Cleanup of shader building system

src/gpu/gl/builders/GrGLProgramBuilder.h

 /*
  * 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 GrGLProgramBuilder_DEFINED
 #define GrGLProgramBuilder_DEFINED
 
-#include "GrAllocator.h"
-#include "GrBackendProcessorFactory.h"
-#include "GrColor.h"
-#include "GrProcessor.h"
 #include "GrGLFragmentShaderBuilder.h"
 #include "GrGLGeometryShaderBuilder.h"
 #include "GrGLVertexShaderBuilder.h"
-#include "SkTypes.h"
-#include "gl/GrGLProcessor.h"
-#include "gl/GrGLProgramDesc.h"
-#include "gl/GrGLProgramEffects.h"
-#include "gl/GrGLSL.h"
-#include "gl/GrGLProgramDataManager.h"
+#include "../GrGLProgramDataManager.h"
+#include "../GrGLUniformHandle.h"
 
-#include <stdarg.h>
+class GrGLInstalledProcessors;
 
-class GrGLContextInfo;
-class GrProcessorStage;
-class GrGLProgramDesc;
-
-/**
-  Contains all the incremental state of a shader as it is being built,as well as helpers to
-  manipulate that state.
-*/
-class GrGLProgramBuilder {
+/*
+ * This is the base class for a series of interfaces.  This base class *MUST* remain abstract with
+ * NO data members because it is used in multiple interface inheritance.
+ * Heirarchy:
+ *                      GrGLUniformBuilder
+ *                     /                  \
+ *                GrGLFPBuilder       GrGLGPBuilder
+ *                     \                  /
+ *                     GrGLProgramBuilder(internal use only)
+ */
+class GrGLUniformBuilder {
 public:
     enum ShaderVisibility {
         kVertex_Visibility   = 0x1,
         kGeometry_Visibility = 0x2,
         kFragment_Visibility = 0x4,
     };
 
+    virtual ~GrGLUniformBuilder() {}
+
     typedef GrGLProgramDataManager::UniformHandle UniformHandle;
-    typedef GrGLProgramDataManager::VaryingHandle VaryingHandle;
 
-    // Handles for program uniforms (other than per-effect uniforms)
-    struct BuiltinUniformHandles {
-        UniformHandle       fViewMatrixUni;
-        UniformHandle       fRTAdjustmentUni;
-        UniformHandle       fColorUni;
-        UniformHandle       fCoverageUni;
+    /** Add a uniform variable to the current program, that has visibility in one or more shaders.
+        visibility is a bitfield of ShaderVisibility values indicating from which shaders the
+        uniform should be accessible. At least one bit must be set. Geometry shader uniforms are not
+        supported at this time. The actual uniform name will be mangled. If outName is not NULL then
+        it will refer to the final uniform name after return. Use the addUniformArray variant to add
+        an array of uniforms. */
+    virtual UniformHandle addUniform(uint32_t visibility,
+                                     GrSLType type,
+                                     const char* name,
+                                     const char** outName = NULL) = 0;
+    virtual UniformHandle addUniformArray(uint32_t visibility,
+                                          GrSLType type,
+                                          const char* name,
+                                          int arrayCount,
+                                          const char** outName = NULL) = 0;
 
-        // We use the render target height to provide a y-down frag coord when specifying
-        // origin_upper_left is not supported.
-        UniformHandle       fRTHeightUni;
+    virtual const GrGLShaderVar& getUniformVariable(UniformHandle u) const = 0;
 
-        // Uniforms for computing texture coords to do the dst-copy lookup
-        UniformHandle       fDstCopyTopLeftUni;
-        UniformHandle       fDstCopyScaleUni;
-        UniformHandle       fDstCopySamplerUni;
-    };
+    /**
+     * Shortcut for getUniformVariable(u).c_str()
+     */
+    virtual const char* getUniformCStr(UniformHandle u) const = 0;
 
