blob: 5d5741ef9bc8f4cb04379b6e1dc60b73d34698de [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 "GrGLFragmentShaderBuilder.h"
#include "GrGLShaderStringBuilder.h"
#include "GrGLProgramBuilder.h"
#include "../GrGpuGL.h"
#define GL_CALL(X) GR_GL_CALL(fProgramBuilder->gpu()->glInterface(), X)
#define GL_CALL_RET(R, X) GR_GL_CALL_RET(fProgramBuilder->gpu()->glInterface(), R, X)
// ES2 FS only guarantees mediump and lowp support
static const GrGLShaderVar::Precision kDefaultFragmentPrecision = GrGLShaderVar::kMedium_Precision;
const char* GrGLFragmentShaderBuilder::kDstCopyColorName = "_dstColor";
static const char* declared_color_output_name() { return "fsColorOut"; }
static const char* dual_source_output_name() { return "dualSourceOut"; }
static void append_default_precision_qualifier(GrGLShaderVar::Precision p,
GrGLStandard standard,
SkString* str) {
// Desktop GLSL has added precision qualifiers but they don't do anything.
if (kGLES_GrGLStandard == standard) {
switch (p) {
case GrGLShaderVar::kHigh_Precision:
str->append("precision highp float;\n");
break;
case GrGLShaderVar::kMedium_Precision:
str->append("precision mediump float;\n");
break;
case GrGLShaderVar::kLow_Precision:
str->append("precision lowp float;\n");
break;
case GrGLShaderVar::kDefault_Precision:
SkFAIL("Default precision now allowed.");
default:
SkFAIL("Unknown precision value.");
}
}
}
GrGLFragmentShaderBuilder::DstReadKey
GrGLFragmentShaderBuilder::KeyForDstRead(const GrTexture* dstCopy, const GrGLCaps& caps) {
uint32_t key = kYesDstRead_DstReadKeyBit;
if (caps.fbFetchSupport()) {
return key;
}
SkASSERT(dstCopy);
if (!caps.textureSwizzleSupport() && GrPixelConfigIsAlphaOnly(dstCopy->config())) {
// The fact that the config is alpha-only must be considered when generating code.
key |= kUseAlphaConfig_DstReadKeyBit;
}
if (kTopLeft_GrSurfaceOrigin == dstCopy->origin()) {
key |= kTopLeftOrigin_DstReadKeyBit;
}
SkASSERT(static_cast<DstReadKey>(key) == key);
return static_cast<DstReadKey>(key);
}
GrGLFragmentShaderBuilder::FragPosKey
GrGLFragmentShaderBuilder::KeyForFragmentPosition(const GrRenderTarget* dst, const GrGLCaps&) {
if (kTopLeft_GrSurfaceOrigin == dst->origin()) {
return kTopLeftFragPosRead_FragPosKey;
} else {
return kBottomLeftFragPosRead_FragPosKey;
}
}
GrGLFragmentShaderBuilder::GrGLFragmentShaderBuilder(GrGLProgramBuilder* program,
const GrGLProgramDesc& desc)
: INHERITED(program)
, fHasCustomColorOutput(false)
, fHasSecondaryOutput(false)
, fSetupFragPosition(false)
, fTopLeftFragPosRead(kTopLeftFragPosRead_FragPosKey == desc.getHeader().fFragPosKey)
, fHasReadDstColor(false)
, fHasReadFragmentPosition(false) {
}
bool GrGLFragmentShaderBuilder::enableFeature(GLSLFeature feature) {
switch (feature) {
case kStandardDerivatives_GLSLFeature: {
GrGpuGL* gpu = fProgramBuilder->gpu();
if (!gpu->glCaps().shaderDerivativeSupport()) {
return false;
}
if (kGLES_GrGLStandard == gpu->glStandard() &&
k110_GrGLSLGeneration == gpu->glslGeneration()) {
this->addFeature(1 << kStandardDerivatives_GLSLFeature,
"GL_OES_standard_derivatives");
}
return true;
}
default:
SkFAIL("Unexpected GLSLFeature requested.");
return false;
}
}
SkString GrGLFragmentShaderBuilder::ensureFSCoords2D(
const GrGLProcessor::TransformedCoordsArray& coords, int index) {
if (kVec3f_GrSLType != coords[index].getType()) {
SkASSERT(kVec2f_GrSLType == coords[index].getType());
return coords[index].getName();
}
SkString coords2D("coords2D");
if (0 != index) {
coords2D.appendf("_%i", index);
}
this->codeAppendf("\tvec2 %s = %s.xy / %s.z;",
coords2D.c_str(), coords[index].c_str(), coords[index].c_str());
return coords2D;
}
const char* GrGLFragmentShaderBuilder::fragmentPosition() {
fHasReadFragmentPosition = true;
GrGpuGL* gpu = fProgramBuilder->gpu();
// 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 (fTopLeftFragPosRead) {
fSetupFragPosition = true;
return "gl_FragCoord";
} else if (gpu->glCaps().fragCoordConventionsSupport()) {
if (!fSetupFragPosition) {
if (gpu->glslGeneration() < k150_GrGLSLGeneration) {
this->addFeature(1 << kFragCoordConventions_GLSLPrivateFeature,
"GL_ARB_fragment_coord_conventions");
}
fInputs.push_back().set(kVec4f_GrSLType,
GrGLShaderVar::kIn_TypeModifier,
"gl_FragCoord",
GrGLShaderVar::kDefault_Precision,
GrGLShaderVar::kUpperLeft_Origin);
fSetupFragPosition = true;
}
return "gl_FragCoord";
} else {
static const char* kCoordName = "fragCoordYDown";
if (!fSetupFragPosition) {
// temporarily change the stage index because we're inserting non-stage code.
