//
//   Copyright 2013 Pixar
//
//   Licensed under the terms set forth in the LICENSE.txt file available at
//   https://opensubdiv.org/license.
//

#ifndef OPENSUBDIV3_OSD_D3D11_VERTEX_BUFFER_H
#define OPENSUBDIV3_OSD_D3D11_VERTEX_BUFFER_H

#include "../version.h"

struct ID3D11Buffer;
struct ID3D11Device;
struct ID3D11DeviceContext;
struct ID3D11UnorderedAccessView;

namespace OpenSubdiv {
namespace OPENSUBDIV_VERSION {

namespace Osd {

///
/// \brief Concrete vertex buffer class for DirectX subdivision and DirectX drawing.
///
/// D3D11VertexBuffer implements D3D11VertexBufferInterface. An instance
/// of this buffer class can be passed to D3D11ComputeEvaluator.
///
class D3D11VertexBuffer {
public:
    /// Creator. Returns NULL if error.
    static D3D11VertexBuffer * Create(int numElements, int numVertices,
                                      ID3D11DeviceContext *deviceContext);

    /// Destructor.
    virtual ~D3D11VertexBuffer();

    /// This method is meant to be used in client code in order to provide coarse
    /// vertices data to Osd.
    void UpdateData(const float *src, int startVertex, int numVertices,
                    ID3D11DeviceContext *deviceContext);

    /// Returns how many elements defined in this vertex buffer.
    int GetNumElements() const;

    /// Returns how many vertices allocated in this vertex buffer.
    int GetNumVertices() const;

    /// Returns the D3D11 buffer object.
    ID3D11Buffer *BindD3D11Buffer(ID3D11DeviceContext *deviceContext);

    /// Returns the D3D11 buffer object (for Osd::Mesh interface)
    ID3D11Buffer *BindVBO(ID3D11DeviceContext *deviceContext) {
        return BindD3D11Buffer(deviceContext);
    }

    /// Returns the D3D11 UAV
    ID3D11UnorderedAccessView *BindD3D11UAV(ID3D11DeviceContext *deviceContext);

protected:
    /// Constructor.
    D3D11VertexBuffer(int numElements, int numVertices);

    // Allocates D3D11 buffer
    bool allocate(ID3D11Device *device);

private:
    int _numElements;
    int _numVertices;
    ID3D11Buffer *_buffer;
    ID3D11Buffer *_uploadBuffer;
    ID3D11UnorderedAccessView *_uav;
};

}  // end namespace Osd

}  // end namespace OPENSUBDIV_VERSION
using namespace OPENSUBDIV_VERSION;

}  // end namespace OpenSubdiv

#endif  // OPENSUBDIV3_OSD_D3D11_VERTEX_BUFFER_H