public void fillRect(short colix, int x, int y, int z, int zSlab, int widthFill, int heightFill) {
		// hover and labels only -- slab at atom or front -- simple Z/window clip
		if (isClippedZ(zSlab))
			return;
		if (x < 0) {
			widthFill += x;
			if (widthFill <= 0)
				return;
			x = 0;
		}
		if (x + widthFill > width) {
			widthFill = width - x;
			if (widthFill <= 0)
				return;
		}
		if (y < 0) {
			heightFill += y;
			if (heightFill <= 0)
				return;
			y = 0;
		}
		setColix(colix);
		if (y + heightFill > height)
			heightFill = height - y;
		while (--heightFill >= 0)
			plotPixelsUnclipped(widthFill, x, y++, z);
	}