-    struct UniformInfo {
-        GrGLShaderVar fVariable;
-        uint32_t      fVisibility;
-        GrGLint       fLocation;
-    };
+    virtual const GrGLContextInfo& ctxInfo() const = 0;
 
-    // This uses an allocator rather than array so that the GrGLShaderVars don't move in memory
-    // after they are inserted. Users of GrGLShaderBuilder get refs to the vars and ptrs to their
-    // name strings. Otherwise, we'd have to hand out copies.
-    typedef GrTAllocator<UniformInfo> UniformInfoArray;
+    virtual GrGpuGL* gpu() const = 0;
 
-    struct SeparableVaryingInfo {
-        GrGLShaderVar fVariable;
-        GrGLint       fLocation;
-    };
+    /*
+     * *NOTE* NO MEMBERS ALLOWED, MULTIPLE INHERITANCE
+     */
+};
 
-    typedef GrTAllocator<SeparableVaryingInfo> SeparableVaryingInfoArray;
+/* a specialization of the above for GPs.  Lets the user add uniforms, varyings, and VS / FS code */
+class GrGLGPBuilder : public virtual GrGLUniformBuilder {
+public:
+    virtual void addVarying(GrSLType type,
+                            const char* name,
+                            const char** vsOutName = NULL,
+                            const char** fsInName = NULL,
+                            GrGLShaderVar::Precision fsPrecision=GrGLShaderVar::kDefault_Precision) = 0;
 
+    virtual GrGLGPFragmentShaderBuilder* getFragmentShaderBuilder() = 0;
+    virtual GrGLVertexShaderBuilder* getVertexShaderBuilder() = 0;
+
+    /*
+     * *NOTE* NO MEMBERS ALLOWED, MULTIPLE INHERITANCE
+     */
+};
+
+/* a specializations for FPs. Lets the user add uniforms and FS code */
+class GrGLFPBuilder : public virtual GrGLUniformBuilder {
+public:
+    virtual GrGLFPShaderBuilder* getFragmentShaderBuilder() = 0;
+
+    /*
+     * *NOTE* NO MEMBERS ALLOWED, MULTIPLE INHERITANCE
+     */
+};
+
+/*
+ * Please note - no diamond problems because of virtual inheritance.  Also, both base classes
+ * are pure virtual with no data members.  This is the base class for program building.
+ * Subclasses are nearly identical but each has their own way of emitting transforms.  State for
+ * each of the elements of the shader pipeline, ie vertex, fragment, geometry, etc, lives in those
+ * respective builders
+*/
+class GrGLProgramBuilder : public GrGLGPBuilder,
+                           public GrGLFPBuilder {
+public:
     /** Generates a shader program.
      *
      * The program implements what is specified in the stages given as input.
      * After successful generation, the builder result objects are available
      * to be used.
      * @return true if generation was successful.
      */
-
-    bool genProgram(const GrGeometryStage* inGeometryProcessor,
-                    const GrFragmentStage* inColorStages[],
-                    const GrFragmentStage* inCoverageStages[]);
-
-    GrGLProgramEffects* getGeometryProcessor() const {
-        SkASSERT(fProgramID); return fGeometryProcessor.get();
-    }
-    GrGLProgramEffects* getColorEffects() const { SkASSERT(fProgramID); return fColorEffects.get(); }
-    GrGLProgramEffects* getCoverageEffects() const { SkASSERT(fProgramID); return fCoverageEffects.get(); }
-    const BuiltinUniformHandles& getBuiltinUniformHandles() const {
-        SkASSERT(fProgramID);
-        return fUniformHandles;
-    }
-    GrGLuint getProgramID() const { SkASSERT(fProgramID); return fProgramID; }
-    bool hasVertexShader() const { SkASSERT(fProgramID); return !fFragOnly; }
-    int getTexCoordSetCount() const { SkASSERT(fProgramID); return fTexCoordSetCnt; }
-    const UniformInfoArray& getUniformInfos() const { return fUniforms; }
-    const SeparableVaryingInfoArray& getSeparableVaryingInfos() const {
-        return fSeparableVaryingInfos;
-    }
-
-    virtual ~GrGLProgramBuilder() {}
-
-    /** Add a uniform variable to the current program, that has visibility in one or more shaders.
-        visibility is a bitfield of ShaderVisibility values indicating from which shaders the
-        uniform should be accessible. At least one bit must be set. Geometry shader uniforms are not
-        supported at this time. The actual uniform name will be mangled. If outName is not NULL then
-        it will refer to the final uniform name after return. Use the addUniformArray variant to add
-        an array of uniforms. */
-    GrGLProgramDataManager::UniformHandle addUniform(uint32_t visibility,
-                                                     GrSLType type,
-                                                     const char* name,
-                                                     const char** outName = NULL) {
+    static GrGLProgram* CreateProgram(const GrGLProgramDesc&,
+                                      GrGpu::DrawType,
+                                      const GrGeometryStage* inGeometryProcessor,
+                                      const GrFragmentStage* inColorStages[],
+                                      const GrFragmentStage* inCoverageStages[],
+                                      GrGpuGL* gpu);
+
+    virtual UniformHandle addUniform(uint32_t visibility,
+                                     GrSLType type,
+                                     const char* name,
+                                     const char** outName = NULL) SK_OVERRIDE {
         return this->addUniformArray(visibility, type, name, GrGLShaderVar::kNonArray, outName);
     }
-    GrGLProgramDataManager::UniformHandle addUniformArray(uint32_t visibility,
-                                                          GrSLType type,
-                                                          const char* name,
-                                                          int arrayCount,
-                                                          const char** outName = NULL);
-
-    const GrGLShaderVar& getUniformVariable(GrGLProgramDataManager::UniformHandle u) const {
+    virtual UniformHandle addUniformArray(uint32_t visibility,
+                                          GrSLType type,
+                                          const char* name,
+                                          int arrayCount,
+                                          const char** outName = NULL) SK_OVERRIDE;
+
+    virtual const GrGLShaderVar& getUniformVariable(UniformHandle u) const SK_OVERRIDE {
         return fUniforms[u.toShaderBuilderIndex()].fVariable;
     }
 
