Ports https://github.com/tgstation/tgstation/pull/50497

tgui/packages/common/math.js

@@ -0,0 +1,84 @@
+/**
+ * Limits a number to the range between 'min' and 'max'.
+ */
+export const clamp = (value, min, max) => {
+  return value < min ? min : value > max ? max : value;
+};
+
+/**
+ * Limits a number between 0 and 1.
+ */
+export const clamp01 = value => {
+  return value < 0 ? 0 : value > 1 ? 1 : value;
+};
+
+/**
+ * Scales a number to fit into the range between min and max.
+ */
+export const scale = (value, min, max) => {
+  return (value - min) / (max - min);
+};
+
+/**
+ * Robust number rounding.
+ *
+ * Adapted from Locutus, see: http://locutus.io/php/math/round/
+ *
+ * @param  {number} value
+ * @param  {number} precision
+ * @return {number}
+ */
+export const round = (value, precision) => {
+  if (!value || isNaN(value)) {
+    return value;
+  }
+  // helper variables
+  let m, f, isHalf, sgn;
+  // making sure precision is integer
+  precision |= 0;
+  m = Math.pow(10, precision);
+  value *= m;
+  // sign of the number
+  sgn = (value > 0) | -(value < 0);
+  // isHalf = value % 1 === 0.5 * sgn;
+  isHalf = Math.abs(value % 1) >= 0.4999999999854481;
+  f = Math.floor(value);
+  if (isHalf) {
+    // rounds .5 away from zero
+    value = f + (sgn > 0);
+  }
+  return (isHalf ? value : Math.round(value)) / m;
+};
+
+/**
+ * Returns a string representing a number in fixed point notation.
+ */
+export const toFixed = (value, fractionDigits = 0) => {
+  return Number(value).toFixed(Math.max(fractionDigits, 0));
+};
+
+/**
+ * Checks whether a value is within the provided range.
+ *
+ * Range is an array of two numbers, for example: [0, 15].
+ */
+export const inRange = (value, range) => {
+  return range
+    && value >= range[0]
+    && value <= range[1];
+};
+
+/**
+ * Walks over the object with ranges, comparing value against every range,
+ * and returns the key of the first matching range.
+ *
+ * Range is an array of two numbers, for example: [0, 15].
+ */
+export const keyOfMatchingRange = (value, ranges) => {
+  for (let rangeName of Object.keys(ranges)) {
+    const range = ranges[rangeName];
+    if (inRange(value, range)) {
+      return rangeName;
+    }
+  }
+};