Make GrGLSLProgramBuilder base class for ProgramBuilder

src/gpu/glsl/GrGLSLProgramBuilder.h

+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrGLSLProgramBuilder_DEFINED
+#define GrGLSLProgramBuilder_DEFINED
+
+#include "GrGeometryProcessor.h"
+#include "GrGpu.h"
+#include "gl/builders/GrGLFragmentShaderBuilder.h"
+#include "gl/builders/GrGLGeometryShaderBuilder.h"
+#include "gl/builders/GrGLVertexShaderBuilder.h"
+#include "glsl/GrGLSLProgramDataManager.h"
+
+class GrGLSLCaps;
+class GrGLSLShaderVar;
+
+class GrGLSLUniformBuilder {
+public:
+    enum ShaderVisibility {
+        kVertex_Visibility   = 1 << kVertex_GrShaderType,
+        kGeometry_Visibility = 1 << kGeometry_GrShaderType,
+        kFragment_Visibility = 1 << kFragment_GrShaderType,
+    };
+
+    virtual ~GrGLSLUniformBuilder() {}
+
+    typedef GrGLSLProgramDataManager::UniformHandle UniformHandle;
+    typedef GrGLSLProgramDataManager::SeparableVaryingHandle SeparableVaryingHandle;
+
+    /** 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 nullptr
+        then it will refer to the final uniform name after return. Use the addUniformArray variant
+        to add an array of uniforms. */
+    UniformHandle addUniform(uint32_t visibility,
+                             GrSLType type,
+                             GrSLPrecision precision,
+                             const char* name,
+                             const char** outName = nullptr) {
+        return this->addUniformArray(visibility, type, precision, name, 0, outName);
+    }
+
+    UniformHandle addUniformArray(uint32_t visibility,
+                                  GrSLType type,
+                                  GrSLPrecision precision,
+                                  const char* name,
+                                  int arrayCount,
+                                  const char** outName = nullptr) {
+        return this->internalAddUniformArray(visibility, type, precision, name, true, arrayCount,
+                                             outName);
+    }
+
+    virtual const GrGLSLShaderVar& getUniformVariable(UniformHandle u) const = 0;
+
+    /**
+     * Shortcut for getUniformVariable(u).c_str()
+     */
+    virtual const char* getUniformCStr(UniformHandle u) const = 0;
+
+    virtual const GrGLSLCaps* glslCaps() const = 0;
+
+    /*
+     * *NOTE* NO MEMBERS ALLOWED, MULTIPLE INHERITANCE
+     */
+protected:
+    virtual UniformHandle internalAddUniformArray(
+        uint32_t visibility,
+        GrSLType type,
+        GrSLPrecision precision,
+        const char* name,
+        bool mangleName,
+        int arrayCount,
+        const char** outName) = 0;
+};
+
+// TODO move this into GrGLSLGPBuilder and move them both out of this file
+class GrGLSLVarying {
+public:
+    bool vsVarying() const { return kVertToFrag_Varying == fVarying ||
+                                    kVertToGeo_Varying == fVarying; }
+    bool fsVarying() const { return kVertToFrag_Varying == fVarying ||
+                                    kGeoToFrag_Varying == fVarying; }
+    const char* vsOut() const { return fVsOut; }
+    const char* gsIn() const { return fGsIn; }
+    const char* gsOut() const { return fGsOut; }
+    const char* fsIn() const { return fFsIn; }
+    GrSLType type() const { return fType; }
+
+protected:
+    enum Varying {
+        kVertToFrag_Varying,
+        kVertToGeo_Varying,
+        kGeoToFrag_Varying,
+    };
+
+    GrGLSLVarying(GrSLType type, Varying varying)
+        : fVarying(varying), fType(type), fVsOut(nullptr), fGsIn(nullptr), fGsOut(nullptr),
+          fFsIn(nullptr) {}
+
+    Varying fVarying;
+
+private:
+    GrSLType fType;
+    const char* fVsOut;
+    const char* fGsIn;
+    const char* fGsOut;
+    const char* fFsIn;
+
+    friend class GrGLVertexBuilder;
+    friend class GrGLGeometryBuilder;
+    friend class GrGLXferBuilder;
+    friend class GrGLFragmentShaderBuilder;
+};
+
+struct GrGLSLVertToFrag : public GrGLSLVarying {
+    GrGLSLVertToFrag(GrSLType type)
+        : GrGLSLVarying(type, kVertToFrag_Varying) {}
+};
+
+struct GrGLSLVertToGeo : public GrGLSLVarying {
+    GrGLSLVertToGeo(GrSLType type)
+        : GrGLSLVarying(type, kVertToGeo_Varying) {}
+};
+
+struct GrGLSLGeoToFrag : public GrGLSLVarying {
+    GrGLSLGeoToFrag(GrSLType type)
+        : GrGLSLVarying(type, kGeoToFrag_Varying) {}
+};
+
+/* a specialization of the above for GPs.  Lets the user add uniforms, varyings, and VS / FS code */
+class GrGLSLGPBuilder : public virtual GrGLSLUniformBuilder {
+public:
+    /*
+     * addVarying allows fine grained control for setting up varyings between stages.  If you just
+     * need to take an attribute and pass it through to an output value in a fragment shader, use
+     * addPassThroughAttribute.
