/** Bit-mask layer system for selective rendering and raycasting. */
export class Layers {
	#mask = 1;

	/** Current bitmask. */
	get mask(): number {
		return this.#mask;
	}

	/** Set the mask to a single layer. */
	set(layer: number): void {
		this.#mask = 1 << layer;
	}

	/** Enable a layer (add it to the mask). */
	enable(layer: number): void {
		this.#mask |= 1 << layer;
	}

	/** Enable all 32 layers. */
	enableAll(): void {
		this.#mask = 0xffffffff;
	}

	/** Toggle a layer on/off. */
	toggle(layer: number): void {
		this.#mask ^= 1 << layer;
	}

	/** Disable a layer (remove it from the mask). */
	disable(layer: number): void {
		this.#mask &= ~(1 << layer);
	}

	/** Disable all layers. */
	disableAll(): void {
		this.#mask = 0;
	}

	/** Test whether this mask overlaps another Layers mask. */
	test(layers: Layers): boolean {
		return (this.#mask & layers.mask) !== 0;
	}

	/** Test if a specific layer is enabled. */
	isEnabled(layer: number): boolean {
		return (this.#mask & (1 << layer)) !== 0;
	}
}