//
//   Copyright 2015 Pixar
//
//   Licensed under the terms set forth in the LICENSE.txt file available at
//   https://opensubdiv.org/license.
//

#ifndef OPENSUBDIV3_OSD_GL_PATCH_TABLE_H
#define OPENSUBDIV3_OSD_GL_PATCH_TABLE_H

#include "../version.h"

#include "../osd/nonCopyable.h"
#include "../osd/types.h"

#include <vector>

namespace OpenSubdiv {
namespace OPENSUBDIV_VERSION {

namespace Far{
    class PatchTable;
};

namespace Osd {

class GLPatchTable : private NonCopyable<GLPatchTable> {
public:
    using ID = unsigned int;        // GLuint resource ID
    using VertexBufferBinding = ID; // buffer binding type

    ~GLPatchTable();

    static GLPatchTable *Create(Far::PatchTable const *farPatchTable,
                                void *deviceContext = NULL);

    /// Returns the patch arrays for vertex index buffer data
    PatchArrayVector const &GetPatchArrays() const {
        return _patchArrays;
    }

    /// Returns the GL index buffer containing the patch control vertices
    ID GetPatchIndexBuffer() const {
        return _patchIndexBuffer;
    }

    /// Returns the GL index buffer containing the patch parameter
    ID GetPatchParamBuffer() const {
        return _patchParamBuffer;
    }

    /// Returns the GL texture buffer containing the patch control vertices
    ID GetPatchIndexTextureBuffer() const {
        return _patchIndexTexture;
    }

    /// Returns the GL texture buffer containing the patch parameter
    ID GetPatchParamTextureBuffer() const {
        return _patchParamTexture;
    }

    /// Returns the patch arrays for varying index buffer data
    PatchArrayVector const &GetVaryingPatchArrays() const {
        return _varyingPatchArrays;
    }

    /// Returns the GL index buffer containing the varying control vertices
    ID GetVaryingPatchIndexBuffer() const {
        return _varyingIndexBuffer;
    }

    /// Returns the GL texture buffer containing the varying control vertices
    ID GetVaryingPatchIndexTextureBuffer() const {
        return _varyingIndexTexture;
    }

    /// Returns the number of face-varying channel buffers
    int GetNumFVarChannels() const { return (int)_fvarPatchArrays.size(); }

    /// Returns the patch arrays for face-varying index buffer data
    PatchArrayVector const &GetFVarPatchArrays(int fvarChannel = 0) const {
        return _fvarPatchArrays[fvarChannel];
    }

    /// Returns the GL index buffer containing face-varying control vertices
    ID GetFVarPatchIndexBuffer(int fvarChannel = 0) const {
        return _fvarIndexBuffers[fvarChannel];
    }

    /// Returns the GL texture buffer containing face-varying control vertices
    ID GetFVarPatchIndexTextureBuffer(int fvarChannel = 0) const {
        return _fvarIndexTextures[fvarChannel];
    }

    /// Returns the GL index buffer containing face-varying patch params
    ID GetFVarPatchParamBuffer(int fvarChannel = 0) const {
        return _fvarParamBuffers[fvarChannel];
    }

    /// Returns the GL texture buffer containing face-varying patch params
    ID GetFVarPatchParamTextureBuffer(int fvarChannel = 0) const {
        return _fvarParamTextures[fvarChannel];
    }

protected:
    GLPatchTable();

    // allocate buffers from patchTable
    bool allocate(Far::PatchTable const *farPatchTable);

    PatchArrayVector _patchArrays;

    ID _patchIndexBuffer;
    ID _patchParamBuffer;

    ID _patchIndexTexture;
    ID _patchParamTexture;

    PatchArrayVector _varyingPatchArrays;
    ID _varyingIndexBuffer;
    ID _varyingIndexTexture;

    std::vector<PatchArrayVector> _fvarPatchArrays;
    std::vector<ID> _fvarIndexBuffers;
    std::vector<ID> _fvarIndexTextures;

    std::vector<ID> _fvarParamBuffers;
    std::vector<ID> _fvarParamTextures;
};


}  // end namespace Osd

}  // end namespace OPENSUBDIV_VERSION
using namespace OPENSUBDIV_VERSION;

}  // end namespace OpenSubdiv

#endif  // OPENSUBDIV3_OSD_GL_PATCH_TABLE_H