fonteditor-core/lib/ttf/table/cff/parseCFFEncoding.js

fonts (ttf, woff, woff2, eot, svg, otf) parse, write, transform, glyph adjust.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = parseCFFEncoding;
/**
 * @file 解析cff编码
 * @author mengke01(kekee000@gmail.com)
 */

/**
 * 解析cff encoding数据
 * See Adobe TN #5176 chapter 12, "Encodings".
 *
 * @param  {Reader} reader 读取器
 * @param  {number=} start  偏移
 * @return {Object}        编码表
 */
function parseCFFEncoding(reader, start) {
  if (null != start) {
    reader.seek(start);
  }
  var i;
  var code;
  var encoding = {};
  var format = reader.readUint8();
  if (format === 0) {
    var nCodes = reader.readUint8();
    for (i = 0; i < nCodes; i += 1) {
      code = reader.readUint8();
      encoding[code] = i;
    }
  } else if (format === 1) {
    var nRanges = reader.readUint8();
    code = 1;
    for (i = 0; i < nRanges; i += 1) {
      var first = reader.readUint8();
      var nLeft = reader.readUint8();
      for (var j = first; j <= first + nLeft; j += 1) {
        encoding[j] = code;
        code += 1;
      }
    }
  } else {
    console.warn('unknown encoding format:' + format);
  }
  return encoding;
}