Add support for simple periodic sprite animations

src/model/data/entity.ts

@@ -1,19 +1,29 @@
 import { Collision } from './collision';
 
+export interface EntityAnimation {
+	readonly sequence: ReadonlyArray<[number, number]>;
+}
+
 export interface EntityDataInput {
 	readonly sprite: string;
 	readonly anchor?: [number, number];
 	readonly collision?: Collision[];
+	readonly frames?: number;
+	readonly animation?: EntityAnimation;
 }
 
 export class EntityData {
 	public readonly sprite: string;
 	public readonly anchor: [number, number];
 	public readonly collision: Collision[];
+	public readonly frames: number;
+	public readonly animation?: EntityAnimation;
 
 	constructor(input: EntityDataInput) {
 		this.sprite = input.sprite;
 		this.anchor = input.anchor || [0.5, 0.5];
 		this.collision = input.collision || [];
+		this.frames = input.frames || 1;
+		this.animation = input.animation;
 	}
 }