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//
#ifndef OSD_GLSL_COMPUTE_CONTEXT_H
#define OSD_GLSL_COMPUTE_CONTEXT_H

#if defined(__APPLE__)
    #include "TargetConditionals.h"
    #if TARGET_OS_IPHONE or TARGET_IPHONE_SIMULATOR
        #include <OpenGLES/ES2/gl.h>
    #else
        #include <OpenGL/gl3.h>
    #endif
#elif defined(ANDROID)
    #include <GLES2/gl2.h>
#else
    #if defined(_WIN32)
        #include <windows.h>
    #endif
    #include <GL/gl.h>
#endif

#include "../version.h"

#include "../far/vertexEditTables.h"
#include "../osd/vertex.h"
#include "../osd/nonCopyable.h"

#include <vector>

namespace OpenSubdiv {
namespace OPENSUBDIV_VERSION {

class OsdGLSLComputeKernelBundle;

// ----------------------------------------------------------------------------

class OsdGLSLComputeTable : OsdNonCopyable<OsdGLSLComputeTable> {
public:
    template<typename T>
    explicit OsdGLSLComputeTable(const std::vector<T> &table) {
        createBuffer(table.size() * sizeof(unsigned int), &table[0]);
    }

    virtual ~OsdGLSLComputeTable();

    GLuint GetBuffer() const;

private:
    void createBuffer(size_t size, const void *ptr);

    GLuint _buffer;
};

// ----------------------------------------------------------------------------

class OsdGLSLComputeHEditTable : OsdNonCopyable<OsdGLSLComputeHEditTable> {
public:
    OsdGLSLComputeHEditTable(const FarVertexEditTables<OsdVertex>::
                      VertexEditBatch &batch);

    virtual ~OsdGLSLComputeHEditTable();

    const OsdGLSLComputeTable * GetPrimvarIndices() const;

    const OsdGLSLComputeTable * GetEditValues() const;

    int GetOperation() const;

    int GetPrimvarOffset() const;

    int GetPrimvarWidth() const;

private:
    OsdGLSLComputeTable *_primvarIndicesTable;
    OsdGLSLComputeTable *_editValuesTable;

    int _operation;
    int _primvarOffset;
    int _primvarWidth;
};

// ----------------------------------------------------------------------------

class OsdGLSLComputeContext {
public:
    static OsdGLSLComputeContext * Create(FarMesh<OsdVertex> *farmesh);

    virtual ~OsdGLSLComputeContext();

    template<class VERTEX_BUFFER, class VARYING_BUFFER>
    void Bind(VERTEX_BUFFER *vertex, VARYING_BUFFER *varying) {

        _currentVertexBuffer = vertex ? vertex->BindVBO() : 0;
        _currentVaryingBuffer = varying ? varying->BindVBO() : 0;

        _numVertexElements = vertex ? vertex->GetNumElements() : 0;
        _numVaryingElements = varying ? varying->GetNumElements() : 0;

        bindShaderStorageBuffers();
    }

    void Unbind() {
        _currentVertexBuffer = 0;
        _currentVaryingBuffer = 0;

        unbindShaderStorageBuffers();
    }

    const OsdGLSLComputeTable * GetTable(int tableIndex) const;

    int GetNumEditTables() const;

    const OsdGLSLComputeHEditTable * GetEditTable(int tableIndex) const;

    GLuint GetCurrentVertexBuffer() const;

    GLuint GetCurrentVaryingBuffer() const;

    int GetNumCurrentVertexElements() const;

    int GetNumCurrentVaryingElements() const;

    OsdGLSLComputeKernelBundle * GetKernelBundle() const;

    void SetKernelBundle(OsdGLSLComputeKernelBundle *kernelBundle);

    void BindUniformBlockBilinearFace(GLuint program, int level);

    void BindUniformBlockBilinearEdge(GLuint program, int level);

    void BindUniformBlockBilinearVertex(GLuint program, int level);

    void BindUniformBlockCatmarkFace(GLuint program, int level);

    void BindUniformBlockCatmarkEdge(GLuint program, int level);

    void BindUniformBlockCatmarkVertexA0(GLuint program, int level);

    void BindUniformBlockCatmarkVertexA1(GLuint program, int level);

    void BindUniformBlockCatmarkVertexB(GLuint program, int level);

    void BindUniformBlockLoopEdge(GLuint program, int level);

    void BindUniformBlockLoopVertexA(GLuint program, int level);

    void BindUniformBlockLoopVertexB(GLuint program, int level);

    void BindEditShaderStorageBuffers(int editIndex);

    void UnbindEditShaderStorageBuffers();

protected:
    explicit OsdGLSLComputeContext(FarMesh<OsdVertex> *farMesh);

    void bindShaderStorageBuffers();

    void unbindShaderStorageBuffers();

private:
    std::vector<OsdGLSLComputeTable*> _tables;
    std::vector<OsdGLSLComputeHEditTable*> _editTables;

    GLuint _vertexTexture;
    GLuint _varyingTexture;

    int _numVertexElements;
    int _numVaryingElements;

    GLuint _currentVertexBuffer, _currentVaryingBuffer;

    OsdGLSLComputeKernelBundle * _kernelBundle;
};

}  // end namespace OPENSUBDIV_VERSION
using namespace OPENSUBDIV_VERSION;

}  // end namespace OpenSubdiv

#endif  // OSD_GLSL_COMPUTE_CONTEXT_H