docs: public void addKnot(int x, int color) {
  		int[] nx = new int[numKnots+1];
  		int[] ny = new int[numKnots+1];
  		System.arraycopy(xKnots, 0, nx, 0, numKnots);
  		System.arraycopy(yKnots, 0, ny, 0, numKnots);
  		xKnots = nx;
  		yKnots = ny;
  		xKnots[numKnots] = x;
  		yKnots[numKnots] = color;
  		numKnots++;
  		sortKnots();
  		rebuildGradient();
  	}