+void World_Start(world_t *world);
+void World_End(world_t *world);
+
+// update physics
+// this is called by SV_Physics
+void World_Physics_Frame(world_t *world, double frametime, double gravity);
+
+// change physics properties of entity
+struct prvm_edict_s;
+struct edict_odefunc_s;
+void World_Physics_ApplyCmd(struct prvm_edict_s *ed, struct edict_odefunc_s *f);
+
+// remove physics data from entity
+// this is called by entity removal
+void World_Physics_RemoveFromEntity(world_t *world, struct prvm_edict_s *ed);
+void World_Physics_RemoveJointFromEntity(world_t *world, struct prvm_edict_s *ed);
+