1/* 2 * Copyright 2012 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#ifndef GrGLShaderBuilder_DEFINED 9#define GrGLShaderBuilder_DEFINED 10 11#include "GrAllocator.h" 12#include "GrBackendEffectFactory.h" 13#include "GrColor.h" 14#include "GrEffect.h" 15#include "SkTypes.h" 16#include "gl/GrGLProgramEffects.h" 17#include "gl/GrGLSL.h" 18#include "gl/GrGLUniformManager.h" 19 20#include <stdarg.h> 21 22class GrGLContextInfo; 23class GrEffectStage; 24class GrGLProgramDesc; 25 26/** 27 Contains all the incremental state of a shader as it is being built,as well as helpers to 28 manipulate that state. 29*/ 30class GrGLShaderBuilder { 31public: 32 typedef GrTAllocator<GrGLShaderVar> VarArray; 33 typedef GrBackendEffectFactory::EffectKey EffectKey; 34 typedef GrGLProgramEffects::TextureSampler TextureSampler; 35 typedef GrGLProgramEffects::TransformedCoordsArray TransformedCoordsArray; 36 typedef GrGLUniformManager::BuilderUniform BuilderUniform; 37 38 enum ShaderVisibility { 39 kVertex_Visibility = 0x1, 40 kGeometry_Visibility = 0x2, 41 kFragment_Visibility = 0x4, 42 }; 43 44 GrGLShaderBuilder(GrGpuGL*, GrGLUniformManager&, const GrGLProgramDesc&); 45 virtual ~GrGLShaderBuilder() {} 46 47 /** 48 * Use of these features may require a GLSL extension to be enabled. Shaders may not compile 49 * if code is added that uses one of these features without calling enableFeature() 50 */ 51 enum GLSLFeature { 52 kStandardDerivatives_GLSLFeature = 0, 53 54 kLastGLSLFeature = kStandardDerivatives_GLSLFeature 55 }; 56 57 /** 58 * If the feature is supported then true is returned and any necessary #extension declarations 59 * are added to the shaders. If the feature is not supported then false will be returned. 60 */ 61 bool enableFeature(GLSLFeature); 62 63 /** 64 * Called by GrGLEffects to add code the fragment shader. 65 */ 66 void fsCodeAppendf(const char format[], ...) SK_PRINTF_LIKE(2, 3) { 67 va_list args; 68 va_start(args, format); 69 fFSCode.appendVAList(format, args); 70 va_end(args); 71 } 72 73 void fsCodeAppend(const char* str) { fFSCode.append(str); } 74 75 /** Appends a 2D texture sample with projection if necessary. coordType must either be Vec2f or 76 Vec3f. The latter is interpreted as projective texture coords. The vec length and swizzle 77 order of the result depends on the GrTextureAccess associated with the TextureSampler. */ 78 void appendTextureLookup(SkString* out, 79 const TextureSampler&, 80 const char* coordName, 81 GrSLType coordType = kVec2f_GrSLType) const; 82 83 /** Version of above that appends the result to the fragment shader code instead.*/ 84 void fsAppendTextureLookup(const TextureSampler&, 85 const char* coordName, 86 GrSLType coordType = kVec2f_GrSLType); 87 88 89 /** Does the work of appendTextureLookup and modulates the result by modulation. The result is 90 always a vec4. modulation and the swizzle specified by TextureSampler must both be vec4 or 91 float. If modulation is "" or NULL it this function acts as though appendTextureLookup were 92 called. */ 93 void fsAppendTextureLookupAndModulate(const char* modulation, 94 const TextureSampler&, 95 const char* coordName, 96 GrSLType coordType = kVec2f_GrSLType); 97 98 /** Emits a helper function outside of main() in the fragment shader. */ 99 void fsEmitFunction(GrSLType returnType, 100 const char* name, 101 int argCnt, 102 const GrGLShaderVar* args, 103 const char* body, 104 SkString* outName); 