fix projectiles phasing through stuff

src/projectile.js

@@ -6,6 +6,7 @@ export default class Projectile {
   id = crypto.randomUUID()
   after = null
   height = 50
+  memory = {} // TODO: WARNING: currently only used for hit detection (code smell?)
   onCollide = null
   owner = null
   position = new Vector2()
@@ -29,18 +30,18 @@ export default class Projectile {
     Object.entries(options).forEach(([key, value]) => this[key] = value)
   }
 
-  checkCollisions() {
+  checkCollisions(collider) {
     (this.game?.entities ?? []).filter((e) => e.id != this.id).forEach((e) => {
       if (e.id == this.owner?.id) { return }
 
-      if (SATX.collideObject(this.collider(), e.collider())) {
-        this.onCollide(this, e)
+      if (SATX.collideObject(collider, e.collider())) {
+        if (this.onCollide != null) { this.onCollide(this, e) }
       }
     })
   }
   
   collider() {
-    return new SAT.Circle(new SAT.Vector(this.x, this.y), this.radius)
+    return new SAT.Circle(new SAT.Vector(this.position.x, this.position.y), this.radius)
   }
 
   despawn() {
@@ -55,11 +56,12 @@ export default class Projectile {
 
   update() {
     this.#move()
-    if (this.onCollide != null) { this.checkCollisions() }
+    if (this.onCollide != null) { this.checkCollisions(this.collider()) }
     this.#checkIfArrived()
   }
 
   #checkIfArrived() {
+    if (this.destination == null) { return }
     if (!this.position.equals(this.destination)) { return }
 
     if (this.after != null) {
@@ -71,11 +73,16 @@ export default class Projectile {
 
   #move() {
     const speed = (this.speed / (this.game?.tickBudget ?? 1000))
+    const prevPos = this.position.clone()
     if (this.position.distanceTo(this.destination) < speed) {
       this.position.copy(this.destination)
     }
+    else {
+      const step = this.destination.clone().sub(this.position).normalize().multiplyScalar(speed)
+      this.position.add(step)
+    }
 
-    const step = this.destination.clone().sub(this.position).normalize().multiplyScalar(speed)
-    this.position.add(step)
+    const tunnel = SATX.entityTunnel(prevPos.x, prevPos.y, this.position.x, this.position.y, this.radius)
+    if (this.onCollide != null) { this.checkCollisions(tunnel) }
   }
 }