[GRASS5] New NVIZ fly navigation

[Helena]

It works fine, I got an error message on my home machine too, but it showed up
only the first time I loaded g3d file and never again, so I assume it was my local
problem.

thank you once more,

Helena
> 
> Thank you.
> 
>> I had only one problem - when I tried to read g3d file to see whether it
>> will work with the volume data I got an error message
>> id in get_drawmode is invalid.
>> I will try at home on a different machine, but maybe be somebody who 
>> has the slovakia3d data set installed could test it for volume data too.
>>
>> Helena
> 
> 
> I didn't have the chance to try it with volume data. As I changed 
> something to the command Ndraw_all I can expect some problem, but I used 
> the same functions as in draw.c eliminating only the swap buffer 
> functions between the drawing of surf, vect, sites and volumes to avoid 
> the flickering. Check the differences between Ndraw_all_cmd (draw.c) and 
> Ndraw_all_together_cmd (togl_flythrough.c) if you want to see what has 
> changed.
> 
> Please, let me know what happens with the further tests.
> 
> Massimo
>