105 106 typedef uint8_t DstReadKey; 107 typedef uint8_t FragPosKey; 108 109 /** Returns a key for adding code to read the copy-of-dst color in service of effects that 110 require reading the dst. It must not return 0 because 0 indicates that there is no dst 111 copy read at all (in which case this function should not be called). */ 112 static DstReadKey KeyForDstRead(const GrTexture* dstCopy, const GrGLCaps&); 113 114 /** Returns a key for reading the fragment location. This should only be called if there is an 115 effect that will requires the fragment position. If the fragment position is not required, 116 the key is 0. */ 117 static FragPosKey KeyForFragmentPosition(const GrRenderTarget* dst, const GrGLCaps&); 118 119 /** If texture swizzling is available using tex parameters then it is preferred over mangling 120 the generated shader code. This potentially allows greater reuse of cached shaders. */ 121 static const GrGLenum* GetTexParamSwizzle(GrPixelConfig config, const GrGLCaps& caps); 122 123 /** Add a uniform variable to the current program, that has visibility in one or more shaders. 124 visibility is a bitfield of ShaderVisibility values indicating from which shaders the 125 uniform should be accessible. At least one bit must be set. Geometry shader uniforms are not 126 supported at this time. The actual uniform name will be mangled. If outName is not NULL then 127 it will refer to the final uniform name after return. Use the addUniformArray variant to add 128 an array of uniforms. 129 */ 130 GrGLUniformManager::UniformHandle addUniform(uint32_t visibility, 131 GrSLType type, 132 const char* name, 133 const char** outName = NULL) { 134 return this->addUniformArray(visibility, type, name, GrGLShaderVar::kNonArray, outName); 135 } 136 GrGLUniformManager::UniformHandle addUniformArray(uint32_t visibility, 137 GrSLType type, 138 const char* name, 139 int arrayCount, 140 const char** outName = NULL); 141 142 const GrGLShaderVar& getUniformVariable(GrGLUniformManager::UniformHandle u) const { 143 return fUniformManager.getBuilderUniform(fUniforms, u).fVariable; 144 } 145 146 /** 147 * Shortcut for getUniformVariable(u).c_str() 148 */ 149 const char* getUniformCStr(GrGLUniformManager::UniformHandle u) const { 150 return this->getUniformVariable(u).c_str(); 151 } 152 153 /** 154 * This returns a variable name to access the 2D, perspective correct version of the coords in 155 * the fragment shader. If the coordinates at index are 3-dimensional, it immediately emits a 156 * perspective divide into the fragment shader (xy / z) to convert them to 2D. 157 */ 158 SkString ensureFSCoords2D(const TransformedCoordsArray&, int index); 159 160 /** Returns a variable name that represents the position of the fragment in the FS. The position 161 is in device space (e.g. 0,0 is the top left and pixel centers are at half-integers). */ 162 const char* fragmentPosition(); 163 164 /** Returns the color of the destination pixel. This may be NULL if no effect advertised 165 that it will read the destination. */ 166 const char* dstColor(); 167 168 /** 169 * Interfaces used by GrGLProgram. 170 */ 171 const GrGLSLExpr4& getInputColor() const { 172 return fInputColor; 173 } 174 const GrGLSLExpr4& getInputCoverage() const { 175 return fInputCoverage; 176 } 177 178 /** 179 * Adds code for effects and returns a GrGLProgramEffects* object. The caller is responsible for 180 * deleting it when finished. effectStages contains the effects to add. effectKeys[i] is the key 181 * generated from effectStages[i]. inOutFSColor specifies the input color to the first stage and 182 * is updated to be the output color of the last stage. 