joshualitt | 30ba436 | 2014-08-21 20:18:45 -0700 | [diff] [blame^] | 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 "GrGLFragmentShaderBuilder.h" |
| 9 | #include "GrGLShaderStringBuilder.h" |
| 10 | #include "GrGLProgramBuilder.h" |
| 11 | #include "../GrGpuGL.h" |
| 12 | |
| 13 | namespace { |
| 14 | #define GL_CALL(X) GR_GL_CALL(gpu->glInterface(), X) |
| 15 | #define GL_CALL_RET(R, X) GR_GL_CALL_RET(gpu->glInterface(), R, X) |
| 16 | // ES2 FS only guarantees mediump and lowp support |
| 17 | static const GrGLShaderVar::Precision kDefaultFragmentPrecision = GrGLShaderVar::kMedium_Precision; |
| 18 | static const char kDstCopyColorName[] = "_dstColor"; |
| 19 | inline const char* declared_color_output_name() { return "fsColorOut"; } |
| 20 | inline const char* dual_source_output_name() { return "dualSourceOut"; } |
| 21 | inline void append_default_precision_qualifier(GrGLShaderVar::Precision p, |
| 22 | GrGLStandard standard, |
| 23 | SkString* str) { |
| 24 | // Desktop GLSL has added precision qualifiers but they don't do anything. |
| 25 | if (kGLES_GrGLStandard == standard) { |
| 26 | switch (p) { |
| 27 | case GrGLShaderVar::kHigh_Precision: |
| 28 | str->append("precision highp float;\n"); |
| 29 | break; |
| 30 | case GrGLShaderVar::kMedium_Precision: |
| 31 | str->append("precision mediump float;\n"); |
| 32 | break; |
| 33 | case GrGLShaderVar::kLow_Precision: |
| 34 | str->append("precision lowp float;\n"); |
| 35 | break; |
| 36 | case GrGLShaderVar::kDefault_Precision: |
| 37 | SkFAIL("Default precision now allowed."); |
| 38 | default: |
| 39 | SkFAIL("Unknown precision value."); |
| 40 | } |
| 41 | } |
| 42 | } |
| 43 | } |
| 44 | |
| 45 | GrGLFragmentShaderBuilder::DstReadKey GrGLFragmentShaderBuilder::KeyForDstRead( |
| 46 | const GrTexture* dstCopy, const GrGLCaps& caps) { |
| 47 | uint32_t key = kYesDstRead_DstReadKeyBit; |
| 48 | if (caps.fbFetchSupport()) { |
| 49 | return key; |
| 50 | } |
| 51 | SkASSERT(NULL != dstCopy); |
| 52 | if (!caps.textureSwizzleSupport() && GrPixelConfigIsAlphaOnly(dstCopy->config())) { |
| 53 | // The fact that the config is alpha-only must be considered when generating code. |
| 54 | key |= kUseAlphaConfig_DstReadKeyBit; |
| 55 | } |
| 56 | if (kTopLeft_GrSurfaceOrigin == dstCopy->origin()) { |
| 57 | key |= kTopLeftOrigin_DstReadKeyBit; |
| 58 | } |
| 59 | SkASSERT(static_cast<DstReadKey>(key) == key); |
| 60 | return static_cast<DstReadKey>(key); |
| 61 | } |
| 62 | |
| 63 | GrGLFragmentShaderBuilder::FragPosKey GrGLFragmentShaderBuilder::KeyForFragmentPosition( |
| 64 | const GrRenderTarget* dst, const GrGLCaps&) { |
| 65 | if (kTopLeft_GrSurfaceOrigin == dst->origin()) { |
| 66 | return kTopLeftFragPosRead_FragPosKey; |
| 67 | } else { |
| 68 | return kBottomLeftFragPosRead_FragPosKey; |
| 69 | } |
| 70 | } |
| 71 | |
| 72 | GrGLFragmentShaderBuilder::GrGLFragmentShaderBuilder(GrGLProgramBuilder* program, |
| 73 | const GrGLProgramDesc& desc) |
| 74 | : INHERITED(program) |
| 75 | , fHasCustomColorOutput(false) |
| 76 | , fHasSecondaryOutput(false) |
