/*
* Copyright 2012 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "GrConfigConversionEffect.h"
#include "GrContext.h"
#include "GrTBackendEffectFactory.h"
#include "GrSimpleTextureEffect.h"
#include "gl/GrGLEffect.h"
#include "SkMatrix.h"
class GrGLConfigConversionEffect : public GrGLEffect {
public:
GrGLConfigConversionEffect(const GrBackendEffectFactory& factory,
const GrDrawEffect& drawEffect)
: INHERITED (factory) {
const GrConfigConversionEffect& effect = drawEffect.castEffect<GrConfigConversionEffect>();
fSwapRedAndBlue = effect.swapsRedAndBlue();
fPMConversion = effect.pmConversion();
}
virtual void emitCode(GrGLShaderBuilder* builder,
const GrDrawEffect&,
EffectKey key,
const char* outputColor,
const char* inputColor,
const TransformedCoordsArray& coords,
const TextureSamplerArray& samplers) SK_OVERRIDE {
builder->fsCodeAppendf("\t\t%s = ", outputColor);
builder->fsAppendTextureLookup(samplers[0], coords[0].c_str(), coords[0].type());
builder->fsCodeAppend(";\n");
if (GrConfigConversionEffect::kNone_PMConversion == fPMConversion) {
SkASSERT(fSwapRedAndBlue);
builder->fsCodeAppendf("\t%s = %s.bgra;\n", outputColor, outputColor);
} else {
const char* swiz = fSwapRedAndBlue ? "bgr" : "rgb";
switch (fPMConversion) {
case GrConfigConversionEffect::kMulByAlpha_RoundUp_PMConversion:
builder->fsCodeAppendf(
"\t\t%s = vec4(ceil(%s.%s * %s.a * 255.0) / 255.0, %s.a);\n",
outputColor, outputColor, swiz, outputColor, outputColor);
break;
case GrConfigConversionEffect::kMulByAlpha_RoundDown_PMConversion:
// Add a compensation(0.001) here to avoid the side effect of the floor operation.
// In Intel GPUs, the integer value converted from floor(%s.r * 255.0) / 255.0
// is less than the integer value converted from %s.r by 1 when the %s.r is
// converted from the integer value 2^n, such as 1, 2, 4, 8, etc.
builder->fsCodeAppendf(
"\t\t%s = vec4(floor(%s.%s * %s.a * 255.0 + 0.001) / 255.0, %s.a);\n",
outputColor, outputColor, swiz, outputColor, outputColor);
break;
case GrConfigConversionEffect::kDivByAlpha_RoundUp_PMConversion:
builder->fsCodeAppendf("\t\t%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(ceil(%s.%s / %s.a * 255.0) / 255.0, %s.a);\n",
outputColor, outputColor, outputColor, swiz, outputColor, outputColor);
break;
case GrConfigConversionEffect::kDivByAlpha_RoundDown_PMConversion:
builder->fsCodeAppendf("\t\t%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(floor(%s.%s / %s.a * 255.0) / 255.0, %s.a);\n",
outputColor, outputColor, outputColor, swiz, outputColor, outputColor);
break;
default:
SkFAIL("Unknown conversion op.");
break;
}
}
SkString modulate;
GrGLSLMulVarBy4f(&modulate, 2, outputColor, inputColor);
builder->fsCodeAppend(modulate.c_str());
}
static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
const GrConfigConversionEffect& conv = drawEffect.castEffect<GrConfigConversionEffect>();
return static_cast<EffectKey>(conv.swapsRedAndBlue()) | (conv.pmConversion() << 1);
}
private:
bool fSwapRedAndBlue;
GrConfigConversionEffect::PMConversion fPMConversion;
typedef GrGLEffect INHERITED;
};
///////////////////////////////////////////////////////////////////////////////
GrConfigConversionEffect::GrConfigConversionEffect(GrTexture* texture,
bool swapRedAndBlue,
PMConversion pmConversion,
const SkMatrix& matrix)
: GrSingleTextureEffect(texture, matrix)
, fSwapRedAndBlue(swapRedAndBlue)
, fPMConversion(pmConversion) {
SkASSERT(kRGBA_8888_GrPixelConfig == texture->config() ||
kBGRA_8888_GrPixelConfig == texture->config());
// Why did we pollute our texture cache instead of using a GrSingleTextureEffect?