-    /**
-     * Shortcut for getUniformVariable(u).c_str()
-     */
-    const char* getUniformCStr(GrGLProgramDataManager::UniformHandle u) const {
+    virtual const char* getUniformCStr(UniformHandle u) const SK_OVERRIDE {
         return this->getUniformVariable(u).c_str();
     }
 
-    const GrGLContextInfo& ctxInfo() const;
-
-    GrGLFragmentShaderBuilder* getFragmentShaderBuilder() { return &fFS; }
-    GrGpuGL* gpu() const { return fGpu; }
+    virtual const GrGLContextInfo& ctxInfo() const SK_OVERRIDE;
+
+    virtual GrGpuGL* gpu() const SK_OVERRIDE { return fGpu; }
+
+    virtual GrGLFragmentShaderBuilder* getFragmentShaderBuilder() SK_OVERRIDE { return &fFS; }
+    virtual GrGLVertexShaderBuilder* getVertexShaderBuilder() SK_OVERRIDE { return &fVS; }
+
+    virtual void addVarying(GrSLType type,
+                            const char* name,
+                            const char** vsOutName = NULL,
+                            const char** fsInName = NULL,
+                            GrGLShaderVar::Precision fsPrecision=GrGLShaderVar::kDefault_Precision);
+
+    // Handles for program uniforms (other than per-effect uniforms)
+    struct BuiltinUniformHandles {
+        UniformHandle       fViewMatrixUni;
+        UniformHandle       fRTAdjustmentUni;
+        UniformHandle       fColorUni;
+        UniformHandle       fCoverageUni;
+
+        // We use the render target height to provide a y-down frag coord when specifying
+        // origin_upper_left is not supported.
+        UniformHandle       fRTHeightUni;
+
+        // Uniforms for computing texture coords to do the dst-copy lookup
+        UniformHandle       fDstCopyTopLeftUni;
+        UniformHandle       fDstCopyScaleUni;
+        UniformHandle       fDstCopySamplerUni;
+    };
 