| 77 | , fSetupFragPosition(false) |
| 78 | , fTopLeftFragPosRead(kTopLeftFragPosRead_FragPosKey == desc.getHeader().fFragPosKey){ |
| 79 | } |
| 80 | |
| 81 | const char* GrGLFragmentShaderBuilder::dstColor() { |
| 82 | if (fProgramBuilder->fCodeStage.inStageCode()) { |
| 83 | const GrEffect* effect = fProgramBuilder->fCodeStage.effectStage()->getEffect(); |
| 84 | if (!effect->willReadDstColor()) { |
| 85 | SkDEBUGFAIL("GrGLEffect asked for dst color but its generating GrEffect " |
| 86 | "did not request access."); |
| 87 | return ""; |
| 88 | } |
| 89 | } |
| 90 | |
| 91 | GrGpuGL* gpu = fProgramBuilder->gpu(); |
| 92 | if (gpu->glCaps().fbFetchSupport()) { |
| 93 | this->addFeature(1 << (GrGLFragmentShaderBuilder::kLastGLSLPrivateFeature + 1), |
| 94 | gpu->glCaps().fbFetchExtensionString()); |
| 95 | return gpu->glCaps().fbFetchColorName(); |
| 96 | } else if (fProgramBuilder->fUniformHandles.fDstCopySamplerUni.isValid()) { |
| 97 | return kDstCopyColorName; |
| 98 | } else { |
| 99 | return ""; |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | bool GrGLFragmentShaderBuilder::enableFeature(GLSLFeature feature) { |
| 104 | switch (feature) { |
| 105 | case kStandardDerivatives_GLSLFeature: { |
| 106 | GrGpuGL* gpu = fProgramBuilder->gpu(); |
| 107 | if (!gpu->glCaps().shaderDerivativeSupport()) { |
| 108 | return false; |
| 109 | } |
| 110 | if (kGLES_GrGLStandard == gpu->glStandard()) { |
| 111 | this->addFeature(1 << kStandardDerivatives_GLSLFeature, |
| 112 | "GL_OES_standard_derivatives"); |
| 113 | } |
| 114 | return true; |
| 115 | } |
| 116 | default: |
| 117 | SkFAIL("Unexpected GLSLFeature requested."); |
| 118 | return false; |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | SkString GrGLFragmentShaderBuilder::ensureFSCoords2D(const TransformedCoordsArray& coords, int index) { |
| 123 | if (kVec3f_GrSLType != coords[index].type()) { |
| 124 | SkASSERT(kVec2f_GrSLType == coords[index].type()); |
| 125 | return coords[index].getName(); |
| 126 | } |
| 127 | |
| 128 | SkString coords2D("coords2D"); |
| 129 | if (0 != index) { |
| 130 | coords2D.appendf("_%i", index); |
| 131 | } |
| 132 | this->codeAppendf("\tvec2 %s = %s.xy / %s.z;", |
| 133 | coords2D.c_str(), coords[index].c_str(), coords[index].c_str()); |
| 134 | return coords2D; |
| 135 | } |
| 136 | |
| 137 | const char* GrGLFragmentShaderBuilder::fragmentPosition() { |
| 138 | GrGLProgramBuilder::CodeStage* cs = &fProgramBuilder->fCodeStage; |
| 139 | if (cs->inStageCode()) { |
| 140 | const GrEffect* effect = cs->effectStage()->getEffect(); |
| 141 | if (!effect->willReadFragmentPosition()) { |
| 142 | SkDEBUGFAIL("GrGLEffect asked for frag position but its generating GrEffect " |
| 143 | "did not request access."); |
| 144 | return ""; |
| 145 | } |
| 146 | } |
| 147 | |
| 148 | GrGpuGL* gpu = fProgramBuilder->gpu(); |
| 149 | // We only declare "gl_FragCoord" when we're in the case where we want to use layout qualifiers |
| 150 | // to reverse y. Otherwise it isn't necessary and whether the "in" qualifier appears in the |
