A real mathematical "mod 4", not a Javascript-ish one

Author: xcontcom

cnn/cnn2.js

@@ -231,6 +231,7 @@ function drawFractal() {
 			}
 			else if (mode === "mod4") {
 				const s = Math.round(raw);
+				const r = ((s % 4) + 4) % 4;
 				color = (s % 4 === 0 || s % 4 === 1) ? "#000" : "#fff";
 			}
 			else if (mode === "livingstone") {