import * as Vector from './vector';

// Vertice operations.

// **Vertice** is a utility class to help with vertice operations. A vertice
// is implemented as a 2-element array. Element 0 is *x* and element 1 is *y*.

// Translate a vertice from an origin point using rotation and scale.
export function translate (vertice, origin, rotation = 0, scale = 1) {
  // nop?
  if (0 === rotation && 1 === scale) {
    return vertice;
  }
  // Rotate.
  const difference = Vector.sub(vertice, origin);
  rotation += Vector.angle(difference);
  const magnitude = Vector.magnitude(vertice, origin);
  vertice = Vector.add(
    origin,
    Vector.scale([Math.cos(rotation), Math.sin(rotation)], magnitude)
  );
  // Scale.
  vertice = Vector.scale(vertice, scale);
  return vertice;
}