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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.
*/
#include "GrGLSLFragmentShaderBuilder.h"
#include "GrRenderTarget.h"
#include "GrRenderTargetPriv.h"
#include "gl/GrGLGpu.h"
#include "glsl/GrGLSL.h"
#include "glsl/GrGLSLCaps.h"
#include "glsl/GrGLSLProgramBuilder.h"
#include "glsl/GrGLSLUniformHandler.h"
#include "glsl/GrGLSLVarying.h"
const char* GrGLSLFragmentShaderBuilder::kDstColorName = "_dstColor";
static const char* sample_offset_array_name(GrGLSLFPFragmentBuilder::Coordinates coords) {
static const char* kArrayNames[] = {
"deviceSpaceSampleOffsets",
"windowSpaceSampleOffsets"
};
return kArrayNames[coords];
GR_STATIC_ASSERT(0 == GrGLSLFPFragmentBuilder::kSkiaDevice_Coordinates);
GR_STATIC_ASSERT(1 == GrGLSLFPFragmentBuilder::kGLSLWindow_Coordinates);
GR_STATIC_ASSERT(SK_ARRAY_COUNT(kArrayNames) == GrGLSLFPFragmentBuilder::kLast_Coordinates + 1);
}
static const char* specific_layout_qualifier_name(GrBlendEquation equation) {
SkASSERT(GrBlendEquationIsAdvanced(equation));
static const char* kLayoutQualifierNames[] = {
"blend_support_screen",
"blend_support_overlay",
"blend_support_darken",
"blend_support_lighten",
"blend_support_colordodge",
"blend_support_colorburn",
"blend_support_hardlight",
"blend_support_softlight",
"blend_support_difference",
"blend_support_exclusion",
"blend_support_multiply",
"blend_support_hsl_hue",
"blend_support_hsl_saturation",
"blend_support_hsl_color",
"blend_support_hsl_luminosity"
};
return kLayoutQualifierNames[equation - kFirstAdvancedGrBlendEquation];
GR_STATIC_ASSERT(0 == kScreen_GrBlendEquation - kFirstAdvancedGrBlendEquation);
GR_STATIC_ASSERT(1 == kOverlay_GrBlendEquation - kFirstAdvancedGrBlendEquation);
GR_STATIC_ASSERT(2 == kDarken_GrBlendEquation - kFirstAdvancedGrBlendEquation);
GR_STATIC_ASSERT(3 == kLighten_GrBlendEquation - kFirstAdvancedGrBlendEquation);
GR_STATIC_ASSERT(4 == kColorDodge_GrBlendEquation - kFirstAdvancedGrBlendEquation);
GR_STATIC_ASSERT(5 == kColorBurn_GrBlendEquation - kFirstAdvancedGrBlendEquation);
GR_STATIC_ASSERT(6 == kHardLight_GrBlendEquation - kFirstAdvancedGrBlendEquation);
GR_STATIC_ASSERT(7 == kSoftLight_GrBlendEquation - kFirstAdvancedGrBlendEquation);
GR_STATIC_ASSERT(8 == kDifference_GrBlendEquation - kFirstAdvancedGrBlendEquation);
GR_STATIC_ASSERT(9 == kExclusion_GrBlendEquation - kFirstAdvancedGrBlendEquation);
GR_STATIC_ASSERT(10 == kMultiply_GrBlendEquation - kFirstAdvancedGrBlendEquation);
GR_STATIC_ASSERT(11 == kHSLHue_GrBlendEquation - kFirstAdvancedGrBlendEquation);
GR_STATIC_ASSERT(12 == kHSLSaturation_GrBlendEquation - kFirstAdvancedGrBlendEquation);
GR_STATIC_ASSERT(13 == kHSLColor_GrBlendEquation - kFirstAdvancedGrBlendEquation);
GR_STATIC_ASSERT(14 == kHSLLuminosity_GrBlendEquation - kFirstAdvancedGrBlendEquation);
GR_STATIC_ASSERT(SK_ARRAY_COUNT(kLayoutQualifierNames) ==
kGrBlendEquationCnt - kFirstAdvancedGrBlendEquation);
}
uint8_t GrGLSLFragmentShaderBuilder::KeyForSurfaceOrigin(GrSurfaceOrigin origin) {
SkASSERT(kTopLeft_GrSurfaceOrigin == origin || kBottomLeft_GrSurfaceOrigin == origin);
return origin;
GR_STATIC_ASSERT(1 == kTopLeft_GrSurfaceOrigin);
