From 7febbfc70fd3b887504cfa28315b3a9263a14f87 Mon Sep 17 00:00:00 2001
From: Viktor Lidholt <viktorl@google.com>
Date: Fri, 16 Oct 2015 10:18:35 -0700
Subject: [PATCH 1/2] Correctly resets targets for kinematic sprite physics
 bodies

---
 packages/flutter_sprites/lib/src/physics_node.dart | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/packages/flutter_sprites/lib/src/physics_node.dart b/packages/flutter_sprites/lib/src/physics_node.dart
index 12685c0c5c..004917433f 100644
--- a/packages/flutter_sprites/lib/src/physics_node.dart
+++ b/packages/flutter_sprites/lib/src/physics_node.dart
@@ -112,6 +112,13 @@ class PhysicsNode extends Node {
     for (box2d.Body b2Body = b2World.bodyList; b2Body != null; b2Body = b2Body.getNext()) {
       // Update visual position and rotation
       PhysicsBody body = b2Body.userData;
+
+      if (b2Body.getType() == box2d.BodyType.KINEMATIC) {
+        body._targetPosition = null;
+        body._targetAngle = null;
+      }
+
+      // Update visual position and rotation
       body._node._setPositionFromPhysics(new Point(
         b2Body.position.x * b2WorldToNodeConversionFactor,
         b2Body.position.y * b2WorldToNodeConversionFactor

From 23bae330771723e0af0c652d44e3181751d40d50 Mon Sep 17 00:00:00 2001
From: Viktor Lidholt <viktorl@google.com>
Date: Fri, 16 Oct 2015 10:19:25 -0700
Subject: [PATCH 2/2] Adds teleporting methods for moving sprite kinematic
 physics bodies without assigning velocities

---
 packages/flutter_sprites/lib/src/node.dart | 27 ++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/packages/flutter_sprites/lib/src/node.dart b/packages/flutter_sprites/lib/src/node.dart
index e3151585a7..13b98427a8 100644
--- a/packages/flutter_sprites/lib/src/node.dart
+++ b/packages/flutter_sprites/lib/src/node.dart
@@ -148,6 +148,16 @@ class Node {
     invalidateTransformMatrix();
   }
 
+  void teleportRotation(double rotation) {
+    assert(rotation != null);
+    if (_physicsBody != null && parent is PhysicsNode) {
+      _physicsBody._body.setTransform(_physicsBody._body.position, radians(rotation));
+      _physicsBody._body.angularVelocity = 0.0;
+      _physicsBody._body.setType(box2d.BodyType.STATIC);
+    }
+    _setRotationFromPhysics(rotation);
+  }
+
   /// The position of this node relative to its parent.
   ///
   ///     myNode.position = new Point(42.0, 42.0);
@@ -172,6 +182,23 @@ class Node {
     invalidateTransformMatrix();
   }
 
+  void teleportPosition(Point position) {
+    assert(position != null);
+    if (_physicsBody != null && parent is PhysicsNode) {
+      PhysicsNode physicsNode = parent;
+      _physicsBody._body.setTransform(
+        new Vector2(
+          position.x / physicsNode.b2WorldToNodeConversionFactor,
+          position.y / physicsNode.b2WorldToNodeConversionFactor
+        ),
+        _physicsBody._body.getAngle()
+      );
+      _physicsBody._body.linearVelocity = new Vector2.zero();
+      _physicsBody._body.setType(box2d.BodyType.STATIC);
+    }
+    _setPositionFromPhysics(position);
+  }
+
   /// The skew along the x-axis of this node in degrees.
   ///
   ///     myNode.skewX = 45.0;