--- /dev/null
+// IEEE754 conversions based on https://github.com/feross/ieee754
+var abs = Math.abs;
+var pow = Math.pow;
+var floor = Math.floor;
+var log = Math.log;
+var LN2 = Math.LN2;
+
+var pack = function (number, mantissaLength, bytes) {
+ var buffer = new Array(bytes);
+ var exponentLength = bytes * 8 - mantissaLength - 1;
+ var eMax = (1 << exponentLength) - 1;
+ var eBias = eMax >> 1;
+ var rt = mantissaLength === 23 ? pow(2, -24) - pow(2, -77) : 0;
+ var sign = number < 0 || number === 0 && 1 / number < 0 ? 1 : 0;
+ var index = 0;
+ var exponent, mantissa, c;
+ number = abs(number);
+ // eslint-disable-next-line no-self-compare -- NaN check
+ if (number != number || number === Infinity) {
+ // eslint-disable-next-line no-self-compare -- NaN check
+ mantissa = number != number ? 1 : 0;
+ exponent = eMax;
+ } else {
+ exponent = floor(log(number) / LN2);
+ if (number * (c = pow(2, -exponent)) < 1) {
+ exponent--;
+ c *= 2;
+ }
+ if (exponent + eBias >= 1) {
+ number += rt / c;
+ } else {
+ number += rt * pow(2, 1 - eBias);
+ }
+ if (number * c >= 2) {
+ exponent++;
+ c /= 2;
+ }
+ if (exponent + eBias >= eMax) {
+ mantissa = 0;
+ exponent = eMax;
+ } else if (exponent + eBias >= 1) {
+ mantissa = (number * c - 1) * pow(2, mantissaLength);
+ exponent = exponent + eBias;
+ } else {
+ mantissa = number * pow(2, eBias - 1) * pow(2, mantissaLength);
+ exponent = 0;
+ }
+ }
+ for (; mantissaLength >= 8; buffer[index++] = mantissa & 255, mantissa /= 256, mantissaLength -= 8);
+ exponent = exponent << mantissaLength | mantissa;
+ exponentLength += mantissaLength;
+ for (; exponentLength > 0; buffer[index++] = exponent & 255, exponent /= 256, exponentLength -= 8);
+ buffer[--index] |= sign * 128;
+ return buffer;
+};
+
+var unpack = function (buffer, mantissaLength) {
+ var bytes = buffer.length;
+ var exponentLength = bytes * 8 - mantissaLength - 1;
+ var eMax = (1 << exponentLength) - 1;
+ var eBias = eMax >> 1;
+ var nBits = exponentLength - 7;
+ var index = bytes - 1;
+ var sign = buffer[index--];
+ var exponent = sign & 127;
+ var mantissa;
+ sign >>= 7;
+ for (; nBits > 0; exponent = exponent * 256 + buffer[index], index--, nBits -= 8);
+ mantissa = exponent & (1 << -nBits) - 1;
+ exponent >>= -nBits;
+ nBits += mantissaLength;
+ for (; nBits > 0; mantissa = mantissa * 256 + buffer[index], index--, nBits -= 8);
+ if (exponent === 0) {
+ exponent = 1 - eBias;
+ } else if (exponent === eMax) {
+ return mantissa ? NaN : sign ? -Infinity : Infinity;
+ } else {
+ mantissa = mantissa + pow(2, mantissaLength);
+ exponent = exponent - eBias;
+ } return (sign ? -1 : 1) * mantissa * pow(2, exponent - mantissaLength);
+};
+
+module.exports = {
+ pack: pack,
+ unpack: unpack
+};