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/glsl/GrGLSLShaderBuilder.h"
9
10 #include "src/gpu/GrShaderCaps.h"
11 #include "src/gpu/GrShaderVar.h"
12 #include "src/gpu/GrSwizzle.h"
13 #include "src/gpu/glsl/GrGLSLColorSpaceXformHelper.h"
14 #include "src/gpu/glsl/GrGLSLProgramBuilder.h"
15
GrGLSLShaderBuilder(GrGLSLProgramBuilder * program)16 GrGLSLShaderBuilder::GrGLSLShaderBuilder(GrGLSLProgramBuilder* program)
17 : fProgramBuilder(program)
18 , fInputs(GrGLSLProgramBuilder::kVarsPerBlock)
19 , fOutputs(GrGLSLProgramBuilder::kVarsPerBlock)
20 , fFeaturesAddedMask(0)
21 , fCodeIndex(kCode)
22 , fFinalized(false) {
23 // We push back some dummy pointers which will later become our header
24 for (int i = 0; i <= kCode; i++) {
25 fShaderStrings.push_back();
26 }
27
28 this->main() = "void main() {";
29 }
30
declAppend(const GrShaderVar & var)31 void GrGLSLShaderBuilder::declAppend(const GrShaderVar& var) {
32 SkString tempDecl;
33 var.appendDecl(fProgramBuilder->shaderCaps(), &tempDecl);
34 this->codeAppendf("%s;", tempDecl.c_str());
35 }
36
declareGlobal(const GrShaderVar & v)37 void GrGLSLShaderBuilder::declareGlobal(const GrShaderVar& v) {
38 v.appendDecl(this->getProgramBuilder()->shaderCaps(), &this->definitions());
39 this->definitions().append(";");
40 }
41
emitFunction(GrSLType returnType,const char * name,int argCnt,const GrShaderVar * args,const char * body,SkString * outName)42 void GrGLSLShaderBuilder::emitFunction(GrSLType returnType,
43 const char* name,
44 int argCnt,
45 const GrShaderVar* args,
46 const char* body,
47 SkString* outName) {
48 this->functions().append(GrGLSLTypeString(returnType));
49 fProgramBuilder->nameVariable(outName, '\0', name);
50 this->functions().appendf(" %s", outName->c_str());
51 this->functions().append("(");
52 for (int i = 0; i < argCnt; ++i) {
53 args[i].appendDecl(fProgramBuilder->shaderCaps(), &this->functions());
54 if (i < argCnt - 1) {
55 this->functions().append(", ");
56 }
57 }
58 this->functions().append(") {\n");
59 this->functions().append(body);
60 this->functions().append("}\n\n");
61 }
62
append_texture_swizzle(SkString * out,GrSwizzle swizzle)63 static inline void append_texture_swizzle(SkString* out, GrSwizzle swizzle) {
64 if (swizzle != GrSwizzle::RGBA()) {
65 out->appendf(".%s", swizzle.c_str());
66 }
67 }
68
appendTextureLookup(SkString * out,SamplerHandle samplerHandle,const char * coordName,GrSLType varyingType) const69 void GrGLSLShaderBuilder::appendTextureLookup(SkString* out,
70 SamplerHandle samplerHandle,
71 const char* coordName,
72 GrSLType varyingType) const {
73 const char* sampler = fProgramBuilder->samplerVariable(samplerHandle);
74 out->appendf("sample(%s, %s)", sampler, coordName);
75 append_texture_swizzle(out, fProgramBuilder->samplerSwizzle(samplerHandle));
76 }
77
appendTextureLookup(SamplerHandle samplerHandle,const char * coordName,GrSLType varyingType,GrGLSLColorSpaceXformHelper * colorXformHelper)78 void GrGLSLShaderBuilder::appendTextureLookup(SamplerHandle samplerHandle,
79 const char* coordName,
80 GrSLType varyingType,
81 GrGLSLColorSpaceXformHelper* colorXformHelper) {
82 SkString lookup;
83 this->appendTextureLookup(&lookup, samplerHandle, coordName, varyingType);
84 this->appendColorGamutXform(lookup.c_str(), colorXformHelper);
85 }
86
appendTextureLookupAndModulate(const char * modulation,SamplerHandle samplerHandle,const char * coordName,GrSLType varyingType,GrGLSLColorSpaceXformHelper * colorXformHelper)87 void GrGLSLShaderBuilder::appendTextureLookupAndModulate(
88 const char* modulation,
89 SamplerHandle samplerHandle,
90 const char* coordName,
91 GrSLType varyingType,
92 GrGLSLColorSpaceXformHelper* colorXformHelper) {
93 SkString lookup;
94 this->appendTextureLookup(&lookup, samplerHandle, coordName, varyingType);
95 this->appendColorGamutXform(lookup.c_str(), colorXformHelper);
96 if (modulation) {
97 this->codeAppendf(" * %s", modulation);
98 }
99 }
100
appendColorGamutXform(SkString * out,const char * srcColor,GrGLSLColorSpaceXformHelper * colorXformHelper)101 void GrGLSLShaderBuilder::appendColorGamutXform(SkString* out,
102 const char* srcColor,
103 GrGLSLColorSpaceXformHelper* colorXformHelper) {
104 if (!colorXformHelper || colorXformHelper->isNoop()) {
105 *out = srcColor;
106 return;
107 }
108
109 GrGLSLUniformHandler* uniformHandler = fProgramBuilder->uniformHandler();
110
111 // We define up to three helper functions, to keep things clearer. One for the source transfer
112 // function, one for the (inverse) destination transfer function, and one for the gamut xform.
