Fix physics

backend/src/objects/stone-physical.ts

@@ -0,0 +1,78 @@
+import { vec2 } from 'gl-matrix';
+import { clamp01, id, serializesTo, StoneBase } from 'shared';
+
+import { ImmutableBoundingBox } from '../physics/bounding-boxes/immutable-bounding-box';
+import { StaticPhysical } from '../physics/containers/static-physical';
+
+@serializesTo(StoneBase)
+export class StonePhysical extends StoneBase implements StaticPhysical {
+  public readonly canCollide = true;
+  public readonly canMove = false;
+
+  private _boundingBox?: ImmutableBoundingBox;
+
+  constructor(vertices: Array<vec2>) {
+    super(id(), vertices);
+  }
+
+  public distance(target: vec2): number {
+    const startEnd = this.vertices[0];
+    let vb = startEnd;
+
+    let d = vec2.squaredDistance(target, vb);
+    let sign = 1;
+
+    for (let i = 1; i <= this.vertices.length; i++) {
+      const va = vb;
+      vb = i === this.vertices.length ? startEnd : this.vertices[i];
+      const targetFromDelta = vec2.subtract(vec2.create(), target, va);
+      const toFromDelta = vec2.subtract(vec2.create(), vb, va);
+      const h = clamp01(
+        vec2.dot(targetFromDelta, toFromDelta) / vec2.squaredLength(toFromDelta),
+      );
+
+      const ds = vec2.fromValues(
+        vec2.dist(targetFromDelta, vec2.scale(vec2.create(), toFromDelta, h)),
+        toFromDelta.x * targetFromDelta.y - toFromDelta.y * targetFromDelta.x,
+      );
+
+      if (
+        (target.y >= va.y && target.y < vb.y && ds.y > 0) ||
+        (target.y < va.y && target.y >= vb.y && ds.y <= 0)
+      ) {
+        sign *= -1;
+      }
+
+      d = Math.min(d, ds.x);
+    }
+
+    return sign * d;
+  }
+
+  public get boundingBox(): ImmutableBoundingBox {
+    if (!this._boundingBox) {
+      const { xMin, xMax, yMin, yMax } = this.vertices.reduce(
+        (extremities, vertex) => ({
+          xMin: Math.min(extremities.xMin, vertex.x),
+          xMax: Math.max(extremities.xMax, vertex.x),
+          yMin: Math.min(extremities.yMin, vertex.y),
+          yMax: Math.max(extremities.yMax, vertex.y),
+        }),
+        {
+          xMin: Infinity,
+          xMax: -Infinity,
+          yMin: Infinity,
+          yMax: -Infinity,
+        },
+      );
+
+      this._boundingBox = new ImmutableBoundingBox(xMin, xMax, yMin, yMax);
+    }
+
+    return this._boundingBox;
+  }
+
+  public get gameObject(): this {
+    return this;
+  }
+}