refactor: Abstract physics

packages/entity/traits/physical.js

@@ -40,8 +40,10 @@ export class Physical extends decorate(Trait) {
   set world(world) {
     this._world = world;
     if (world) {
-      this._body = world.createBodyForEntity(this.entity);
-      world.addBody(this._body);
+      const body = world.createBody(this.entity.shape);
+      world.associateBodyWithEntity(body, this.entity);
+      world.addBody(body);
+      this._body = body;
     }
   }
 

packages/physics/abstract/body.js

@@ -0,0 +1,18 @@
+import {compose, virtualize} from '@avocado/core';
+
+const decorate = compose(
+  virtualize([
+    'applyForce',
+    'applyImpulse',
+  ]),
+);
+
+class AbstractBodyBase {
+
+  constructor(shape) {
+    this.shape = shape;
+  }
+
+}
+
+export class AbstractBody extends decorate(AbstractBodyBase) {}

packages/physics/abstract/world.js

@@ -0,0 +1,34 @@
+import {compose, virtualize} from '@avocado/core';
+
+const decorate = compose(
+  virtualize([
+    'addBody',
+    'createBody',
+  ]),
+);
+
+class AbstractWorldBase {
+
+  constructor() {
+    this.entities = new Map();
+  }
+
+  associateBodyWithEntity(body, entity) {
+    this.entities.set(body, entity);
+    body.position = entity.position;
+  }
+
+  removeBody(body) {
+    this.entities.delete(body);
+  }
+
+  tick(elapsed) {
+    // Propagate position updates.
+    for (const entity of this.entities.values()) {
+      entity.position = entity.body.position;
+    }
+  }
+
+}
+
+export class AbstractWorld extends decorate(AbstractWorldBase) {}

packages/physics/dummy/body.js

@@ -1,9 +1,11 @@
 import * as I from 'immutable';
 
-import {compose} from '@avocado/core';
+import {compose, virtualize} from '@avocado/core';
 import {Rectangle, Vector} from '@avocado/math';
 import {EventEmitter} from '@avocado/mixins';
 
+import {AbstractBody} from '../abstract/body';
+
 const decorate = compose(
   EventEmitter,
   Vector.Mixin('position', 'x', 'y', {
@@ -12,13 +14,13 @@ const decorate = compose(
   }),
 );
 
-class BodyBase {
+export class Body extends decorate(AbstractBody) {
 
   constructor(shape) {
+    super(shape);
     this.force = [0, 0];
     this.impulse = [0, 0];
     this.contacts = I.Set();
-    this.shape = shape;
   }
 
   get aabb() {
@@ -34,6 +36,3 @@ class BodyBase {
   }
 
 }
-
-export class Body extends decorate(BodyBase) {}
-

packages/physics/dummy/world.js

@@ -4,12 +4,13 @@ import {arrayUnique} from '@avocado/core';
 import {Rectangle, QuadTree, Vector} from '@avocado/math';
 
 import {Body} from './body';
+import {AbstractWorld} from '../abstract/world';
 
-export class World {
+export class World extends AbstractWorld {
 
   constructor() {
+    super();
     this.bodies = [];
-    this.entities = new Map();
     this.quadTree = new QuadTree();
     this.quadTreeNodes = new Map();
   }
@@ -46,19 +47,16 @@ export class World {
     }
   }
 
-  createBodyForEntity(entity) {
-    const body = new Body(entity.shape);
-    body.position = entity.position;
-    this.entities.set(body, entity);
-    return body;
+  createBody(shape) {
+    return new Body(shape);
   }
 
   removeBody(body) {
+    super.removeBody(body);
     const index = this.bodies.indexOf(body);
     if (-1 === index) {
       return;
     }
-    this.entities.delete(body);
     this.removeQuadTreeNodes(body);
     this.bodies.splice(index, 1);
   }
@@ -185,10 +183,7 @@ export class World {
       body.force = [0, 0];
       body.impulse = [0, 0];
     }
-    // Propagate position updates.
-    for (const entity of this.entities.values()) {
-      entity.position = entity.body.position;
-    }
+    super.tick(elapsed);
   }
 
 }