GR_STATIC_ASSERT(2 == kBottomLeft_GrSurfaceOrigin);
}
GrGLSLFragmentShaderBuilder::GrGLSLFragmentShaderBuilder(GrGLSLProgramBuilder* program)
: GrGLSLFragmentBuilder(program)
, fSetupFragPosition(false)
, fHasCustomColorOutput(false)
, fCustomColorOutputIndex(-1)
, fHasSecondaryOutput(false)
, fUsedSampleOffsetArrays(0)
, fHasInitializedSampleMask(false) {
fSubstageIndices.push_back(0);
#ifdef SK_DEBUG
fUsedProcessorFeatures = GrProcessor::kNone_RequiredFeatures;
fHasReadDstColor = false;
#endif
}
bool GrGLSLFragmentShaderBuilder::enableFeature(GLSLFeature feature) {
const GrGLSLCaps& glslCaps = *fProgramBuilder->glslCaps();
switch (feature) {
case kStandardDerivatives_GLSLFeature:
if (!glslCaps.shaderDerivativeSupport()) {
return false;
}
if (const char* extension = glslCaps.shaderDerivativeExtensionString()) {
this->addFeature(1 << kStandardDerivatives_GLSLFeature, extension);
}
return true;
case kPixelLocalStorage_GLSLFeature:
if (glslCaps.pixelLocalStorageSize() <= 0) {
return false;
}
this->addFeature(1 << kPixelLocalStorage_GLSLFeature,
"GL_EXT_shader_pixel_local_storage");
return true;
case kMultisampleInterpolation_GLSLFeature:
if (!glslCaps.multisampleInterpolationSupport()) {
return false;
}
if (const char* extension = glslCaps.multisampleInterpolationExtensionString()) {
this->addFeature(1 << kMultisampleInterpolation_GLSLFeature, extension);
}
return true;
default:
SkFAIL("Unexpected GLSLFeature requested.");
return false;
}
}
SkString GrGLSLFragmentShaderBuilder::ensureCoords2D(const GrShaderVar& coords) {
if (kVec3f_GrSLType != coords.getType()) {
SkASSERT(kVec2f_GrSLType == coords.getType());
return coords.getName();
}
SkString coords2D;
coords2D.printf("%s_ensure2D", coords.c_str());
this->codeAppendf("\tvec2 %s = %s.xy / %s.z;", coords2D.c_str(), coords.c_str(),
coords.c_str());
return coords2D;
}
const char* GrGLSLFragmentShaderBuilder::fragmentPosition() {
SkDEBUGCODE(fUsedProcessorFeatures |= GrProcessor::kFragmentPosition_RequiredFeature;)
const GrGLSLCaps* glslCaps = fProgramBuilder->glslCaps();
// We only declare "gl_FragCoord" when we're in the case where we want to use layout qualifiers
// to reverse y. Otherwise it isn't necessary and whether the "in" qualifier appears in the
// declaration varies in earlier GLSL specs. So it is simpler to omit it.
if (kTopLeft_GrSurfaceOrigin == this->getSurfaceOrigin()) {
fSetupFragPosition = true;
return "gl_FragCoord";
} else if (const char* extension = glslCaps->fragCoordConventionsExtensionString()) {
if (!fSetupFragPosition) {
if (glslCaps->generation() < k150_GrGLSLGeneration) {
this->addFeature(1 << kFragCoordConventions_GLSLPrivateFeature,
extension);
}
fInputs.push_back().set(kVec4f_GrSLType,
GrGLSLShaderVar::kIn_TypeModifier,
"gl_FragCoord",
kDefault_GrSLPrecision,
"origin_upper_left");
fSetupFragPosition = true;
}
return "gl_FragCoord";
} else {
static const char* kTempName = "tmpXYFragCoord";
static const char* kCoordName = "fragCoordYDown";
if (!fSetupFragPosition) {
const char* rtHeightName;
fProgramBuilder->addRTHeightUniform("RTHeight", &rtHeightName);
// The Adreno compiler seems to be very touchy about access to "gl_FragCoord".
