git.r.bdr.sh - rbdr/sumo/blob - lib/systems/physics_world_control.js

   1 import { System } from '@serpentity/serpentity';
   2 import { Engine, World } from 'matter-js';
   3
   4 import PhysicalNode from '../nodes/physical';
   5
   6 const internals = {
   7   kNoEngine: 'No matter js physics engine found. Make sure you set the `engine` key in the config object when initializing.'
   8 };
   9
  10 /**
  11  * Adds and removes objects to the physics world and calls update
  12  *
  13  * @extends {external:Serpentity.System}
  14  * @class PhysicsWorldControlSystem
  15  * @param {object} config a configuration object to extend.
  16  */
  17 export default class PhysicsWorldControlSystem extends System {
  18
  19   constructor(config = {}) {
  20
  21     super();
  22
  23     /**
  24      * The node collection of physics entities
  25      *
  26      * @property {external:Serpentity.NodeCollection} physicalEntities
  27      * @instance
  28      * @memberof PhysicsWorldControlSystem
  29      */
  30     this.physicalEntities = null;
  31
  32     /**
  33      * The matter-js engine we will use to process physics
  34      *
  35      * @property {external:MatterJs.Engine} engine
  36      * @instance
  37      * @memberof PhysicsWorldControlSystem
  38      */
  39     this.engine = config.engine;
  40
  41     if (!this.engine) {
  42       throw new Error(internals.kNoEngine);
  43     }
  44   }
  45
  46   /**
  47    * Initializes system when added. Requests physics nodes and
  48    * attaches to event listeners to add / remove them to pixi stage
  49    *
  50    * @function added
  51    * @memberof PhysicsWorldControlSystem
  52    * @instance
  53    * @param {external:Serpentity.Engine} engine the serpentity engine to
  54    * which we are getting added
  55    */
  56   added(engine) {
  57
  58     this.physicalEntities = engine.getNodes(PhysicalNode);
  59     this.physicalEntities.on('nodeAdded', (event) => {
  60
  61       World.add(this.engine.world, [event.node.body.body]);
  62     });
  63     this.physicalEntities.on('nodeRemoved', (event) => {
  64
  65       World.remove(this.engine.world, [event.node.body.body]);
  66     });
  67   }
  68
  69   /**
  70    * Clears system resources when removed.
  71    *
  72    * @function removed
  73    * @instance
  74    * @memberof PhysicsWorldControlSystem
  75    */
  76   removed() {
  77
  78     this.physicalEntities.removeAllListeners('nodeAdded');
  79     this.physicalEntities.removeAllListeners('nodeRemoved');
  80     this.physicalEntities = null;
  81   }
  82
  83   /**
  84    * Runs on every update of the loop. Updates the physics
  85    *
  86    * @function update
  87    * @instance
  88    * @param {Number} currentFrameDuration the duration of the current
  89    * frame
  90    * @memberof PhysicsWorldControlSystem
  91    */
  92   update(currentFrameDuration) {
  93
  94     Engine.run(this.engine);
  95   }
  96 };
  97
  98