public static void drawHorizontalLine(int x, int y, int width, int colour) {
		if (x < topY || x >= bottomY)
			return;
		if (y < topX) {
			width -= topX - y;
			y = topX;
		}
		if (y + width > bottomX)
			width = bottomX - y;
		int pointer = y + x * DrawingArea.width;
		for (int column = 0; column < width; column++)
			pixels[pointer + column] = colour;
	}