Repurpose GrGLCoordTransform as GrGLEffectArray

src/gpu/gl/GrGLProgramEffects.h

+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrGLProgramEffects_DEFINED
+#define GrGLProgramEffects_DEFINED
+
+#include "GrBackendEffectFactory.h"
+#include "GrTexture.h"
+#include "GrTextureAccess.h"
+#include "GrGLUniformManager.h"
+
+class GrEffectStage;
+class GrGLProgramEffectsBuilder;
+class GrGLShaderBuilder;
+
+/**
+ * This class encapsulates an array of GrGLEffects and their supporting data (coord transforms
+ * and textures). It is built with GrGLProgramEffectsBuilder, then used to manage the necessary GL
+ * state and shader uniforms.
+ */
+class GrGLProgramEffects {
+public:
+    typedef GrBackendEffectFactory::EffectKey EffectKey;
+    typedef GrGLUniformManager::UniformHandle UniformHandle;
+
+    /**
+     * These methods generate different portions of an effect's final key.
+     */
+    static EffectKey GenAttribKey(const GrDrawEffect&);
+    static EffectKey GenTransformKey(const GrDrawEffect&);
+    static EffectKey GenTextureKey(const GrDrawEffect&, const GrGLCaps&);
+
+    ~GrGLProgramEffects();
+
+    /**
+     * Assigns a texture unit to each sampler. It starts on *texUnitIdx and writes the next
+     * available unit to *texUnitIdx when it returns.
+     */
+    void initSamplers(const GrGLUniformManager&, int* texUnitIdx);
+
+    /**
+     * Calls setData() on each effect, and sets their transformation matrices and texture bindings.
+     */
+    void setData(GrGpuGL*,
+                 const GrGLUniformManager&,
+                 const GrEffectStage* effectStages[]);
+
+    /**
+     * Passed to GrGLEffects so they can add transformed coordinates to their shader code.
+     */
+    class TransformedCoords {
+    public:
+        TransformedCoords(const char* name, GrSLType type, const char* vsName)
+            : fName(name), fType(type), fVSName(vsName) {
+        }
+
+        const char* c_str() const { return fName.c_str(); }
+        GrSLType type() const { return fType; }
+        const SkString& getName() const { return fName; }
+        // TODO: Remove the VS name when we have vertexless shaders, and gradients are reworked.
+        const SkString& getVSName() const { return fVSName; }
+
+    private:
+        SkString fName;
+        GrSLType fType;
+        SkString fVSName;
+    };
+
+    typedef SkTArray<TransformedCoords> TransformedCoordsArray;
+
+    /**
+     * Passed to GrGLEffects so they can add texture reads to their shader code.
+     */
+    class TextureSampler {
+    public:
+        TextureSampler(UniformHandle uniform, const GrTextureAccess& access)
+            : fSamplerUniform(uniform)
+            , fConfigComponentMask(GrPixelConfigComponentMask(access.getTexture()->config())) {
+            SkASSERT(0 != fConfigComponentMask);
+            memcpy(fSwizzle, access.getSwizzle(), 5);
+        }
+
+        UniformHandle samplerUniform() const { return fSamplerUniform; }
+        // bitfield of GrColorComponentFlags present in the texture's config.
+        uint32_t configComponentMask() const { return fConfigComponentMask; }
+        const char* swizzle() const { return fSwizzle; }
+
+    private:
+        UniformHandle fSamplerUniform;
+        uint32_t      fConfigComponentMask;
+        char          fSwizzle[5];
+    };
+
+    typedef SkTArray<TextureSampler> TextureSamplerArray;
+
+private:
+    friend class GrGLProgramEffectsBuilder;
+
+    GrGLProgramEffects(int reserveCount, bool explicitLocalCoords)
+        : fGLEffects(reserveCount)
+        , fTransforms(reserveCount)
+        , fSamplers(reserveCount)
+        , fHasExplicitLocalCoords(explicitLocalCoords) {
+    }
+
+    /**
+     * Helper for setData(). Sets all the transform matrices for an effect.
+     */
+    void setTransformData(const GrGLUniformManager&, const GrDrawEffect&, int effectIdx);
+
+    /**
+     * Helper for setData(). Binds all the textures for an effect.
+     */
+    void bindTextures(GrGpuGL*, const GrEffectRef&, int effectIdx);
+
+    struct Transform {
+        Transform() { fCurrentValue = SkMatrix::InvalidMatrix(); }
+        UniformHandle fHandle;
+        GrSLType      fType;
+        SkMatrix      fCurrentValue;
+    };
+
+    struct Sampler {
+        SkDEBUGCODE(Sampler() : fTextureUnit(-1) {})
+        UniformHandle fUniform;
+        int           fTextureUnit;
+    };
+
+    SkTArray<GrGLEffect*>                    fGLEffects;
+    SkTArray<SkSTArray<2, Transform, true> > fTransforms;
+    SkTArray<SkSTArray<4, Sampler, true> >   fSamplers;
+    bool                                     fHasExplicitLocalCoords;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+/**
+ * This class is used to construct a GrGLProgramEffects.
+ */
+class GrGLProgramEffectsBuilder {
+public:
+    GrGLProgramEffectsBuilder(GrGLShaderBuilder* builder, int reserveCount);
+
+    /**
+     * Emits the effect's shader code, and stores the necessary uniforms internally.
+     */
+    void emitEffect(const GrEffectStage&,
+                    GrGLProgramEffects::EffectKey,
+                    const char* outColor,
+                    const char* inColor,
+                    int stageIndex);
+
+    /**
+     * Finalizes the building process and returns the effect array. After this call, the builder
+     * becomes invalid.
+     */
+    GrGLProgramEffects* finish() { return fProgramEffects.detach(); }
+
+private:
+    /**
+     * Helper for emitEffect(). Emits any attributes an effect might have.
+     */
+    void emitAttributes(const GrEffectStage&);
+
+    /**
+     * Helper for emitEffect(). Emits code to implement an effect's coord transforms in the VS.
+     * Varyings are added as an outputs of the VS and inputs to the FS. The varyings may be either a
+     * vec2f or vec3f depending upon whether perspective interpolation is required or not. The names
+     * of the varyings in the VS and FS as well their types are appended to the
+     * TransformedCoordsArray* object, which is in turn passed to the effect's emitCode() function.
+     */
+    void emitTransforms(const GrEffectRef&,
+                        GrGLProgramEffects::EffectKey,
+                        GrGLProgramEffects::TransformedCoordsArray*);
+
+    /**
+     * Helper for emitEffect(). Emits uniforms for an effect's texture accesses. The uniform info
+     * as well as texture access parameters are appended to the TextureSamplerArray* object, which
+     * is in turn passed to the effect's emitCode() function.
+     */
+    void emitSamplers(const GrEffectRef&,
+                      GrGLProgramEffects::TextureSamplerArray*);
+
+    GrGLShaderBuilder*                fBuilder;
+    SkAutoTDelete<GrGLProgramEffects> fProgramEffects;
+};
+
+#endif