Fix physics

backend/src/objects/projectile-physical.ts

@@ -0,0 +1,67 @@
+import { vec2 } from 'gl-matrix';
+import {
+  id,
+  settings,
+  serializesTo,
+  ProjectileBase,
+  GameObject,
+  rotate90Deg,
+} from 'shared';
+import { ImmutableBoundingBox } from '../physics/bounding-boxes/immutable-bounding-box';
+import { CirclePhysical } from './circle-physical';
+import { DynamicPhysical } from '../physics/conatiners/dynamic-physical';
+import { PhysicalContainer } from '../physics/containers/physical-container';
+
+@serializesTo(ProjectileBase)
+export class ProjectilePhysical extends ProjectileBase implements DynamicPhysical {
+  public readonly canCollide = true;
+  public readonly canMove = true;
+
+  public object: CirclePhysical;
+
+  constructor(
+    center: vec2,
+    radius: number,
+    private velocity: vec2,
+    readonly container: PhysicalContainer,
+  ) {
+    super(id(), center, radius);
+    this.object = new CirclePhysical(center, radius, this, container, 0.9);
+  }
+
+  private _boundingBox?: ImmutableBoundingBox;
+
+  public get boundingBox(): ImmutableBoundingBox {
+    if (!this._boundingBox) {
+      this._boundingBox = (this.object as CirclePhysical).boundingBox;
+    }
+
+    return this._boundingBox;
+  }
+
+  public get gameObject(): this {
+    return this;
+  }
+
+  public distance(target: vec2): number {
+    return this.object.distance(target);
+  }
+
+  public onCollision(normal: vec2, other: GameObject) {
+    const tangent = rotate90Deg(normal);
+    vec2.scale(this.velocity, tangent, vec2.dot(tangent, this.velocity));
+  }
+
+  public step(deltaTimeInMiliseconds: number) {
+    const deltaTime = deltaTimeInMiliseconds / 1000;
+
+    vec2.add(
+      this.velocity,
+      this.velocity,
+      vec2.scale(vec2.create(), settings.gravitationalForce, deltaTime),
+    );
+
+    this.object.velocity = this.velocity;
+    this.object.step2(deltaTime);
+  }
+}