#include "fbo.h"

#include "demo_data.h"
#include <memory>

BEGIN_NAMESPACE

fbo::fbo(int w, int h)
        : width(w),
          height(h) {

    glGenFramebuffers(1, &frame_buffer_id);
    glGenTextures(1, &color_buffer_id);
    glGenRenderbuffers(1, &depth_buffer_id);

    glBindFramebuffer(GL_FRAMEBUFFER, frame_buffer_id);

    glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, color_buffer_id);
    glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE,
                            4, // number of samples for multisampling
                            GL_RGBA8,
                            width, height,
                            false);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D_MULTISAMPLE, color_buffer_id,
                           0);

    glBindRenderbuffer(GL_RENDERBUFFER, depth_buffer_id);
    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, width, height);
    glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depth_buffer_id);
}

int fbo::get_width() const {
    return width;
}

int fbo::get_height() const {
    return height;
}

GLuint fbo::get_color_buffer_id() const {
    return color_buffer_id;
}

GLuint fbo::get_depth_buffer_id() const {
    return depth_buffer_id;
}

void fbo::use() {
    old_width = demo_data::screen_width;
    old_height = demo_data::screen_height;

    demo_data::screen_height = width;
    demo_data::screen_height = height;

    glBindFramebuffer(GL_FRAMEBUFFER, frame_buffer_id);
    glViewport(0, 0, width, height);
}

void fbo::unuse() const {
    glBindFramebuffer(GL_FRAMEBUFFER, 0);
    glViewport(0, 0, old_width, old_height);

    demo_data::screen_width = old_width;
    demo_data::screen_height = old_height;
}

std::shared_ptr<texture> fbo::get_texture() {
    return std::make_shared<texture>(color_buffer_id, width, height);
}

END_NAMESPACE