Further hunt mode refactors

src/engine/internal/drawing.ts

@@ -10,6 +10,15 @@ class Drawing {
     this.camera = new Point(0, 0);
   }
 
+  withCamera(point: Point, cb: () => void) {
+    let oldCamera = this.camera;
+    this.camera = this.camera = point;
+
+    cb();
+
+    this.camera = oldCamera;
+  }
+
   get size() { return getScreen().size; }
 
   invertRect(position: Point, size: Size) {