code: function resolve(ttf) {
  
  
              // 如果是svg格式字体，则去小数
              // 由于svg格式导入时候会出现字形重复问题，这里进行优化
              if (ttf.from === 'svgfont' && ttf.head.unitsPerEm > 128) {
                  ttf.glyf.forEach(function (g) {
                      if (g.contours) {
                          glyfAdjust(g);
                          reduceGlyf(g);
                      }
                  });
              }
              // 否则重新计算字形大小，缩放到1024的em
              else {
                  var xMin = 16384;
                  var xMax = -16384;
                  var yMin = 16384;
                  var yMax = -16384;
  
                  ttf.glyf.forEach(function (g) {
                      if (g.contours) {
                          var bound = computeBoundingBox.computePathBox.apply(null, g.contours);
                          if (bound) {
                              xMin = Math.min(xMin, bound.x);
                              xMax = Math.max(xMax, bound.x + bound.width);
                              yMin = Math.min(yMin, bound.y);
                              yMax = Math.max(yMax, bound.y + bound.height);
                          }
                      }
                  });
  
                  var unitsPerEm = getUnitsPerEm(xMin, xMax, yMin, yMax);
                  var scale = 1024 / unitsPerEm;
  
                  ttf.glyf.forEach(function (g) {
                      glyfAdjust(g, scale, scale);
                      reduceGlyf(g);
                  });
                  ttf.head.unitsPerEm = 1024;
              }
  
              return ttf;
          }
docs: 对ttfObject进行处理，去除小数
  
  @param {Object} ttf ttfObject
  @return {Object} ttfObject