import { lineToCubic } from "./line-to-cubic.js";
import { quadraticToCubic } from "./quadratic-to-cubic.js";


/**
 * Returns a cubic bezier curve that is equivalent to the given linear or
 * quadratic bezier curve. 
 * 
 * Cubics are just returned unaltered. 
 * 
 * This function simply uses `lineToCubic` or `quadraticToCubic` internally.
 * 
 * @param ps an order 0,1,2 or 3 bezier curve given as an ordered array of its
 * control point coordinates, e.g. `[[0,0],[1,1],[2,1],[2,0]]`
 * 
 * @doc mdx
 */
function toCubic(ps: number[][]): number[][] {
	if (ps.length === 4) { // Cubic
		return ps;
	}

	if (ps.length === 3) { // Quadratic
		return quadraticToCubic(ps); 
	} 

	if (ps.length === 2) { // Linear
		return lineToCubic(ps); 
	}
	
	if (ps.length === 1) { // Point
		const p = ps[0];
		return [p,p,p,p]; 
	}

	throw new Error('The given bezier curve must be of order <= 3.');
}


export { toCubic }