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Diffstat (limited to 'src/gpu/gl/builders/GrGLShaderBuilder.h')
-rw-r--r-- | src/gpu/gl/builders/GrGLShaderBuilder.h | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/src/gpu/gl/builders/GrGLShaderBuilder.h b/src/gpu/gl/builders/GrGLShaderBuilder.h new file mode 100644 index 0000000000..1d0fa6a790 --- /dev/null +++ b/src/gpu/gl/builders/GrGLShaderBuilder.h @@ -0,0 +1,170 @@ +/* + * Copyright 2014 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#ifndef GrGLShaderBuilder_DEFINED +#define GrGLShaderBuilder_DEFINED + +#include "gl/GrGLProgramDesc.h" +#include "gl/GrGLProgramEffects.h" +#include "gl/GrGLSL.h" +#include "gl/GrGLProgramDataManager.h" +#include "GrAllocator.h" +#include "GrBackendEffectFactory.h" +#include "GrColor.h" +#include "GrEffect.h" +#include "SkTypes.h" + +#include <stdarg.h> + +class GrGLContextInfo; +class GrEffectStage; +class GrGLProgramDesc; +class GrGLProgramBuilder; +class GrGLFullProgramBuilder; + +/** + base class for all shaders builders +*/ +class GrGLShaderBuilder { +public: + typedef GrGLProgramEffects::TransformedCoordsArray TransformedCoordsArray; + typedef GrGLProgramEffects::TextureSampler TextureSampler; + GrGLShaderBuilder(GrGLProgramBuilder* program); + + void addInput(GrGLShaderVar i) { fInputs.push_back(i); } + void addOutput(GrGLShaderVar i) { fOutputs.push_back(i); } + + /* + * We put texture lookups in the base class because it is TECHNICALLY possible to do texture + * lookups in any kind of shader. However, for the time being using these calls on non-fragment + * shaders will result in a shader compilation error as texture sampler uniforms are only + * visible to the fragment shader. It would not be hard to change this behavior, if someone + * actually wants to do texture lookups in a non-fragment shader + * + * TODO if append texture lookup is used on a non-fragment shader, sampler uniforms should be + * made visible to that shaders + */ + /** Appends a 2D texture sample with projection if necessary. coordType must either be Vec2f or + Vec3f. The latter is interpreted as projective texture coords. The vec length and swizzle + order of the result depends on the GrTextureAccess associated with the TextureSampler. */ + void appendTextureLookup(SkString* out, + const TextureSampler&, + const char* coordName, + GrSLType coordType = kVec2f_GrSLType) const; + + /** Version of above that appends the result to the fragment shader code instead.*/ + void appendTextureLookup(const TextureSampler&, + const char* coordName, + GrSLType coordType = kVec2f_GrSLType); + + + /** Does the work of appendTextureLookup and modulates the result by modulation. The result is + always a vec4. modulation and the swizzle specified by TextureSampler must both be vec4 or + float. If modulation is "" or NULL it this function acts as though appendTextureLookup were + called. */ + void appendTextureLookupAndModulate(const char* modulation, + const TextureSampler&, + const char* coordName, + GrSLType coordType = kVec2f_GrSLType); + + /** If texture swizzling is available using tex parameters then it is preferred over mangling + the generated shader code. This potentially allows greater reuse of cached shaders. */ + static const GrGLenum* GetTexParamSwizzle(GrPixelConfig config, const GrGLCaps& caps); + + /** + * Called by GrGLEffects to add code to one of the shaders. + */ + void codeAppendf(const char format[], ...) SK_PRINTF_LIKE(2, 3) { + va_list args; + va_start(args, format); + fCode.appendVAList(format, args); + va_end(args); + } + + void codeAppend(const char* str) { fCode.append(str); } + + void codePrependf(const char format[], ...) SK_PRINTF_LIKE(2, 3) { + va_list args; + va_start(args, format); + fCode.prependVAList(format, args); + va_end(args); + } + + /** Emits a helper function outside of main() in the fragment shader. */ + void emitFunction(GrSLType returnType, + const char* name, + int argCnt, + const GrGLShaderVar* args, + const char* body, + SkString* outName); + + /* + * Get parent builder for adding uniforms + */ + GrGLProgramBuilder* getProgramBuilder() { return fProgramBuilder; } + + /** + * Helper for begining and ending a block in the fragment code. + */ + class ShaderBlock { + public: + ShaderBlock(GrGLShaderBuilder* builder) : fBuilder(builder) { + SkASSERT(NULL != builder); + fBuilder->codeAppend("{"); + } + + ~ShaderBlock() { + fBuilder->codeAppend("}"); + } + private: + GrGLShaderBuilder* fBuilder; + }; +protected: + + /* + * this super low level function is just for use internally to builders + */ + void appendTextureLookup(const char* samplerName, + const char* coordName, + uint32_t configComponentMask, + const char* swizzle); + + /* + * A general function which enables an extension in a shader if the feature bit is not present + */ + void addFeature(uint32_t featureBit, const char* extensionName); + + typedef GrTAllocator<GrGLShaderVar> VarArray; + + GrGLProgramBuilder* fProgramBuilder; + + SkString fCode; + SkString fFunctions; + SkString fExtensions; + + VarArray fInputs; + VarArray fOutputs; + uint32_t fFeaturesAddedMask; +}; + + +/* + * Full Shader builder is the base class for shaders which are only accessible through full program + * builder, ie vertex, geometry, and later TCU / TES. Using this base class, they can access the + * full program builder functionality through the full program pointer + */ +class GrGLFullShaderBuilder : public GrGLShaderBuilder { +public: + GrGLFullShaderBuilder(GrGLFullProgramBuilder* program); + + GrGLFullProgramBuilder* fullProgramBuilder() { return fFullProgramBuilder; } +protected: + GrGLFullProgramBuilder* fFullProgramBuilder; +private: + typedef GrGLShaderBuilder INHERITED; +}; +#endif |