Add documentation for math-util functions.

src/util/math-util.js

@@ -1,17 +1,45 @@
 function MathUtil () {}
 
+/**
+ * Convert a value from degrees to radians.
+ * @param {!number} deg Value in degrees.
+ * @return {!number} Equivalent value in radians.
+ */
 MathUtil.degToRad = function (deg) {
     return (Math.PI * (90 - deg)) / 180;
 };
 
+/**
+ * Convert a value from radians to degrees.
+ * @param {!number} rad Value in radians.
+ * @return {!number} Equivalent value in degrees.
+ */
 MathUtil.radToDeg = function (rad) {
     return rad * 180 / Math.PI;
 };
 
+/**
+ * Clamp a number between two limits.
+ * If n < min, return min. If n > max, return max. Else, return n.
+ * @param {!number} n Number to clamp.
+ * @param {!number} min Minimum limit.
+ * @param {!number} max Maximum limit.
+ * @return {!number} Value of n clamped to min and max.
+ */
 MathUtil.clamp = function (n, min, max) {
     return Math.min(Math.max(n, min), max);
 };
 
+/**
+ * Keep a number between two limits, wrapping "extra" into the range.
+ * e.g., wrapClamp(7, 1, 5) == 2
+ * wrapClamp(0, 1, 5) == 5
+ * wrapClamp(-11, -10, 6) == 6, etc.
+ * @param {!number} n Number to wrap.
+ * @param {!number} min Minimum limit.
+ * @param {!number} max Maximum limit.
+ * @return {!number} Value of n wrapped between min and max.
+ */
 MathUtil.wrapClamp = function (n, min, max) {
     var range = (max - min) + 1;
     return n - Math.floor((n - min) / range) * range;