Move all ShaderBuilder files to GLSL

src/gpu/gl/builders/GrGLFragmentShaderBuilder.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 GrGLFragmentShaderBuilder_DEFINED
-#define GrGLFragmentShaderBuilder_DEFINED
-
-#include "GrGLShaderBuilder.h"
-
-#include "glsl/GrGLSLProcessorTypes.h"
-
-class GrRenderTarget;
-class GrGLSLVarying;
-
-/*
- * This base class encapsulates the functionality which the GP uses to build fragment shaders
- */
-class GrGLFragmentBuilder : public GrGLShaderBuilder {
-public:
-    GrGLFragmentBuilder(GrGLSLProgramBuilder* program)
-        : INHERITED(program)
-        , fHasCustomColorOutput(false)
-        , fHasSecondaryOutput(false) {
-        fSubstageIndices.push_back(0);
-    }
-    virtual ~GrGLFragmentBuilder() {}
-    /**
-     * Use of these features may require a GLSL extension to be enabled. Shaders may not compile
-     * if code is added that uses one of these features without calling enableFeature()
-     */
-    enum GLSLFeature {
-        kStandardDerivatives_GLSLFeature = 0,
-        kLastGLSLFeature = kStandardDerivatives_GLSLFeature
-    };
-
-    /**
-     * If the feature is supported then true is returned and any necessary #extension declarations
-     * are added to the shaders. If the feature is not supported then false will be returned.
-     */
-    virtual bool enableFeature(GLSLFeature) = 0;
-
-    /**
-     * This returns a variable name to access the 2D, perspective correct version of the coords in
-     * the fragment shader. If the coordinates at index are 3-dimensional, it immediately emits a
-     * perspective divide into the fragment shader (xy / z) to convert them to 2D.
-     */
-    virtual SkString ensureFSCoords2D(const GrGLSLTransformedCoordsArray& coords, int index) = 0;
-
-
-    /** Returns a variable name that represents the position of the fragment in the FS. The position
-        is in device space (e.g. 0,0 is the top left and pixel centers are at half-integers). */
-    virtual const char* fragmentPosition() = 0;
-
-    /**
-     * Fragment procs with child procs should call these functions before/after calling emitCode
-     * on a child proc.
-     */
-    void onBeforeChildProcEmitCode();
-    void onAfterChildProcEmitCode();
-
-    const SkString& getMangleString() const { return fMangleString; }
-
-    bool hasCustomColorOutput() const { return fHasCustomColorOutput; }
-    bool hasSecondaryOutput() const { return fHasSecondaryOutput; }
-
-protected:
-    bool fHasCustomColorOutput;
-    bool fHasSecondaryOutput;
-
-private:
-    /*
-     * State that tracks which child proc in the proc tree is currently emitting code.  This is
-     * used to update the fMangleString, which is used to mangle the names of uniforms and functions
-     * emitted by the proc.  fSubstageIndices is a stack: its count indicates how many levels deep
-     * we are in the tree, and its second-to-last value is the index of the child proc at that
-     * level which is currently emitting code. For example, if fSubstageIndices = [3, 1, 2, 0], that
-     * means we're currently emitting code for the base proc's 3rd child's 1st child's 2nd child.
-     */
-    SkTArray<int> fSubstageIndices;
-
-    /*
-     * The mangle string is used to mangle the names of uniforms/functions emitted by the child
-     * procs so no duplicate uniforms/functions appear in the generated shader program. The mangle
-     * string is simply based on fSubstageIndices. For example, if fSubstageIndices = [3, 1, 2, 0],
-     * then the manglestring will be "_c3_c1_c2", and any uniform/function emitted by that proc will
-     * have "_c3_c1_c2" appended to its name, which can be interpreted as "base proc's 3rd child's
-     * 1st child's 2nd child".