// Accessing glFragCoord.zw can cause a program to fail to link. Additionally,
// depending on the surrounding code, accessing .xy with a uniform involved can
// do the same thing. Copying gl_FragCoord.xy into a temp vec2 beforehand
// (and only accessing .xy) seems to "fix" things.
const char* precision = glslCaps->usesPrecisionModifiers() ? "highp " : "";
this->codePrependf("\t%svec4 %s = vec4(%s.x, %s - %s.y, 1.0, 1.0);\n",
precision, kCoordName, kTempName, rtHeightName, kTempName);
this->codePrependf("%svec2 %s = gl_FragCoord.xy;", precision, kTempName);
fSetupFragPosition = true;
}
SkASSERT(fProgramBuilder->fUniformHandles.fRTHeightUni.isValid());
return kCoordName;
}
}
const char* GrGLSLFragmentShaderBuilder::distanceVectorName() const {
return "fsDistanceVector";
}
void GrGLSLFragmentShaderBuilder::appendOffsetToSample(const char* sampleIdx, Coordinates coords) {
SkASSERT(fProgramBuilder->header().fSamplePatternKey);
SkDEBUGCODE(fUsedProcessorFeatures |= GrProcessor::kSampleLocations_RequiredFeature);
if (kTopLeft_GrSurfaceOrigin == this->getSurfaceOrigin()) {
// With a top left origin, device and window space are equal, so we only use device coords.
coords = kSkiaDevice_Coordinates;
}
this->codeAppendf("%s[%s]", sample_offset_array_name(coords), sampleIdx);
fUsedSampleOffsetArrays |= (1 << coords);
}
void GrGLSLFragmentShaderBuilder::maskSampleCoverage(const char* mask, bool invert) {
const GrGLSLCaps& glslCaps = *fProgramBuilder->glslCaps();
if (!glslCaps.sampleVariablesSupport()) {
SkDEBUGFAIL("Attempted to mask sample coverage without support.");
return;
}
if (const char* extension = glslCaps.sampleVariablesExtensionString()) {
this->addFeature(1 << kSampleVariables_GLSLPrivateFeature, extension);
}
if (!fHasInitializedSampleMask) {
this->codePrependf("gl_SampleMask[0] = -1;");
fHasInitializedSampleMask = true;
}
if (invert) {
this->codeAppendf("gl_SampleMask[0] &= ~(%s);", mask);
} else {
this->codeAppendf("gl_SampleMask[0] &= %s;", mask);
}
}
void GrGLSLFragmentShaderBuilder::overrideSampleCoverage(const char* mask) {
const GrGLSLCaps& glslCaps = *fProgramBuilder->glslCaps();
if (!glslCaps.sampleMaskOverrideCoverageSupport()) {
SkDEBUGFAIL("Attempted to override sample coverage without support.");
return;
}
SkASSERT(glslCaps.sampleVariablesSupport());
if (const char* extension = glslCaps.sampleVariablesExtensionString()) {
this->addFeature(1 << kSampleVariables_GLSLPrivateFeature, extension);
}
if (this->addFeature(1 << kSampleMaskOverrideCoverage_GLSLPrivateFeature,
"GL_NV_sample_mask_override_coverage")) {
// Redeclare gl_SampleMask with layout(override_coverage) if we haven't already.
