import {ITiledMap} from "../Map/ITiledMap"; export type PropertyChangeCallback = (oldValue: string | number | boolean | undefined, newValue: string | number | boolean | undefined) => void; /** * A wrapper around a ITiledMap interface to provide additional capabilities. * It is used to handle layer properties. */ export class GameMap { private key: number|undefined; private lastProperties = new Map(); private callbacks = new Map>(); public constructor(private map: ITiledMap) { } /** * Sets the position of the current player (in pixels) * This will trigger events if properties are changing. */ public setPosition(x: number, y: number) { const xMap = Math.floor(x / this.map.tilewidth); const yMap = Math.floor(y / this.map.tileheight); const key = xMap + yMap * this.map.width; if (key === this.key) { return; } this.key = key; const newProps = this.getProperties(key); const oldProps = this.lastProperties; // Let's compare the 2 maps: // First new properties vs oldProperties for (const [newPropName, newPropValue] of newProps.entries()) { const oldPropValue = oldProps.get(newPropName); if (oldPropValue !== newPropValue) { this.trigger(newPropName, oldPropValue, newPropValue); } } for (const [oldPropName, oldPropValue] of oldProps.entries()) { if (!newProps.has(oldPropName)) { // We found a property that disappeared this.trigger(oldPropName, oldPropValue, undefined); } } this.lastProperties = newProps; } private getProperties(key: number): Map { const properties = new Map(); for (const layer of this.map.layers) { if (layer.type !== 'tilelayer') { continue; } const tiles = layer.data as number[]; if (tiles[key] == 0) { continue; } // There is a tile in this layer, let's embed the properties if (layer.properties !== undefined) { for (const layerProperty of layer.properties) { if (layerProperty.value === undefined) { continue; } properties.set(layerProperty.name, layerProperty.value); } } } return properties; } private trigger(propName: string, oldValue: string | number | boolean | undefined, newValue: string | number | boolean | undefined) { let callbacksArray = this.callbacks.get(propName); if (callbacksArray !== undefined) { for (const callback of callbacksArray) { callback(oldValue, newValue); } } } /** * Registers a callback called when the user moves to a tile where the property propName is different from the last tile the user was on. */ public onPropertyChange(propName: string, callback: PropertyChangeCallback) { let callbacksArray = this.callbacks.get(propName); if (callbacksArray === undefined) { callbacksArray = new Array(); this.callbacks.set(propName, callbacksArray); } callbacksArray.push(callback); } }