SFrameBuffer.h

#pragma once
 
#include "../../Object/SResource.h"
#include "../../OGLDef.h"
#include "../Vector.h"
#include <vector>
 
namespace CSE {
 
    class STexture;
 
    class GLProgramHandle;
 
    class SFrameBuffer : public SResource {
    public:
        enum BufferType {
            RENDER = 0, DEPTH = 1, STENCIL = 2,
        };
        enum BufferDimension {
            PLANE = 0, CUBE = 1,
        };
        enum BufferStatus {
            NONE = 0, COLOR_ONLY = 1, DEPTH_ONLY = 2, MULTI = 3,
        };
        enum BlitType {
            IN_ORDER = 0, REVERSE = 1,
        };
 
    private:
        struct BufferObject {
            BufferType type = RENDER;
            unsigned int renderbufferId = 0;
            STexture* texture = nullptr;
            int format = 0;
            short level = 0;
        };
        struct BlitObject {
            GLProgramHandle* handle = nullptr;
            int aColor = -1;
            int bColor = -1;
            int aDepth = -1;
            int bDepth = -1;
        };
 
    public:
        SFrameBuffer();
 
        ~SFrameBuffer() override;
 
        void GenerateFramebuffer(BufferDimension dimension, int width, int height);
 
        unsigned int GenerateRenderbuffer(BufferType type, int internalFormat);
 
        STexture* GenerateTexturebuffer(BufferType type, int channel, int level = 0);
 
        void RasterizeFramebuffer();
 
        void AttachCubeBuffer(int index, int level = 0) const;
 
        void AttachFrameBuffer(int target = GL_FRAMEBUFFER) const;
 
        void DetachFrameBuffer() const;
 
        void ResizeFrameBuffer(int width, int height);
 
        void Exterminate() override;
 
        void BlitFrameBuffer(const SFrameBuffer& dst, BlitType type = IN_ORDER);
 
        int GetWidth() const;
 
        int GetHeight() const;
 
        const ivec2& GetSize() const {
            return *m_size;
        }
 
        BufferStatus GetBufferStatus() const;
 
        STexture* GetTexture(int index) const;
 
        STexture* GetTexture(const char* id) const;
 
        unsigned int GetRenderbufferID(int index) const;
 
        STexture* GetMainColorTexture() const {
            if (m_mainColorBuffer == nullptr) return nullptr;
            return m_mainColorBuffer->texture;
        }
 
        STexture* GetDepthTexture() const {
            if (m_depthBuffer == nullptr) return nullptr;
            return m_depthBuffer->texture;
        }
 
    protected:
        void Init(const AssetMgr::AssetReference* asset) override;
 
    private:
        int GenerateAttachmentType(SFrameBuffer::BufferType type, bool isIncreaseAttachment = true) const;
 
        int GenerateInternalFormat(int channel) const;
 
        int GenerateInternalType(int channel) const;
 
        void ReleaseBufferObject(const SFrameBuffer::BufferObject* bufferObject);
 
    private:
        ivec2* m_size = new ivec2(512, 512);
        BufferDimension m_dimension = PLANE;
 
        unsigned int m_fbo = 0;
        std::vector<BufferObject*> m_buffers;
        BufferObject* m_mainColorBuffer = nullptr;
        BufferObject* m_depthBuffer = nullptr;
 
        mutable BufferStatus m_bufferStatus = BufferStatus::NONE;
        mutable unsigned short m_colorAttachmentSize = 0;
 
        static BlitObject m_blitObject;
    };
}