function ttfGlyphLoader(font, index, parseGlyph, data, position, buildPath) {
    return function() {
        var glyph = new _glyph.Glyph({index: index, font: font});

        glyph.path = function() {
            parseGlyph(glyph, data, position);
            var path = buildPath(font.glyphs, glyph);
            path.unitsPerEm = font.unitsPerEm;
            return path;
        };

        return glyph;
    };
}
Generate a stub glyph that can be filled with all metadata *except*
the "points" and "path" properties, which must be loaded only once
the glyph's path is actually requested for text shaping.