refactor: flipper position and angle (#161)

* chore: board todos

* refactor: flipper position and angle

* fix: unused import

* style: add space in comment

* chore: half sweeping angle

lib/game/components/board.dart

@@ -12,11 +12,14 @@ class Board extends Component {
 
   @override
   Future<void> onLoad() async {
+    // TODO(allisonryan0002): add bottom group and flutter forest to pinball
+    // game directly. Then remove board.
     final bottomGroup = _BottomGroup();
 
     final flutterForest = FlutterForest();
 
     // TODO(alestiago): adjust positioning to real design.
+    // TODO(alestiago): add dino in pinball game.
     final dino = ChromeDino()
       ..initialPosition = Vector2(
         BoardDimensions.bounds.center.dx + 25,
@@ -74,7 +77,7 @@ class _BottomGroupSide extends Component {
 
     final flipper = ControlledFlipper(
       side: _side,
-    )..initialPosition = Vector2((11.0 * direction) + centerXAdjustment, -42.4);
+    )..initialPosition = Vector2((11.8 * direction) + centerXAdjustment, -43.6);
     final baseboard = Baseboard(side: _side)
       ..initialPosition = Vector2(
         (25.58 * direction) + centerXAdjustment,

packages/pinball_components/lib/src/components/flipper.dart

@@ -1,5 +1,4 @@
 import 'dart:async';
-import 'dart:math' as math;
 
 import 'package:flame/components.dart';
 import 'package:flame_forge2d/flame_forge2d.dart';
@@ -198,8 +197,8 @@ class _FlipperJoint extends RevoluteJoint {
     lock();
   }
 
-  /// The total angle of the arc motion.
+  /// Half the angle of the arc motion.
-  static const _sweepingAngle = math.pi / 3.5;
+  static const _halfSweepingAngle = 0.611;
 
   final BoardSide side;
 
@@ -208,7 +207,7 @@ class _FlipperJoint extends RevoluteJoint {
   /// The joint is locked when initialized in order to force the [Flipper]
   /// at its resting position.
   void lock() {
-    const angle = _sweepingAngle / 2;
+    const angle = _halfSweepingAngle;
     setLimits(
       -angle * side.direction,
       -angle * side.direction,
@@ -217,7 +216,7 @@ class _FlipperJoint extends RevoluteJoint {
 
   /// Unlocks the [Flipper] from its resting position.
   void unlock() {
-    const angle = _sweepingAngle / 2;
+    const angle = _halfSweepingAngle;
     setLimits(-angle, angle);
   }
 }