SkASSERT(swapRedAndBlue || kNone_PMConversion != pmConversion);
}
const GrBackendEffectFactory& GrConfigConversionEffect::getFactory() const {
return GrTBackendEffectFactory<GrConfigConversionEffect>::getInstance();
}
bool GrConfigConversionEffect::onIsEqual(const GrEffect& s) const {
const GrConfigConversionEffect& other = CastEffect<GrConfigConversionEffect>(s);
return this->texture(0) == s.texture(0) &&
other.fSwapRedAndBlue == fSwapRedAndBlue &&
other.fPMConversion == fPMConversion;
}
void GrConfigConversionEffect::getConstantColorComponents(GrColor* color,
uint32_t* validFlags) const {
this->updateConstantColorComponentsForModulation(color, validFlags);
}
///////////////////////////////////////////////////////////////////////////////
GR_DEFINE_EFFECT_TEST(GrConfigConversionEffect);
GrEffectRef* GrConfigConversionEffect::TestCreate(SkRandom* random,
GrContext*,
const GrDrawTargetCaps&,
GrTexture* textures[]) {
PMConversion pmConv = static_cast<PMConversion>(random->nextULessThan(kPMConversionCnt));
bool swapRB;
if (kNone_PMConversion == pmConv) {
swapRB = true;
} else {
swapRB = random->nextBool();
}
AutoEffectUnref effect(SkNEW_ARGS(GrConfigConversionEffect,
(textures[GrEffectUnitTest::kSkiaPMTextureIdx],
swapRB,
pmConv,
GrEffectUnitTest::TestMatrix(random))));
return CreateEffectRef(effect);
}
///////////////////////////////////////////////////////////////////////////////
void GrConfigConversionEffect::TestForPreservingPMConversions(GrContext* context,
PMConversion* pmToUPMRule,
PMConversion* upmToPMRule) {
*pmToUPMRule = kNone_PMConversion;
*upmToPMRule = kNone_PMConversion;
SkAutoTMalloc<uint32_t> data(256 * 256 * 3);
uint32_t* srcData = data.get();
uint32_t* firstRead = data.get() + 256 * 256;
uint32_t* secondRead = data.get() + 2 * 256 * 256;
// Fill with every possible premultiplied A, color channel value. There will be 256-y duplicate
// values in row y. We set r,g, and b to the same value since they are handled identically.
for (int y = 0; y < 256; ++y) {
for (int x = 0; x < 256; ++x) {
uint8_t* color = reinterpret_cast<uint8_t*>(&srcData[256*y + x]);
color[3] = y;
color[2] = SkTMin(x, y);
color[1] = SkTMin(x, y);
color[0] = SkTMin(x, y);
}
}
GrTextureDesc desc;
desc.fFlags = kRenderTarget_GrTextureFlagBit |
kNoStencil_GrTextureFlagBit;
desc.fWidth = 256;
desc.fHeight = 256;
desc.fConfig = kRGBA_8888_GrPixelConfig;
SkAutoTUnref<GrTexture> readTex(context->createUncachedTexture(desc, NULL, 0));
if (!readTex.get()) {
return;
}
SkAutoTUnref<GrTexture> tempTex(context->createUncachedTexture(desc, NULL, 0));
if (!tempTex.get()) {
return;
}
desc.fFlags = kNone_GrTextureFlags;
SkAutoTUnref<GrTexture> dataTex(context->createUncachedTexture(desc, data, 0));
if (!dataTex.get()) {
return;
}
static const PMConversion kConversionRules[][2] = {
{kDivByAlpha_RoundDown_PMConversion, kMulByAlpha_RoundUp_PMConversion},
{kDivByAlpha_RoundUp_PMConversion, kMulByAlpha_RoundDown_PMConversion},
};
GrContext::AutoWideOpenIdentityDraw awoid(context, NULL);
bool failed = true;
for (size_t i = 0; i < SK_ARRAY_COUNT(kConversionRules) && failed; ++i) {
*pmToUPMRule = kConversionRules[i][0];
*upmToPMRule = kConversionRules[i][1];
static const SkRect kDstRect = SkRect::MakeWH(SkIntToScalar(256), SkIntToScalar(256));
static const SkRect kSrcRect = SkRect::MakeWH(SK_Scalar1, SK_Scalar1);
// We do a PM->UPM draw from dataTex to readTex and read the data. Then we do a UPM->PM draw
// from readTex to tempTex followed by a PM->UPM draw to readTex and finally read the data.
