How to fix:
Thank LigH mentioned, I forgot to open the DRI support, then I read the
http://gentoo-wiki.com/HOWTO_Direct_rendering_on_Intel_Extreme_Graphics_%28855GM%29_chipsetsDue to my lspci is:
00:00.0 Host bridge: Intel Corporation Mobile 945GM/PM/GMS, 943/940GML and 945GT Express Memory Controller Hub (rev 03)
00:02.0 VGA compatible controller: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03)
00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03)
...
And glxinfo | grep rendering shown direct rendering: No
So I followed the Gentoo wiki`s HOWTO_Direct_rendering_on_Intel_Extreme_Graphics, I checked the kernel config created before, it chosed i810 but not the i915, it might be the key reason why without direct rendering support.
What`s more, I checked glxgears:
3920 frames in 5.0 seconds = 783.947 FPS
3848 frames in 5.0 seconds = 769.480 FPS
3873 frames in 5.0 seconds = 774.420 FPS
7346 frames in 5.0 seconds = 1469.092 FPS
11242 frames in 5.0 seconds = 2248.260 FPS
11436 frames in 5.0 seconds = 2286.838 FPS
...
Huh, not a good Video Card for playing big game

What I met the issue:
I downloaded PlaneShift_CBV0.3.019-x86.bin for my Gentoo box (2.6.20-gentoo-r8 i686 Genuine Intel(R) CPU T1350 @ 1.86GHz GenuineIntel GNU/Linux).
But after simple installation, when I clicked the PlaneShift Client Desktop icon, it shown as below:

And on my wife`s MacBook it shown as below with correct font:

Then I thought it might be the fonts issue, so I created tarball from MacBook Fonts, and installed them on Gentoo box, but it still failed to show correct font.
Can someone give me advice? Thanks a lot