GrGLProgramBuilder::AutoStageRestore asr(fProgramBuilder);
SkASSERT(!fProgramBuilder->fUniformHandles.fRTHeightUni.isValid());
const char* rtHeightName;
fProgramBuilder->fUniformHandles.fRTHeightUni =
fProgramBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
kFloat_GrSLType,
"RTHeight",
&rtHeightName);
// Using glFragCoord.zw for the last two components tickles an Adreno driver bug that
// causes programs to fail to link. Making this function return a vec2() didn't fix the
// problem but using 1.0 for the last two components does.
this->codePrependf("\tvec4 %s = vec4(gl_FragCoord.x, %s - gl_FragCoord.y, 1.0, "
"1.0);\n", kCoordName, rtHeightName);
fSetupFragPosition = true;
}
SkASSERT(fProgramBuilder->fUniformHandles.fRTHeightUni.isValid());
return kCoordName;
}
}
const char* GrGLFragmentShaderBuilder::dstColor() {
fHasReadDstColor = true;
GrGpuGL* gpu = fProgramBuilder->gpu();
if (gpu->glCaps().fbFetchSupport()) {
this->addFeature(1 << (GrGLFragmentShaderBuilder::kLastGLSLPrivateFeature + 1),
gpu->glCaps().fbFetchExtensionString());
return gpu->glCaps().fbFetchColorName();
} else if (fProgramBuilder->fUniformHandles.fDstCopySamplerUni.isValid()) {
return kDstCopyColorName;
} else {
return "";
}
}
void GrGLFragmentShaderBuilder::emitCodeToReadDstTexture() {
bool topDown = SkToBool(kTopLeftOrigin_DstReadKeyBit & fProgramBuilder->header().fDstReadKey);
const char* dstCopyTopLeftName;
const char* dstCopyCoordScaleName;
const char* dstCopySamplerName;
uint32_t configMask;
if (SkToBool(kUseAlphaConfig_DstReadKeyBit & fProgramBuilder->header().fDstReadKey)) {
configMask = kA_GrColorComponentFlag;
} else {
configMask = kRGBA_GrColorComponentFlags;
}
fProgramBuilder->fUniformHandles.fDstCopySamplerUni =
fProgramBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
kSampler2D_GrSLType,
"DstCopySampler",
&dstCopySamplerName);
fProgramBuilder->fUniformHandles.fDstCopyTopLeftUni =
fProgramBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
kVec2f_GrSLType,
"DstCopyUpperLeft",
&dstCopyTopLeftName);
fProgramBuilder->fUniformHandles.fDstCopyScaleUni =
fProgramBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
kVec2f_GrSLType,
"DstCopyCoordScale",
&dstCopyCoordScaleName);
const char* fragPos = this->fragmentPosition();
this->codeAppend("// Read color from copy of the destination.\n");
this->codeAppendf("vec2 _dstTexCoord = (%s.xy - %s) * %s;",
fragPos, dstCopyTopLeftName, dstCopyCoordScaleName);
if (!topDown) {
this->codeAppend("_dstTexCoord.y = 1.0 - _dstTexCoord.y;");
}
this->codeAppendf("vec4 %s = ", GrGLFragmentShaderBuilder::kDstCopyColorName);
this->appendTextureLookup(dstCopySamplerName,
"_dstTexCoord",
configMask,
"rgba");
this->codeAppend(";");
}
void GrGLFragmentShaderBuilder::enableCustomOutput() {
SkASSERT(!fHasCustomColorOutput);
fHasCustomColorOutput = true;
fOutputs.push_back().set(kVec4f_GrSLType,
GrGLShaderVar::kOut_TypeModifier,
declared_color_output_name());
}
void GrGLFragmentShaderBuilder::enableSecondaryOutput() {
SkASSERT(!fHasSecondaryOutput);
fHasSecondaryOutput = true;
fOutputs.push_back().set(kVec4f_GrSLType, GrGLShaderVar::kOut_TypeModifier,
dual_source_output_name());
}
const char* GrGLFragmentShaderBuilder::getPrimaryColorOutputName() const {
return fHasCustomColorOutput ? declared_color_output_name() : "gl_FragColor";
}
const char* GrGLFragmentShaderBuilder::getSecondaryColorOutputName() const {
return dual_source_output_name();
}
void GrGLFragmentShaderBuilder::enableSecondaryOutput(const GrGLSLExpr4& inputColor,
const GrGLSLExpr4& inputCoverage) {
this->enableSecondaryOutput();
const char* secondaryOutputName = this->getSecondaryColorOutputName();
GrGLSLExpr4 coeff(1);
switch (fProgramBuilder->header().fSecondaryOutputType) {
case GrOptDrawState::kCoverage_SecondaryOutputType:
break;
case GrOptDrawState::kCoverageISA_SecondaryOutputType:
// Get (1-A) into coeff
coeff = GrGLSLExpr4::VectorCast(GrGLSLExpr1(1) - inputColor.a());
break;
case GrOptDrawState::kCoverageISC_SecondaryOutputType:
// Get (1-RGBA) into coeff
coeff = GrGLSLExpr4(1) - inputColor;
break;
default:
SkFAIL("Unexpected Secondary Output");
}
// Get coeff * coverage into modulate and then write that to the dual source output.
