RenderSystem.hpp

#pragma once
 
#include <functional>
#include <stdexcept>
#include <vector>
 
#include "components/Transform.hpp"
#include <ISystem.hpp>
#include <Logger/Logger.hpp>
 
#include "systems/RenderConcept.hpp"
 
namespace rtk::systems {
template <rtk::ecs::concepts::IsRenderWindow WindowType>
class RenderSystem final : public rtk::ecs::ISystem {
public:
  RenderSystem(std::reference_wrapper<WindowType> window)
      : _window(window.get()) {}
 
  ~RenderSystem() = default;
 
  void onStart(rtk::ecs::Registry &) override {
    LOG_INFO("Load Render System");
  }
 
  void update(rtk::ecs::Registry &reg, float) override {
    _spritesToDraw.clear();
 
    auto view =
        reg.view<component::Transform, rtk::ecs::concepts::SpriteData>();
 
    auto &transforms = reg.get_components<component::Transform>();
    auto &sprites = reg.get_components<rtk::ecs::concepts::SpriteData>();
 
    for (auto entity : view) {
      const auto *transform = transforms.get(entity);
      const auto *sourceSprite = sprites.get(entity);
 
      if (!transform || !sourceSprite)
        continue;
 
      rtk::ecs::concepts::SpriteData sprite = *sourceSprite;
 
      sprite.position = transform->position;
      sprite.rotation = transform->rotation;
      sprite.scale = transform->scale;
 
      _spritesToDraw.push_back(std::move(sprite));
    }
 
    if (!_window.beginFrame(rtk::ecs::concepts::ColorRGBA8{0, 0, 0, 255}))
      return;
 
    _window.draw(_spritesToDraw);
    _window.endFrame();
  }
 
  void onStop(rtk::ecs::Registry &) override {}
 
private:
  WindowType &_window;
  std::vector<rtk::ecs::concepts::SpriteData> _spritesToDraw;
};
 
} // namespace rtk::systems