INNER CODE UNIT · JavaScript

rot

lh3/psmc · utils/dec2img.js:104

function rot(n, x, y, rx, ry)
{
	if (ry == 0) {
		if (rx == 1)
			x = n - 1 - x, y = n - 1 - y;
		var t = x; x = y; y = t;
	}
	return [x, y];
}

function d2xy(n, d)
{
	var t = d, x = 0, y = 0;
    for (var s = 1; s < n; s <<= 1) {
        var rx = 1 & (t >> 1);
        var ry = 1 & (t ^ rx);
        var r = rot(s, x, y, rx, ry);
		x = r[0], y = r[1];

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