@cantoo/pdf-lib
Version:
Create and modify PDF files with JavaScript
60 lines • 1.98 kB
JavaScript
;
// tslint:disable radix
Object.defineProperty(exports, "__esModule", { value: true });
exports.bytesFor = exports.sizeInBytes = exports.numberToString = void 0;
/**
* Converts a number to its string representation in decimal. This function
* differs from simply converting a number to a string with `.toString()`
* because this function's output string will **not** contain exponential
* notation.
*
* Credit: https://stackoverflow.com/a/46545519
*/
const numberToString = (num) => {
let numStr = String(num);
if (Math.abs(num) < 1.0) {
const e = parseInt(num.toString().split('e-')[1]);
if (e) {
const negative = num < 0;
if (negative)
num *= -1;
num *= Math.pow(10, e - 1);
numStr = '0.' + new Array(e).join('0') + num.toString().substring(2);
if (negative)
numStr = '-' + numStr;
}
}
else {
let e = parseInt(num.toString().split('+')[1]);
if (e > 20) {
e -= 20;
num /= Math.pow(10, e);
numStr = num.toString() + new Array(e + 1).join('0');
}
}
return numStr;
};
exports.numberToString = numberToString;
const sizeInBytes = (n) => Math.ceil(n.toString(2).length / 8);
exports.sizeInBytes = sizeInBytes;
/**
* Converts a number into its constituent bytes and returns them as
* a number[].
*
* Returns most significant byte as first element in array. It may be necessary
* to call .reverse() to get the bits in the desired order.
*
* Example:
* bytesFor(0x02A41E) => [ 0b10, 0b10100100, 0b11110 ]
*
* Credit for algorithm: https://stackoverflow.com/a/1936865
*/
const bytesFor = (n) => {
const bytes = new Uint8Array((0, exports.sizeInBytes)(n));
for (let i = 1; i <= bytes.length; i++) {
bytes[i - 1] = n >> ((bytes.length - i) * 8);
}
return bytes;
};
exports.bytesFor = bytesFor;
//# sourceMappingURL=numbers.js.map