/**
 ******************************************************************************
 * Xenia : Xbox 360 Emulator Research Project                                 *
 ******************************************************************************
 * Copyright 2018 Ben Vanik. All rights reserved.                             *
 * Released under the BSD license - see LICENSE in the root for more details. *
 ******************************************************************************
 */

#ifndef XENIA_GPU_D3D12_TEXTURE_CACHE_H_
#define XENIA_GPU_D3D12_TEXTURE_CACHE_H_

#include "xenia/gpu/register_file.h"
#include "xenia/gpu/xenos.h"
#include "xenia/ui/d3d12/d3d12_api.h"

namespace xe {
namespace gpu {
namespace d3d12 {

class D3D12CommandProcessor;

// Manages host copies of guest textures, performing untiling, format and endian
// conversion of textures stored in the shared memory, and also handling
// invalidation.
//
// Mipmaps are treated the following way, according to the GPU hang message
// found in game executables explaining the valid usage of BaseAddress when
// streaming the largest LOD (it says games should not use 0 as the base address
// when the largest LOD isn't loaded, but rather, either allocate a valid
// address for it or make it the same as MipAddress):
// - If the texture has a base address, but no mip address, it's not mipmapped -
//   the host texture has only the largest level too.
// - If the texture has different non-zero base address and mip address, a host
//   texture with mip_max_level+1 mipmaps is created - mip_min_level is ignored
//   and treated purely as sampler state because there are tfetch instructions
//   working directly with LOD values - including fetching with an explicit LOD.
//   However, the max level is not ignored because any mip count can be
//   specified when creating a texture, and another texture may be placed after
//   the last one.
// - If the texture has a mip address, but the base address is 0 or the same as
//   the mip address, a mipmapped texture is created, but min/max LOD is clamped
//   to the lower bound of 1 - the game is expected to do that anyway until the
//   largest LOD is loaded.
//   TODO(Triang3l): Check if there are any games with BaseAddress==MipAddress
//   but min or max LOD being 0, especially check Modern Warfare 2/3.
//   TODO(Triang3l): Attach the largest LOD to existing textures with a valid
//   MipAddress but no BaseAddress to save memory because textures are streamed
//   this way anyway.
class TextureCache {
 public:
  TextureCache(D3D12CommandProcessor* command_processor,
               RegisterFile* register_file);
  ~TextureCache();

  void Shutdown();

  void ClearCache();

  void WriteTextureSRV(uint32_t fetch_constant,
                       TextureDimension shader_dimension,
                       D3D12_CPU_DESCRIPTOR_HANDLE handle);
  void WriteSampler(uint32_t fetch_constant,
                    D3D12_CPU_DESCRIPTOR_HANDLE handle);

 private:
  D3D12CommandProcessor* command_processor_;
  RegisterFile* register_file_;
};

}  // namespace d3d12
}  // namespace gpu
}  // namespace xe

#endif  // XENIA_GPU_D3D12_TEXTURE_CACHE_H_