-     */
-    SkString fMangleString;
-
-    friend class GrGLPathProcessor;
-
-    typedef GrGLShaderBuilder INHERITED;
-};
-
-/*
- * Fragment processor's, in addition to all of the above, may need to use dst color so they use
- * this builder to create their shader.  Because this is the only shader builder the FP sees, we
- * just call it FPShaderBuilder
- */
-class GrGLXPFragmentBuilder : public GrGLFragmentBuilder {
-public:
-    GrGLXPFragmentBuilder(GrGLSLProgramBuilder* program) : INHERITED(program) {}
-
-    /** Returns the variable name that holds the color of the destination pixel. This may be nullptr if
-        no effect advertised that it will read the destination. */
-    virtual const char* dstColor() = 0;
-
-    /** Adds any necessary layout qualifiers in order to legalize the supplied blend equation with
-        this shader. It is only legal to call this method with an advanced blend equation, and only
-        if these equations are supported. */
-    virtual void enableAdvancedBlendEquationIfNeeded(GrBlendEquation) = 0;
-
-private:
-    typedef GrGLFragmentBuilder INHERITED;
-};
-
-// TODO rename to Fragment Builder
-class GrGLFragmentShaderBuilder : public GrGLXPFragmentBuilder {
-public:
-    typedef uint8_t FragPosKey;
-
-    /** Returns a key for reading the fragment location. This should only be called if there is an
-       effect that will requires the fragment position. If the fragment position is not required,
-       the key is 0. */
-    static FragPosKey KeyForFragmentPosition(const GrRenderTarget* dst);
-
-    GrGLFragmentShaderBuilder(GrGLSLProgramBuilder* program, uint8_t fragPosKey);
-
-    // true public interface, defined explicitly in the abstract interfaces above
-    bool enableFeature(GLSLFeature) override;
-    virtual SkString ensureFSCoords2D(const GrGLSLTransformedCoordsArray& coords,
-                                      int index) override;
-    const char* fragmentPosition() override;
-    const char* dstColor() override;
-
-    void enableAdvancedBlendEquationIfNeeded(GrBlendEquation) override;
-
-private:
-    // Private public interface, used by GrGLProgramBuilder to build a fragment shader
-    void enableCustomOutput();
-    void enableSecondaryOutput();
-    const char* getPrimaryColorOutputName() const;
-    const char* getSecondaryColorOutputName() const;
-
-    // As GLProcessors emit code, there are some conditions we need to verify.  We use the below
-    // state to track this.  The reset call is called per processor emitted.
-    bool hasReadDstColor() const { return fHasReadDstColor; }
-    bool hasReadFragmentPosition() const { return fHasReadFragmentPosition; }
-    void reset() {
-        fHasReadDstColor = false;
-        fHasReadFragmentPosition = false;
-    }
-
-    static const char* DeclaredColorOutputName() { return "fsColorOut"; }
-    static const char* DeclaredSecondaryColorOutputName() { return "fsSecondaryColorOut"; }
-
-    /*
-     * An internal call for GrGLProgramBuilder to use to add varyings to the vertex shader
-     */
-    void addVarying(GrGLSLVarying*, GrSLPrecision);
-
-    void onFinalize() override;
-
-    /**
-     * Features that should only be enabled by GrGLFragmentShaderBuilder itself.
-     */
-    enum GLSLPrivateFeature {
-        kFragCoordConventions_GLSLPrivateFeature = kLastGLSLFeature + 1,
-        kBlendEquationAdvanced_GLSLPrivateFeature,
-        kBlendFuncExtended_GLSLPrivateFeature,
-        kLastGLSLPrivateFeature = kBlendFuncExtended_GLSLPrivateFeature
-    };
-
-    // Interpretation of FragPosKey when generating code
-    enum {
-        kNoFragPosRead_FragPosKey           = 0,  // The fragment positition will not be needed.
-        kTopLeftFragPosRead_FragPosKey      = 0x1,// Read frag pos relative to top-left.
-        kBottomLeftFragPosRead_FragPosKey   = 0x2,// Read frag pos relative to bottom-left.
-    };
-
-    static const char* kDstTextureColorName;
-
-    bool fSetupFragPosition;
-    bool fTopLeftFragPosRead;
-    int  fCustomColorOutputIndex;
-
-    // some state to verify shaders and effects are consistent, this is reset between effects by
-    // the program creator
-    bool fHasReadDstColor;
-    bool fHasReadFragmentPosition;
-
-    friend class GrGLProgramBuilder;
-
-    typedef GrGLXPFragmentBuilder INHERITED;
-};
-
-#endif