Common: Move GL classes to subdirectory

src/common/gl/stream_buffer.h

@@ -0,0 +1,44 @@
+#pragma once
+#include "../types.h"
+#include <glad.h>
+#include <memory>
+#include <tuple>
+#include <vector>
+
+namespace GL {
+// TODO: Persistent mapping-based implementation
+class StreamBuffer
+{
+public:
+  ~StreamBuffer();
+
+  ALWAYS_INLINE GLuint GetGLBufferId() const { return m_buffer_id; }
+  ALWAYS_INLINE GLenum GetGLTarget() const { return m_target; }
+  ALWAYS_INLINE u32 GetSize() const { return m_size; }
+
+  void Bind();
+  void Unbind();
+
+  struct MappingResult
+  {
+    void* pointer;
+    u32 buffer_offset;
+    u32 index_aligned; // offset / alignment, suitable for base vertex
+    u32 space_aligned; // remaining space / alignment
+  };
+
+  MappingResult Map(u32 alignment, u32 min_size);
+  void Unmap(u32 used_size);
+
+  static std::unique_ptr<StreamBuffer> Create(GLenum target, u32 size);
+
+private:
+  StreamBuffer(GLenum target, GLuint buffer_id, u32 size);
+
+  GLenum m_target;
+  GLuint m_buffer_id;
+  u32 m_size;
+
+  std::vector<u8> m_cpu_buffer;
+};
+} // namespace GL