| 151 | // declaration varies in earlier GLSL specs. So it is simpler to omit it. |
| 152 | if (fTopLeftFragPosRead) { |
| 153 | fSetupFragPosition = true; |
| 154 | return "gl_FragCoord"; |
| 155 | } else if (gpu->glCaps().fragCoordConventionsSupport()) { |
| 156 | if (!fSetupFragPosition) { |
| 157 | if (gpu->glslGeneration() < k150_GrGLSLGeneration) { |
| 158 | this->addFeature(1 << kFragCoordConventions_GLSLPrivateFeature, |
| 159 | "GL_ARB_fragment_coord_conventions"); |
| 160 | } |
| 161 | fInputs.push_back().set(kVec4f_GrSLType, |
| 162 | GrGLShaderVar::kIn_TypeModifier, |
| 163 | "gl_FragCoord", |
| 164 | GrGLShaderVar::kDefault_Precision, |
| 165 | GrGLShaderVar::kUpperLeft_Origin); |
| 166 | fSetupFragPosition = true; |
| 167 | } |
| 168 | return "gl_FragCoord"; |
| 169 | } else { |
| 170 | static const char* kCoordName = "fragCoordYDown"; |
| 171 | if (!fSetupFragPosition) { |
| 172 | // temporarily change the stage index because we're inserting non-stage code. |
| 173 | GrGLProgramBuilder::CodeStage::AutoStageRestore csar(cs, NULL); |
| 174 | |
| 175 | SkASSERT(!fProgramBuilder->fUniformHandles.fRTHeightUni.isValid()); |
| 176 | const char* rtHeightName; |
| 177 | |
| 178 | fProgramBuilder->fUniformHandles.fRTHeightUni = |
| 179 | fProgramBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility, |
| 180 | kFloat_GrSLType, |
| 181 | "RTHeight", |
| 182 | &rtHeightName); |
| 183 | |
| 184 | // Using glFragCoord.zw for the last two components tickles an Adreno driver bug that |
| 185 | // causes programs to fail to link. Making this function return a vec2() didn't fix the |
| 186 | // problem but using 1.0 for the last two components does. |
| 187 | this->codePrependf("\tvec4 %s = vec4(gl_FragCoord.x, %s - gl_FragCoord.y, 1.0, " |
| 188 | "1.0);\n", kCoordName, rtHeightName); |
| 189 | fSetupFragPosition = true; |
| 190 | } |
| 191 | SkASSERT(fProgramBuilder->fUniformHandles.fRTHeightUni.isValid()); |
| 192 | return kCoordName; |
| 193 | } |
| 194 | } |
| 195 | |
| 196 | void GrGLFragmentShaderBuilder::addVarying(GrSLType type, |
| 197 | const char* name, |
| 198 | const char** fsInName) { |
| 199 | fInputs.push_back().set(type, GrGLShaderVar::kVaryingIn_TypeModifier, name); |
| 200 | if (fsInName) { |
| 201 | *fsInName = name; |
| 202 | } |
| 203 | } |
| 204 | |
| 205 | void GrGLFragmentShaderBuilder::bindProgramLocations(GrGLuint programId) { |
| 206 | GrGpuGL* gpu = fProgramBuilder->gpu(); |
| 207 | if (fHasCustomColorOutput) { |
| 208 | GL_CALL(BindFragDataLocation(programId, 0, declared_color_output_name())); |
| 209 | } |
| 210 | if (fHasSecondaryOutput) { |
| 211 | GL_CALL(BindFragDataLocationIndexed(programId, 0, 1, dual_source_output_name())); |
| 212 | } |
| 213 | } |
| 214 | |
| 215 | bool GrGLFragmentShaderBuilder::compileAndAttachShaders(GrGLuint programId, |
| 216 | SkTDArray<GrGLuint>* shaderIds) const { |
| 217 | GrGpuGL* gpu = fProgramBuilder->gpu(); |
| 218 | SkString fragShaderSrc(GrGetGLSLVersionDecl(gpu->ctxInfo())); |
| 219 | fragShaderSrc.append(fExtensions); |
