Extra2D/Extra2D/include/extra2d/render/backends/opengl/gl_rhi_buffer.h

#pragma once

#include <extra2d/render/rhi/rhi_buffer.h>
#include <glad/glad.h>
#include <string>

namespace extra2d {
namespace rhi {

/**
 * @brief OpenGL 缓冲区实现
 * 
 * 使用 OpenGL 4.5 DSA (Direct State Access) 特性
 */
class GLRHIBuffer : public RHIBuffer {
public:
    /**
     * @brief 构造函数
     */
    GLRHIBuffer();

    /**
     * @brief 析构函数
     */
    ~GLRHIBuffer() override;

    /**
     * @brief 初始化缓冲区
     * @param desc 缓冲区描述
     * @return 成功返回 true
     */
    bool init(const BufferDesc& desc);

    /**
     * @brief 释放资源
     */
    void shutdown();

    // RHIBuffer 接口实现
    BufferType getType() const override { return type_; }
    size_t getSize() const override { return size_; }
    BufferUsage getUsage() const override { return usage_; }
    void setData(const void* data, size_t size, size_t offset = 0) override;
    void getData(void* data, size_t size, size_t offset = 0) const override;
    void* map(size_t offset, size_t size, bool read = false, bool write = true) override;
    void unmap() override;
    bool isValid() const override { return bufferID_ != 0; }
    uintptr_t getNativeHandle() const override { return static_cast<uintptr_t>(bufferID_); }
    const std::string& getDebugName() const override { return debugName_; }
    void setDebugName(const std::string& name) override { debugName_ = name; }

    /**
     * @brief 获取 OpenGL 缓冲区 ID
     */
    GLuint getBufferID() const { return bufferID_; }

    /**
     * @brief 获取 OpenGL 目标类型
     */
    GLenum getTarget() const { return target_; }

    /**
     * @brief 绑定到指定绑定点
     */
    void bindBase(uint32_t index);

private:
    GLuint bufferID_ = 0;
    GLenum target_ = GL_ARRAY_BUFFER;
    size_t size_ = 0;
    BufferType type_ = BufferType::Vertex;
    BufferUsage usage_ = BufferUsage::Static;
    std::string debugName_;
    bool mapped_ = false;
    void* mappedPtr_ = nullptr;

    /**
     * @brief 转换缓冲区类型到 OpenGL 目标
     */
    static GLenum convertType(BufferType type);

    /**
     * @brief 转换使用方式到 OpenGL 枚举
     */
    static GLenum convertUsage(BufferUsage usage);
};

/**
 * @brief OpenGL 顶点缓冲区实现
 */
class GLRHIVertexBuffer : public RHIVertexBuffer {
public:
    GLRHIVertexBuffer() = default;
    ~GLRHIVertexBuffer() override = default;

    bool init(size_t size, BufferUsage usage, const void* data = nullptr);
    void shutdown();

    BufferType getType() const override { return BufferType::Vertex; }
    size_t getSize() const override { return buffer_.getSize(); }
    BufferUsage getUsage() const override { return buffer_.getUsage(); }
    void setData(const void* data, size_t size, size_t offset = 0) override { buffer_.setData(data, size, offset); }
    void getData(void* data, size_t size, size_t offset = 0) const override { buffer_.getData(data, size, offset); }
    void* map(size_t offset, size_t size, bool read = false, bool write = true) override { return buffer_.map(offset, size, read, write); }
    void unmap() override { buffer_.unmap(); }
    bool isValid() const override { return buffer_.isValid(); }
    uintptr_t getNativeHandle() const override { return buffer_.getNativeHandle(); }
    const std::string& getDebugName() const override { return buffer_.getDebugName(); }
    void setDebugName(const std::string& name) override { buffer_.setDebugName(name); }

    GLuint getBufferID() const { return buffer_.getBufferID(); }

private:
    GLRHIBuffer buffer_;
};

/**
 * @brief OpenGL 索引缓冲区实现
 */
class GLRHIIndexBuffer : public RHIIndexBuffer {
public:
    GLRHIIndexBuffer() = default;
    ~GLRHIIndexBuffer() override = default;

    bool init(size_t size, BufferUsage usage, const void* data = nullptr);
    void shutdown();

    BufferType getType() const override { return BufferType::Index; }
    size_t getSize() const override { return buffer_.getSize(); }
    BufferUsage getUsage() const override { return buffer_.getUsage(); }
    void setData(const void* data, size_t size, size_t offset = 0) override { buffer_.setData(data, size, offset); }
    void getData(void* data, size_t size, size_t offset = 0) const override { buffer_.getData(data, size, offset); }
    void* map(size_t offset, size_t size, bool read = false, bool write = true) override { return buffer_.map(offset, size, read, write); }
    void unmap() override { buffer_.unmap(); }
    bool isValid() const override { return buffer_.isValid(); }
    uintptr_t getNativeHandle() const override { return buffer_.getNativeHandle(); }
    const std::string& getDebugName() const override { return buffer_.getDebugName(); }
    void setDebugName(const std::string& name) override { buffer_.setDebugName(name); }

    GLuint getBufferID() const { return buffer_.getBufferID(); }

private:
    GLRHIBuffer buffer_;
};

/**
 * @brief OpenGL Uniform 缓冲区实现
 */
class GLRHIUniformBuffer : public RHIUniformBuffer {
public:
    GLRHIUniformBuffer() = default;
    ~GLRHIUniformBuffer() override = default;

    bool init(size_t size, BufferUsage usage);
    void shutdown();

    BufferType getType() const override { return BufferType::Uniform; }
    size_t getSize() const override { return buffer_.getSize(); }
    BufferUsage getUsage() const override { return buffer_.getUsage(); }
    void setData(const void* data, size_t size, size_t offset = 0) override { buffer_.setData(data, size, offset); }
    void getData(void* data, size_t size, size_t offset = 0) const override { buffer_.getData(data, size, offset); }
    void* map(size_t offset, size_t size, bool read = false, bool write = true) override { return buffer_.map(offset, size, read, write); }
    void unmap() override { buffer_.unmap(); }
    bool isValid() const override { return buffer_.isValid(); }
    uintptr_t getNativeHandle() const override { return buffer_.getNativeHandle(); }
    const std::string& getDebugName() const override { return buffer_.getDebugName(); }
    void setDebugName(const std::string& name) override { buffer_.setDebugName(name); }

    GLuint getBufferID() const { return buffer_.getBufferID(); }
    void bindBase(uint32_t index) { buffer_.bindBase(index); }

private:
    GLRHIBuffer buffer_;
};

} // namespace rhi
} // namespace extra2d