linking errors - X11 libs missing

hi,

after compiling torque i get the following linker errors:

out.GCC2.DEBUG/platformX86UNIX/x86UNIXFont.obj: In function 'loadFont(char const *, int, _XDisplay *, char *, int)':
/home/chris/torque/torque/engine/platformX86UNIX/x86UNIXFont.cc:79: undefined reference to 'XLoadQueryFont'
/home/chris/torque/torque/engine/platformX86UNIX/x86UNIXFont.cc:99: undefined reference to 'XLoadQueryFont'
out.GCC2.DEBUG/platformX86UNIX/x86UNIXFont.obj: In function 'createFont(char const
*, int)':
/home/chris/torque/torque/engine/platformX86UNIX/x86UNIXFont.cc:113: undefined reference to 'XOpenDisplay'
/home/chris/torque/torque/engine/platformX86UNIX/x86UNIXFont.cc:141: undefined reference to 'XCreatePixmap'
/home/chris/torque/torque/engine/platformX86UNIX/x86UNIXFont.cc:145: undefined reference to 'XCreateGC'
/home/chris/torque/torque/engine/platformX86UNIX/x86UNIXFont.cc:146: undefined reference to 'XSetFont'
/home/chris/torque/torque/engine/platformX86UNIX/x86UNIXFont.cc:176: undefined reference to 'XTextExtents'
/home/chris/torque/torque/engine/platformX86UNIX/x86UNIXFont.cc:190: undefined reference to 'XSetForeground'
/home/chris/torque/torque/engine/platformX86UNIX/x86UNIXFont.cc:191: undefined reference to 'XFillRectangle'
/home/chris/torque/torque/engine/platformX86UNIX/x86UNIXFont.cc:193: undefined reference to 'XSetForeground'

[...]

/usr/lib/libSDL.a(SDL_x11wm.lo): In function 'X11_IconifyWindow':
SDL_x11wm.lo(.text+0xa40): undefined reference to 'XIconifyWindow'
SDL_x11wm.lo(.text+0xa56): undefined reference to 'XSync'
/usr/lib/libSDL.a(SDL_x11wm.lo): In function 'X11_GrabInputNoLock':
SDL_x11wm.lo(.text+0xabe): undefined reference to 'XUngrabPointer'
SDL_x11wm.lo(.text+0xad2): undefined reference to 'XUngrabKeyboard'
SDL_x11wm.lo(.text+0xaef): undefined reference to 'XUngrabPointer'
SDL_x11wm.lo(.text+0xb24): undefined reference to 'XGrabPointer'
SDL_x11wm.lo(.text+0xb49): undefined reference to 'XGrabKeyboard'
SDL_x11wm.lo(.text+0xb6d): undefined reference to 'XRaiseWindow'
SDL_x11wm.lo(.text+0xb93): undefined reference to 'XSync'
/usr/lib/libSDL.a(SDL_x11wm.lo): In function 'unlock_display':
SDL_x11wm.lo(.text+0xc32): undefined reference to 'XSync'
/usr/lib/libSDL.a(SDL_x11yuv.lo): In function 'X11_CreateYUVOverlay':
SDL_x11yuv.lo(.text+0x234): undefined reference to 'XFree'
SDL_x11yuv.lo(.text+0x3fd): undefined reference to 'XFree'
SDL_x11yuv.lo(.text+0x4af): undefined reference to 'XShmAttach'
SDL_x11yuv.lo(.text+0x4c9): undefined reference to 'XSync'
/u

(and many more - i have deleted the rest.)

I guess i need development libraries of some XFree-libraries, but what exactly do i need? I have no clue. Can anybody help me?

Thanks
Chris