ttfinfo.js

#!/usr/bin/env node

/*
 * Internal utility qu quickly check ttf tables size
 */

/*eslint-disable no-console*/

'use strict';


var fs      = require('fs');
var _       = require('lodash');
var format  = require('util').format;

var ArgumentParser = require('argparse').ArgumentParser;

var parser = new ArgumentParser({
  add_help: true,
  description: 'Dump TTF tables info'
});

parser.add_argument('infile', {
  nargs: 1,
  help: 'Input file'
});

parser.add_argument('-d', '--details', {
  help: 'Show table dump',
  action: 'store_true',
  required: false
});

var args = parser.parse_args();
var ttf;

try {
  ttf = fs.readFileSync(args.infile[0]);
} catch (e) {
  console.error("Can't open input file (%s)", args.infile[0]);
  process.exit(1);
}

var tablesCount = ttf.readUInt16BE(4);

var i, offset, headers = [];

for (i = 0; i < tablesCount; i++) {
  offset = 12 + i * 16;
  headers.push({
    name: String.fromCharCode(
      ttf.readUInt8(offset),
      ttf.readUInt8(offset + 1),
      ttf.readUInt8(offset + 2),
      ttf.readUInt8(offset + 3)
    ),
    offset: ttf.readUInt32BE(offset + 8),
    length: ttf.readUInt32BE(offset + 12)
  });
}

console.log(format('Tables count: %d'), tablesCount);

_.forEach(_.sortBy(headers, 'offset'), function (info) {
  console.log('- %s: %d bytes (%d offset)', info.name, info.length, info.offset);
  if (args.details) {
    var bufTable = ttf.slice(info.offset, info.offset + info.length);
    var count = Math.floor(bufTable.length / 32);
    var offset = 0;

    //split buffer to the small chunks to fit the screen
    for (var i = 0; i < count; i++) {
      console.log(bufTable.slice(offset, offset + 32));
      offset += 32;
    }

    //output the rest
    if (offset < (info.length)) {
      console.log(bufTable.slice(offset, info.length));
    }

    console.log('');
  }
});