.
static bool TestForPreservingPMConversions(GrContext* context);
GrGLSLFragmentProcessor* onCreateGLSLInstance() const override;
void onGetGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder*) const override;
bool onIsEqual(const GrFragmentProcessor&) const override;
PMConversion fPMConversion;
typedef GrFragmentProcessor INHERITED;