delted_utils.ts

/**
 * Get a point along an arc.
 *
 * @param center - The arc's center.
 * @param radius - The arc's radius.
 * @param startAngle - The start point of the arc.
 * @param size - The size of the arc.
 * @param t - The point along the arc to get.
 */
export function getPointOnArc(
	center: VecLike,
	radius: number,
	startAngle: number,
	size: number,
	t: number
) {
	const angle = startAngle + size * t
	return new Vec(center.x + radius * Math.cos(angle), center.y + radius * Math.sin(angle))
}

/**
 * Get a bounding box for an arc.
 *
 * @param center - The arc's center.
 * @param radius - The arc's radius.
 * @param start - The start point of the arc.
 * @param size - The size of the arc.
 */
export function getArcBoundingBox(center: VecLike, radius: number, start: VecLike, size: number) {
	let minX = Infinity
	let minY = Infinity
	let maxX = -Infinity
	let maxY = -Infinity

	const startAngle = Vec.Angle(center, start)

	// Test 20 points along the arc
	for (let i = 0; i < 20; i++) {
		const angle = startAngle + size * (i / 19)
		const x = center.x + radius * Math.cos(angle)
		const y = center.y + radius * Math.sin(angle)

		minX = Math.min(x, minX)
		minY = Math.min(y, minY)
		maxX = Math.max(x, maxX)
		maxY = Math.max(y, maxY)
	}

	return new Box(minX, minY, maxX - minX, maxY - minY)
}