Interface Pivotal<T>
interface Pivotal<T> {
rotateAbout(value: T, pivot: { x: number; y: number }, dθ: number): T;
scaleAbout(value: T, pivot: { x: number; y: number }, k: number): T;
}
rotateAbout(value: T, pivot: { x: number; y: number }, dθ: number): T;
scaleAbout(value: T, pivot: { x: number; y: number }, k: number): T;
}
Type Parameters
- T
2-D group action: rotation + uniform scale about a pivot. Used by closed-form aggregate lenses ("rotate/scale the cluster about its centroid"). Per-value-class semantics — Pose rotates position AND orientation, Vec only position; pivot is always a 2-D
{x, y}. Caller passes signed dθ (wraps) and k (k < 0 reflects).