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 "GrGLSLFragmentShaderBuilder.h"
9 #include "GrRenderTarget.h"
10 #include "GrRenderTargetPriv.h"
11 #include "GrShaderCaps.h"
12 #include "gl/GrGLGpu.h"
13 #include "glsl/GrGLSLProgramBuilder.h"
14 #include "glsl/GrGLSLUniformHandler.h"
15 #include "glsl/GrGLSLVarying.h"
16
17 const char* GrGLSLFragmentShaderBuilder::kDstColorName = "_dstColor";
18
specific_layout_qualifier_name(GrBlendEquation equation)19 static const char* specific_layout_qualifier_name(GrBlendEquation equation) {
20 SkASSERT(GrBlendEquationIsAdvanced(equation));
21
22 static const char* kLayoutQualifierNames[] = {
23 "blend_support_screen",
24 "blend_support_overlay",
25 "blend_support_darken",
26 "blend_support_lighten",
27 "blend_support_colordodge",
28 "blend_support_colorburn",
29 "blend_support_hardlight",
30 "blend_support_softlight",
31 "blend_support_difference",
32 "blend_support_exclusion",
33 "blend_support_multiply",
34 "blend_support_hsl_hue",
35 "blend_support_hsl_saturation",
36 "blend_support_hsl_color",
37 "blend_support_hsl_luminosity"
38 };
39 return kLayoutQualifierNames[equation - kFirstAdvancedGrBlendEquation];
40
41 GR_STATIC_ASSERT(0 == kScreen_GrBlendEquation - kFirstAdvancedGrBlendEquation);
42 GR_STATIC_ASSERT(1 == kOverlay_GrBlendEquation - kFirstAdvancedGrBlendEquation);
43 GR_STATIC_ASSERT(2 == kDarken_GrBlendEquation - kFirstAdvancedGrBlendEquation);
44 GR_STATIC_ASSERT(3 == kLighten_GrBlendEquation - kFirstAdvancedGrBlendEquation);
45 GR_STATIC_ASSERT(4 == kColorDodge_GrBlendEquation - kFirstAdvancedGrBlendEquation);
46 GR_STATIC_ASSERT(5 == kColorBurn_GrBlendEquation - kFirstAdvancedGrBlendEquation);
47 GR_STATIC_ASSERT(6 == kHardLight_GrBlendEquation - kFirstAdvancedGrBlendEquation);
48 GR_STATIC_ASSERT(7 == kSoftLight_GrBlendEquation - kFirstAdvancedGrBlendEquation);
49 GR_STATIC_ASSERT(8 == kDifference_GrBlendEquation - kFirstAdvancedGrBlendEquation);
50 GR_STATIC_ASSERT(9 == kExclusion_GrBlendEquation - kFirstAdvancedGrBlendEquation);
51 GR_STATIC_ASSERT(10 == kMultiply_GrBlendEquation - kFirstAdvancedGrBlendEquation);
52 GR_STATIC_ASSERT(11 == kHSLHue_GrBlendEquation - kFirstAdvancedGrBlendEquation);
53 GR_STATIC_ASSERT(12 == kHSLSaturation_GrBlendEquation - kFirstAdvancedGrBlendEquation);
54 GR_STATIC_ASSERT(13 == kHSLColor_GrBlendEquation - kFirstAdvancedGrBlendEquation);
55 GR_STATIC_ASSERT(14 == kHSLLuminosity_GrBlendEquation - kFirstAdvancedGrBlendEquation);
56 // There's an illegal GrBlendEquation at the end there, hence the -1.
