Moving common GL code out of gpu/.

src/xenia/ui/gl/circular_buffer.h

@@ -0,0 +1,71 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2014 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_UI_GL_CIRCULAR_BUFFER_H_
+#define XENIA_UI_GL_CIRCULAR_BUFFER_H_
+
+#include <unordered_map>
+
+#include "xenia/ui/gl/gl_context.h"
+
+namespace xe {
+namespace ui {
+namespace gl {
+
+// TODO(benvanik): uh, make this circular.
+// TODO(benvanik): fences to prevent this from ever flushing.
+class CircularBuffer {
+ public:
+  CircularBuffer(size_t capacity, size_t alignment = 256);
+  ~CircularBuffer();
+
+  struct Allocation {
+    void* host_ptr;
+    GLuint64 gpu_ptr;
+    size_t offset;
+    size_t length;
+    size_t aligned_length;
+    uint64_t cache_key;  // 0 if caching disabled.
+  };
+
+  bool Initialize();
+  void Shutdown();
+
+  GLuint handle() const { return buffer_; }
+  GLuint64 gpu_handle() const { return gpu_base_; }
+  size_t capacity() const { return capacity_; }
+
+  bool CanAcquire(size_t length);
+  Allocation Acquire(size_t length);
+  bool AcquireCached(uint32_t key, size_t length, Allocation* out_allocation);
+  void Discard(Allocation allocation);
+  void Commit(Allocation allocation);
+  void Flush();
+  void ClearCache();
+
+  void WaitUntilClean();
+
+ private:
+  size_t capacity_;
+  size_t alignment_;
+  uintptr_t write_head_;
+  uintptr_t dirty_start_;
+  uintptr_t dirty_end_;
+  GLuint buffer_;
+  GLuint64 gpu_base_;
+  uint8_t* host_base_;
+
+  std::unordered_map<uint64_t, uintptr_t> allocation_cache_;
+};
+
+}  // namespace gl
+}  // namespace ui
+}  // namespace xe
+
+#endif  // XENIA_UI_GL_CIRCULAR_BUFFER_H_