| 220 | append_default_precision_qualifier(kDefaultFragmentPrecision, |
| 221 | gpu->glStandard(), |
| 222 | &fragShaderSrc); |
| 223 | fProgramBuilder->appendUniformDecls(GrGLProgramBuilder::kFragment_Visibility, &fragShaderSrc); |
| 224 | fProgramBuilder->appendDecls(fInputs, &fragShaderSrc); |
| 225 | // We shouldn't have declared outputs on 1.10 |
| 226 | SkASSERT(k110_GrGLSLGeneration != gpu->glslGeneration() || fOutputs.empty()); |
| 227 | fProgramBuilder->appendDecls(fOutputs, &fragShaderSrc); |
| 228 | fragShaderSrc.append(fFunctions); |
| 229 | fragShaderSrc.append("void main() {\n"); |
| 230 | fragShaderSrc.append(fCode); |
| 231 | fragShaderSrc.append("}\n"); |
| 232 | |
| 233 | GrGLuint fragShaderId = GrGLCompileAndAttachShader(gpu->glContext(), |
| 234 | programId, GR_GL_FRAGMENT_SHADER, fragShaderSrc); |
| 235 | if (!fragShaderId) { |
| 236 | return false; |
| 237 | } |
| 238 | |
| 239 | *shaderIds->append() = fragShaderId; |
| 240 | |
| 241 | return true; |
| 242 | } |
| 243 | |
| 244 | void GrGLFragmentShaderBuilder::emitCodeBeforeEffects() { |
| 245 | const GrGLProgramDesc::KeyHeader& header = fProgramBuilder->desc().getHeader(); |
| 246 | GrGpuGL* gpu = fProgramBuilder->gpu(); |
| 247 | |
| 248 | /////////////////////////////////////////////////////////////////////////// |
| 249 | // emit code to read the dst copy texture, if necessary |
| 250 | if (kNoDstRead_DstReadKey != header.fDstReadKey && !gpu->glCaps().fbFetchSupport()) { |
| 251 | bool topDown = SkToBool(kTopLeftOrigin_DstReadKeyBit & header.fDstReadKey); |
| 252 | const char* dstCopyTopLeftName; |
| 253 | const char* dstCopyCoordScaleName; |
| 254 | const char* dstCopySamplerName; |
| 255 | uint32_t configMask; |
| 256 | if (SkToBool(kUseAlphaConfig_DstReadKeyBit & header.fDstReadKey)) { |
| 257 | configMask = kA_GrColorComponentFlag; |
| 258 | } else { |
| 259 | configMask = kRGBA_GrColorComponentFlags; |
| 260 | } |
| 261 | fProgramBuilder->fUniformHandles.fDstCopySamplerUni = |
| 262 | fProgramBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility, |
| 263 | kSampler2D_GrSLType, |
| 264 | "DstCopySampler", |
| 265 | &dstCopySamplerName); |
| 266 | fProgramBuilder->fUniformHandles.fDstCopyTopLeftUni = |
| 267 | fProgramBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility, |
| 268 | kVec2f_GrSLType, |
| 269 | "DstCopyUpperLeft", |
| 270 | &dstCopyTopLeftName); |
| 271 | fProgramBuilder->fUniformHandles.fDstCopyScaleUni = |
| 272 | fProgramBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility, |
| 273 | kVec2f_GrSLType, |
| 274 | "DstCopyCoordScale", |
| 275 | &dstCopyCoordScaleName); |
| 276 | const char* fragPos = fragmentPosition(); |
| 277 | |
| 278 | this->codeAppend("// Read color from copy of the destination.\n"); |
| 279 | this->codeAppendf("vec2 _dstTexCoord = (%s.xy - %s) * %s;", |
| 280 | fragPos, dstCopyTopLeftName, dstCopyCoordScaleName); |
| 281 | if (!topDown) { |
| 282 | this->codeAppend("_dstTexCoord.y = 1.0 - _dstTexCoord.y;"); |
| 283 | } |
| 284 | this->codeAppendf("vec4 %s = ", kDstCopyColorName); |