 protected:
-    typedef GrTAllocator<GrGLShaderVar> VarArray;
+    static GrGLProgramBuilder* CreateProgramBuilder(const GrGLProgramDesc&,
+                                                    GrGpu::DrawType,
+                                                    bool hasGeometryProcessor,
+                                                    GrGpuGL*);
+
     GrGLProgramBuilder(GrGpuGL*, const GrGLProgramDesc&);
 
     const GrGLProgramDesc& desc() const { return fDesc; }
-
-    // Helper for emitEffects().
-    void createAndEmitEffects(const GrFragmentStage* effectStages[],
-                              int effectCnt,
-                              const GrGLProgramDesc::EffectKeyProvider&,
-                              GrGLSLExpr4* inOutFSColor);
-
-    /*
-     * A helper function called to emit the geometry processor as well as individual coverage
-     * and color stages.  this will call into subclasses emit effect
-     */
-    void emitEffect(const GrProcessorStage& effectStage,
-                    int effectIndex,
-                    const GrGLProgramDesc::EffectKeyProvider& keyProvider,
-                    GrGLSLExpr4* inColor,
-                    GrGLSLExpr4* outColor);
-
-    /**
-     * Helper for emitEffect() in subclasses. Emits uniforms for an effect's texture accesses and
-     * appends the necessary data to the TextureSamplerArray* object so effects can add texture
-     * lookups to their code. This method is only meant to be called during the construction phase.
-     */
-    void emitSamplers(const GrProcessor& effect,
-                      GrGLProcessor::TextureSamplerArray* outSamplers);
+    const GrGLProgramDesc::KeyHeader& header() const { return fDesc.getHeader(); }
 
     // Generates a name for a variable. The generated string will be name prefixed by the prefix
     // char (unless the prefix is '\0'). It also mangles the name to be stage-specific if we're
     // generating stage code.
     void nameVariable(SkString* out, char prefix, const char* name);
-
-    virtual bool compileAndAttachShaders(GrGLuint programId, SkTDArray<GrGLuint>* shaderIds) const;
-
-    virtual void bindProgramLocations(GrGLuint programId);
-    void resolveProgramLocations(GrGLuint programId);
-
-    void appendDecls(const VarArray&, SkString*) const;
+    void setupUniformColorAndCoverageIfNeeded(GrGLSLExpr4* inputColor, GrGLSLExpr4* inputCoverage);
+    void createAndEmitProcessors(const GrGeometryStage* geometryProcessor,
+                                 const GrFragmentStage* colorStages[],
+                                 const GrFragmentStage* coverageStages[],
+                                 GrGLSLExpr4* inputColor,
+                                 GrGLSLExpr4* inputCoverage);
+    template <class ProcessorStage>
+    void createAndEmitProcessors(const ProcessorStage*[],
+                                 int effectCnt,
+                                 const GrGLProgramDesc::EffectKeyProvider&,
+                                 GrGLSLExpr4* fsInOutColor,
+                                 GrGLInstalledProcessors*);
+    void verify(const GrGeometryProcessor&);
+    void verify(const GrFragmentProcessor&);
+    void emitSamplers(const GrProcessor&,
+                      GrGLProcessor::TextureSamplerArray* outSamplers,
+                      GrGLInstalledProcessors*);
+
+    // each specific program builder has a distinct transform and must override this function
+    virtual void emitTransforms(const GrProcessorStage&,
+                                GrGLProcessor::TransformedCoordsArray* outCoords,
+                                GrGLInstalledProcessors*);
+    GrGLProgram* compileBindLinkCreate();
+    void bindUniformLocations(GrGLuint programID);
+    bool checkLinkStatus(GrGLuint programID);
+    void resolveUniformLocations(GrGLuint programID);
+
+    void cleanupProgram(GrGLuint programID, const SkTDArray<GrGLuint>& shaderIDs);
+    void cleanupShaders(const SkTDArray<GrGLuint>& shaderIDs);
+
+    // Subclasses create different programs
+    virtual GrGLProgram* createProgram(GrGLuint programID);
+
     void appendUniformDecls(ShaderVisibility, SkString*) const;
 