57 GR_STATIC_ASSERT(SK_ARRAY_COUNT(kLayoutQualifierNames) ==
58 kGrBlendEquationCnt - kFirstAdvancedGrBlendEquation - 1);
59 }
60
KeyForSurfaceOrigin(GrSurfaceOrigin origin)61 uint8_t GrGLSLFragmentShaderBuilder::KeyForSurfaceOrigin(GrSurfaceOrigin origin) {
62 SkASSERT(kTopLeft_GrSurfaceOrigin == origin || kBottomLeft_GrSurfaceOrigin == origin);
63 return origin + 1;
64
65 GR_STATIC_ASSERT(0 == kTopLeft_GrSurfaceOrigin);
66 GR_STATIC_ASSERT(1 == kBottomLeft_GrSurfaceOrigin);
67 }
68
GrGLSLFragmentShaderBuilder(GrGLSLProgramBuilder * program)69 GrGLSLFragmentShaderBuilder::GrGLSLFragmentShaderBuilder(GrGLSLProgramBuilder* program)
70 : GrGLSLFragmentBuilder(program)
71 , fSetupFragPosition(false)
72 , fHasCustomColorOutput(false)
73 , fCustomColorOutputIndex(-1)
74 , fHasSecondaryOutput(false)
75 , fForceHighPrecision(false) {
76 fSubstageIndices.push_back(0);
77 #ifdef SK_DEBUG
78 fHasReadDstColor = false;
79 #endif
80 }
81
ensureCoords2D(const GrShaderVar & coords)82 SkString GrGLSLFragmentShaderBuilder::ensureCoords2D(const GrShaderVar& coords) {
83 if (kFloat3_GrSLType != coords.getType() && kHalf3_GrSLType != coords.getType()) {
84 SkASSERT(kFloat2_GrSLType == coords.getType() || kHalf2_GrSLType == coords.getType());
85 return coords.getName();
86 }
87
88 SkString coords2D;
89 coords2D.printf("%s_ensure2D", coords.c_str());
90 this->codeAppendf("\tfloat2 %s = %s.xy / %s.z;", coords2D.c_str(), coords.c_str(),
91 coords.c_str());
92 return coords2D;
93 }
94
dstColor()95 const char* GrGLSLFragmentShaderBuilder::dstColor() {
96 SkDEBUGCODE(fHasReadDstColor = true;)
97
98 const GrShaderCaps* shaderCaps = fProgramBuilder->shaderCaps();
99 if (shaderCaps->fbFetchSupport()) {
100 this->addFeature(1 << kFramebufferFetch_GLSLPrivateFeature,
101 shaderCaps->fbFetchExtensionString());
102
103 // Some versions of this extension string require declaring custom color output on ES 3.0+
104 const char* fbFetchColorName = "sk_LastFragColor";
105 if (shaderCaps->fbFetchNeedsCustomOutput()) {
106 this->enableCustomOutput();
107 fOutputs[fCustomColorOutputIndex].setTypeModifier(GrShaderVar::kInOut_TypeModifier);
108 fbFetchColorName = DeclaredColorOutputName();
109 // Set the dstColor to an intermediate variable so we don't override it with the output
110 this->codeAppendf("half4 %s = %s;", kDstColorName, fbFetchColorName);
111 } else {
112 return fbFetchColorName;
113 }
114 }
115 return kDstColorName;
116 }
117
enableAdvancedBlendEquationIfNeeded(GrBlendEquation equation)118 void GrGLSLFragmentShaderBuilder::enableAdvancedBlendEquationIfNeeded(GrBlendEquation equation) {
119 SkASSERT(GrBlendEquationIsAdvanced(equation));
120
121 const GrShaderCaps& caps = *fProgramBuilder->shaderCaps();
122 if (!caps.mustEnableAdvBlendEqs()) {
123 return;
124 }
125
126 this->addFeature(1 << kBlendEquationAdvanced_GLSLPrivateFeature,
127 "GL_KHR_blend_equation_advanced");
128 if (caps.mustEnableSpecificAdvBlendEqs()) {
129 this->addLayoutQualifier(specific_layout_qualifier_name(equation), kOut_InterfaceQualifier);
130 } else {
131 this->addLayoutQualifier("blend_support_all_equations", kOut_InterfaceQualifier);
132 }
133 }
134
enableCustomOutput()135 void GrGLSLFragmentShaderBuilder::enableCustomOutput() {
136 if (!fHasCustomColorOutput) {
137 fHasCustomColorOutput = true;
138 fCustomColorOutputIndex = fOutputs.count();
139 fOutputs.push_back().set(kHalf4_GrSLType, DeclaredColorOutputName(),
140 GrShaderVar::kOut_TypeModifier);
141 fProgramBuilder->finalizeFragmentOutputColor(fOutputs.back());
142 }
143 }
144
enableSecondaryOutput()145 void GrGLSLFragmentShaderBuilder::enableSecondaryOutput() {
146 SkASSERT(!fHasSecondaryOutput);
147 fHasSecondaryOutput = true;
148 const GrShaderCaps& caps = *fProgramBuilder->shaderCaps();
149 if (const char* extension = caps.secondaryOutputExtensionString()) {
150 this->addFeature(1 << kBlendFuncExtended_GLSLPrivateFeature, extension);
151 }
152
153 // If the primary output is declared, we must declare also the secondary output
154 // and vice versa, since it is not allowed to use a built-in gl_FragColor and a custom
155 // output. The condition also co-incides with the condition in whici GLES SL 2.0
156 // requires the built-in gl_SecondaryFragColorEXT, where as 3.0 requires a custom output.
