penguin_trackball.o penguin_trackball.o: trackball.c /usr/include/math.h \
  /usr/include/features.h /usr/include/sys/cdefs.h \
  /usr/include/gnu/stubs.h /usr/include/bits/huge_val.h \
  /usr/include/bits/mathdef.h /usr/include/bits/mathcalls.h trackball.h