-    class CodeStage : SkNoncopyable {
+    // reset is called by program creator between each processor's emit code.  It increments the
+    // stage offset for variable name mangling, and also ensures verfication variables in the
+    // fragment shader are cleared.
+    void reset() {
+        this->enterStage();
+        this->addStage();
+        fFS.reset();
+    }
+    void addStage() { fStageIndex++; }
+
+    // This simple class exits the stage and then restores the stage when it goes out of scope
+    class AutoStageRestore {
     public:
-        CodeStage() : fNextIndex(0), fCurrentIndex(-1), fEffectStage(NULL) {}
-
-        bool inStageCode() const {
-            this->validate();
-            return SkToBool(fEffectStage);
-        }
-
-        const GrProcessorStage* effectStage() const {
-            this->validate();
-            return fEffectStage;
-        }
-
-        int stageIndex() const {
-            this->validate();
-            return fCurrentIndex;
-        }
-
-        class AutoStageRestore : SkNoncopyable {
-        public:
-            AutoStageRestore(CodeStage* codeStage, const GrProcessorStage* newStage) {
-                SkASSERT(codeStage);
-                fSavedIndex = codeStage->fCurrentIndex;
-                fSavedEffectStage = codeStage->fEffectStage;
-
-                if (NULL == newStage) {
-                    codeStage->fCurrentIndex = -1;
-                } else {
-                    codeStage->fCurrentIndex = codeStage->fNextIndex++;
-                }
-                codeStage->fEffectStage = newStage;
-
-                fCodeStage = codeStage;
-            }
-            ~AutoStageRestore() {
-                fCodeStage->fCurrentIndex = fSavedIndex;
-                fCodeStage->fEffectStage = fSavedEffectStage;
-            }
-        private:
-            CodeStage*              fCodeStage;
-            int                     fSavedIndex;
-            const GrProcessorStage*    fSavedEffectStage;
-        };
+        AutoStageRestore(GrGLProgramBuilder* pb)
+            : fPB(pb), fOutOfStage(pb->fOutOfStage) { pb->exitStage(); }
+        ~AutoStageRestore() { fPB->fOutOfStage = fOutOfStage; }
     private:
-        void validate() const { SkASSERT((NULL == fEffectStage) == (-1 == fCurrentIndex)); }
-        int                     fNextIndex;
-        int                     fCurrentIndex;
-        const GrProcessorStage*    fEffectStage;
-    };
-
-    class GrGLProcessorEmitterInterface {
-     public:
-        virtual ~GrGLProcessorEmitterInterface() {}
-        virtual GrGLProcessor* createGLInstance() = 0;
-        virtual void emit(const GrProcessorKey& key,
-                          const char* outColor,
-                          const char* inColor,
-                          const GrGLProcessor::TransformedCoordsArray& coords,
-                          const GrGLProcessor::TextureSamplerArray& samplers) = 0;
-    };
-
-    class GrGLFragmentProcessorEmitter  : public GrGLProcessorEmitterInterface {
-    public:
-        GrGLFragmentProcessorEmitter(GrGLProgramBuilder* builder)
-            : fBuilder(builder)
-            , fFragmentProcessor(NULL)
-            , fGLFragmentProcessor(NULL) {}
-        virtual ~GrGLFragmentProcessorEmitter() {}
-        void set(const GrFragmentProcessor* fp) {
-            SkASSERT(NULL == fFragmentProcessor);
-            fFragmentProcessor = fp;
-        }
-        virtual GrGLProcessor* createGLInstance() {
-            SkASSERT(fFragmentProcessor);
-            SkASSERT(NULL == fGLFragmentProcessor);
-            fGLFragmentProcessor =
-                    fFragmentProcessor->getFactory().createGLInstance(*fFragmentProcessor);
-            return fGLFragmentProcessor;
-        }
-        virtual void emit(const GrProcessorKey& key,
-                          const char* outColor,
