code: function compound2simpleglyf(glyf, ttf) {
  
      if (!glyf.compound || !glyf.glyfs) {
          return glyf;
      }
  
      var glyfs = glyf.glyfs;
      var compoundContours = [];
      glyfs.forEach(function (g) {
          var glyph = ttf.glyf[g.glyphIndex];
  
          if (!glyph && !glyph.length) {
              return;
          }
  
          var contours = lang.clone(glyph.contours); // 这里需要进行matrix变换，需要复制一份
          var transform = g.transform;
          for (var i = 0, l = contours.length; i < l; i++) {
              pathTransform(
                  contours[i],
                  transform.a,
                  transform.b,
                  transform.c,
                  transform.d,
                  transform.e,
                  transform.f
              );
              compoundContours.push(pathCeil(contours[i]));
          }
      });
  
      glyf.contours = compoundContours;
  
      delete glyf.compound;
      delete glyf.glyfs;
      // 这里hinting信息会失效，删除hinting信息
      delete glyf.instructions;
  
      return glyf;
  }
docs: ttf复合字形转简单字形
  
  @param  {Object} glyf glyf对象
  @param  {Object} ttf ttfObject对象
  @return {Object} 转换后的对象