git.r.bdr.sh - rbdr/serpentity/blob - README.md

   1 # Serpentity
   2
   3 Serpentity is a simple entity framework inspired by Ash.
   4
   5 Usage:
   6
   7     require('serpentity');
   8
   9 ## Instantiating an engine
  10
  11     var engine = Serpentity();
  12
  13 Add entities or systems:
  14
  15     engine.addEntity(entityFactory());
  16     engine.addSystem(new GameSystem());
  17
  18 Update all systems:
  19
  20     engine.update(dt);
  21
  22 Remove entities or systems:
  23
  24     engine.removeEntity(entityReference);
  25     engine.removeSystem(systemReference);
  26
  27 ## Creating Entities
  28
  29 Entities are the basic object of Serpentity, and they do nothing.
  30
  31     var entity = new Serpentity.Entity();
  32
  33 All the behavior is added through components
  34
  35 ## Creating Components
  36
  37 Components define data that we can add to an entity. This data will
  38 eventually be consumed by "Systems"
  39
  40     Class("PositionComponent").inherits(Serpentity.Component)({
  41         prototype : {
  42             x : 0,
  43             y : 0
  44         }
  45     });
  46
  47 You can add components to entities by using the add method:
  48
  49     entity.add(new PositionComponent());
  50
  51
  52 Systems can refer to entities by requesting nodes.
  53
  54 ## Working with Nodes
  55
  56 Nodes are sets of components that you define, so your system can require
  57 entities that always follow the API defined in the node.
  58
  59     Class("MovementNode").inherits(Serpentity.Node)({
  60         types : {
  61             position : PositionComponent,
  62             motion : MotionComponent
  63         }
  64     });
  65
  66 You can then request an array of all the nodes representing entities
  67 that comply with that API
  68
  69     engine.getNodes(MovementNode);
  70
  71 ## Creating Systems
  72
  73 Systems are called on every update, and they use components through nodes.
  74
  75     Class("TestSystem").inherits(Serpentity.System)({
  76         prototype : {
  77             added : function added(engine){
  78                 this.nodeList = engine.getNodes(MovementNode);
  79             },
  80             removed : function removed(engine){
  81                 this.nodeList = undefined;
  82             }
  83             update : function update(dt){
  84                 this.nodeList.forEach(function (node) {
  85                     console.log("Current position is: " + node.position.x + "," + node.position.y);
  86                 });
  87             }
  88         }
  89     });
  90
  91 ## That's it
  92
  93 Just run `engine.update(dt)` in your game loop :D
  94
  95 ## TO-DO
  96
  97 * Removing components
  98 * Implement the ashteroids demo (Serpentoids)
  99 * Actually check performance