-                          const char* inColor,
-                          const GrGLProcessor::TransformedCoordsArray& coords,
-                          const GrGLProcessor::TextureSamplerArray& samplers) {
-            SkASSERT(fFragmentProcessor);
-            SkASSERT(fGLFragmentProcessor);
-            fGLFragmentProcessor->emitCode(fBuilder, *fFragmentProcessor, key, outColor, inColor,
-                                           coords, samplers);
-            // this will not leak because it hasa already been used by createGLInstance
-            fGLFragmentProcessor = NULL;
-            fFragmentProcessor = NULL;
-        }
-    private:
-        GrGLProgramBuilder*         fBuilder;
-        const GrFragmentProcessor*  fFragmentProcessor;
-        GrGLFragmentProcessor*      fGLFragmentProcessor;
-    };
-
-    GrGLProcessorEmitterInterface*   fEffectEmitter;
-    CodeStage                        fCodeStage;
-    SkAutoTUnref<GrGLProgramEffects> fGeometryProcessor;
-    SkAutoTUnref<GrGLProgramEffects> fColorEffects;
-    SkAutoTUnref<GrGLProgramEffects> fCoverageEffects;
-    BuiltinUniformHandles            fUniformHandles;
-    bool                             fFragOnly;
-    int                              fTexCoordSetCnt;
-    GrGLuint                         fProgramID;
-    GrGLFragmentShaderBuilder        fFS;
-    SeparableVaryingInfoArray        fSeparableVaryingInfos;
-
-private:
-    virtual void createAndEmitEffects(const GrGeometryStage* geometryProcessor,
-                                      const GrFragmentStage* colorStages[],
-                                      const GrFragmentStage* coverageStages[],
-                                      GrGLSLExpr4* inputColor,
-                                      GrGLSLExpr4* inputCoverage) = 0;
-    /*
-     * Subclasses override emitEffect below to emit data and code for a specific single effect
-     */
-    virtual void emitEffect(const GrProcessorStage&,
-                            const GrProcessorKey&,
-                            const char* outColor,
-                            const char* inColor,
-                            int stageIndex) = 0;
-
-    /*
-     * Because we have fragment only builders, and those builders need to implement a subclass
-     * of program effects, we have to have base classes overload the program effects here
-     */
-    virtual GrGLProgramEffects* getProgramEffects() = 0;
-
-    /**
-     * Compiles all the shaders, links them into a program, and writes the program id to the output
-     * struct.
-     **/
-    bool finish();
-
-    GrGLFragmentProcessorEmitter            fGrProcessorEmitter;
-
-    const GrGLProgramDesc&                  fDesc;
-    GrGpuGL*                                fGpu;
-    UniformInfoArray                        fUniforms;
+        GrGLProgramBuilder* fPB;
+        bool fOutOfStage;
+    };
+    void exitStage() { fOutOfStage = true; }
+    void enterStage() { fOutOfStage = false; }
+    int stageIndex() const { return fStageIndex; }
+
+    typedef GrGLProgramDesc::EffectKeyProvider EffectKeyProvider;
+    typedef GrGLProgramDataManager::UniformInfo UniformInfo;
+    typedef GrGLProgramDataManager::UniformInfoArray UniformInfoArray;
+
+    // number of each input/output type in a single allocation block, used by many builders
+    static const int kVarsPerBlock;
+
+    BuiltinUniformHandles fUniformHandles;
+    GrGLVertexShaderBuilder fVS;
+    GrGLGeometryShaderBuilder fGS;
+    GrGLFragmentShaderBuilder fFS;
+    bool fOutOfStage;
+    int fStageIndex;
+
+    SkAutoTUnref<GrGLInstalledProcessors> fGeometryProcessor;
+    SkAutoTUnref<GrGLInstalledProcessors> fColorEffects;
+    SkAutoTUnref<GrGLInstalledProcessors> fCoverageEffects;
+
+    const GrGLProgramDesc& fDesc;
+    GrGpuGL* fGpu;
+    UniformInfoArray fUniforms;
 
