[game] Big actor refactor, spawn actors from world

game/actor.ts

@@ -3,8 +3,7 @@ import { btn, Button } from "./input";
 import { Vec2, new_v2, vadd, vnorm, vmul } from "./vector";
 import { spr, use_texture, Texture } from "./graphics";
 
-interface ActorSnapshot {
-  __type__: string;
+export interface ActorProps {
   velocity: Vec2;
   friction: number;
   id: string;
@@ -12,23 +11,33 @@ interface ActorSnapshot {
   bounds: Vec2;
 }
 
-export class Actor {
-  velocity: Vec2 = new_v2(0);
-  friction: number = 0.6;
-  id: string;
-  position: Vec2;
-  bounds: Vec2;
+export function new_actor_props(
+  id: string,
+  position: Vec2,
+  bounds: Vec2
+): ActorProps {
+  return {
+    velocity: new_v2(0),
+    friction: 0.6,
+    id,
+    position,
+    bounds,
+  };
+}
 
-  constructor(id: string, position: Vec2, bounds: Vec2) {
-    this.id = id;
-    this.position = position;
-    this.bounds = bounds;
+export class Actor {
+  type: ActorType;
+  props: ActorProps;
+
+  constructor(type: ActorType, props: ActorProps) {
+    this.type = type;
+    this.props = props;
   }
 
   update() {}
 
   update_physics() {
-    const velocity = vmul(this.velocity, this.friction);
+    const velocity = vmul(this.props.velocity, this.props.friction);
     // Zero if we're smaller than some epsilon.
     if (Math.abs(velocity.x) < 0.01) {
       velocity.x = 0;
@@ -37,36 +46,22 @@ export class Actor {
       velocity.y = 0;
     }
 
-    const new_position = vadd(this.position, velocity);
+    const new_position = vadd(this.props.position, velocity);
 
     // TODO: Collision detection
     // const { w, h } = this.bounds;
 
-    this.velocity = velocity;
-    this.position = new_position;
+    this.props.velocity = velocity;
+    this.props.position = new_position;
   }
 
   draw(_clock: number) {}
 
   bonk(_other: Actor) {}
-
-  snapshot(): ActorSnapshot {
-    return { ...this, __type__: "??" };
-  }
-
-  assign_snapshot(s: ActorSnapshot) {
-    this.id = s.id;
-    this.position = s.position;
-    this.bounds = s.bounds;
-    this.velocity = s.velocity;
-    this.friction = s.friction;
-    return this;
-  }
 }
 
 const robo_info = {
-  width: 32,
-  height: 32,
+  bounds: new_v2(32),
   sprite: "./bot.png",
   animations: [
     { start: 0, length: 1, speed: 20 },
@@ -74,15 +69,11 @@ const robo_info = {
   ],
 };
 
-interface RoboSnapshot extends ActorSnapshot {
-  __type__: "robo";
-}
-
 export class Robo extends Actor {
   bot_sprite: Texture | undefined = undefined;
 
-  constructor(pos: Vec2) {
-    super("robo", pos, new_v2(robo_info.width, robo_info.height));
+  constructor(props: ActorProps) {
+    super("robo", props);
     load_texture(robo_info.sprite).then((texture) => {
       this.bot_sprite = texture;
     });
@@ -104,43 +95,36 @@ export class Robo extends Actor {
       a.x += 1;
     }
     vnorm(a);
-    this.velocity = vadd(this.velocity, vmul(a, 1.5));
+    this.props.velocity = vadd(this.props.velocity, vmul(a, 1.5));
   }
 
   draw(clock: number) {
     if (this.bot_sprite != undefined) {
       use_texture(this.bot_sprite);
 
-      const vel = this.velocity;
+      const vel = this.props.velocity;
       const moving = vel.x != 0 || vel.y != 0;
       const anim = robo_info.animations[moving ? 1 : 0];
 
-      const { x: w, y: h } = this.bounds;
-      const { x, y } = this.position;
+      const { x: w, y: h } = this.props.bounds;
+      const { x, y } = this.props.position;
 
       const frame = (anim.start + ((clock / anim.speed) % anim.length)) >> 0;
       spr(x, y, w, h, frame * w, 0, 32, 32);
     }
   }
-
-  snapshot(): RoboSnapshot {
-    return { ...super.snapshot(), __type__: "robo" };
-  }
-
-  assign_snapshot(s: RoboSnapshot) {
-    super.assign_snapshot(s);
-    return this;
-  }
 }
 
