move systems + update contributing.md

1 files changed, 42 insertions, 0 deletions

diff --git a/src/crepe/system/RenderSystem.cpp b/src/crepe/system/RenderSystem.cpp
new file mode 100644
index 0000000..599087a
--- /dev/null
+++ b/src/crepe/system/RenderSystem.cpp
@@ -0,0 +1,42 @@
+#include <functional>
+#include <vector>
+
+#include "../api/Sprite.h"
+#include "../api/Transform.h"
+#include "../util/log.h"
+#include "../SDLContext.h"
+#include "../ComponentManager.h"
+
+#include "RenderSystem.h"
+
+using namespace crepe;
+using namespace crepe::api;
+
+RenderSystem::RenderSystem() { dbg_trace(); }
+
+RenderSystem::~RenderSystem() { dbg_trace(); }
+
+RenderSystem & RenderSystem::get_instance() {
+	static RenderSystem instance;
+	return instance;
+}
+
+void RenderSystem::update() {
+
+	ComponentManager & mgr = ComponentManager::get_instance();
+
+	std::vector<std::reference_wrapper<Sprite>> sprites
+		= mgr.get_components_by_type<Sprite>();
+
+	SDLContext & render = SDLContext::get_instance();
+	render.clear_screen();
+
+	for (const Sprite & sprite : sprites) {
+		std::vector<std::reference_wrapper<Transform>> transforms
+			= mgr.get_components_by_id<Transform>(sprite.game_object_id);
+		for (const Transform & transform : transforms) {
+			render.draw(sprite, transform);
+		}
+	}
+	render.present_screen();
+}