Map loading times are very slow for areas with CJK labels

[glzcc]

**mapbox-gl-js version0.28:

Steps to Trigger Behavior

1.The internet 50kb/s
2.map need 4min load
3.

Expected Behavior

Actual Behavior

[glzcc]

I was wondering if I could load the requested resource locally! /(ㄒoㄒ)/~~

[mourner]

This is a known issue when loading map areas with CJK glyphs, especially when you use multiple font styles. Mapbox GL loads fonts, depending on which glyphs are used in the current view, as chunks of 256-sized unicode intervals. This mechanism works great for most languages, but makes download times pretty big for CJK.

It's a very challenging issue to solve, but we're working on it.

[mourner]

Also see #3466; the issue is being tracked at mapbox/node-fontnik#36.

[glzcc]

@mourner O(∩_∩)Othinks