panel) {
			context.fillStyle = button_bg_color;
			context.fillRect(w, 0, panel_w, h);

			context.font = "14px monospace";
			context.textAlign = "left";
			context.textBaseline = "top";
			context.strokeStyle = "#000000";
			context.lineWidth = 1;

			context.fillStyle = button_color;
			context.fillText("x: " + (x_value >= 0 ? '+' : '') + x_value.toFixed(5), buttons_x, x_y);
			context.fillText("y: " + (y_value >= 0 ? '+' : '') + y_value.toFixed(5), buttons_x, y_y);
		
			context.fillStyle = linear_scal