[game] Factor into actor

game/actor.ts

@@ -0,0 +1,99 @@
+import { load_texture } from "./assets";
+import { btn, Button } from "./input";
+import { Vec2, new_v2, vadd, vnorm, vmul } from "./vector";
+import { spr, use_texture, Texture } from "./graphics";
+
+export class Actor {
+  velocity: Vec2 = new_v2(0);
+  friction: number = 0.6;
+  id: string;
+  position: Vec2;
+  bounds: Vec2;
+
+  constructor(id: string, position: Vec2, bounds: Vec2) {
+    this.id = id;
+    this.position = position;
+    this.bounds = bounds;
+  }
+
+  update() {}
+
+  update_physics() {
+    const velocity = vmul(this.velocity, this.friction);
+    // Zero if we're smaller than some epsilon.
+    if (Math.abs(velocity.x) < 0.01) {
+      velocity.x = 0;
+    }
+    if (Math.abs(velocity.y) < 0.01) {
+      velocity.y = 0;
+    }
+
+    const new_position = vadd(this.position, velocity);
+
+    // TODO: Collision detection
+    // const { w, h } = this.bounds;
+
+    this.velocity = velocity;
+    this.position = new_position;
+  }
+
+  draw(_clock: number) {}
+
+  bonk(_other: Actor) {}
+}
+
+const robo_info = {
+  width: 32,
+  height: 32,
+  sprite: "./bot.png",
+  animations: [
+    { start: 0, length: 1, speed: 20 },
+    { start: 1, length: 4, speed: 8 },
+  ],
+};
+
+export class Robo extends Actor {
+  bot_sprite: Texture | undefined = undefined;
+
+  constructor(pos: Vec2) {
+    super("robo", pos, new_v2(robo_info.width, robo_info.height));
+    load_texture(robo_info.sprite).then((texture) => {
+      this.bot_sprite = texture;
+    });
+  }
+
+  update() {
+    // Acceleration from input
+    let a = new_v2(0);
+    if (btn(Button.Up)) {
+      a.y -= 1;
+    }
+    if (btn(Button.Down)) {
+      a.y += 1;
+    }
+    if (btn(Button.Left)) {
+      a.x -= 1;
+    }
+    if (btn(Button.Right)) {
+      a.x += 1;
+    }
+    vnorm(a);
+    this.velocity = vadd(this.velocity, vmul(a, 1.5));
+  }
+
+  draw(clock: number) {
+    if (this.bot_sprite != undefined) {
+      use_texture(this.bot_sprite);
+
+      const vel = this.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 frame = (anim.start + ((clock / anim.speed) % anim.length)) >> 0;
+      spr(x, y, w, h, frame * w, 0, 32, 32);
+    }
+  }
+}