Re: [vistavrtoolkit-general] Problems with DFN-Node: Could not fetch movements of mouse scrollwheel on linux

[Ingo A. <iar...@ya...>]

Hi!

There are some shortcomings on the current implementation as it is in
Vista with regards to the wheel handling.

a) if you are using freeglut (which is most often default on Linux), you
are fine off, but make sure that you compile the library using the
USE_NATIVE_GLUT=0 preprocessor flag. Check your cmake cache file to see
the value, os normally the cmake scripts make sure to detect whether you
have freeglut or the 'only' the normal glut.

b) depending on your version of glut (here is where the 'luck' part
starts), it reports mouse wheels as mouse button events. Check if you
can find GLUT_WHEEL_<UP|DOWN> flags in your glut(.h). If that is the
case, the Vista implementation is plainly not working good, as it does
dispatch only the first three buttons and waits for magics to happen to
the scroll wheel state. (In a nutshell: current glut implementations
show the wheel as additional button).

Here is why you see 0 as a value:

in case the mouse button callback gets called (which happens if you use
glut and not freeglut and you use the wheel), the mouse driver records
the current state of the mouse. The right file to look at for your case
would be
VistaDeviceDrivers/VistaGlutMouseDriver/VistaGlutMouseDriver.cpp, l.
92f). This includes the current state of the variables for the wheel and
the wheel state. As they are only changed in the case of freeglut
installed, the state variables do not get updated. Are you sure you see
"(0,0)" only? And not "(-1,0)"?


The code, as it is right now can crash, so its good you pointed that
out. It needs to be fixed. It would be very good to know what version of
glut you are using and where we can peek at the source.

Thanks, hope it helps,

Ingo.



On 10/04/2012 02:36 PM, Dominik Rausch wrote:
> What version of glut are you using? Standard glut does not support mouse
> wheels, but freeglut does, so you’ll have to built Vista with freeglut.