1 /*
2 * Copyright 2014 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "src/gpu/ganesh/GrRenderTarget.h"
9 #include "src/gpu/ganesh/GrShaderCaps.h"
10 #include "src/gpu/ganesh/glsl/GrGLSLFragmentShaderBuilder.h"
11 #include "src/gpu/ganesh/glsl/GrGLSLProgramBuilder.h"
12 #include "src/gpu/ganesh/glsl/GrGLSLUniformHandler.h"
13 #include "src/gpu/ganesh/glsl/GrGLSLVarying.h"
14
GrGLSLFragmentShaderBuilder(GrGLSLProgramBuilder * program)15 GrGLSLFragmentShaderBuilder::GrGLSLFragmentShaderBuilder(GrGLSLProgramBuilder* program)
16 : GrGLSLShaderBuilder(program) {}
17
dstColor()18 const char* GrGLSLFragmentShaderBuilder::dstColor() {
19 SkDEBUGCODE(fHasReadDstColorThisStage_DebugOnly = true;)
20
21 const GrShaderCaps* shaderCaps = fProgramBuilder->shaderCaps();
22 if (shaderCaps->fFBFetchSupport) {
23 this->addFeature(1 << kFramebufferFetch_GLSLPrivateFeature,
24 shaderCaps->fFBFetchExtensionString);
25
26 // Some versions of this extension string require declaring custom color output on ES 3.0+
27 const char* fbFetchColorName = "sk_LastFragColor";
28 if (shaderCaps->fFBFetchNeedsCustomOutput) {
29 fPrimaryColorIsInOut = true;
30 fbFetchColorName = DeclaredColorOutputName();
31 // Set the dstColor to an intermediate variable so we don't override it with the output
32 this->codeAppendf("half4 %s = %s;", kDstColorName, fbFetchColorName);
33 } else {
34 return fbFetchColorName;
35 }
36 }
37 return kDstColorName;
38 }
39
enableAdvancedBlendEquationIfNeeded(skgpu::BlendEquation equation)40 void GrGLSLFragmentShaderBuilder::enableAdvancedBlendEquationIfNeeded(
41 skgpu::BlendEquation equation) {
42 SkASSERT(skgpu::BlendEquationIsAdvanced(equation));
43
44 if (fProgramBuilder->shaderCaps()->mustEnableAdvBlendEqs()) {
45 this->addFeature(1 << kBlendEquationAdvanced_GLSLPrivateFeature,
46 "GL_KHR_blend_equation_advanced");
47 this->addLayoutQualifier("blend_support_all_equations", kOut_InterfaceQualifier);
48 }
49 }
50
enableSecondaryOutput()51 void GrGLSLFragmentShaderBuilder::enableSecondaryOutput() {
52 SkASSERT(!fHasSecondaryOutput);
53 fHasSecondaryOutput = true;
54 const GrShaderCaps& caps = *fProgramBuilder->shaderCaps();
55 if (const char* extension = caps.fSecondaryOutputExtensionString) {
56 this->addFeature(1 << kBlendFuncExtended_GLSLPrivateFeature, extension);
57 }
58
59 // If the primary output is declared, we must declare also the secondary output
60 // and vice versa, since it is not allowed to use a built-in gl_FragColor and a custom
61 // output. The condition also co-incides with the condition in which GLSL ES 2.0
62 // requires the built-in gl_SecondaryFragColorEXT, whereas 3.0 requires a custom output.
63 if (caps.mustDeclareFragmentShaderOutput()) {
64 fOutputs.emplace_back(DeclaredSecondaryColorOutputName(), SkSLType::kHalf4,
65 GrShaderVar::TypeModifier::Out);
66 fProgramBuilder->finalizeFragmentSecondaryColor(fOutputs.back());
67 }
68 }
69
getPrimaryColorOutputName() const70 const char* GrGLSLFragmentShaderBuilder::getPrimaryColorOutputName() const {
71 return DeclaredColorOutputName();
72 }
73
primaryColorOutputIsInOut() const74 bool GrGLSLFragmentShaderBuilder::primaryColorOutputIsInOut() const {
75 return fPrimaryColorIsInOut;
76 }
77
getSecondaryColorOutputName() const78 const char* GrGLSLFragmentShaderBuilder::getSecondaryColorOutputName() const {
79 if (this->hasSecondaryOutput()) {
80 return (fProgramBuilder->shaderCaps()->mustDeclareFragmentShaderOutput())
81 ? DeclaredSecondaryColorOutputName()
82 : "sk_SecondaryFragColor";
83 }
84 return nullptr;
85 }
86
getSurfaceOrigin() const87 GrSurfaceOrigin GrGLSLFragmentShaderBuilder::getSurfaceOrigin() const {
88 return fProgramBuilder->origin();
89 }
90
onFinalize()91 void GrGLSLFragmentShaderBuilder::onFinalize() {
92 fProgramBuilder->varyingHandler()->getFragDecls(&this->inputs(), &this->outputs());
93 }
94