Framebuffer.cpp

// Copyright 2019 Arthur Sonzogni. All rights reserved.
// Use of this source code is governed by the MIT license that can be found in
// the LICENSE file.
 
#include <smk/Color.hpp>
#include <smk/Drawable.hpp>
#include <smk/Framebuffer.hpp>
#include <smk/RenderState.hpp>
 
namespace smk {
 
/// @brief Construct a Framebuffer of a given dimensions.
/// @param width The width of the drawing surface.
/// @param height The width of the drawing surface.
Framebuffer::Framebuffer(int width, int height) {
  Texture::Option option;
  option.internal_format = GL_RGB;
  option.format = GL_RGB;
  option.type = GL_UNSIGNED_BYTE;
  option.generate_mipmap = false;
  option.min_filter = GL_LINEAR;
  option.mag_filter = GL_LINEAR;
  color_textures_.emplace_back(nullptr, width, height, option);
 
  Init();
}
 
/// @brief Construct a Framebuffer from a list of color textures. Those textures
/// must be constructed with not mipmap. See Texture::Option::generate_mipma^
// /and Texture::Option::min_filter.
/// @param width The width of the drawing surface.
/// @param height The width of the drawing surface.
Framebuffer::Framebuffer(std::vector<Texture> color_textures)
    : color_textures_(std::move(color_textures)) {
  Init();
}
 
void Framebuffer::Init() {
  width_ = color_texture().width();
  height_ = color_texture().height();
 
  // The frame buffer.
  glGenFramebuffers(1, &frame_buffer_);
  glBindFramebuffer(GL_FRAMEBUFFER, frame_buffer_);
 
  // Attach the textures to the framebuffer.
  for (size_t i = 0; i < color_textures_.size(); ++i) {
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + i,
                           GL_TEXTURE_2D, color_textures_[i].id(), 0);
  }
 
  // The render buffer.
  glGenRenderbuffers(1, &render_buffer_);
  glBindRenderbuffer(GL_RENDERBUFFER, render_buffer_);
  glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, width_, height_);
  glBindRenderbuffer(GL_RENDERBUFFER, 0);
 
  // Attach it to the framebuffer.
  glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT,
                            GL_RENDERBUFFER, render_buffer_);
 
  if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
    std::cout << "ERROR::FRAMEBUFFER:: Framebuffer is not complete!"
              << std::endl;
  }
 
  glBindFramebuffer(GL_FRAMEBUFFER, 0);
 
  InitRenderTarget();
}
 
Framebuffer::~Framebuffer() {
  if (frame_buffer_) {
    glDeleteFramebuffers(1, &frame_buffer_);
    frame_buffer_ = 0;
  }
 
  if (render_buffer_) {
    glDeleteRenderbuffers(1, &render_buffer_);
    render_buffer_ = 0;
  }
}
 
Framebuffer::Framebuffer(Framebuffer&& other) noexcept {
  this->operator=(std::move(other));
}
 
Framebuffer& Framebuffer::operator=(Framebuffer&& other) noexcept {
  RenderTarget::operator=(std::move(other));
  std::swap(color_textures_, other.color_textures_);  // NOLINT
  std::swap(render_buffer_, other.render_buffer_);    // NOLINT
  return *this;
}
 
smk::Texture& Framebuffer::color_texture() {
  return color_textures_[0];
}
 
}  // namespace smk