113 // Any combination of these may be present, although some configurations are much more likely.
114
115 auto emitTFFunc = [=](const char* name, GrGLSLProgramDataManager::UniformHandle uniform,
116 TFKind kind) {
117 const GrShaderVar gTFArgs[] = { GrShaderVar("x", kHalf_GrSLType) };
118 const char* coeffs = uniformHandler->getUniformCStr(uniform);
119 SkString body;
120 // Temporaries to make evaluation line readable. We always use the sRGBish names, so the
121 // PQ and HLG math is confusing.
122 body.appendf("half G = %s[0];", coeffs);
123 body.appendf("half A = %s[1];", coeffs);
124 body.appendf("half B = %s[2];", coeffs);
125 body.appendf("half C = %s[3];", coeffs);
126 body.appendf("half D = %s[4];", coeffs);
127 body.appendf("half E = %s[5];", coeffs);
128 body.appendf("half F = %s[6];", coeffs);
129 body.append("half s = sign(x);");
130 body.append("x = abs(x);");
131 switch (kind) {
132 case TFKind::sRGBish_TF:
133 body.append("x = (x < D) ? (C * x) + F : pow(A * x + B, G) + E;");
134 break;
135 case TFKind::PQish_TF:
136 body.append("x = pow(max(A + B * pow(x, C), 0) / (D + E * pow(x, C)), F);");
137 break;
138 case TFKind::HLGish_TF:
139 body.append("x = (x*A <= 1) ? pow(x*A, B) : exp((x-E)*C) + D;");
140 break;
141 case TFKind::HLGinvish_TF:
142 body.append("x = (x <= 1) ? A * pow(x, B) : C * log(x - D) + E;");
143 break;
144 default:
145 SkASSERT(false);
146 break;
147 }
148 body.append("return s * x;");
149 SkString funcName;
150 this->emitFunction(kHalf_GrSLType, name, SK_ARRAY_COUNT(gTFArgs), gTFArgs, body.c_str(),
151 &funcName);
152 return funcName;
153 };
154
155 SkString srcTFFuncName;
156 if (colorXformHelper->applySrcTF()) {
157 srcTFFuncName = emitTFFunc("src_tf", colorXformHelper->srcTFUniform(),
158 colorXformHelper->srcTFKind());
159 }
160
161 SkString dstTFFuncName;
162 if (colorXformHelper->applyDstTF()) {
163 dstTFFuncName = emitTFFunc("dst_tf", colorXformHelper->dstTFUniform(),
164 colorXformHelper->dstTFKind());
165 }
166
167 SkString gamutXformFuncName;
168 if (colorXformHelper->applyGamutXform()) {
169 const GrShaderVar gGamutXformArgs[] = { GrShaderVar("color", kHalf4_GrSLType) };
170 const char* xform = uniformHandler->getUniformCStr(colorXformHelper->gamutXformUniform());
171 SkString body;
172 body.appendf("color.rgb = (%s * color.rgb);", xform);
173 body.append("return color;");
174 this->emitFunction(kHalf4_GrSLType, "gamut_xform", SK_ARRAY_COUNT(gGamutXformArgs),
175 gGamutXformArgs, body.c_str(), &gamutXformFuncName);
176 }
177
178 // Now define a wrapper function that applies all the intermediate steps
179 {
180 const GrShaderVar gColorXformArgs[] = { GrShaderVar("color", kHalf4_GrSLType) };
181 SkString body;
182 if (colorXformHelper->applyUnpremul()) {
183 body.append("half nonZeroAlpha = max(color.a, 0.0001);");
184 body.append("color = half4(color.rgb / nonZeroAlpha, nonZeroAlpha);");
185 }
186 if (colorXformHelper->applySrcTF()) {
187 body.appendf("color.r = %s(color.r);", srcTFFuncName.c_str());
188 body.appendf("color.g = %s(color.g);", srcTFFuncName.c_str());
189 body.appendf("color.b = %s(color.b);", srcTFFuncName.c_str());
190 }
191 if (colorXformHelper->applyGamutXform()) {
192 body.appendf("color = %s(color);", gamutXformFuncName.c_str());
193 }
194 if (colorXformHelper->applyDstTF()) {
195 body.appendf("color.r = %s(color.r);", dstTFFuncName.c_str());
196 body.appendf("color.g = %s(color.g);", dstTFFuncName.c_str());
