a bit more progress

kennel/kennel.py

@@ -8,6 +8,8 @@ from kennel.engine.systems.network import (
     EventProcessor,
     Event,
     EventType,
+    Entity,
+    EntityPositionUpdateEvent,
 )
 from kennel.engine.systems.world import WorldSystem
 from kennel.config import config
@@ -35,24 +37,28 @@ class KennelEventProcessor(EventProcessor):
             self._process_entity_position_update(entity_manager, event, client_id)
 
     def _process_entity_position_update(
-        self, entity_manager: EntityManager, event: Event, client_id: str
+        self,
+        entity_manager: EntityManager,
+        event: EntityPositionUpdateEvent,
+        client_id: str,
     ) -> None:
         entity = entity_manager.get_entity(event.data["id"])
         if entity is None:
             logger.error(f"Entity(id={event.data['id']}) does not exist")
             return
         controllable = entity.get_component(ComponentType.CONTROLLABLE)
-        if controllable is None:
-            logger.error(f"Entity {entity} is not controllable")
-            return
-        if controllable.by != client_id:
+        if controllable is None or controllable.by != client_id:
             logger.error(f"Entity {entity} is not controllable by client {client_id}")
             return
         position = entity.get_component(ComponentType.POSITION)
         if position is None:
             logger.error(f"Entity {entity} has no position")
             return
+        position.x = event.data["position"]["x"]
+        position.y = event.data["position"]["y"]
+
         entity.add_component(position)
+        entity_manager.add_entity(entity)
 
 
 system_manager.add_system(WorldSystem(config.WORLD_WIDTH, config.WORLD_HEIGHT))

static/src/event.ts

@@ -1,28 +0,0 @@
-export enum EventType {
-  INITIAL_STATE = "INITIAL_STATE",
-  SET_CONTROLLABLE = "SET_CONTROLLABLE",
-  ENTITY_BORN = "ENTITY_BORN",
-  ENTITY_DEATH = "ENTITY_DEATH",
-  ENTITY_POSITION_UPDATE = "ENTITY_POSITION_UPDATE",
-}
-
-export interface Event {
-  event_type: EventType;
-  data: any;
-}
-
-export interface InitialStateEvent extends Event {
-  event_type: EventType.INITIAL_STATE;
-  data: {
-    world: { width: number; height: number };
-    entities: any[];
-  };
-}
-
-export interface SetControllableEvent extends Event {
-  event_type: EventType.SET_CONTROLLABLE;
-  data: {
-    id: string;
-    client_id: string;
-  };
-}

static/src/main.ts

@@ -1,51 +1,93 @@
 import $ from "jquery";
 import { Vec2 } from "./vector";
-import { EventType, type SetControllableEvent, type Event } from "./event";
+import {
+  EventType,
+  type SetControllableEvent,
+  type Event,
+  type EventPublisher,
+} from "./event";
 import { MouseController } from "./mouse_controller";
+import {
+  EntityPositionUpdateEvent,
+  EventProcessor,
+  EventQueue,
+  WebSocketEventQueue,
+} from "./network";
 
-$(document).ready(async () => {
+class KennelClient {
+  private running: boolean;
+  private last_update: number;
+
+  private controllable_entities: Set<string>;
+  private mouse_controller: MouseController;
+
+  constructor(
+    private readonly event_queue: EventQueue,
+    private readonly event_publisher: EventPublisher,
+  ) {
+    this.last_update = 0;
+    this.running = false;
+
+    this.mouse_controller = new MouseController((position: Vec2) =>
+      this.on_mouse_move(position),
+    );
+  }
+
+  public start() {
+    this.running = true;
+    this.last_update = performance.now();
+    this.mouse_controller.start();
+
+    const loop = (timestamp: number) => {
+      const dt = timestamp - this.last_update;
+      this.propogate_state_after(dt);
+      requestAnimationFrame(loop); // tail call recursion! /s
+    };
+    requestAnimationFrame(loop);
+  }
+
+  public close() {
+    this.running = false;
+    this.mouse_controller.stop();
+    this.controllable_entities.clear();
+  }
+
+  private propogate_state_after(dt: number) {
+    // TODO: interpolate cats and lasers and stuff
+  }
+
+  private on_mouse_move(position: Vec2) {
+    for (const id of this.controllable_entities) {
+      const event: EntityPositionUpdateEvent = {
+        event_type: EventType.ENTITY_POSITION_UPDATE,
+        data: { id, position: { x: position.x, y: position.y } },
+      };
+      this.event_publisher.send(event);
+    }
+  }
+}
+
+$(async () => {
   const session_id = await fetch("/assign", {
     credentials: "include",
   })
     .then((res) => res.json())
     .then(({ session }) => session);
 
