fix: physics apply stepTime as impulse

packages/entity/traits/mobile.trait.js

@@ -62,7 +62,7 @@ class MobileBase extends Trait {
       return;
     }
     if (this.entity.is('physical')) {
-      this.entity.applyImpulse(this.requestedMovement, elapsed);
+      this.entity.applyImpulse(this.requestedMovement);
     }
     else {
       const requestedMovement = Vector.scale(

packages/physics/abstract/body.js

@@ -10,9 +10,10 @@ const decorate = compose(
 
 export class AbstractBody extends decorate(class {}) {
 
-  constructor(shape) {
+  constructor(world, shape) {
     super();
     this.shape = shape;
+    this.world = world;
   }
 
 }

packages/physics/abstract/world.js

@@ -34,6 +34,7 @@ export class AbstractWorld extends decorate(class {}) {
         this.entitiesList.splice(index, 1);
       }
     }
+    body.world = null;
   }
 
   tick(elapsed) {

packages/physics/dummy/body.js

@@ -15,8 +15,8 @@ const decorate = compose(
 
 export class Body extends decorate(AbstractBody) {
 
-  constructor(shape) {
-    super(shape);
+  constructor(world, shape) {
+    super(world, shape);
     this.force = [0, 0];
     this.impulse = [0, 0];
     this.contacts = I.Set();
@@ -30,10 +30,10 @@ export class Body extends decorate(AbstractBody) {
     this.force = Vector.add(this.force, vector);
   }
 
-  applyImpulse(vector, elapsed) {
+  applyImpulse(vector) {
     this.impulse = Vector.add(
       this.impulse,
-      Vector.scale(vector, elapsed)
+      Vector.scale(vector, this.world.stepTime)
     );
   }
 

packages/physics/dummy/world.js

@@ -37,7 +37,7 @@ export class World extends AbstractWorld {
   }
 
   createBody(shape) {
-    return new Body(shape);
+    return new Body(this, shape);
   }
 
   removeBody(body) {

packages/physics/matter/body.js

@@ -47,8 +47,8 @@ export class Body extends AbstractBody {
     this.bodies.set(matterBody, avocadoBody);
   }
 
-  constructor(shape) {
-    super(shape);
+  constructor(world, shape) {
+    super(world, shape);
     const [body, position, origin] = this.constructor.bodyFromShape(shape);
     // Set body first, then origin, then position. Order important.
     this.matterBody = body;
@@ -73,9 +73,9 @@ export class Body extends AbstractBody {
     MatterBody.applyForce(this.matterBody, this.matterBody.position, {x, y});
   }
 
-  applyImpulse(impulse, elapsed) {
+  applyImpulse(impulse) {
     impulse = Vector.scale(impulse, 1 / SCALE);
-    impulse = Vector.scale(impulse, elapsed);
+    impulse = Vector.scale(impulse, this.world.stepTime);
     const [x, y] = impulse;
     MatterBody.translate(this.matterBody, {x, y});
   }

packages/physics/matter/world.js

@@ -27,7 +27,7 @@ export class World extends AbstractWorld {
   }
 
   createBody(shape) {
-    return new Body(shape);
+    return new Body(this, shape);
   }
 
   handleCollisions(eventName) {

packages/physics/traits/physical.trait.js

@@ -115,9 +115,9 @@ export class Physical extends decorate(Trait) {
         }
       },
 
-      applyImpulse: (impulse, elapsed) => {
+      applyImpulse: (impulse) => {
         if (this._world && this._body) {
-          this._body.applyImpulse(impulse, elapsed);
+          this._body.applyImpulse(impulse);
         }
       },