text: /*     Copyright 2019 Diligent Graphics LLC
   *  
   *  Licensed under the Apache License, Version 2.0 (the "License");
   *  you may not use this file except in compliance with the License.
   *  You may obtain a copy of the License at
   * 
   *     http://www.apache.org/licenses/LICENSE-2.0
   * 
   *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF ANY PROPRIETARY RIGHTS.
   *
   *  In no event and under no legal theory, whether in tort (including negligence), 
   *  contract, or otherwise, unless required by applicable law (such as deliberate 
   *  and grossly negligent acts) or agreed to in writing, shall any Contributor be
   *  liable for any damages, including any direct, indirect, special, incidental, 
   *  or consequential damages of any character arising as a result of this License or 
   *  out of the use or inability to use the software (including but not limited to damages 
   *  for loss of goodwill, work stoppage, computer failure or malfunction, or any and 
   *  all other commercial damages or losses), even if such Contributor has been advised 
   *  of the possibility of such damages.
   */
  
  #pragma once
  
  /// \file
  /// Implementation of the Diligent::BufferViewBase template class
  
  #include "BufferView.h"
  #include "DeviceObjectBase.h"
  #include "GraphicsTypes.h"
  #include "RefCntAutoPtr.h"
  
  namespace Diligent
  {
  
  class IRenderDevice;
  class IBuffer;
  
  /// Template class implementing base functionality for a buffer view object
  
  /// \tparam BaseInterface - base interface that this class will inheret
  ///                         (Diligent::IBufferViewD3D11, Diligent::IBufferViewD3D12,
  ///                          Diligent::IBufferViewGL or Diligent::IBufferViewVk).
  /// \tparam RenderDeviceImplType - type of the render device implementation
  ///                                (Diligent::RenderDeviceD3D11Impl, Diligent::RenderDeviceD3D12Impl,
  ///                                 Diligent::RenderDeviceGLImpl, or Diligent::RenderDeviceVkImpl)
  template<class BaseInterface, class RenderDeviceImplType>
  class BufferViewBase : public DeviceObjectBase<BaseInterface, RenderDeviceImplType, BufferViewDesc>
  {
  public:
      using TDeviceObjectBase = DeviceObjectBase<BaseInterface, RenderDeviceImplType, BufferViewDesc>;
  
      /// \param pRefCounters - reference counters object that controls the lifetime of this buffer view.
  	/// \param pDevice - pointer to the render device.
  	/// \param ViewDesc - buffer view description.
  	/// \param pBuffer - pointer to the buffer that the view is to be created for.
  	/// \param bIsDefaultView - flag indicating if the view is default view, and is thus
  	///						    part of the buffer object. In this case the view will attach 
  	///							to the buffer's reference counters.
      BufferViewBase( IReferenceCounters*   pRefCounters,
                      RenderDeviceImplType* pDevice,
                      const BufferViewDesc& ViewDesc, 
                      IBuffer*              pBuffer,
                      bool                  bIsDefaultView ) :
          // Default views are created as part of the buffer, so we cannot not keep strong 
          // reference to the buffer to avoid cyclic links. Instead, we will attach to the 
          // reference counters of the buffer.
          TDeviceObjectBase( pRefCounters, pDevice, ViewDesc),
          m_pBuffer( pBuffer ),
          // For non-default view, we will keep strong reference to buffer
          m_spBuffer(bIsDefaultView ? nullptr : pBuffer)
      {}
  
      IMPLEMENT_QUERY_INTERFACE_IN_PLACE( IID_BufferView, TDeviceObjectBase )
  
      /// Implementation of IBufferView::GetBuffer()
      virtual IBuffer* GetBuffer()override final
      {
          return m_pBuffer;
      }
  
      template<typename BufferType>
      BufferType* GetBuffer()
      {
          return ValidatedCast<BufferType>(m_pBuffer);
      }
  
      template<typename BufferType>
      BufferType* GetBuffer()const
      {
          return ValidatedCast<BufferType>(m_pBuffer);
      }
  
  protected:
  
      /// Pointer to the buffer
      IBuffer* const m_pBuffer;
  
      /// Strong reference to the buffer. Used for non-default views
      /// to keep the buffer alive
      RefCntAutoPtr<IBuffer> m_spBuffer;
  };
  
  }
  