1/*
2 * Copyright 2015 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/GrShaderCaps.h"
9#include "src/gpu/glsl/GrGLSLProgramBuilder.h"
10#include "src/gpu/glsl/GrGLSLVarying.h"
11
12void GrGLSLVaryingHandler::addPassThroughAttribute(const GrGeometryProcessor::Attribute& input,
13 const char* output,
14 Interpolation interpolation) {
15 SkASSERT(input.isInitialized());
16 SkASSERT(!fProgramBuilder->primitiveProcessor().willUseGeoShader());
17 GrGLSLVarying v(input.gpuType());
18 this->addVarying(input.name(), &v, interpolation);
19 fProgramBuilder->fVS.codeAppendf("%s = %s;", v.vsOut(), input.name());
20 fProgramBuilder->fFS.codeAppendf("%s = %s;", output, v.fsIn());
21}
22
23static bool use_flat_interpolation(GrGLSLVaryingHandler::Interpolation interpolation,
24 const GrShaderCaps& shaderCaps) {
25 switch (interpolation) {
26 using Interpolation = GrGLSLVaryingHandler::Interpolation;
27 case Interpolation::kInterpolated:
28 return false;
29 case Interpolation::kCanBeFlat:
30 SkASSERT(!shaderCaps.preferFlatInterpolation() ||
31 shaderCaps.flatInterpolationSupport());
32 return shaderCaps.preferFlatInterpolation();
33 case Interpolation::kMustBeFlat:
34 SkASSERT(shaderCaps.flatInterpolationSupport());
35 return true;
36 }
37 SK_ABORT("Invalid interpolation");
38}
39
40void GrGLSLVaryingHandler::addVarying(const char* name, GrGLSLVarying* varying,
41 Interpolation interpolation) {
42 SkASSERT(GrSLTypeIsFloatType(varying->type()) || Interpolation::kMustBeFlat == interpolation);
43 bool willUseGeoShader = fProgramBuilder->primitiveProcessor().willUseGeoShader();
44 VaryingInfo& v = fVaryings.push_back();
45
46 SkASSERT(varying);
47 SkASSERT(kVoid_GrSLType != varying->fType);
48 v.fType = varying->fType;
49 v.fIsFlat = use_flat_interpolation(interpolation, *fProgramBuilder->shaderCaps());
50 fProgramBuilder->nameVariable(&v.fVsOut, 'v', name);
51 v.fVisibility = kNone_GrShaderFlags;
52 if (varying->isInVertexShader()) {
53 varying->fVsOut = v.fVsOut.c_str();
54 v.fVisibility |= kVertex_GrShaderFlag;
55 }
56 if (willUseGeoShader) {
57 fProgramBuilder->nameVariable(&v.fGsOut, 'g', name);
58 varying->fGsIn = v.fVsOut.c_str();
59 varying->fGsOut = v.fGsOut.c_str();
60 v.fVisibility |= kGeometry_GrShaderFlag;
61 }
62 if (varying->isInFragmentShader()) {
63 varying->fFsIn = (willUseGeoShader ? v.fGsOut : v.fVsOut).c_str();
64 v.fVisibility |= kFragment_GrShaderFlag;
65 }
66}
67
68void GrGLSLVaryingHandler::emitAttributes(const GrGeometryProcessor& gp) {
69 for (const auto& attr : gp.vertexAttributes()) {
70 this->addAttribute(attr.asShaderVar());
71 }
72 for (const auto& attr : gp.instanceAttributes()) {
73 this->addAttribute(attr.asShaderVar());
74 }
75}
76
77void GrGLSLVaryingHandler::addAttribute(const GrShaderVar& var) {
78 SkASSERT(GrShaderVar::TypeModifier::In == var.getTypeModifier());
79 for (const GrShaderVar& attr : fVertexInputs.items()) {
80 // if attribute already added, don't add it again
81 if (attr.getName().equals(var.getName())) {
82 return;
83 }
84 }
85 fVertexInputs.push_back(var);
86}
87
88void GrGLSLVaryingHandler::setNoPerspective() {
89 const GrShaderCaps& caps = *fProgramBuilder->shaderCaps();
90 if (!caps.noperspectiveInterpolationSupport()) {
91 return;
92 }
93 if (const char* extension = caps.noperspectiveInterpolationExtensionString()) {
94 int bit = 1 << GrGLSLFragmentBuilder::kNoPerspectiveInterpolation_GLSLPrivateFeature;
95 fProgramBuilder->fVS.addFeature(bit, extension);
96 if (fProgramBuilder->primitiveProcessor().willUseGeoShader()) {
97 fProgramBuilder->fGS.addFeature(bit, extension);
98 }
99 fProgramBuilder->fFS.addFeature(bit, extension);
100 }
101 fDefaultInterpolationModifier = "noperspective";
102}
103
104void GrGLSLVaryingHandler::finalize() {
105 for (const VaryingInfo& v : fVaryings.items()) {
106 const char* modifier = v.fIsFlat ? "flat" : fDefaultInterpolationModifier;
107 if (v.fVisibility & kVertex_GrShaderFlag) {
108 fVertexOutputs.emplace_back(v.fVsOut, v.fType, GrShaderVar::TypeModifier::Out,
109 GrShaderVar::kNonArray, SkString(), SkString(modifier));
110 if (v.fVisibility & kGeometry_GrShaderFlag) {
111 fGeomInputs.emplace_back(v.fVsOut, v.fType, GrShaderVar::TypeModifier::In,
112 GrShaderVar::kUnsizedArray, SkString(), SkString(modifier));
113 }
114 }
115 if (v.fVisibility & kFragment_GrShaderFlag) {
116 const char* fsIn = v.fVsOut.c_str();
117 if (v.fVisibility & kGeometry_GrShaderFlag) {
118 fGeomOutputs.emplace_back(v.fGsOut, v.fType, GrShaderVar::TypeModifier::Out,
119 GrShaderVar::kNonArray, SkString(), SkString(modifier));
120 fsIn = v.fGsOut.c_str();
121 }
122 fFragInputs.emplace_back(SkString(fsIn), v.fType, GrShaderVar::TypeModifier::In,
123 GrShaderVar::kNonArray, SkString(), SkString(modifier));
124 }
125 }
126 this->onFinalize();
127}
128
129void GrGLSLVaryingHandler::appendDecls(const VarArray& vars, SkString* out) const {
130 for (const GrShaderVar& varying : vars.items()) {
131 varying.appendDecl(fProgramBuilder->shaderCaps(), out);
132 out->append(";");
133 }
134}
135
136void GrGLSLVaryingHandler::getVertexDecls(SkString* inputDecls, SkString* outputDecls) const {
137 this->appendDecls(fVertexInputs, inputDecls);
138 this->appendDecls(fVertexOutputs, outputDecls);
139}
140
141void GrGLSLVaryingHandler::getGeomDecls(SkString* inputDecls, SkString* outputDecls) const {
142 this->appendDecls(fGeomInputs, inputDecls);
143 this->appendDecls(fGeomOutputs, outputDecls);
144}
145
146void GrGLSLVaryingHandler::getFragDecls(SkString* inputDecls, SkString* outputDecls) const {
147 // We should not have any outputs in the fragment shader when using version 1.10
148 SkASSERT(k110_GrGLSLGeneration != fProgramBuilder->shaderCaps()->generation() ||
149 fFragOutputs.empty());
150 this->appendDecls(fFragInputs, inputDecls);
151 this->appendDecls(fFragOutputs, outputDecls);
152}
153