RenderTarget.hpp

// 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.
 
#ifndef SMK_RENDER_TARGET_HPP
#define SMK_RENDER_TARGET_HPP
 
#include <glm/glm.hpp>
#include <memory>
#include <smk/RenderState.hpp>
#include <smk/Shader.hpp>
#include <smk/VertexArray.hpp>
#include <smk/View.hpp>
 
namespace smk {
 
class Drawable;
struct RenderState;
 
/// A texture where things can be / a smk::Drawable can be drawn on.
///
/// Implemented by:
///  * Window
///  * Framebuffer.
class RenderTarget {
 public:
  RenderTarget();
  RenderTarget(RenderTarget&& other) noexcept;
  RenderTarget(const RenderTarget& rhs) = delete;
  RenderTarget& operator=(RenderTarget&& other) noexcept;
  RenderTarget& operator=(const RenderTarget& rhs) = delete;
 
  // 0. Clear the framebuffer
  void Clear(const glm::vec4& color);
 
  // 1. Set the view
  void SetView(const View& view);
  void SetView(const glm::mat4& mat);
  const View& view() const;
 
  // 2. Set a shader to render elements.
  void SetShaderProgram(ShaderProgram& shader_program);
  ShaderProgram& shader_program_2d();
  ShaderProgram& shader_program_3d();
 
  // 3. Draw some stuff.
  virtual void Draw(const Drawable& drawable);
  virtual void Draw(RenderState& state);
 
  // Surface dimensions:
  glm::vec2 dimensions() const;
  int width() const;
  int height() const;
 
  // Bind the OpenGL RenderFrame. This function is useless, because it is called
  // automatically for you. Use this only when you use direct OpenGL call.
  static void Bind(RenderTarget* target);
 
 protected:
  void InitRenderTarget();
 
  int width_ = 0;
  int height_ = 0;
 
  // View:
  glm::mat4 projection_matrix_ = glm::mat4(1);
  smk::View view_;
 
  // Shaders:
  Shader vertex_shader_2d_;
  Shader fragment_shader_2d_;
  ShaderProgram shader_program_2d_;
 
  Shader vertex_shader_3d_;
  Shader fragment_shader_3d_;
  ShaderProgram shader_program_3d_;
 
  // Current shader program.
  ShaderProgram shader_program_;
 
  GLuint frame_buffer_ = 0;
};
 
}  // namespace smk
 
#endif /* end of include guard: SMK_RENDER_TARGET_HPP */