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Last change
on this file since d565449 was d565449, checked in by stefan toskovski <stefantoska84@…>, 4 weeks ago |
Update repo after prototype presentation
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100644
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File size:
1.2 KB
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[d565449] | 1 | 'use strict';
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| 2 |
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| 3 | var GetIntrinsic = require('get-intrinsic');
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| 4 |
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| 5 | var $pow = GetIntrinsic('%Math.pow%');
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| 6 |
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| 7 | module.exports = function bytesAsFloat32(rawBytes) {
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| 8 | // return new $Float32Array(new $Uint8Array(rawBytes).buffer)[0];
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| 9 |
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| 10 | /*
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| 11 | Let value be the byte elements of rawBytes concatenated and interpreted as a little-endian bit string encoding of an IEEE 754-2008 binary32 value.
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| 12 | If value is an IEEE 754-2008 binary32 NaN value, return the NaN Number value.
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| 13 | Return the Number value that corresponds to value.
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| 14 | */
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| 15 | var sign = rawBytes[3] & 0x80 ? -1 : 1; // Check the sign bit
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| 16 | var exponent = ((rawBytes[3] & 0x7F) << 1)
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| 17 | | (rawBytes[2] >> 7); // Combine bits for exponent
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| 18 | var mantissa = ((rawBytes[2] & 0x7F) << 16)
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| 19 | | (rawBytes[1] << 8)
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| 20 | | rawBytes[0]; // Combine bits for mantissa
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| 21 |
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| 22 | if (exponent === 0 && mantissa === 0) {
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| 23 | return sign === 1 ? 0 : -0;
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| 24 | }
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| 25 | if (exponent === 0xFF && mantissa === 0) {
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| 26 | return sign === 1 ? Infinity : -Infinity;
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| 27 | }
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| 28 | if (exponent === 0xFF && mantissa !== 0) {
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| 29 | return NaN;
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| 30 | }
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| 31 |
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| 32 | exponent -= 127; // subtract the bias
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| 33 |
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| 34 | if (exponent === -127) {
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| 35 | return sign * mantissa * $pow(2, -126 - 23);
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| 36 | }
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| 37 | return sign * (1 + (mantissa * $pow(2, -23))) * $pow(2, exponent);
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| 38 | };
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