/*

 * Copyright 2017 Google Inc.

 *

 * Use of this source code is governed by a BSD-style license that can be

 * found in the LICENSE file.

 */

#ifndef GrGLSLVertexGeoBuilder_DEFINED

#define GrGLSLVertexGeoBuilder_DEFINED

#include "src/gpu/GrGeometryProcessor.h"

#include "src/gpu/glsl/GrGLSLShaderBuilder.h"

/**

 * Base class for vertex and geometry shader builders. This is the stage that computes input

 * geometry for the rasterizer.

 */

class GrGLSLVertexGeoBuilder : public GrGLSLShaderBuilder {

public:

    // Copies the given text verbatim to the function definitions section. Does not mangle the name.

    // 'functionDefinition' should be a fully valid SkSL function, complete with return type, name,

    // arguments, braces, and a body.

    void insertFunction(const char* functionDefinition) {

        this->functions().append(functionDefinition);

    }

    using GrGLSLShaderBuilder::functions;

    using GrGLSLShaderBuilder::code;

protected:

    GrGLSLVertexGeoBuilder(GrGLSLProgramBuilder* program) : INHERITED(program) {}

    void emitNormalizedSkPosition(const char* devPos,

                                  GrSLType devPosType = GrSLType::kFloat2_GrSLType) {

        this->emitNormalizedSkPosition(&this->code(), devPos, devPosType);

    }

    void emitNormalizedSkPosition(SkString* out, const char* devPos,

                                  GrSLType devPosType = GrSLType::kFloat2_GrSLType);

    friend class GrGeometryProcessor::ProgramImpl;

    using INHERITED = GrGLSLShaderBuilder;

};

class GrGLSLVertexBuilder : public GrGLSLVertexGeoBuilder {

public:

    GrGLSLVertexBuilder(GrGLSLProgramBuilder* program) : INHERITED(program) {}

private:

    void onFinalize() override;

    friend class GrGLProgramBuilder;

    using INHERITED = GrGLSLVertexGeoBuilder;

};

class GrGLSLGeometryBuilder : public GrGLSLVertexGeoBuilder {

public:

    GrGLSLGeometryBuilder(GrGLSLProgramBuilder* program) : INHERITED(program) {}

    enum class InputType {

        kPoints,

        kLines,

        kTriangles,

    };

    enum class OutputType {

        kPoints,

        kLineStrip,

        kTriangleStrip

    };

    void configure(InputType, OutputType, int maxVertices, int numInvocations = 1);

    bool isConfigured() const { return fNumInvocations; }

    void emitVertex(const char* devPos, GrSLType devPosType = GrSLType::kFloat2_GrSLType) {

        this->emitVertex(&this->code(), devPos, devPosType);

    }

    void emitVertex(SkString* out, const char* devPos,

                    GrSLType devPosType = GrSLType::kFloat2_GrSLType);

    void endPrimitive();

private:

    void onFinalize() override;

    int fNumInvocations = 0;

    friend class GrGLProgramBuilder;

    using INHERITED = GrGLSLVertexGeoBuilder;

};

#endif