fOutputs.push_back().set(kInt_GrSLType, GrShaderVar::kOut_TypeModifier,
"gl_SampleMask", 1, kHigh_GrSLPrecision,
"override_coverage");
}
this->codeAppendf("gl_SampleMask[0] = %s;", mask);
fHasInitializedSampleMask = true;
}
const char* GrGLSLFragmentShaderBuilder::dstColor() {
SkDEBUGCODE(fHasReadDstColor = true;)
const char* override = fProgramBuilder->primitiveProcessor().getDestColorOverride();
if (override != nullptr) {
return override;
}
const GrGLSLCaps* glslCaps = fProgramBuilder->glslCaps();
if (glslCaps->fbFetchSupport()) {
this->addFeature(1 << kFramebufferFetch_GLSLPrivateFeature,
glslCaps->fbFetchExtensionString());
// Some versions of this extension string require declaring custom color output on ES 3.0+
const char* fbFetchColorName = glslCaps->fbFetchColorName();
if (glslCaps->fbFetchNeedsCustomOutput()) {
this->enableCustomOutput();
fOutputs[fCustomColorOutputIndex].setTypeModifier(GrShaderVar::kInOut_TypeModifier);
fbFetchColorName = DeclaredColorOutputName();
// Set the dstColor to an intermediate variable so we don't override it with the output
this->codeAppendf("vec4 %s = %s;", kDstColorName, fbFetchColorName);
} else {
return fbFetchColorName;
}
}
return kDstColorName;
}
void GrGLSLFragmentShaderBuilder::enableAdvancedBlendEquationIfNeeded(GrBlendEquation equation) {
SkASSERT(GrBlendEquationIsAdvanced(equation));
const GrGLSLCaps& caps = *fProgramBuilder->glslCaps();
if (!caps.mustEnableAdvBlendEqs()) {
return;
}
this->addFeature(1 << kBlendEquationAdvanced_GLSLPrivateFeature,
"GL_KHR_blend_equation_advanced");
if (caps.mustEnableSpecificAdvBlendEqs()) {
this->addLayoutQualifier(specific_layout_qualifier_name(equation), kOut_InterfaceQualifier);
} else {
this->addLayoutQualifier("blend_support_all_equations", kOut_InterfaceQualifier);
}
}
void GrGLSLFragmentShaderBuilder::enableCustomOutput() {
if (!fHasCustomColorOutput) {
fHasCustomColorOutput = true;
fCustomColorOutputIndex = fOutputs.count();
fOutputs.push_back().set(kVec4f_GrSLType,
GrGLSLShaderVar::kOut_TypeModifier,
DeclaredColorOutputName());
fProgramBuilder->finalizeFragmentOutputColor(fOutputs.back());
}
}
void GrGLSLFragmentShaderBuilder::enableSecondaryOutput() {
SkASSERT(!fHasSecondaryOutput);
fHasSecondaryOutput = true;
const GrGLSLCaps& caps = *fProgramBuilder->glslCaps();
if (const char* extension = caps.secondaryOutputExtensionString()) {
this->addFeature(1 << kBlendFuncExtended_GLSLPrivateFeature, extension);
}
// If the primary output is declared, we must declare also the secondary output
// and vice versa, since it is not allowed to use a built-in gl_FragColor and a custom
// output. The condition also co-incides with the condition in whici GLES SL 2.0
// requires the built-in gl_SecondaryFragColorEXT, where as 3.0 requires a custom output.
