partey_workadventure/back/src/Model/PositionNotifier.ts
2021-06-24 10:09:10 +02:00

110 lines
4.1 KiB
TypeScript

/**
* Tracks the position of every player on the map, and sends notifications to the players interested in knowing about the move
* (i.e. players that are looking at the zone the player is currently in)
*
* Internally, the PositionNotifier works with Zones. A zone is a square area of a map.
* Each player is in a given zone, and each player tracks one or many zones (depending on the player viewport)
*
* The PositionNotifier is important for performance. It allows us to send the position of players only to a restricted
* number of players around the current player.
*/
import { EmoteCallback, EntersCallback, LeavesCallback, MovesCallback, Zone } from "./Zone";
import { Movable } from "_Model/Movable";
import { PositionInterface } from "_Model/PositionInterface";
import { ZoneSocket } from "../RoomManager";
import { User } from "_Model/User";
import { EmoteEventMessage } from "../Messages/generated/messages_pb";
interface ZoneDescriptor {
i: number;
j: number;
}
export class PositionNotifier {
// TODO: we need a way to clean the zones if noone is in the zone and noone listening (to free memory!)
private zones: Zone[][] = [];
constructor(
private zoneWidth: number,
private zoneHeight: number,
private onUserEnters: EntersCallback,
private onUserMoves: MovesCallback,
private onUserLeaves: LeavesCallback,
private onEmote: EmoteCallback
) {}
private getZoneDescriptorFromCoordinates(x: number, y: number): ZoneDescriptor {
return {
i: Math.floor(x / this.zoneWidth),
j: Math.floor(y / this.zoneHeight),
};
}
public enter(thing: Movable): void {
const position = thing.getPosition();
const zoneDesc = this.getZoneDescriptorFromCoordinates(position.x, position.y);
const zone = this.getZone(zoneDesc.i, zoneDesc.j);
zone.enter(thing, null, position);
}
public updatePosition(thing: Movable, newPosition: PositionInterface, oldPosition: PositionInterface): void {
// Did we change zone?
const oldZoneDesc = this.getZoneDescriptorFromCoordinates(oldPosition.x, oldPosition.y);
const newZoneDesc = this.getZoneDescriptorFromCoordinates(newPosition.x, newPosition.y);
if (oldZoneDesc.i != newZoneDesc.i || oldZoneDesc.j != newZoneDesc.j) {
const oldZone = this.getZone(oldZoneDesc.i, oldZoneDesc.j);
const newZone = this.getZone(newZoneDesc.i, newZoneDesc.j);
// Leave old zone
oldZone.leave(thing, newZone);
// Enter new zone
newZone.enter(thing, oldZone, newPosition);
} else {
const zone = this.getZone(oldZoneDesc.i, oldZoneDesc.j);
zone.move(thing, newPosition);
}
}
public leave(thing: Movable): void {
const oldPosition = thing.getPosition();
const oldZoneDesc = this.getZoneDescriptorFromCoordinates(oldPosition.x, oldPosition.y);
const oldZone = this.getZone(oldZoneDesc.i, oldZoneDesc.j);
oldZone.leave(thing, null);
}
private getZone(i: number, j: number): Zone {
let zoneRow = this.zones[j];
if (zoneRow === undefined) {
zoneRow = new Array<Zone>();
this.zones[j] = zoneRow;
}
let zone = this.zones[j][i];
if (zone === undefined) {
zone = new Zone(this.onUserEnters, this.onUserMoves, this.onUserLeaves, this.onEmote, i, j);
this.zones[j][i] = zone;
}
return zone;
}
public addZoneListener(call: ZoneSocket, x: number, y: number): Set<Movable> {
const zone = this.getZone(x, y);
zone.addListener(call);
return zone.getThings();
}
public removeZoneListener(call: ZoneSocket, x: number, y: number): void {
const zone = this.getZone(x, y);
zone.removeListener(call);
}
public emitEmoteEvent(user: User, emoteEventMessage: EmoteEventMessage) {
const zoneDesc = this.getZoneDescriptorFromCoordinates(user.getPosition().x, user.getPosition().y);
const zone = this.getZone(zoneDesc.i, zoneDesc.j);
zone.emitEmoteEvent(emoteEventMessage);
}
}