Spring RTS Engine

Is there any way to use GLSL to modify how certain Spring objects get drawn?
I mostly want to know about using shaders for:
- map
- unit*
- feature*
- projectile

* I've seen behe's magical forest thingy, so I assume units (his trees were actually units, not features) can be affected by GLSL.

I guess units and features drawing can be affected within DrawUnit/DrawFeature?

drawing units in different scales, by PicassoCT & zwzsg:
http://springrts.com/phpbb/viewtopic.php?f=23&t=29934

wrong name order, actually should be praise all alone for zwzsg. He really got it to work.

map

no

unit*

yes

feature*

no

projectile

no

I guess units and features drawing can be affected within DrawUnit/DrawFeature?

yes/yes