1 files changed, 63 insertions, 0 deletions
diff --git a/src/engine/systems/FacingDirection.ts b/src/engine/systems/FacingDirection.ts
new file mode 100644
index 0000000..f831bf6
--- /dev/null
+++ b/src/engine/systems/FacingDirection.ts
@@ -0,0 +1,63 @@
+import {
+  ComponentNames,
+  FacingDirection as FacingDirectionComponent,
+  BoundingBox,
+  Sprite,
+} from "../components";
+import { Game } from "../Game";
+import { System, SystemNames, Input } from ".";
+import { Direction, angleToDirection } from "../interfaces";
+
+export class FacingDirection extends System {
+  private input: Input;
+
+  constructor(input: Input) {
+    super(SystemNames.FacingDirection);
+
+    this.input = input;
+  }
+
+  public update(_dt: number, game: Game) {
+    const mousePosition = this.input.getMousePosition();
+    const mouseBoundingBox = new BoundingBox(mousePosition, {
+      width: 0,
+      height: 0,
+    });
+
+    game.forEachEntityWithComponent(
+      ComponentNames.FacingDirection,
+      (entity) => {
+        if (!entity.hasComponent(ComponentNames.BoundingBox)) {
+          return;
+        }
+
+        const boundingBox = entity.getComponent<BoundingBox>(
+          ComponentNames.BoundingBox,
+        )!;
+        const facingDirection = entity.getComponent<FacingDirectionComponent>(
+          ComponentNames.FacingDirection,
+        );
+
+        const { center } = boundingBox;
+        const angle = Math.atan2(
+          mousePosition.y - center.y,
+          mousePosition.x - center.x,
+        );
+
+        const mouseInBoundingBox =
+          boundingBox.isCollidingWith(mouseBoundingBox);
+        const direction = mouseInBoundingBox
+          ? Direction.NONE
+          : angleToDirection(angle);
+
+        facingDirection.setDirection(direction);
+
+        const oldSprite = entity.getComponent<Sprite>(ComponentNames.Sprite);
+        const sprite = facingDirection.directionSprites.get(direction)!;
+        sprite.fillTimingsFromSprite(oldSprite);
+
+        entity.addComponent(sprite);
+      },
+    );
+  }
+}