@hqtsm/dataview/script/float/16.js

DataView utilities

"use strict";
/**
 * @module
 *
 * 16-bit float operations.
 */
Object.defineProperty(exports, "__esModule", { value: true });
exports.getFloat16 = getFloat16;
exports.setFloat16 = setFloat16;
let b;
/**
 * Get 16-bit float.
 *
 * @param dataView Data view.
 * @param byteOffset Byte offset.
 * @param littleEndian Little endian.
 * @returns Float value.
 */
function getFloat16(dataView, offset, littleEndian = false) {
    let m = dataView.getUint16(offset, littleEndian);
    let s = m >> 8;
    let e = s & 127;
    s >>= 7;
    m = (e & 3) * 256 + (m & 255);
    if ((e >>= 2) === 31) {
        return m ? NaN : (s ? -Infinity : Infinity);
    }
    if (e) {
        m += 1024;
        e--;
    }
    m *= 2 ** (e - 24);
    return s ? -m : m;
}
/**
 * Set 16-bit float.
 *
 * @param dataView Data view.
 * @param byteOffset Byte offset.
 * @param value Float value.
 * @param littleEndian Little endian.
 */
function setFloat16(dataView, offset, value, littleEndian = false) {
    b ??= new DataView(new ArrayBuffer(4));
    b.setFloat32(0, value);
    let f = b.getUint32(0);
    let v = f & 0x80000000;
    f ^= v;
    v >>= 16;
    if (f >= 0x47800000) {
        v |= 0x7c00 | (f > 0x7f800000 ? 512 | f >> 13 & 1023 : 0);
    }
    else if (f >= 0x33000000) {
        let e = f >> 23;
        if (f >= 0x38800000) {
            v |= e - 112 << 10 | f >> 13 & 1023;
            v += f >> 12 & (f << 20 ? 1 : v & 1);
        }
        else {
            e = 126 - e;
            f = f & 0x7fffff | 0x800000;
            v |= f >> e--;
            v += f >> e & (f << 32 - e ? 1 : v & 1);
        }
    }
    dataView.setUint16(offset, v, littleEndian);
}
//# sourceMappingURL=16.js.map