[D3D12] Upload buffer pool class

src/xenia/ui/d3d12/pools.h

@@ -0,0 +1,68 @@
+/**
+ ******************************************************************************
+ * 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_UI_D3D12_POOLS_H_
+#define XENIA_UI_D3D12_POOLS_H_
+
+#include "xenia/ui/d3d12/d3d12_api.h"
+#include "xenia/ui/d3d12/d3d12_context.h"
+
+namespace xe {
+namespace ui {
+namespace d3d12 {
+
+class UploadBufferPool {
+ public:
+  UploadBufferPool(D3D12Context* context, uint32_t page_size);
+  ~UploadBufferPool();
+
+  void BeginFrame();
+  void EndFrame();
+  void ClearCache();
+
+  // Request to write data in a single piece, creating a new page if the current
+  // one doesn't have enough free space.
+  uint8_t* RequestFull(uint32_t size, ID3D12Resource*& buffer_out,
+                       uint32_t& offset_out);
+  // Request to write data in multiple parts, filling the buffer entirely.
+  uint8_t* RequestPartial(uint32_t size, ID3D12Resource*& buffer_out,
+                          uint32_t& offset_out, uint32_t& size_out);
+
+ private:
+  D3D12Context* context_;
+  uint32_t page_size_;
+
+  void EndPage();
+  bool BeginNextPage();
+
+  struct UploadBuffer {
+    ID3D12Resource* buffer;
+    UploadBuffer* next;
+    uint64_t frame_sent;
+  };
+
+  // A list of unsent buffers, with the first one being the current.
+  UploadBuffer* unsent_ = nullptr;
+  // A list of sent buffers, moved to unsent in the beginning of a frame.
+  UploadBuffer* sent_first_ = nullptr;
+  UploadBuffer* sent_last_ = nullptr;
+
+  uint32_t current_size_ = 0;
+  uint8_t* current_mapping_ = nullptr;
+
+  // Reset in the beginning of a frame - don't try and fail to create a new
+  // buffer if failed to create one in the current frame.
+  bool creation_failed_ = false;
+};
+
+}  // namespace d3d12
+}  // namespace ui
+}  // namespace xe
+
+#endif  // XENIA_UI_D3D12_POOLS_H_