glgrav.o: glgrav.cpp global.h config.h mass.h vec3d.h particles.h \
  sparks.h
mass.o: mass.cpp mass.h global.h vec3d.h
config.o: config.cpp config.h global.h mass.h vec3d.h
particles.o: particles.cpp particles.h global.h
sparks.o: sparks.cpp sparks.h global.h
vec3d.o: vec3d.cpp vec3d.h global.h