gaming-core/wrapper/Framebuffer.h

#ifndef FRAMEBUFFER_H
#define FRAMEBUFFER_H

#include <iostream>

#include "utils/List.h"
#include "utils/Size.h"
#include "wrapper/Texture.h"

template<int N>
class Framebuffer final {
    List<Texture, N> textures;
    GLuint buffer;

public:
    template<typename... Args>
    Framebuffer(const TextureFormat& a, Args&&... args) : buffer(0) {
        const int size = sizeof...(args) + 1;
        TextureFormat init[size] = {a, args...};
        static_assert(N == size, "framebuffer size and amount of arguments do not match");
        for(int i = 0; i < N; i++) {
            textures.add(init[i]);
            textures[i].setClampWrap();
        }
    }

    ~Framebuffer() {
        glDeleteFramebuffers(1, &buffer);
    }

    Framebuffer(const Framebuffer&) = delete;
    Framebuffer(Framebuffer&&) = delete;
    Framebuffer& operator=(const Framebuffer&) = delete;
    Framebuffer& operator=(Framebuffer&&) = delete;

    bool init(const Size& size) {
        glGenFramebuffers(1, &buffer);
        glBindFramebuffer(GL_FRAMEBUFFER, buffer);

        List<GLenum, N> attachments;
        for(Texture& t : textures) {
            t.setData(size.width, size.height);
            if(t.format.depth) {
                glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, t.texture, 0);
            } else {
                GLenum c = GL_COLOR_ATTACHMENT0 + attachments.getLength();
                glFramebufferTexture2D(GL_FRAMEBUFFER, c, GL_TEXTURE_2D, t.texture, 0);
                attachments.add(c);
            }
        }
        glDrawBuffers(attachments.getLength(), attachments.begin());

        return hasError();
    }

    void bindAndClear() {
        glBindFramebuffer(GL_FRAMEBUFFER, buffer);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
    }

    void bindTextureTo(int index, int textureUnit) const {
        textures[index].bindTo(textureUnit);
    }

    void resize(const Size& size) {
        for(Texture& t : textures) {
            t.setData(size.width, size.height);
        }
    }

private:
    bool hasError() const {
        GLenum error = glCheckFramebufferStatus(GL_FRAMEBUFFER);
        if(error == GL_FRAMEBUFFER_COMPLETE) {
            return false;
        }
        switch(error) {
            case GL_FRAMEBUFFER_UNDEFINED: std::cout << "undefined framebuffer\n"; return true;
            case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT: std::cout << "incomplete framebuffer attachment\n"; return true;
            case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT:
                std::cout << "incomplete missing framebuffer attachment\n";
                return true;
            case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER:
                std::cout << "incomplete framebuffer draw buffer\n";
                return true;
            case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER:
                std::cout << "incomplete framebuffer read buffer\n";
                return true;
            case GL_FRAMEBUFFER_UNSUPPORTED: std::cout << "unsupported framebuffer\n"; return true;
            case GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE:
                std::cout << "incomplete framebuffer multisample\n";
                return true;
            case GL_FRAMEBUFFER_INCOMPLETE_LAYER_TARGETS:
                std::cout << "incomplete framebuffer layer targets\n";
                return true;
        }
        return "unknown error";
    }
};

#endif