183 * The handles to texture samplers for effectStage[i] are added to 184 * effectSamplerHandles[i]. 185 */ 186 virtual GrGLProgramEffects* createAndEmitEffects(const GrEffectStage* effectStages[], 187 const EffectKey effectKeys[], 188 int effectCnt, 189 GrGLSLExpr4* inOutFSColor) = 0; 190 191 const char* getColorOutputName() const; 192 const char* enableSecondaryOutput(); 193 194 GrGLUniformManager::UniformHandle getRTHeightUniform() const { return fRTHeightUniform; } 195 GrGLUniformManager::UniformHandle getDstCopyTopLeftUniform() const { 196 return fDstCopyTopLeftUniform; 197 } 198 GrGLUniformManager::UniformHandle getDstCopyScaleUniform() const { 199 return fDstCopyScaleUniform; 200 } 201 GrGLUniformManager::UniformHandle getColorUniform() const { return fColorUniform; } 202 GrGLUniformManager::UniformHandle getCoverageUniform() const { return fCoverageUniform; } 203 GrGLUniformManager::UniformHandle getDstCopySamplerUniform() const { 204 return fDstCopySamplerUniform; 205 } 206 207 bool finish(GrGLuint* outProgramId); 208 209 const GrGLContextInfo& ctxInfo() const; 210 211 /** 212 * Helper for begining and ending a block in the fragment code. TODO: Make GrGLShaderBuilder 213 * aware of all blocks and turn single \t's into the correct number of tabs (or spaces) so that 214 * our shaders print pretty without effect writers tracking indentation. 215 */ 216 class FSBlock { 217 public: 218 FSBlock(GrGLShaderBuilder* builder) : fBuilder(builder) { 219 SkASSERT(NULL != builder); 220 fBuilder->fsCodeAppend("\t{\n"); 221 } 222 223 ~FSBlock() { 224 fBuilder->fsCodeAppend("\t}\n"); 225 } 226 private: 227 GrGLShaderBuilder* fBuilder; 228 }; 229 230protected: 231 GrGpuGL* gpu() const { return fGpu; } 232 233 void setInputColor(const GrGLSLExpr4& inputColor) { fInputColor = inputColor; } 234 void setInputCoverage(const GrGLSLExpr4& inputCoverage) { fInputCoverage = inputCoverage; } 235 236 /** Add input/output variable declarations (i.e. 'varying') to the fragment shader. */ 237 GrGLShaderVar& fsInputAppend() { return fFSInputs.push_back(); } 238 239 // Generates a name for a variable. The generated string will be name prefixed by the prefix 240 // char (unless the prefix is '\0'). It also mangles the name to be stage-specific if we're 241 // generating stage code. 242 void nameVariable(SkString* out, char prefix, const char* name); 243 244 // Helper for emitEffects(). 245 void createAndEmitEffects(GrGLProgramEffectsBuilder*, 246 const GrEffectStage* effectStages[], 247 const EffectKey effectKeys[], 248 int effectCnt, 249 GrGLSLExpr4* inOutFSColor); 250 251 virtual bool compileAndAttachShaders(GrGLuint programId) const; 252 virtual void bindProgramLocations(GrGLuint programId) const; 253 254 void appendDecls(const VarArray&, SkString*) const; 255 void appendUniformDecls(ShaderVisibility, SkString*) const; 256 257private: 258 class CodeStage : public SkNoncopyable { 259 public: 260 CodeStage() : fNextIndex(0), fCurrentIndex(-1), fEffectStage(NULL) {} 261 262 bool inStageCode() const { 263 this->validate(); 264 return NULL != fEffectStage; 265 } 266 267 const GrEffectStage* effectStage() const { 268 this->validate(); 269 return fEffectStage; 270 } 271 272 