if (caps.mustDeclareFragmentShaderOutput()) {
fOutputs.push_back().set(kVec4f_GrSLType, GrGLSLShaderVar::kOut_TypeModifier,
DeclaredSecondaryColorOutputName());
fProgramBuilder->finalizeFragmentSecondaryColor(fOutputs.back());
}
}
const char* GrGLSLFragmentShaderBuilder::getPrimaryColorOutputName() const {
return fHasCustomColorOutput ? DeclaredColorOutputName() : "sk_FragColor";
}
void GrGLSLFragmentBuilder::declAppendf(const char* fmt, ...) {
va_list argp;
va_start(argp, fmt);
inputs().appendVAList(fmt, argp);
va_end(argp);
}
const char* GrGLSLFragmentShaderBuilder::getSecondaryColorOutputName() const {
const GrGLSLCaps& caps = *fProgramBuilder->glslCaps();
return caps.mustDeclareFragmentShaderOutput() ? DeclaredSecondaryColorOutputName()
: "gl_SecondaryFragColorEXT";
}
GrSurfaceOrigin GrGLSLFragmentShaderBuilder::getSurfaceOrigin() const {
SkASSERT(fProgramBuilder->header().fSurfaceOriginKey);
return static_cast<GrSurfaceOrigin>(fProgramBuilder->header().fSurfaceOriginKey);
GR_STATIC_ASSERT(1 == kTopLeft_GrSurfaceOrigin);
GR_STATIC_ASSERT(2 == kBottomLeft_GrSurfaceOrigin);
}
void GrGLSLFragmentShaderBuilder::onFinalize() {
fProgramBuilder->varyingHandler()->getFragDecls(&this->inputs(), &this->outputs());
GrGLSLAppendDefaultFloatPrecisionDeclaration(kDefault_GrSLPrecision,
*fProgramBuilder->glslCaps(),
&this->precisionQualifier());
if (fUsedSampleOffsetArrays & (1 << kSkiaDevice_Coordinates)) {
this->defineSampleOffsetArray(sample_offset_array_name(kSkiaDevice_Coordinates),
SkMatrix::MakeTrans(-0.5f, -0.5f));
}
if (fUsedSampleOffsetArrays & (1 << kGLSLWindow_Coordinates)) {
// With a top left origin, device and window space are equal, so we only use device coords.
SkASSERT(kBottomLeft_GrSurfaceOrigin == this->getSurfaceOrigin());
SkMatrix m;
m.setScale(1, -1);
m.preTranslate(-0.5f, -0.5f);
this->defineSampleOffsetArray(sample_offset_array_name(kGLSLWindow_Coordinates), m);
}
}
void GrGLSLFragmentShaderBuilder::defineSampleOffsetArray(const char* name, const SkMatrix& m) {
SkASSERT(fProgramBuilder->caps()->sampleLocationsSupport());
const GrPipeline& pipeline = fProgramBuilder->pipeline();
const GrRenderTargetPriv& rtp = pipeline.getRenderTarget()->renderTargetPriv();
const GrGpu::MultisampleSpecs& specs = rtp.getMultisampleSpecs(pipeline.getStencil());
SkSTArray<16, SkPoint, true> offsets;
offsets.push_back_n(specs.fEffectiveSampleCnt);
m.mapPoints(offsets.begin(), specs.fSampleLocations, specs.fEffectiveSampleCnt);
this->definitions().append("const ");
if (fProgramBuilder->glslCaps()->usesPrecisionModifiers()) {
this->definitions().append("highp ");
}
this->definitions().appendf("vec2 %s[] = vec2[](", name);
for (int i = 0; i < specs.fEffectiveSampleCnt; ++i) {
this->definitions().appendf("vec2(%f, %f)", offsets[i].x(), offsets[i].y());
this->definitions().append(i + 1 != specs.fEffectiveSampleCnt ? ", " : ");\n");
}
}
void GrGLSLFragmentShaderBuilder::onBeforeChildProcEmitCode() {
SkASSERT(fSubstageIndices.count() >= 1);
fSubstageIndices.push_back(0);
// second-to-last value in the fSubstageIndices stack is the index of the child proc
// at that level which is currently emitting code.
fMangleString.appendf("_c%d", fSubstageIndices[fSubstageIndices.count() - 2]);
}
void GrGLSLFragmentShaderBuilder::onAfterChildProcEmitCode() {
SkASSERT(fSubstageIndices.count() >= 2);
fSubstageIndices.pop_back();
fSubstageIndices.back()++;
int removeAt = fMangleString.findLastOf('_');
fMangleString.remove(removeAt, fMangleString.size() - removeAt);
}