Vector2 for position and size on PositionComponent

lib/components/position_component.dart

@@ -1,5 +1,4 @@
 import 'dart:ui';
-import 'dart:math';
 
 import 'package:meta/meta.dart';
 import 'package:ordered_set/comparing.dart';
@@ -15,8 +14,8 @@ import 'component.dart';
 /// A [Component] implementation that represents a component that has a
 /// specific, possibly dynamic position on the screen.
 ///
-/// It represents a rectangle of dimension ([width], [height]), on the position
-/// ([x], [y]), rotate around its center with angle [angle].
+/// It represents a rectangle of dimension [size], on the [position],
+/// rotated around its [anchor] with angle [angle].
 ///
 /// It also uses the [anchor] property to properly position itself.
 ///
@@ -25,24 +24,31 @@ import 'component.dart';
 /// They are translated by this component's (x,y). They do not need to fit
 /// within this component's (width, height).
 abstract class PositionComponent extends Component {
+  /// The position of this component on the screen (measured from the top left corner).
+  Vector2 position = Vector2.zero();
+
   /// X position of this component on the screen (measured from the top left corner).
-  double x = 0.0;
+  double get x => position.x;
+  set x(double x) => position.x = x;
 
   /// Y position of this component on the screen (measured from the top left corner).
-  double y = 0.0;
+  double get y => position.y;
+  set y(double y) => position.y = y;
+
+  /// The size that this component is rendered with.
+  /// This is not necessarily the source size of the asset.
+  Vector2 size = Vector2.zero();
+
+  /// Width (size) that this component is rendered with.
+  double get width => size.x;
+
+  /// Height (size) that this component is rendered with.
+  double get height => size.y;
 
   /// Angle (with respect to the x-axis) this component should be rendered with.
   /// It is rotated around its anchor.
   double angle = 0.0;
 
-  /// Width (size) that this component is rendered with.
-  /// This is not necessarily the source width of the asset.
-  double width = 0.0;
-
-  /// Height (size) that this component is rendered with.
-  /// This is not necessarily the source height of the asset.
-  double height = 0.0;
-
   /// Anchor point for this component. This is where flame "grabs it".
   /// The [x], [y] coordinates are relative to this point inside the component.
   /// The [angle] is rotated around this point.
@@ -72,51 +78,33 @@ abstract class PositionComponent extends Component {
 
   TextConfig get debugTextConfig => TextConfig(color: debugColor, fontSize: 12);
 
-  Vector2 get position => Vector2(x, y);
-  void setPosition(Vector2 position) {
-    x = position.x;
-    y = position.y;
-  }
-
-  Vector2 get size => Vector2(width, height);
-  void setBySize(Vector2 size) {
-    width = size.x;
-    height = size.y;
-  }
-
-  /// Returns the size of this component starting at (0, 0).
-  /// Effectively this is it's position with respect to itself.
-  /// Use this if the canvas is already translated by (x, y).
-  Rect toOriginRect() => Rect.fromLTWH(0, 0, width, height);
-
   /// Returns the relative position/size of this component.
   /// Relative because it might be translated by their parents (which is not considered here).
-  Rect toRect() => Rect.fromLTWH(
-        x - anchor.relativePosition.x * width,
-        y - anchor.relativePosition.y * height,
-        width,
-        height,
-      );
+  Rect toRect() {
+    return Rect.fromLTWH(
+      x - anchor.relativePosition.x * width,
+      y - anchor.relativePosition.y * height,
+      width,
+      height,
+    );
+  }
 
   /// Mutates x, y, width and height using the provided [rect] as basis.
   /// This is a relative rect, same definition that [toRect] use (therefore both methods are compatible, i.e. setByRect ∘ toRect = identity).
   void setByRect(Rect rect) {
-    x = rect.left + anchor.relativePosition.x * rect.width;
-    y = rect.top + anchor.relativePosition.y * rect.height;
-    width = rect.width;
-    height = rect.height;
+    position.setValues(
+      rect.left + anchor.relativePosition.x * rect.width,
+      rect.top + anchor.relativePosition.y * rect.height,
+    );
+    size.setValues(rect.width, rect.height);
   }
 
-  double angleBetween(PositionComponent c) {
-    return (atan2(c.x - x, y - c.y) - pi / 2) % (2 * pi);
-  }
+  double angleTo(PositionComponent c) => position.angleTo(c.position);
 
-  double distance(PositionComponent c) {
-    return c.position.distanceTo(position);
-  }
+  double distance(PositionComponent c) => position.distanceTo(c.position);
 
   void renderDebugMode(Canvas canvas) {
-    canvas.drawRect(toOriginRect(), _debugPaint);
+    canvas.drawRect(size.toRect(), _debugPaint);
     debugTextConfig.render(
       canvas,
       'x: ${x.toStringAsFixed(2)} y:${y.toStringAsFixed(2)}',