-const SNAPSHOT_TABLE: { [key: string]: (s: any) => Actor } = {
-  robo: (s: any) => new Robo(new_v2(0)).assign_snapshot(s),
+const ACTOR_TABLE = {
+  robo: (s: ActorProps) => new Robo(s),
 };
 
-export function actor_from_snapshot(s: ActorSnapshot): Actor {
-  const f = SNAPSHOT_TABLE[s.__type__];
-  if (f == undefined) {
-    throw new Error("No handler for " + s.__type__);
-  }
-  return f(s);
+export type ActorType = keyof typeof ACTOR_TABLE;
+
+export function is_actor_type(type: string): type is ActorType {
+  return ACTOR_TABLE.hasOwnProperty(type);
+}
+
+export function spawn_actor(type: ActorType, props: ActorProps): Actor {
+  return ACTOR_TABLE[type](props);
 }

game/level.ts

@@ -23,14 +23,26 @@ export type TileLayer = {
   tiles: Tile[];
 };
 
-export type Layer = TileLayer;
+export type Entity = {
+  type: string;
+  id: string;
+  px: [number, number];
+  bounds: [number, number];
+  // TODO: More props here.
+};
+
+export type EntityLayer = {
+  type: "entity";
+  entities: Entity[];
+};
 
 export type Level = {
   world_x: number;
   world_y: number;
   width: number;
   height: number;
-  layers: Layer[];
+  tile_layers: TileLayer[];
+  entity_layers: EntityLayer[];
 };
 
 export type TileSet = { id: number; texture: Texture };
@@ -52,6 +64,74 @@ async function load_tileset(def: {
   return { id: def.uid, texture };
 }
 
+type TileLayerInstance = {
+  __type: "Tiles";
+  __gridSize: number;
+  __pxTotalOffsetX: number;
+  __pxTotalOffsetY: number;
+  __tilesetDefUid: number;
+  gridTiles: {
+    px: [number, number];
+    src: [number, number];
+    f: number;
+    t: number;
+    a: number;
+  }[];
+};
+
+function load_tile_layer_instance(
+  tile_sets: Map<number, TileSet>,
+  li: TileLayerInstance
+): TileLayer {
+  const tileset = tile_sets.get(li.__tilesetDefUid);
+  if (!tileset) {
+    throw new Error("Unable to find texture!!! " + li.__tilesetDefUid);
+  }
+
+  return {
+    type: "tile",
+    texture: tileset.texture,
+    grid_size: li.__gridSize,
+    offset: [li.__pxTotalOffsetX, li.__pxTotalOffsetY],
+    tiles: li.gridTiles,
+  };
+}
+
+type EntityLayerInstance = {
+  __type: "Entities";
+  entityInstances: {
+    __identifier: string;
+    iid: string;
+    width: number;
+    height: number;
+    px: [number, number];
+  }[];
+};
+
+function load_entity_layer_instance(li: EntityLayerInstance): EntityLayer {
+  return {
+    type: "entity",
+    entities: li.entityInstances.map((ei) => {
+      return {
+        type: ei.__identifier,
+        id: ei.iid,
+        px: ei.px,
+        bounds: [ei.width, ei.height],
+      };
+    }),
+  };
+}
+
+type LayerInstance = TileLayerInstance | EntityLayerInstance;
+
+function is_tile_layer_instance(x: LayerInstance): x is TileLayerInstance {
+  return x.__type == "Tiles";
+}
+
+function is_entity_layer_instance(x: LayerInstance): x is EntityLayerInstance {
+  return x.__type == "Entities";
+}
+
 function load_level(
   tile_sets: Map<number, TileSet>,
   def: {
@@ -59,41 +139,27 @@ function load_level(
     worldY: number;
     pxWid: number;
     pxHei: number;
-    layerInstances: {
-      __gridSize: number;
-      __pxTotalOffsetX: number;
-      __pxTotalOffsetY: number;
-      __tilesetDefUid: number;
-      gridTiles: {
-        px: [number, number];
-        src: [number, number];
-        f: number;
-        t: number;
-        a: number;
-      }[];
-    }[];
+    layerInstances: LayerInstance[];
   }
 ): Level {
-  return {
+  const result: Level = {
     world_x: def.worldX,
     world_y: def.worldY,
     width: def.pxWid,
     height: def.pxHei,
-    layers: def.layerInstances.map((li) => {
-      const tileset = tile_sets.get(li.__tilesetDefUid);
-      if (!tileset) {
-        throw new Error("Unable to find texture!!! " + li.__tilesetDefUid);
-      }
-
-      return {
-        type: "tile",
-        texture: tileset.texture,
-        grid_size: li.__gridSize,
-        offset: [li.__pxTotalOffsetX, li.__pxTotalOffsetY],
-        tiles: li.gridTiles,
-      };
-    }),
+    tile_layers: [],
+    entity_layers: [],
   };
+
+  for (const li of def.layerInstances) {
+    if (is_tile_layer_instance(li)) {
+      result.tile_layers.push(load_tile_layer_instance(tile_sets, li));
+    } else if (is_entity_layer_instance(li)) {
+      result.entity_layers.push(load_entity_layer_instance(li));
+    }
+  }
+
+  return result;
 }
 