+     * TODO convert most uses of addVarying to addPassThroughAttribute
+     */
+    virtual void addVarying(const char* name,
+                            GrGLSLVarying*,
+                            GrSLPrecision precision = kDefault_GrSLPrecision) = 0;
+
+    /*
+     * This call can be used by GP to pass an attribute through all shaders directly to 'output' in
+     * the fragment shader.  Though this call effects both the vertex shader and fragment shader,
+     * it expects 'output' to be defined in the fragment shader before this call is made.
+     * TODO it might be nicer behavior to have a flag to declare output inside this call
+     */
+    virtual void addPassThroughAttribute(const GrGeometryProcessor::Attribute*,
+                                         const char* output) = 0;
+
+    /*
+     * Creates a fragment shader varying that can be referred to.
+     * Comparable to GrGLSLUniformBuilder::addUniform().
+     */
+    virtual SeparableVaryingHandle addSeparableVarying(
+        const char* name, GrGLSLVertToFrag*,
+        GrSLPrecision fsPrecision = kDefault_GrSLPrecision) = 0;
+
+    // TODO rename getFragmentBuilder
+    virtual GrGLFragmentBuilder* getFragmentShaderBuilder() = 0;
+    virtual GrGLVertexBuilder* getVertexShaderBuilder() = 0;
+
+    /*
+     * *NOTE* NO MEMBERS ALLOWED, MULTIPLE INHERITANCE
+     */
+};
+
+
+/* a specializations for FPs. Lets the user add uniforms and FS code */
+class GrGLSLFPBuilder : public virtual GrGLSLUniformBuilder {
+public:
+    virtual GrGLFragmentBuilder* getFragmentShaderBuilder() = 0;
+
+    /*
+     * *NOTE* NO MEMBERS ALLOWED, MULTIPLE INHERITANCE
+     */
+};
+
+/* a specializations for XPs. Lets the user add uniforms and FS code */
+class GrGLSLXPBuilder : public virtual GrGLSLUniformBuilder {
+public:
+    virtual GrGLXPFragmentBuilder* getFragmentShaderBuilder() = 0;
+
+    /*
+     * *NOTE* NO MEMBERS ALLOWED, MULTIPLE INHERITANCE
+     */
+};
+
+class GrGLSLProgramBuilder : public GrGLSLGPBuilder,
+                             public GrGLSLFPBuilder,
+                             public GrGLSLXPBuilder {
+public:
+    typedef GrGpu::DrawArgs DrawArgs;
+
+    GrGLXPFragmentBuilder* getFragmentShaderBuilder() override { return &fFS; }
+    GrGLVertexBuilder* getVertexShaderBuilder() override { return &fVS; }
+
+    // Handles for program uniforms (other than per-effect uniforms)
+    struct BuiltinUniformHandles {
+        UniformHandle       fRTAdjustmentUni;
+
+        // We use the render target height to provide a y-down frag coord when specifying
+        // origin_upper_left is not supported.
+        UniformHandle       fRTHeightUni;
+    };
+
+protected:
+    explicit GrGLSLProgramBuilder(const DrawArgs& args);
+
+    const GrPrimitiveProcessor& primitiveProcessor() const { return *fArgs.fPrimitiveProcessor; }
+    const GrPipeline& pipeline() const { return *fArgs.fPipeline; }
+    const GrProgramDesc& desc() const { return *fArgs.fDesc; }
+    const GrProgramDesc::KeyHeader& header() const { return fArgs.fDesc->header(); }
+
+    void appendUniformDecls(ShaderVisibility, SkString*) const;
+
+    // Used to add a uniform for frag position without mangling the name of the uniform inside of a
+    // stage.
+    UniformHandle addFragPosUniform(uint32_t visibility,
+                                    GrSLType type,
+                                    GrSLPrecision precision,
+                                    const char* name,
+                                    const char** outName) {
+        return this->internalAddUniformArray(visibility, type, precision, name, false, 0, outName);
+    }
+
+    const char* rtAdjustment() const { return "rtAdjustment"; }
+
+    // Generates a name for a variable. The generated string will be name prefixed by the prefix
+    // char (unless the prefix is '\0'). It also will mangle the name to be stage-specific unless
+    // explicitly asked not to.
+    void nameVariable(SkString* out, char prefix, const char* name, bool mangle = true);
+
+    // number of each input/output type in a single allocation block, used by many builders
+    static const int kVarsPerBlock;
+
+    GrGLVertexBuilder fVS;
+    GrGLGeometryBuilder fGS;
+    GrGLFragmentShaderBuilder fFS;
+    int fStageIndex;
+
+    BuiltinUniformHandles fUniformHandles;
+
+    const DrawArgs& fArgs;
+
+private:
+    virtual void onAppendUniformDecls(ShaderVisibility visibility, SkString* out) const = 0;
+
+    friend class GrGLShaderBuilder;
+    friend class GrGLVertexBuilder;
+    friend class GrGLFragmentShaderBuilder;
+    friend class GrGLGeometryBuilder;
+};
+
+#endif