Box2D Examples
           import QtQuick 2.0
 import Felgo 4.0
 EntityBase {
   width: 50
   height: 50
   
   
   transformOrigin: Item.TopLeft
   BoxCollider {
     id: collider
     sleepingAllowed: false
     bullet: true
     fixedRotation: true
     density: 0.001
     friction: 0.3
     restitution: 0.2
     groupIndex: 1
   }
   Rectangle {
     id: rectangle
     anchors.fill: parent
     color: "red"
   }
   function moveForward() {
     collider.body.linearVelocity.x = 300;
   }
   function moveBackward() {
     collider.body.linearVelocity.x = -300;
   }
   function stopMoving() {
     collider.body.linearVelocity.x = 0;
   }
   function jump() {
     if (collider.body.linearVelocity.y <= 0 &&
         collider.body.linearVelocity.y > -50) {
       var impulse = Qt.point(0, -600);
       collider.body.applyLinearImpulse(impulse, collider.body.getWorldCenter());
     }