-  const controllable_entities = new Set<string>();
-  const control_callback = (movement: Vec2) => {
-    for (const id of controllable_entities) {
-      const message = JSON.stringify({
-        event_type: EventType.ENTITY_POSITION_UPDATE,
-        data: { id, position: movement },
-      });
-      ws.send(message);
-    }
-  };
-  const mouse_controller = new MouseController(control_callback);
+  const ws = new WebSocket("/ws");
+  await new Promise<void>((resolve) => {
+    ws.onopen = () => resolve();
+  });
+
+  const queue: EventQueue = new WebSocketEventQueue(ws);
+
+  const kennel_client = new KennelClient(session_id, null);
+
+  ws.onclose = () => kennel_client.close();
+
+  const mouse_controller = new MouseController(on_mouse_move);
   $(document).on("mousemove", (event) => {
     mouse_controller.move(event.clientX, event.clientY);
   });
   mouse_controller.start();
-
-  const ws = new WebSocket("/ws");
-  await new Promise<void>((resolve) => {
-    ws.onopen = () => {
-      console.log("connected");
-      resolve();
-    };
-  });
-  ws.onmessage = ({ data }) => {
-    const [event_type, event_data] = JSON.parse(data);
-    const message = { event_type, data: event_data } as Event;
-
-    console.log("Received message", message);
-    if (message.event_type === EventType.SET_CONTROLLABLE) {
-      const event = message as SetControllableEvent;
-      if (event.data.client_id === session_id) {
-        controllable_entities.add(event.data.id);
-      }
-    }
-  };
-  ws.onclose = () => {
-    controllable_entities.clear();
-  };
 });

static/src/mouse_controller.ts

@@ -1,21 +1,23 @@
 import { Vec2 } from "./vector";
-
 export class MouseController {
-  private readonly debounce_ms = 400;
-  private readonly movement_threshold = 40;
   private last_event_time = Date.now();
-  private movement_queue: Vec2[] = [];
-  private interval_id: number | null = null;
+  private last_movement: Vec2 | undefined;
+  private interval_id: number | undefined;
 
-  constructor(private readonly callback: (new_movement: Vec2) => void) {}
+  constructor(
+    private readonly publisher: (new_movement: Vec2) => void | Promise<void>,
+    private readonly debounce_ms = 200,
+    private readonly l2_norm_threshold = 40,
+  ) {}
 
   public start() {
-    if (this.interval_id !== null) {
+    if (typeof this.interval_id !== "undefined") {
       return;
     }
-    this.interval_id = setInterval(() => {
-      this.publish_movement();
-    }, this.debounce_ms);
+    this.interval_id = setInterval(
+      () => this.publish_movement(),
+      this.debounce_ms,
+    );
   }
 
   public stop() {
@@ -23,32 +25,30 @@ export class MouseController {
       return;
     }
     clearInterval(this.interval_id);
-    this.interval_id = null;
+    delete this.interval_id;
   }
 
   public move(x: number, y: number) {
     const new_movement = new Vec2(x, y);
-    const last_movement = this.movement_queue.at(-1);
-    this.movement_queue.push(new_movement);
     if (
-      typeof last_movement === "undefined" ||
-      new_movement.distance_to(last_movement) < this.movement_threshold
+      typeof this.last_movement !== "undefined" &&
+      new_movement.distance_to(this.last_movement) >= this.l2_norm_threshold
     ) {
-      return;
+      this.publish_movement();
     }
-    this.publish_movement();
+    this.last_movement = new_movement;
   }
 
   private publish_movement() {
     if (
-      Date.now() - this.last_event_time < this.debounce_ms ||
-      this.movement_queue.length === 0
+      typeof this.last_movement === "undefined" ||
+      Date.now() - this.last_event_time < this.debounce_ms
     ) {
       return;
     }
 
     this.last_event_time = Date.now();
-    this.callback(this.movement_queue.at(-1)!);
-    this.movement_queue = [];
+    this.publisher(this.last_movement.copy());
+    delete this.last_movement;
   }
 }

static/src/network.ts

@@ -0,0 +1,73 @@
+export enum EventType {
+  INITIAL_STATE = "INITIAL_STATE",
+  SET_CONTROLLABLE = "SET_CONTROLLABLE",
+  ENTITY_BORN = "ENTITY_BORN",
+  ENTITY_DEATH = "ENTITY_DEATH",
+  ENTITY_POSITION_UPDATE = "ENTITY_POSITION_UPDATE",
+}
+
+export interface Event {
+  event_type: EventType;
+  data: any;
+}
+
+export interface EntityPositionUpdateEvent extends Event {
+  event_type: EventType.ENTITY_POSITION_UPDATE;
+  data: {
+    id: string;
+    position: {
+      x: number;
+      y: number;
+    };
+  };
+}
+
+export interface InitialStateEvent extends Event {
+  event_type: EventType.INITIAL_STATE;
+  data: {
+    world: { width: number; height: number };
+    entities: any[];
+  };
+}
+
+export interface SetControllableEvent extends Event {
+  event_type: EventType.SET_CONTROLLABLE;
+  data: {
+    id: string;
+    client_id: string;
+  };
+}
+
+export interface EventQueue {
+  peek(): Event[];
+  clear(): void;
+}
+
+export interface EventPublisher {
+  add(event: Event): void;
+  publish(): void;
+}
+
+export class WebSocketEventQueue implements EventQueue {
+  private queue: Event[];
+
+  constructor(websocket: WebSocket) {
+    this.queue = [];
+    this.listen_to(websocket);
+  }
+
+  public peek() {
+    return this.queue;
+  }
+
+  public clear() {
+    this.queue = [];
+  }
+
+  private listen_to(websocket: WebSocket) {
+    websocket.onmessage = ({ data }) => {
+      const [event_type, event_data] = JSON.parse(data);
+      this.queue.push({ event_type, data: event_data } as Event);
+    };
+  }
+}

static/src/vector.ts

@@ -7,4 +7,8 @@ export class Vec2 {
   public distance_to(that: Vec2): number {
     return Math.sqrt((this.x - that.x) ** 2 + (this.y - that.y) ** 2);
   }
+
+  public copy(): Vec2 {
+    return new Vec2(this.x, this.y);
+  }
 }