// We then verify that two reads produced the same values.
AutoEffectUnref pmToUPM1(SkNEW_ARGS(GrConfigConversionEffect, (dataTex,
false,
*pmToUPMRule,
SkMatrix::I())));
AutoEffectUnref upmToPM(SkNEW_ARGS(GrConfigConversionEffect, (readTex,
false,
*upmToPMRule,
SkMatrix::I())));
AutoEffectUnref pmToUPM2(SkNEW_ARGS(GrConfigConversionEffect, (tempTex,
false,
*pmToUPMRule,
SkMatrix::I())));
SkAutoTUnref<GrEffectRef> pmToUPMEffect1(CreateEffectRef(pmToUPM1));
SkAutoTUnref<GrEffectRef> upmToPMEffect(CreateEffectRef(upmToPM));
SkAutoTUnref<GrEffectRef> pmToUPMEffect2(CreateEffectRef(pmToUPM2));
context->setRenderTarget(readTex->asRenderTarget());
GrPaint paint1;
paint1.addColorEffect(pmToUPMEffect1);
context->drawRectToRect(paint1, kDstRect, kSrcRect);
readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, firstRead);
context->setRenderTarget(tempTex->asRenderTarget());
GrPaint paint2;
paint2.addColorEffect(upmToPMEffect);
context->drawRectToRect(paint2, kDstRect, kSrcRect);
context->setRenderTarget(readTex->asRenderTarget());
GrPaint paint3;
paint3.addColorEffect(pmToUPMEffect2);
context->drawRectToRect(paint3, kDstRect, kSrcRect);
readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, secondRead);
failed = false;
for (int y = 0; y < 256 && !failed; ++y) {
for (int x = 0; x <= y; ++x) {
if (firstRead[256 * y + x] != secondRead[256 * y + x]) {
failed = true;
break;
}
}
}
}
if (failed) {
*pmToUPMRule = kNone_PMConversion;
*upmToPMRule = kNone_PMConversion;
}
}
const GrEffectRef* GrConfigConversionEffect::Create(GrTexture* texture,
bool swapRedAndBlue,
PMConversion pmConversion,
const SkMatrix& matrix) {
if (!swapRedAndBlue && kNone_PMConversion == pmConversion) {
// If we returned a GrConfigConversionEffect that was equivalent to a GrSimpleTextureEffect
// then we may pollute our texture cache with redundant shaders. So in the case that no
// conversions were requested we instead return a GrSimpleTextureEffect.
return GrSimpleTextureEffect::Create(texture, matrix);
} else {
if (kRGBA_8888_GrPixelConfig != texture->config() &&
kBGRA_8888_GrPixelConfig != texture->config() &&
kNone_PMConversion != pmConversion) {
// The PM conversions assume colors are 0..255
return NULL;
}
AutoEffectUnref effect(SkNEW_ARGS(GrConfigConversionEffect, (texture,
swapRedAndBlue,
pmConversion,
matrix)));
return CreateEffectRef(effect);
}
}