 export async function load_world(path: string): Promise<World> {
@@ -120,7 +186,7 @@ export function draw_level(
   offset_x: number = 0,
   offset_y: number = 0
 ) {
-  for (const layer of level.layers) {
+  for (const layer of level.tile_layers) {
     use_texture(layer.texture);
 
     let [ofx, ofy] = layer.offset;

game/main.ts

@@ -2,13 +2,21 @@ import { cls, print } from "./graphics";
 import { since_start } from "./time";
 import { new_v2 } from "./vector";
 import { load_world, World, Level, draw_level } from "./level";
-import { Actor, Robo, ActorSnapshot, actor_from_snapshot } from "./actor";
+import {
+  Actor,
+  ActorProps,
+  ActorType,
+  new_actor_props,
+  is_actor_type,
+  spawn_actor,
+} from "./actor";
 
 /// A nice looping frame counter.
 let clock = 0;
 
 let world: World | undefined = undefined;
 let level: Level | undefined = undefined;
+let actors: Actor[] = [];
 
 // Note zelda overworld is 16x8 screens
 //      zelda screen is 16x11 tiles
@@ -27,6 +35,19 @@ function load_assets() {
     }
 
     // TODO: SPAWN ACTORS BASED ON LEVEL.
+    actors.length = 0;
+    for (const entity_layer of level.entity_layers) {
+      for (const entity of entity_layer.entities) {
+        if (is_actor_type(entity.type)) {
+          const [x, y] = entity.px;
+          const [w, h] = entity.bounds;
+          const props = new_actor_props(entity.id, new_v2(x, y), new_v2(w, h));
+          actors.push(spawn_actor(entity.type, props));
+        } else {
+          print("WARNING: Ignoring entity of type", entity.type);
+        }
+      }
+    }
   });
 
   Promise.all([map_load]).then(() => {
@@ -34,32 +55,31 @@ function load_assets() {
   });
 }
 
-let actors: Actor[] = [];
-
 // TODO: Build a system whereby the signatures of the fundamental functions can be checked.
 
 export function init() {
   print("Hello world!");
   load_assets();
-  actors.push(new Robo(new_v2(10, 10)));
 }
 
 interface Snapshot {
   clock: number;
-  actors: ActorSnapshot[];
+  actors: { type: ActorType; props: ActorProps }[];
 }
 
 export function suspend(): Snapshot {
   return {
     clock,
-    actors: actors.map((a) => a.snapshot()),
+    actors: actors.map((a) => {
+      return { type: a.type, props: a.props };
+    }),
   };
 }
 
 export function resume(snapshot: Snapshot | undefined) {
   if (snapshot) {
     clock = snapshot.clock || 0;
-    actors = snapshot.actors.map((a) => actor_from_snapshot(a));
+    actors = snapshot.actors.map((s) => spawn_actor(s.type, s.props));
   }
 }