add skillshots

src/projectile.js

@@ -0,0 +1,86 @@
+import SAT from 'sat'
+import SATX from './satx.js'
+import { Vector2 } from 'three'
+
+export default class Projectile {
+  id = crypto.randomUUID()
+  after = null
+  speed = 1000
+  radius = 5
+  owner = null
+  onCollide = null
+  visualHeight = 50
+
+  #position = new Vector2()
+  #dest = null
+  #game = null
+  
+  get collider() {
+    return new SAT.Circle(new SAT.Vector(this.x, this.y), this.radius)
+  }
+
+  constructor(...options) {
+    Object.entries(options).forEach((value, key) => this[key] = value)
+  }
+
+  get game() { return this.#game }
+  get position() { return this.#position }
+  get x() { return this.position.x }
+  get y() { return this.position.y }
+  set game(value) { this.#game = value }
+  set x(value) { this.position.x = value }
+  set y(value) { this.position.y = value }
+  set destination(value) { this.#dest = value }
+
+  checkCollisions() {
+    (this.game?.entities ?? []).filter((e) => e.id != this.id).forEach((e) => {
+      if (e.id == this.owner) { return }
+
+      if (SATX.collideObject(this.collider, e.collider)) {
+        this.onCollide(this, e)
+      }
+    })
+  }
+
+  checkIfArrived() {
+    if (!this.#position.equals(this.#dest)) { return }
+
+    if (this.after != null) {
+      this.after(this)
+    }
+
+    this.despawn()
+  }
+
+  despawn() {
+    this.game?.despawn(this)
+  }
+
+  state() {
+    return {
+      ...this,
+      position: {
+        x: this.x,
+        y: this.y,
+      },
+    }
+  }
+
+  takeStep() {
+    const speed = (this.speed / (this.game?.tickBudget ?? 1000))
+    const destination = this.#dest
+    const difference = destination.clone().sub(this.position)
+    const distance = difference.length()
+    const direction = difference.clone().normalize()
+    const stepTaken = this.position.clone().add(direction.multiplyScalar(speed))
+    const position = distance <= speed ? destination : stepTaken
+
+    this.position.copy(position)
+  }
+
+  update() {
+    this.takeStep()
+    if (this.onCollide != null) { this.checkCollisions() }
+    this.checkIfArrived()
+  }
+}