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      1 /*
      2  * Copyright 2013 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 GrGLSLPrimitiveProcessor_DEFINED
      9 #define GrGLSLPrimitiveProcessor_DEFINED
     10 
     11 #include "GrFragmentProcessor.h"
     12 #include "GrPrimitiveProcessor.h"
     13 #include "glsl/GrGLSLProgramDataManager.h"
     14 #include "glsl/GrGLSLUniformHandler.h"
     15 
     16 class GrPrimitiveProcessor;
     17 class GrGLSLPPFragmentBuilder;
     18 class GrGLSLGeometryBuilder;
     19 class GrGLSLGPBuilder;
     20 class GrGLSLVaryingHandler;
     21 class GrGLSLVertexBuilder;
     22 class GrShaderCaps;
     23 
     24 class GrGLSLPrimitiveProcessor {
     25 public:
     26     using FPCoordTransformIter = GrFragmentProcessor::CoordTransformIter;
     27 
     28     virtual ~GrGLSLPrimitiveProcessor() {}
     29 
     30     using UniformHandle      = GrGLSLProgramDataManager::UniformHandle;
     31     using SamplerHandle      = GrGLSLUniformHandler::SamplerHandle;
     32     using TexelBufferHandle  = GrGLSLUniformHandler::TexelBufferHandle;
     33 
     34     /**
     35      * This class provides access to the GrCoordTransforms across all GrFragmentProcessors in a
     36      * GrPipeline. It is also used by the primitive processor to specify the fragment shader
     37      * variable that will hold the transformed coords for each GrCoordTransform. It is required that
     38      * the primitive processor iterate over each coord transform and insert a shader var result for
     39      * each. The GrGLSLFragmentProcessors will reference these variables in their fragment code.
     40      */
     41     class FPCoordTransformHandler : public SkNoncopyable {
     42     public:
     43         FPCoordTransformHandler(const GrPipeline& pipeline,
     44                                 SkTArray<GrShaderVar>* transformedCoordVars)
     45                 : fIter(pipeline)
     46                 , fTransformedCoordVars(transformedCoordVars) {}
     47 
     48         ~FPCoordTransformHandler() { SkASSERT(!this->nextCoordTransform());}
     49 
     50         const GrCoordTransform* nextCoordTransform();
     51 
     52         // 'args' are constructor params to GrShaderVar.
     53         template<typename... Args>
     54         void specifyCoordsForCurrCoordTransform(Args&&... args) {
     55             SkASSERT(!fAddedCoord);
     56             fTransformedCoordVars->emplace_back(std::forward<Args>(args)...);
     57             SkDEBUGCODE(fAddedCoord = true;)
     58         }
     59 
     60     private:
     61         GrFragmentProcessor::CoordTransformIter fIter;
     62         SkDEBUGCODE(bool                        fAddedCoord = false;)
     63         SkDEBUGCODE(const GrCoordTransform*     fCurr = nullptr;)
     64         SkTArray<GrShaderVar>*                  fTransformedCoordVars;
     65     };
     66 
     67     struct EmitArgs {
     68         EmitArgs(GrGLSLVertexBuilder* vertBuilder,
     69                  GrGLSLGeometryBuilder* geomBuilder,
     70                  GrGLSLPPFragmentBuilder* fragBuilder,
     71                  GrGLSLVaryingHandler* varyingHandler,
     72                  GrGLSLUniformHandler* uniformHandler,
     73                  const GrShaderCaps* caps,
     74                  const GrPrimitiveProcessor& gp,
     75                  const char* outputColor,
     76                  const char* outputCoverage,
     77                  const char* rtAdjustName,
     78                  const SamplerHandle* texSamplers,
     79                  const TexelBufferHandle* texelBuffers,
     80                  FPCoordTransformHandler* transformHandler)
     81             : fVertBuilder(vertBuilder)
     82             , fGeomBuilder(geomBuilder)
     83             , fFragBuilder(fragBuilder)
     84             , fVaryingHandler(varyingHandler)
     85             , fUniformHandler(uniformHandler)
     86             , fShaderCaps(caps)
     87             , fGP(gp)
     88             , fOutputColor(outputColor)
     89             , fOutputCoverage(outputCoverage)
     90             , fRTAdjustName(rtAdjustName)
     91             , fTexSamplers(texSamplers)
     92             , fTexelBuffers(texelBuffers)
     93             , fFPCoordTransformHandler(transformHandler) {}
     94         GrGLSLVertexBuilder* fVertBuilder;
     95         GrGLSLGeometryBuilder* fGeomBuilder;
     96         GrGLSLPPFragmentBuilder* fFragBuilder;
     97         GrGLSLVaryingHandler* fVaryingHandler;
     98         GrGLSLUniformHandler* fUniformHandler;
     99         const GrShaderCaps* fShaderCaps;
    100         const GrPrimitiveProcessor& fGP;
    101         const char* fOutputColor;
    102         const char* fOutputCoverage;
    103         const char* fRTAdjustName;
    104         const SamplerHandle* fTexSamplers;
    105         const TexelBufferHandle* fTexelBuffers;
    106         FPCoordTransformHandler* fFPCoordTransformHandler;
    107     };
    108 
    109     /**
    110      * This is similar to emitCode() in the base class, except it takes a full shader builder.
    111      * This allows the effect subclass to emit vertex code.
    112      */
    113     virtual void emitCode(EmitArgs&) = 0;
    114 
    115     /**
    116      * A GrGLSLPrimitiveProcessor instance can be reused with any GrGLSLPrimitiveProcessor that
    117      * produces the same stage key; this function reads data from a GrGLSLPrimitiveProcessor and
    118      * uploads any uniform variables required  by the shaders created in emitCode(). The
    119      * GrPrimitiveProcessor parameter is guaranteed to be of the same type and to have an
    120      * identical processor key as the GrPrimitiveProcessor that created this
    121      * GrGLSLPrimitiveProcessor.
    122      * The subclass may use the transform iterator to perform any setup required for the particular
    123      * set of fp transform matrices, such as uploading via uniforms. The iterator will iterate over
    124      * the transforms in the same order as the TransformHandler passed to emitCode.
    125      */
    126     virtual void setData(const GrGLSLProgramDataManager&, const GrPrimitiveProcessor&,
    127                          FPCoordTransformIter&&) = 0;
    128 
    129     static SkMatrix GetTransformMatrix(const SkMatrix& localMatrix, const GrCoordTransform&);
    130 
    131 protected:
    132     void setupUniformColor(GrGLSLPPFragmentBuilder* fragBuilder,
    133                            GrGLSLUniformHandler* uniformHandler,
    134                            const char* outputName,
    135                            UniformHandle* colorUniform);
    136 };
    137 
    138 #endif
    139