| "use strict"; |
| |
| Object.defineProperty(exports, "__esModule", { |
| value: true |
| }); |
| exports.read = read; |
| exports.write = write; |
| |
| function read(buffer, offset, isLE, mLen, nBytes) { |
| var e, m; |
| var eLen = nBytes * 8 - mLen - 1; |
| var eMax = (1 << eLen) - 1; |
| var eBias = eMax >> 1; |
| var nBits = -7; |
| var i = isLE ? nBytes - 1 : 0; |
| var d = isLE ? -1 : 1; |
| var s = buffer[offset + i]; |
| i += d; |
| e = s & (1 << -nBits) - 1; |
| s >>= -nBits; |
| nBits += eLen; |
| |
| for (; nBits > 0; e = e * 256 + buffer[offset + i], i += d, nBits -= 8) {} |
| |
| m = e & (1 << -nBits) - 1; |
| e >>= -nBits; |
| nBits += mLen; |
| |
| for (; nBits > 0; m = m * 256 + buffer[offset + i], i += d, nBits -= 8) {} |
| |
| if (e === 0) { |
| e = 1 - eBias; |
| } else if (e === eMax) { |
| return m ? NaN : (s ? -1 : 1) * Infinity; |
| } else { |
| m = m + Math.pow(2, mLen); |
| e = e - eBias; |
| } |
| |
| return (s ? -1 : 1) * m * Math.pow(2, e - mLen); |
| } |
| |
| function write(buffer, value, offset, isLE, mLen, nBytes) { |
| var e, m, c; |
| var eLen = nBytes * 8 - mLen - 1; |
| var eMax = (1 << eLen) - 1; |
| var eBias = eMax >> 1; |
| var rt = mLen === 23 ? Math.pow(2, -24) - Math.pow(2, -77) : 0; |
| var i = isLE ? 0 : nBytes - 1; |
| var d = isLE ? 1 : -1; |
| var s = value < 0 || value === 0 && 1 / value < 0 ? 1 : 0; |
| value = Math.abs(value); |
| |
| if (isNaN(value) || value === Infinity) { |
| m = isNaN(value) ? 1 : 0; |
| e = eMax; |
| } else { |
| e = Math.floor(Math.log(value) / Math.LN2); |
| |
| if (value * (c = Math.pow(2, -e)) < 1) { |
| e--; |
| c *= 2; |
| } |
| |
| if (e + eBias >= 1) { |
| value += rt / c; |
| } else { |
| value += rt * Math.pow(2, 1 - eBias); |
| } |
| |
| if (value * c >= 2) { |
| e++; |
| c /= 2; |
| } |
| |
| if (e + eBias >= eMax) { |
| m = 0; |
| e = eMax; |
| } else if (e + eBias >= 1) { |
| m = (value * c - 1) * Math.pow(2, mLen); |
| e = e + eBias; |
| } else { |
| m = value * Math.pow(2, eBias - 1) * Math.pow(2, mLen); |
| e = 0; |
| } |
| } |
| |
| for (; mLen >= 8; buffer[offset + i] = m & 0xff, i += d, m /= 256, mLen -= 8) {} |
| |
| e = e << mLen | m; |
| eLen += mLen; |
| |
| for (; eLen > 0; buffer[offset + i] = e & 0xff, i += d, e /= 256, eLen -= 8) {} |
| |
| buffer[offset + i - d] |= s * 128; |
| } |