add homing projectiles

src/ability.js

@@ -4,7 +4,6 @@ import Projectile from './projectile.js'
 export default class Ability {
   static skillshot({ range, radius, speed, onCollide, after }) {
     return function(x, y) {
-      console.log(this)
       const projectile = new Projectile()
       const destination = this.position.clone().add(new Vector2(x, y).sub(this.position).normalize().multiplyScalar(range))
       projectile.owner = this.id
@@ -17,4 +16,31 @@ export default class Ability {
       this.game?.spawnProjectile(projectile)
     }
   }
+
+  static homingProjectile({ range, radius, speed, onCollide, after }) {
+    return function(x, y) {
+      const cursor = new Vector2(x, y)
+      let closest = null
+      let distance = Infinity
+      this.game?.entities.filter((e) => e.id != this.id && e.position.clone().sub(this.position).length() < range).forEach((e) => {
+        const newDistance = e.position.clone().sub(cursor).length() < distance
+        if (newDistance < distance) {
+          closest = e
+          distance = newDistance
+        }
+      })
+
+      if (closest == null) { return } // TODO: refund
+
+      const projectile = new Projectile()
+      projectile.owner = this.id
+      projectile.position.copy(this.position)
+      projectile.homingTarget = closest
+      projectile.radius = radius
+      projectile.speed = speed
+      projectile.after = after
+      projectile.onCollide = onCollide
+      this.game?.spawnProjectile(projectile)
+    }
+  }
 }