this->codeAppendf("\t%s = %s;\n", secondaryOutputName, (coeff * inputCoverage).c_str());
}
void GrGLFragmentShaderBuilder::combineColorAndCoverage(const GrGLSLExpr4& inputColor,
const GrGLSLExpr4& inputCoverage) {
GrGLSLExpr4 fragColor = inputColor * inputCoverage;
switch (fProgramBuilder->header().fPrimaryOutputType) {
case GrOptDrawState::kModulate_PrimaryOutputType:
break;
case GrOptDrawState::kCombineWithDst_PrimaryOutputType:
{
// Tack on "+(1-coverage)dst onto the frag color.
GrGLSLExpr4 dstCoeff = GrGLSLExpr4(1) - inputCoverage;
GrGLSLExpr4 dstContribution = dstCoeff * GrGLSLExpr4(this->dstColor());
fragColor = fragColor + dstContribution;
}
break;
default:
SkFAIL("Unknown Primary Output");
}
// On any post 1.10 GLSL supporting GPU, we declare custom output
if (k110_GrGLSLGeneration != fProgramBuilder->gpu()->glslGeneration()) {
this->enableCustomOutput();
}
this->codeAppendf("\t%s = %s;\n", this->getPrimaryColorOutputName(), fragColor.c_str());
}
bool GrGLFragmentShaderBuilder::compileAndAttachShaders(GrGLuint programId,
SkTDArray<GrGLuint>* shaderIds) const {
GrGpuGL* gpu = fProgramBuilder->gpu();
SkString fragShaderSrc(GrGetGLSLVersionDecl(gpu->ctxInfo()));
fragShaderSrc.append(fExtensions);
append_default_precision_qualifier(kDefaultFragmentPrecision,
gpu->glStandard(),
&fragShaderSrc);
fProgramBuilder->appendUniformDecls(GrGLProgramBuilder::kFragment_Visibility, &fragShaderSrc);
this->appendDecls(fInputs, &fragShaderSrc);
// We shouldn't have declared outputs on 1.10
SkASSERT(k110_GrGLSLGeneration != gpu->glslGeneration() || fOutputs.empty());
this->appendDecls(fOutputs, &fragShaderSrc);
fragShaderSrc.append(fFunctions);
fragShaderSrc.append("void main() {\n");
fragShaderSrc.append(fCode);
fragShaderSrc.append("}\n");
GrGLuint fragShaderId = GrGLCompileAndAttachShader(gpu->glContext(), programId,
GR_GL_FRAGMENT_SHADER, fragShaderSrc,
gpu->gpuStats());
if (!fragShaderId) {
return false;
}
*shaderIds->append() = fragShaderId;
return true;
}
void GrGLFragmentShaderBuilder::bindFragmentShaderLocations(GrGLuint programID) {
// ES 3.00 requires custom color output but doesn't support bindFragDataLocation
if (fHasCustomColorOutput &&
kGLES_GrGLStandard != fProgramBuilder->gpu()->ctxInfo().standard()) {
GL_CALL(BindFragDataLocation(programID, 0, declared_color_output_name()));
}
if (fHasSecondaryOutput) {
GL_CALL(BindFragDataLocationIndexed(programID, 0, 1, dual_source_output_name()));
}
}
void GrGLFragmentShaderBuilder::addVarying(GrSLType type,
const char* name,
const char** fsInName,
GrGLShaderVar::Precision fsPrecision) {
fInputs.push_back().set(type, GrGLShaderVar::kVaryingIn_TypeModifier, name, fsPrecision);
if (fsInName) {
*fsInName = name;
}
}