int stageIndex() const { 273 this->validate(); 274 return fCurrentIndex; 275 } 276 277 class AutoStageRestore : public SkNoncopyable { 278 public: 279 AutoStageRestore(CodeStage* codeStage, const GrEffectStage* newStage) { 280 SkASSERT(NULL != codeStage); 281 fSavedIndex = codeStage->fCurrentIndex; 282 fSavedEffectStage = codeStage->fEffectStage; 283 284 if (NULL == newStage) { 285 codeStage->fCurrentIndex = -1; 286 } else { 287 codeStage->fCurrentIndex = codeStage->fNextIndex++; 288 } 289 codeStage->fEffectStage = newStage; 290 291 fCodeStage = codeStage; 292 } 293 ~AutoStageRestore() { 294 fCodeStage->fCurrentIndex = fSavedIndex; 295 fCodeStage->fEffectStage = fSavedEffectStage; 296 } 297 private: 298 CodeStage* fCodeStage; 299 int fSavedIndex; 300 const GrEffectStage* fSavedEffectStage; 301 }; 302 private: 303 void validate() const { SkASSERT((NULL == fEffectStage) == (-1 == fCurrentIndex)); } 304 int fNextIndex; 305 int fCurrentIndex; 306 const GrEffectStage* fEffectStage; 307 } fCodeStage; 308 309 /** 310 * Features that should only be enabled by GrGLShaderBuilder itself. 311 */ 312 enum GLSLPrivateFeature { 313 kFragCoordConventions_GLSLPrivateFeature = kLastGLSLFeature + 1, 314 kEXTShaderFramebufferFetch_GLSLPrivateFeature, 315 kNVShaderFramebufferFetch_GLSLPrivateFeature, 316 }; 317 bool enablePrivateFeature(GLSLPrivateFeature); 318 319 // If we ever have VS/GS features we can expand this to take a bitmask of ShaderVisibility and 320 // track the enables separately for each shader. 321 void addFSFeature(uint32_t featureBit, const char* extensionName); 322 323 // Interpretation of DstReadKey when generating code 324 enum { 325 kNoDstRead_DstReadKey = 0, 326 kYesDstRead_DstReadKeyBit = 0x1, // Set if we do a dst-copy-read. 327 kUseAlphaConfig_DstReadKeyBit = 0x2, // Set if dst-copy config is alpha only. 328 kTopLeftOrigin_DstReadKeyBit = 0x4, // Set if dst-copy origin is top-left. 329 }; 330 331 enum { 332 kNoFragPosRead_FragPosKey = 0, // The fragment positition will not be needed. 333 kTopLeftFragPosRead_FragPosKey = 0x1,// Read frag pos relative to top-left. 334 kBottomLeftFragPosRead_FragPosKey = 0x2,// Read frag pos relative to bottom-left. 335 }; 336 337 GrGpuGL* fGpu; 338 GrGLUniformManager& fUniformManager; 339 uint32_t fFSFeaturesAddedMask; 340 SkString fFSFunctions; 341 SkString fFSExtensions; 342 VarArray fFSInputs; 343 VarArray fFSOutputs; 344 GrGLUniformManager::BuilderUniformArray fUniforms; 345 346 SkString fFSCode; 347 348 bool fSetupFragPosition; 349 GrGLUniformManager::UniformHandle fDstCopySamplerUniform; 350 351 GrGLSLExpr4 fInputColor; 352 GrGLSLExpr4 fInputCoverage; 353 354 bool fHasCustomColorOutput; 355 bool fHasSecondaryOutput; 356 357 GrGLUniformManager::UniformHandle fRTHeightUniform; 358 GrGLUniformManager::UniformHandle fDstCopyTopLeftUniform; 359 GrGLUniformManager::UniformHandle fDstCopyScaleUniform; 360 GrGLUniformManager::UniformHandle fColorUniform; 361 GrGLUniformManager::UniformHandle fCoverageUniform; 362 363 bool fTopLeftFragPosRead; 364}; 365 366//////////////////////////////////////////////////////////////////////////////// 367 368class GrGLFullShaderBuilder : public GrGLShaderBuilder { 369public: 370 GrGLFullShaderBuilder(GrGpuGL*, GrGLUniformManager&, const GrGLProgramDesc&); 371 372 /** 373 * Called by GrGLEffects to add code to one of the shaders. 