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

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