h - linear_real_to_screen(y, center_y, scale, h);}
		];
	} else if(type == ATAN) {
		return [
			function(i) {return atan_screen_to_real(i, center_x, scale, w);},
			function(x) {return atan_real_to_screen(x, center_x, scale, w);},
			function(i) {return atan_screen_to_real(h - i, center_y, scale, h);},
			function(y) {return h - atan_real_to_screen(y, center_y, scale, h);}
		];
	}
}

function s2x_x2s_s2y_y2s_from_UI() {
	const center_x = Number(document.getElementById("center_x").value);
	const center_y = 