197 body.appendf("color.b = %s(color.b);", dstTFFuncName.c_str());
198 }
199 if (colorXformHelper->applyPremul()) {
200 body.append("color.rgb *= color.a;");
201 }
202 body.append("return color;");
203 SkString colorXformFuncName;
204 this->emitFunction(kHalf4_GrSLType, "color_xform", SK_ARRAY_COUNT(gColorXformArgs),
205 gColorXformArgs, body.c_str(), &colorXformFuncName);
206 out->appendf("%s(%s)", colorXformFuncName.c_str(), srcColor);
207 }
208 }
209
appendColorGamutXform(const char * srcColor,GrGLSLColorSpaceXformHelper * colorXformHelper)210 void GrGLSLShaderBuilder::appendColorGamutXform(const char* srcColor,
211 GrGLSLColorSpaceXformHelper* colorXformHelper) {
212 SkString xform;
213 this->appendColorGamutXform(&xform, srcColor, colorXformHelper);
214 this->codeAppend(xform.c_str());
215 }
216
addFeature(uint32_t featureBit,const char * extensionName)217 bool GrGLSLShaderBuilder::addFeature(uint32_t featureBit, const char* extensionName) {
218 if (featureBit & fFeaturesAddedMask) {
219 return false;
220 }
221 this->extensions().appendf("#extension %s: require\n", extensionName);
222 fFeaturesAddedMask |= featureBit;
223 return true;
224 }
225
appendDecls(const VarArray & vars,SkString * out) const226 void GrGLSLShaderBuilder::appendDecls(const VarArray& vars, SkString* out) const {
227 for (int i = 0; i < vars.count(); ++i) {
228 vars[i].appendDecl(fProgramBuilder->shaderCaps(), out);
229 out->append(";\n");
230 }
231 }
232
addLayoutQualifier(const char * param,InterfaceQualifier interface)233 void GrGLSLShaderBuilder::addLayoutQualifier(const char* param, InterfaceQualifier interface) {
234 SkASSERT(fProgramBuilder->shaderCaps()->generation() >= k330_GrGLSLGeneration ||
235 fProgramBuilder->shaderCaps()->mustEnableAdvBlendEqs());
236 fLayoutParams[interface].push_back() = param;
237 }
238
compileAndAppendLayoutQualifiers()239 void GrGLSLShaderBuilder::compileAndAppendLayoutQualifiers() {
240 static const char* interfaceQualifierNames[] = {
241 "in",
242 "out"
243 };
244
245 for (int interface = 0; interface <= kLastInterfaceQualifier; ++interface) {
246 const SkTArray<SkString>& params = fLayoutParams[interface];
247 if (params.empty()) {
248 continue;
249 }
250 this->layoutQualifiers().appendf("layout(%s", params[0].c_str());
251 for (int i = 1; i < params.count(); ++i) {
252 this->layoutQualifiers().appendf(", %s", params[i].c_str());
253 }
254 this->layoutQualifiers().appendf(") %s;\n", interfaceQualifierNames[interface]);
255 }
256
257 GR_STATIC_ASSERT(0 == GrGLSLShaderBuilder::kIn_InterfaceQualifier);
258 GR_STATIC_ASSERT(1 == GrGLSLShaderBuilder::kOut_InterfaceQualifier);
259 GR_STATIC_ASSERT(SK_ARRAY_COUNT(interfaceQualifierNames) == kLastInterfaceQualifier + 1);
260 }
261
finalize(uint32_t visibility)262 void GrGLSLShaderBuilder::finalize(uint32_t visibility) {
263 SkASSERT(!fFinalized);
264 this->compileAndAppendLayoutQualifiers();
265 SkASSERT(visibility);
266 fProgramBuilder->appendUniformDecls((GrShaderFlags) visibility, &this->uniforms());
267 this->appendDecls(fInputs, &this->inputs());
268 this->appendDecls(fOutputs, &this->outputs());
269 this->onFinalize();
270 // append the 'footer' to code
271 this->code().append("}");
272
273 for (int i = 0; i <= fCodeIndex; i++) {
274 fCompilerString.append(fShaderStrings[i].c_str(), fShaderStrings[i].size());
275 }
276
277 fFinalized = true;
278 }
279