const char* GrGLFragmentShaderBuilder::dstColor() {
fHasReadDstColor = true;
GrGLGpu* gpu = fProgramBuilder->gpu();
if (gpu->glCaps().glslCaps()->fbFetchSupport()) {
this->addFeature(1 << (GrGLFragmentShaderBuilder::kLastGLSLPrivateFeature + 1),
gpu->glCaps().glslCaps()->fbFetchExtensionString());
// Some versions of this extension string require declaring custom color output on ES 3.0+
const char* fbFetchColorName = gpu->glCaps().glslCaps()->fbFetchColorName();
if (gpu->glCaps().glslCaps()->fbFetchNeedsCustomOutput()) {
this->enableCustomOutput();
fOutputs[fCustomColorOutputIndex].setTypeModifier(GrShaderVar::kInOut_TypeModifier);
fbFetchColorName = declared_color_output_name();
}
return fbFetchColorName;
} else {
return kDstTextureColorName;
}
}
const char* GrGLFragmentShaderBuilder::fragmentPosition() {
fHasReadFragmentPosition = true;
GrGLGpu* 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",
kDefault_GrSLPrecision,
GrGLShaderVar::kUpperLeft_Origin);
fSetupFragPosition = true;
}
return "gl_FragCoord";
} else {
static const char* kTempName = "tmpXYFragCoord";
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,
kDefault_GrSLPrecision,
"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.
this->codePrependf("\tvec4 %s = vec4(%s.x, %s - %s.y, 1.0, 1.0);\n",
kCoordName, kTempName, rtHeightName, kTempName);
this->codePrependf("vec2 %s = gl_FragCoord.xy;", kTempName);
fSetupFragPosition = true;
}
SkASSERT(fProgramBuilder->fUniformHandles.fRTHeightUni.isValid());
return kCoordName;
}
}
const char* GrGLFragmentShaderBuilder::dstColor() {
fHasReadDstColor = true;
GrGLGpu* gpu = fProgramBuilder->gpu();
if (gpu->glCaps().fbFetchSupport()) {
this->addFeature(1 << (GrGLFragmentShaderBuilder::kLastGLSLPrivateFeature + 1),
gpu->glCaps().fbFetchExtensionString());
// On ES 3.0 we have to declare this, and use the custom color output name
const char* fbFetchColorName = gpu->glCaps().fbFetchColorName();
if (gpu->glslGeneration() >= k330_GrGLSLGeneration) {
this->enableCustomOutput();
fOutputs[fCustomColorOutputIndex].setTypeModifier(GrShaderVar::kInOut_TypeModifier);
fbFetchColorName = declared_color_output_name();
}
return fbFetchColorName;
} else if (fProgramBuilder->fUniformHandles.fDstCopySamplerUni.isValid()) {
return kDstCopyColorName;
} else {
return "";
}
}
const char* GrGLFragmentShaderBuilder::fragmentPosition() {
fHasReadFragmentPosition = true;
GrGLGpu* 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",
kDefault_GrSLPrecision,
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,
kDefault_GrSLPrecision,
"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;
}
}
bool GrGLFragmentShaderBuilder::enableFeature(GLSLFeature feature) {
switch (feature) {
case kStandardDerivatives_GLSLFeature: {
GrGLGpu* gpu = fProgramBuilder->gpu();
if (!gpu->glCaps().shaderCaps()->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;
}
}