Panda3DS/third_party/duckstation/gl/stream_buffer.h

// SPDX-FileCopyrightText: 2019-2023 Connor McLaughlin <stenzek@gmail.com>
// SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0)

#pragma once

#include <glad/gl.h>
// Comment to avoid clang-format reordering the glad header

#include <memory>
#include <string_view>
#include <tuple>
#include <vector>

#include "duckstation_compat.h"
#include "helpers.hpp"

class OpenGLStreamBuffer {
  public:
	virtual ~OpenGLStreamBuffer();

	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();

	void SetDebugName(std::string_view name);

	struct MappingResult {
		void* pointer;
		u32 buffer_offset;
		u32 index_aligned;  // offset / alignment, suitable for base vertex
		u32 space_aligned;  // remaining space / alignment
	};

	virtual MappingResult Map(u32 alignment, u32 min_size) = 0;

	/// Returns the position in the buffer *before* the start of used_size.
	virtual u32 Unmap(u32 used_size) = 0;

	/// Returns the minimum granularity of blocks which sync objects will be created around.
	virtual u32 GetChunkSize() const = 0;

	static std::unique_ptr<OpenGLStreamBuffer> Create(GLenum target, u32 size);

  protected:
	OpenGLStreamBuffer(GLenum target, GLuint buffer_id, u32 size);

	GLenum m_target;
	GLuint m_buffer_id;
	u32 m_size;
};