1 files changed, 39 insertions, 0 deletions
diff --git a/source/game/systems/CameraSystem.cs b/source/game/systems/CameraSystem.cs
new file mode 100644
index 0000000..be121a5
--- /dev/null
+++ b/source/game/systems/CameraSystem.cs
@@ -0,0 +1,39 @@
+using System;
+using Celesteia.Game.Components;
+using Celesteia.Game.Input;
+using Celesteia.Graphics;
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Input;
+using MonoGame.Extended;
+using MonoGame.Extended.Entities;
+using MonoGame.Extended.Entities.Systems;
+
+namespace Celesteia.Game.Systems {
+    public class CameraSystem : EntityUpdateSystem
+    {
+        private Camera2D _camera;
+        private float smoothing = 128f;
+
+        private ComponentMapper<Transform2> transformMapper;
+
+        public CameraSystem(Camera2D camera) : base(Aspect.All(typeof(Transform2), typeof(CameraFollow)))
+        => _camera = camera;
+
+        public override void Initialize(IComponentMapperService mapperService)
+        => transformMapper = mapperService.GetMapper<Transform2>();
+
+        Vector2 pos;
+        public override void Update(GameTime gameTime)
+        {
+            foreach (int entityId in ActiveEntities) {
+                pos = transformMapper.Get(entityId).Position * smoothing;
+                pos.X = MathF.Round(pos.X) / smoothing;
+                pos.Y = MathF.Round(pos.Y) / smoothing;
+                _camera.Center = pos;
+                break;
+            }
+            
+            if (KeyboardHelper.IsDown(Keys.LeftControl)) _camera.Zoom += (int) Math.Clamp(MouseHelper.ScrollDelta, -1f, 1f);
+        }
+    }
+}
+\ No newline at end of file