     friend class GrGLShaderBuilder;
     friend class GrGLVertexShaderBuilder;
     friend class GrGLFragmentShaderBuilder;
     friend class GrGLGeometryShaderBuilder;
 };
 
+/**
+ * This class encapsulates an array of GrGLProcessors and their supporting data (coord transforms
+ * and textures). It is built by GrGLProgramBuilder, then used to manage the necessary GL
+ * state and shader uniforms in GLPrograms.  Its just Plain old data, and as such is entirely public
+ */
+class GrGLInstalledProcessors : public SkRefCnt {

[bsalomon, 2014/10/06 18:49:40]

Do think it still makes sense for this to be an array of processors rather than
just having one GrGLInstalledProcessor per processor?

[joshua.litt, 2014/10/06 19:16:57]

I agree this class is strange.  Let me leave a TODO to refactor this after I
remove the geometry stage.  Then I can split up this class into two, one for the
GP, one for fragment stages, and we can have arrays.

+public:
+    GrGLInstalledProcessors(int reserveCount, bool hasExplicitLocalCoords = false)
+        : fGLProcessors(reserveCount)
+        , fSamplers(reserveCount)
+        , fTransforms(reserveCount)
+        , fHasExplicitLocalCoords(hasExplicitLocalCoords) {
+    }
+
+    virtual ~GrGLInstalledProcessors();
+
+    typedef GrGLProgramDataManager::UniformHandle UniformHandle;
+
+    struct Sampler {
+        SkDEBUGCODE(Sampler() : fTextureUnit(-1) {})
+        UniformHandle  fUniform;
+        int            fTextureUnit;
+    };
+
+    class ShaderVarHandle {
+    public:
+        bool isValid() const { return fHandle > -1; }
+        ShaderVarHandle() : fHandle(-1) {}
+        ShaderVarHandle(int value) : fHandle(value) { SkASSERT(this->isValid()); }
+        int handle() const { SkASSERT(this->isValid()); return fHandle; }
+        UniformHandle convertToUniformHandle() {
+            SkASSERT(this->isValid());
+            return GrGLProgramDataManager::UniformHandle::CreateFromUniformIndex(fHandle);
+        }
+
+    private:
+        int fHandle;
+    };
+
+    struct Transform {
+        Transform() : fType(kVoid_GrSLType) { fCurrentValue = SkMatrix::InvalidMatrix(); }
+        ShaderVarHandle fHandle;
+        SkMatrix       fCurrentValue;
+        GrSLType       fType;
+    };
+
+    void addEffect(GrGLProcessor* effect) { fGLProcessors.push_back(effect); }
+    SkTArray<Sampler, true>& addSamplers() { return fSamplers.push_back(); }
+    SkTArray<Transform, true>& addTransforms() { return fTransforms.push_back(); }
+
+    SkTArray<GrGLProcessor*>                 fGLProcessors;
+    SkTArray<SkSTArray<4, Sampler, true> >   fSamplers;
+    SkTArray<SkSTArray<2, Transform, true> > fTransforms;
+    bool                                     fHasExplicitLocalCoords;
+
+    typedef SkRefCnt INHERITED;
+};
+
 #endif