| 285 | this->appendTextureLookup(dstCopySamplerName, |
| 286 | "_dstTexCoord", |
| 287 | configMask, |
| 288 | "rgba"); |
| 289 | this->codeAppend(";"); |
| 290 | } |
| 291 | |
| 292 | if (k110_GrGLSLGeneration != gpu->glslGeneration()) { |
| 293 | fOutputs.push_back().set(kVec4f_GrSLType, |
| 294 | GrGLShaderVar::kOut_TypeModifier, |
| 295 | declared_color_output_name()); |
| 296 | fHasCustomColorOutput = true; |
| 297 | } |
| 298 | } |
| 299 | |
| 300 | void GrGLFragmentShaderBuilder::emitCodeAfterEffects(const GrGLSLExpr4& inputColor, const GrGLSLExpr4& inputCoverage) { |
| 301 | const GrGLProgramDesc::KeyHeader& header = fProgramBuilder->desc().getHeader(); |
| 302 | |
| 303 | /////////////////////////////////////////////////////////////////////////// |
| 304 | // write the secondary color output if necessary |
| 305 | if (GrGLProgramDesc::CoverageOutputUsesSecondaryOutput(header.fCoverageOutput)) { |
| 306 | const char* secondaryOutputName = this->enableSecondaryOutput(); |
| 307 | |
| 308 | // default coeff to ones for kCoverage_DualSrcOutput |
| 309 | GrGLSLExpr4 coeff(1); |
| 310 | if (GrGLProgramDesc::kSecondaryCoverageISA_CoverageOutput == header.fCoverageOutput) { |
| 311 | // Get (1-A) into coeff |
| 312 | coeff = GrGLSLExpr4::VectorCast(GrGLSLExpr1(1) - inputColor.a()); |
| 313 | } else if (GrGLProgramDesc::kSecondaryCoverageISC_CoverageOutput == |
| 314 | header.fCoverageOutput){ |
| 315 | // Get (1-RGBA) into coeff |
| 316 | coeff = GrGLSLExpr4(1) - inputColor; |
| 317 | } |
| 318 | // Get coeff * coverage into modulate and then write that to the dual source output. |
| 319 | codeAppendf("\t%s = %s;\n", secondaryOutputName, (coeff * inputCoverage).c_str()); |
| 320 | } |
| 321 | |
| 322 | /////////////////////////////////////////////////////////////////////////// |
| 323 | // combine color and coverage as frag color |
| 324 | |
| 325 | // Get "color * coverage" into fragColor |
| 326 | GrGLSLExpr4 fragColor = inputColor * inputCoverage; |
| 327 | // Now tack on "+(1-coverage)dst onto the frag color if we were asked to do so. |
| 328 | if (GrGLProgramDesc::kCombineWithDst_CoverageOutput == header.fCoverageOutput) { |
| 329 | GrGLSLExpr4 dstCoeff = GrGLSLExpr4(1) - inputCoverage; |
| 330 | |
| 331 | GrGLSLExpr4 dstContribution = dstCoeff * GrGLSLExpr4(dstColor()); |
| 332 | |
| 333 | fragColor = fragColor + dstContribution; |
| 334 | } |
| 335 | codeAppendf("\t%s = %s;\n", this->getColorOutputName(), fragColor.c_str()); |
| 336 | } |
| 337 | |
| 338 | const char* GrGLFragmentShaderBuilder::enableSecondaryOutput() { |
| 339 | if (!fHasSecondaryOutput) { |
| 340 | fOutputs.push_back().set(kVec4f_GrSLType, |
| 341 | GrGLShaderVar::kOut_TypeModifier, |
| 342 | dual_source_output_name()); |
| 343 | fHasSecondaryOutput = true; |
| 344 | } |
| 345 | return dual_source_output_name(); |
| 346 | } |
| 347 | |
| 348 | const char* GrGLFragmentShaderBuilder::getColorOutputName() const { |
| 349 | return fHasCustomColorOutput ? declared_color_output_name() : "gl_FragColor"; |
| 350 | } |
| 351 | |