anh;		const toSource = Math.toSource;
const floor = Math.floor;
const cos = Math.cos;
const sqrt = function(x) {return Math.pow(x, 0.5);}


function linear_real_to_screen (x, dx, scale, w) {
	return (w / 2) + ((x - dx) / scale) * (w / 2);
}

function linear_screen_to_real (x, dx, scale, w) {
	return ((x - (w / 2)) / (w / 2) * scale + dx);
}

function atan_real_to_screen (x, dx, scale, w) {
	return atan((x - dx) / scale) / PI * (w - 1.) + (w / 2);
}

function atan_screen_to_real (x, dx, scale, w) {
	return s