Refactor physics

backend/src/physics/move-circle.ts

@@ -0,0 +1,82 @@
+/*import { vec2 } from 'gl-matrix';
+import { rotate90Deg } from 'shared';
+import { CirclePhysics } from './bounds/circle-physics';
+import { PhysicalGameObject } from './physical-game-object';
+
+export const moveCircle = (
+  circle: CirclePhysics,
+  delta: vec2,
+  possibleIntersectors: Array<PhysicalGameObject>
+): {
+  realDelta: vec2;
+  hitSurface: boolean;
+  normal?: vec2;
+  tangent?: vec2;
+} => {
+  circle.center = vec2.add(circle.center, circle.center, delta);
+
+  const intersecting = possibleIntersectors.filter(
+    (b) => b !== circle && circle.areIntersecting(b) && b.canCollide
+  );
+
+  if (intersecting.length === 0) {
+    return {
+      realDelta: delta,
+      hitSurface: false,
+    };
+  }
+
+  const points = circle.getPerimeterPoints(settings.hitDetectionCirclePointCount);
+
+  const distancesOfPoints = points
+    .map((point) => ({
+      point,
+      closest: intersecting
+        .map((i) => ({
+          inverted: i.isInverted,
+          distance: i.owner.distance(point),
+        }))
+        .sort((a, b) => a.distance - b.distance)[0],
+    }))
+    .filter((i) => i.closest);
+
+  const distancesOfIntersectingPoints = distancesOfPoints.filter(
+    (d) =>
+      (d.closest.distance > 0 && d.closest.inverted) ||
+      (d.closest.distance < 0 && !d.closest.inverted)
+  );
+
+  if (distancesOfIntersectingPoints.length === 0) {
+    return {
+      realDelta: delta,
+      hitSurface: false,
+    };
+  }
+
+  const deltas = distancesOfIntersectingPoints.map((pointDistance) => {
+    vec2.subtract(pointDistance.point, circle.center, pointDistance.point);
+    vec2.normalize(pointDistance.point, pointDistance.point);
+    vec2.scale(
+      pointDistance.point,
+      pointDistance.point,
+      (pointDistance.closest.inverted ? 1 : -1) * pointDistance.closest.distance
+    );
+    return pointDistance.point;
+  });
+
+  const approxNormal = deltas.reduce(
+    (sum, current) => vec2.add(sum, sum, current),
+    vec2.create()
+  );
+  vec2.scale(approxNormal, approxNormal, 1 / deltas.length);
+
+  circle.center = vec2.add(circle.center, circle.center, approxNormal);
+
+  return {
+    realDelta: delta,
+    hitSurface: true,
+    normal: vec2.normalize(approxNormal, approxNormal),
+    tangent: rotate90Deg(approxNormal),
+  };
+};
+*/