157 if (caps.mustDeclareFragmentShaderOutput()) {
158 fOutputs.push_back().set(kHalf4_GrSLType, DeclaredSecondaryColorOutputName(),
159 GrShaderVar::kOut_TypeModifier);
160 fProgramBuilder->finalizeFragmentSecondaryColor(fOutputs.back());
161 }
162 }
163
getPrimaryColorOutputName() const164 const char* GrGLSLFragmentShaderBuilder::getPrimaryColorOutputName() const {
165 return fHasCustomColorOutput ? DeclaredColorOutputName() : "sk_FragColor";
166 }
167
primaryColorOutputIsInOut() const168 bool GrGLSLFragmentShaderBuilder::primaryColorOutputIsInOut() const {
169 return fHasCustomColorOutput &&
170 fOutputs[fCustomColorOutputIndex].getTypeModifier() == GrShaderVar::kInOut_TypeModifier;
171 }
172
declAppendf(const char * fmt,...)173 void GrGLSLFragmentBuilder::declAppendf(const char* fmt, ...) {
174 va_list argp;
175 va_start(argp, fmt);
176 inputs().appendVAList(fmt, argp);
177 va_end(argp);
178 }
179
getSecondaryColorOutputName() const180 const char* GrGLSLFragmentShaderBuilder::getSecondaryColorOutputName() const {
181 const GrShaderCaps& caps = *fProgramBuilder->shaderCaps();
182 return caps.mustDeclareFragmentShaderOutput() ? DeclaredSecondaryColorOutputName()
183 : "gl_SecondaryFragColorEXT";
184 }
185
getSurfaceOrigin() const186 GrSurfaceOrigin GrGLSLFragmentShaderBuilder::getSurfaceOrigin() const {
187 SkASSERT(fProgramBuilder->header().fSurfaceOriginKey);
188 return static_cast<GrSurfaceOrigin>(fProgramBuilder->header().fSurfaceOriginKey-1);
189
190 GR_STATIC_ASSERT(0 == kTopLeft_GrSurfaceOrigin);
191 GR_STATIC_ASSERT(1 == kBottomLeft_GrSurfaceOrigin);
192 }
193
onFinalize()194 void GrGLSLFragmentShaderBuilder::onFinalize() {
195 fProgramBuilder->varyingHandler()->getFragDecls(&this->inputs(), &this->outputs());
196 }
197
onBeforeChildProcEmitCode()198 void GrGLSLFragmentShaderBuilder::onBeforeChildProcEmitCode() {
199 SkASSERT(fSubstageIndices.count() >= 1);
200 fSubstageIndices.push_back(0);
201 // second-to-last value in the fSubstageIndices stack is the index of the child proc
202 // at that level which is currently emitting code.
203 fMangleString.appendf("_c%d", fSubstageIndices[fSubstageIndices.count() - 2]);
204 }
205
onAfterChildProcEmitCode()206 void GrGLSLFragmentShaderBuilder::onAfterChildProcEmitCode() {
207 SkASSERT(fSubstageIndices.count() >= 2);
208 fSubstageIndices.pop_back();
209 fSubstageIndices.back()++;
210 int removeAt = fMangleString.findLastOf('_');
211 fMangleString.remove(removeAt, fMangleString.size() - removeAt);
212 }
213