Module core

Core part of ash.ts - a Typescript port of Ash Framework, an entity framework for game development by Richard Lord

Differences between typescript and AS3 version

As this is a port to a different language there are some changes to the API.

Nodes

Javascript which is a language that typescript is compiling to, is dynamic. Variables that are declared but not yet instantiated doesn't have a type. In AS3 when Node fields are null but they are declared as some type, that information is kept at runtime. Adding typescript to javascript gave us code completion and type checking, but information about type is dropped as soon as code is compiled to javascript and not available at runtime. All you need to add is @keep(Class) to each field of your node. This way type information is available in compile and runtime. Example:

import { Node, keep } from '@ash.ts/ash';
import { Motion, Position } from '../components';

export class MovementNode extends Node {
  
  @keep(Position)
  public position!:Position;
  
  @keep(Motion)
  public motion!:Motion;
  
}

Copy

Exclamation mark used in this example is a non-null assertion operator. If you use "strict": true or "strictNullChecks": true flags in your tsconfig.json file, it's the way to silent compiler. You as a developer can guarantee that these values will never be null, because as soon as they are created by the Engine they are filled with components.

Systems

Base System class is declared as abstract class with these methods marked as required to be declared in an inherited class.

• public abstract addToEngine(engine:Engine):void;
• public abstract removeFromEngine(engine:Engine):void;
• public abstract update(time:number):void;

Example usage:

import { Engine, NodeList, System } from '@ash.ts/ash';
import { RenderNode } from '../nodes';

export class RenderSystem extends System {
  private nodes:NodeList<RenderNode> | null = null;

  constructor(public container:HTMLElement) {
    super();
  }

  public addToEngine(engine:Engine):void {
    this.nodes = engine.getNodeList(RenderNode);
    // some more logic
  }

  public update(time:number):void {
    for (let node = this.nodes!.head; node; node = node.next) {
      // update logic
    }
  }

  public removeFromEngine(engine:Engine):void {
    this.nodes = null;
    // some more logic
  }
}

Copy