#pragma region CPL License
/*
Nuclex Native Framework
Copyright (C) 2002-2013 Nuclex Development Labs

This library is free software; you can redistribute it and/or
modify it under the terms of the IBM Common Public License as
published by the IBM Corporation; either version 1.0 of the
License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
IBM Common Public License for more details.

You should have received a copy of the IBM Common Public
License along with this library
*/
#pragma endregion // CPL License

#ifndef NUCLEX_GRAPHICS_RASTERIZATION_DIRECT3D11VERTEXBUFFEROBSERVER_H
#define NUCLEX_GRAPHICS_RASTERIZATION_DIRECT3D11VERTEXBUFFEROBSERVER_H

#include "Nuclex/Graphics/Config.h"
#include "Nuclex/Graphics/Rasterization/GenericVertexBuffer.h"
#include "../Direct3D11Api.h"

namespace Nuclex { namespace Graphics { namespace Rasterization {

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

  class Direct3D11RasterizerResources;

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

}}} // namespace Nuclex::Graphics::Rasterization

namespace Nuclex { namespace Graphics { namespace Rasterization {

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

  ///<summary>Manages an attached Direct3D 11 vertex buffer</summary>
  class Direct3D11VertexBufferObserver : public GenericVertexBuffer::Observer {

    /// <summary>Initializes a new Direct3D 11 vertex buffer</summary>
    /// <param name="resources">Manager the vertex buffer belongs to</param>
    /// <param name="vertexBuffer">Vertex buffer the observer is attached to</param>
    public: Direct3D11VertexBufferObserver(
      Direct3D11RasterizerResources &resources, GenericVertexBuffer *vertexBuffer
    );

    /// <summary>Frees all resources owned by the vertex buffer observer</summary>
    public: virtual ~Direct3D11VertexBufferObserver();

    /// <summary>Called right before the buffer is destroyed</summary>
    public: void Destroying();

    /// <summary>Called when the buffer has been cleared</summary>
    public: void Cleared();

    /// <summary>Called when the contents of the buffer have changed</summary>
    /// <param name="offset">
    ///   Offset in the buffer from which on its contents have changed
    /// </param>
    /// <param name="count">Number of bytes that have changed in the buffer</param>
    public: void Changed(std::size_t offset, std::size_t count);

    /// <summary>Retrieves the agnostic vertex buffer being observed</summary>
    /// <returns>The agnostic vertex buffer being observed</returns>
    public: GenericVertexBuffer *GetResource() const { return this->vertexBuffer; }

    /// <summary>Retrieves the Direct3D vertex buffer the observer is managing</summary>
    /// <returns>The observer's Direct3D vertex buffer</returns>
    public: const ID3D11BufferPtr &GetDirect3DVertexBuffer() const {
      return this->direct3DVertexBuffer;
    }

    /// <summary>
    ///   Gets and resets the 'replaced' flag that indicates whether the Direct3D buffer
    ///   had to be recreated since the last call
    /// </summary>
    public: bool GetAndResetReplacedFlag() {
      bool wasReplaced = this->wasReplaced;
      this->wasReplaced = false;
      return wasReplaced;
    }

    /// <summary>Creates a Direct3D vertex buffer matching the observed one</summary>
    private: void createDirect3DVertexBuffer();

    private: Direct3D11VertexBufferObserver(const Direct3D11VertexBufferObserver &);
    private: Direct3D11VertexBufferObserver &operator =(const Direct3D11VertexBufferObserver &);

    /// <summary>Resource manager the render target belongs to</summary>
    private: Direct3D11RasterizerResources &resources;
    /// <summary>Vertex buffer this observer is attached to</summary>
    private: GenericVertexBuffer *vertexBuffer;
    /// <summary>Vertex buffer managed by this observer</summary>
    private: ID3D11BufferPtr direct3DVertexBuffer;
    /// <summary>Number of bytes currently used by the buffer</summary>
    private: std::size_t usedBytes;
    /// <summary>Whether the observer's Direct3D buffer needed to be replaced</summary>
    private: bool wasReplaced;

  };

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

}}} // namespace Nuclex::Graphics::Rasterization

#endif // NUCLEX_GRAPHICS_RASTERIZATION_DIRECT3D11VERTEXBUFFEROBSERVER_H