//
// Copyright (c) 2010 Advanced Micro Devices, Inc. All rights reserved.
//

#ifndef GPUCONSTBUF_HPP_
#define GPUCONSTBUF_HPP_

#include "device/gpu/gpumemory.hpp"

//! \namespace gpu GPU Resource Implementation
namespace gpu {

//! Cconstant buffer
class ConstBuffer : public Memory {
 public:
  //! Vector size of the constant buffer
  static const size_t VectorSize = 16;

  //! Constructor for the ConstBuffer class
  ConstBuffer(VirtualGPU& gpu,  //!< Virtual GPU device object
              size_t size       //!< size of the constant buffer in vectors
              );

  //! Destructor for the ConstBuffer class
  ~ConstBuffer();

  //! Creates the real HW constant buffer
  bool create();

  /*! \brief Uploads current constant buffer data from sysMemCopy_ to HW
   *
   *  \return True if the data upload was succesful
   */
  bool uploadDataToHw(size_t size  //!< real data size for upload
                      );

  //! Returns a pointer to the system memory copy for CB
  address sysMemCopy() const { return sysMemCopy_; }

  //! Returns CB size
  size_t size() const { return size_; }

  //! Returns current write offset for the constant buffer
  size_t wrtOffset() const { return wrtOffset_; }

  //! Returns last write size for the constant buffer
  size_t lastWrtSize() const { return lastWrtSize_; }

 private:
  //! Disable copy constructor
  ConstBuffer(const ConstBuffer&);

  //! Disable operator=
  ConstBuffer& operator=(const ConstBuffer&);

  VirtualGPU& gpu_;     //!< Virtual GPU object
  address sysMemCopy_;  //!< System memory copy
  size_t size_;         //!< Constant buffer size
  size_t wrtOffset_;    //!< Current write offset
  size_t lastWrtSize_;  //!< Last write size
  void* wrtAddress_;    //!< Write address in CB
};


/*@}*/} // namespace gpu

#endif /*GPUCONSTBUF_HPP_*/