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

   1 import { Bodies, Constraint } from 'matter-js';
   2 import { Entity } from '@serpentity/serpentity';
   3
   4 import AngleComponent from '../components/angle';
   5 import BodyComponent from '../components/body';
   6 import CoupledEntitiesComponent from '../components/coupled_entities';
   7 import PositionComponent from '@serpentity/components.position';
   8 import PixiContainerComponent from '../components/pixi_container';
   9 import PixiFactory from '../factories/pixi';
  10
  11 const internals = {
  12   kNoEntityError: 'Entity Not Found: This method requires entityA and entityB to be set in the config.',
  13   kEntityHasNoBodyError: 'Entity Has No Body: This method requires entities have a BodyComponent.'
  14 };
  15
  16 /**
  17  * Factory object that contains many methods to create prefab entities.
  18  *
  19  * @type object
  20  * @name SumoFactory
  21  */
  22 export default {
  23
  24   /**
  25    * Creates a sumo entity and adds it to the engine. Can override
  26    * position in the config object
  27    *
  28    * @function createSumo
  29    * @memberof SumoFactory
  30    * @param {external:Serpentity} [engine] the serpentity engine to attach
  31    * to. If not sent, it will not be attached.
  32    * @param {object} [config] the config to override the entity, accepts
  33    * the key `position` as an object with an x and y property.
  34    * @return {external:Serpentity.Entity} the created entity
  35    */
  36   createSumo(engine, config = {}) {
  37
  38     const entity = new Entity();
  39
  40     // POSITION
  41
  42     entity.addComponent(new PositionComponent(config.position));
  43     const position = entity.getComponent(PositionComponent);
  44
  45     entity.addComponent(new AngleComponent(config.angle));
  46     const angle = entity.getComponent(AngleComponent);
  47
  48     // RENDERING
  49
  50     const radius = 25;
  51
  52     const container = config.container || {
  53       container: PixiFactory.createSumo({ radius })
  54     };
  55     container.container.position.x = position.x;
  56     container.container.position.y = position.y;
  57     container.container.rotation = angle.angle;
  58     entity.addComponent(new PixiContainerComponent(container));
  59
  60     // PHYSICS
  61
  62     const frictionAir = 0.00001;
  63     const friction = 0.00001;
  64     const restitution = 0.9;
  65     const density = 0.5;
  66
  67     const body = Bodies.circle(position.x, position.y, radius, {
  68       angle: angle.angle,
  69       density,
  70       frictionAir,
  71       friction,
  72       restitution
  73     });
  74     entity.addComponent(new BodyComponent({ body }));
  75
  76     if (engine) {
  77       engine.addEntity(entity);
  78     }
  79
  80     return entity;
  81   },
  82
  83   /**
  84    * Creates a rubber band entity and adds it to the engine.
  85    *
  86    * @function createRubberBand
  87    * @memberof SumoFactory
  88    * @param {external:Serpentity} [engine] the serpentity engine to attach
  89    * to. If not sent, it will not be attached.
  90    * @param {object} [config] the config to override the entity, it
  91    * must include entityA and entityB which will be tied by it. If they
  92    * are not sent or don't have a physics body, this will throw.
  93    * @return {external:Serpentity.Entity} the created entity
  94    */
  95   createRubberBand(engine, config = {}) {
  96
  97     const entity = new Entity();
  98
  99     if (!config.entityA || !config.entityB) {
 100       throw new Error(internals.kNoEntityError);
 101     }
 102
 103     if (!config.entityA.hasComponent(BodyComponent) || !config.entityB.hasComponent(BodyComponent)) {
 104       throw new Error(internals.kEntityHasNoBodyError);
 105     }
 106
 107     // RENDERING
 108
 109     const container = config.container || {
 110       container: PixiFactory.createEmptyGraphic()
 111     };
 112     entity.addComponent(new PixiContainerComponent(container));
 113
 114     // PHYSICS
 115
 116     const bodyA = config.entityA.getComponent(BodyComponent).body;
 117     const bodyB = config.entityB.getComponent(BodyComponent).body;
 118     const damping = 0.01;
 119     const length = 100;
 120     const stiffness = 0.0001;
 121     const angularStiffness = 0.0001;
 122
 123     const body = Constraint.create({
 124       bodyA,
 125       bodyB,
 126       damping,
 127       length,
 128       stiffness,
 129       angularStiffness
 130     });
 131     entity.addComponent(new BodyComponent({ body }));
 132
 133     entity.addComponent(new CoupledEntitiesComponent({
 134       coupledEntities: [config.entityA, config.entityB]
 135     }));
 136
 137     if (engine) {
 138       engine.addEntity(entity);
 139     }
 140
 141     return entity;
 142   }
 143 };