fixed a bug in the cube example where zero rotational values would destroy the rotation quaternion making the cube disappear

git-svn-id: svn+ssh://svn.code.sf.net/p/spacenav/code/trunk/libspnav@113 ef983eb1-d774-4af8-acfd-baaf7b16a646

examples/cube/cube.c

@@ -258,9 +258,11 @@ int handle_event(XEvent *xev)
 			/* if so deal with motion and button events */
 			if(spev.type == SPNAV_EVENT_MOTION) {
 				/* apply axis/angle rotation to the quaternion */
-				float axis_len = sqrt(SQ(spev.motion.rx) + SQ(spev.motion.ry) + SQ(spev.motion.rz));
-				rot = quat_rotate(rot, axis_len * 0.001, -spev.motion.rx / axis_len,
-						-spev.motion.ry / axis_len, spev.motion.rz / axis_len);
+				if(spev.motion.rx || spev.motion.ry || spev.motion.rz) {
+					float axis_len = sqrt(SQ(spev.motion.rx) + SQ(spev.motion.ry) + SQ(spev.motion.rz));
+					rot = quat_rotate(rot, axis_len * 0.001, -spev.motion.rx / axis_len,
+							-spev.motion.ry / axis_len, spev.motion.rz / axis_len);
+				}
 
 				/* add translation */
 				pos.x += spev.motion.x * 0.001;

spnav.c

@@ -36,7 +36,7 @@ OF SUCH DAMAGE.
 #include <sys/select.h>
 #include "spnav.h"
 
-#define SPNAV_SOCK_PATH "/var/run/spnav.sock" 
+#define SPNAV_SOCK_PATH "/var/run/spnav.sock"
 
 #ifdef USE_X11
 #include <X11/Xlib.h>