374 */ 375 void vsCodeAppendf(const char format[], ...) SK_PRINTF_LIKE(2, 3) { 376 va_list args; 377 va_start(args, format); 378 fVSCode.appendVAList(format, args); 379 va_end(args); 380 } 381 382 void vsCodeAppend(const char* str) { fVSCode.append(str); } 383 384 /** Add a vertex attribute to the current program that is passed in from the vertex data. 385 Returns false if the attribute was already there, true otherwise. */ 386 bool addAttribute(GrSLType type, const char* name); 387 388 /** Add a varying variable to the current program to pass values between vertex and fragment 389 shaders. If the last two parameters are non-NULL, they are filled in with the name 390 generated. */ 391 void addVarying(GrSLType type, 392 const char* name, 393 const char** vsOutName = NULL, 394 const char** fsInName = NULL); 395 396 /** Returns a vertex attribute that represents the vertex position in the VS. This is the 397 pre-matrix position and is commonly used by effects to compute texture coords via a matrix. 398 */ 399 const GrGLShaderVar& positionAttribute() const { return *fPositionVar; } 400 401 /** Returns a vertex attribute that represents the local coords in the VS. This may be the same 402 as positionAttribute() or it may not be. It depends upon whether the rendering code 403 specified explicit local coords or not in the GrDrawState. */ 404 const GrGLShaderVar& localCoordsAttribute() const { return *fLocalCoordsVar; } 405 406 /** 407 * Are explicit local coordinates provided as input to the vertex shader. 408 */ 409 bool hasExplicitLocalCoords() const { return (fLocalCoordsVar != fPositionVar); } 410 411 bool addEffectAttribute(int attributeIndex, GrSLType type, const SkString& name); 412 const SkString* getEffectAttributeName(int attributeIndex) const; 413 414 virtual GrGLProgramEffects* createAndEmitEffects( 415 const GrEffectStage* effectStages[], 416 const EffectKey effectKeys[], 417 int effectCnt, 418 GrGLSLExpr4* inOutFSColor) SK_OVERRIDE; 419 420 GrGLUniformManager::UniformHandle getViewMatrixUniform() const { 421 return fViewMatrixUniform; 422 } 423 424protected: 425 virtual bool compileAndAttachShaders(GrGLuint programId) const SK_OVERRIDE; 426 virtual void bindProgramLocations(GrGLuint programId) const SK_OVERRIDE; 427 428private: 429 const GrGLProgramDesc& fDesc; 430 VarArray fVSAttrs; 431 VarArray fVSOutputs; 432 VarArray fGSInputs; 433 VarArray fGSOutputs; 434 435 SkString fVSCode; 436 437 struct AttributePair { 438 void set(int index, const SkString& name) { 439 fIndex = index; fName = name; 440 } 441 int fIndex; 442 SkString fName; 443 }; 444 SkSTArray<10, AttributePair, true> fEffectAttributes; 445 446 GrGLUniformManager::UniformHandle fViewMatrixUniform; 447 448 GrGLShaderVar* fPositionVar; 449 GrGLShaderVar* fLocalCoordsVar; 450 451 typedef GrGLShaderBuilder INHERITED; 452}; 453 454//////////////////////////////////////////////////////////////////////////////// 455 456class GrGLFragmentOnlyShaderBuilder : public GrGLShaderBuilder { 457public: 458 GrGLFragmentOnlyShaderBuilder(GrGpuGL*, GrGLUniformManager&, const GrGLProgramDesc&); 459 460 int getNumTexCoordSets() const { return fNumTexCoordSets; } 461 int addTexCoordSets(int count); 462 463 virtual GrGLProgramEffects* createAndEmitEffects( 464 const GrEffectStage* effectStages[], 465 const EffectKey effectKeys[], 466 int effectCnt, 467 GrGLSLExpr4* inOutFSColor) SK_OVERRIDE; 468 469private: 470 int fNumTexCoordSets; 471 472 typedef GrGLShaderBuilder INHERITED; 473}; 474 475#endif 476