[GRASS5] NVIZ update (long)

[Bob Covill]

Hello,

Markus has applied some of my recent NVIZ changes to CVS. These changes
include:

1. Ability to save and load key frame animations. 

2. Changes to the DIR[XYZ] keyframe mask to use the center of view in
this field. Now both the eye and center of view can be changed in an
animation.

3. Changes to the "Run and Save" key frame menu to allow user supplied
frame starting numbers. This will allow users to do animations in
sections and start one where the other left off (for example at frame
no. 1051). The numbers are also formatted to 4 digits to allow
compatibility with the gimp animation tool. Note that the "off-screen"
option is disabled in this menu (see below).

4. Accelerated drawing of sites by skipping sites outside of the current
viewport. This routine can be applied at a later date to vectors and
rasters.

5. Changed near and far clip defaults to allow closer and farther views
respectively without being clipped.

6. Added a new display canvas for interactively moving the center of
view (similar to "look here"). This and the eye position canvas are
activated by radiobuttons. The canvases include call-backs to get and
set the canvas cursor to match the respective 
position.

7. The code for off-screen rendering is also included, but commented
out. The off-screen rendering draws to off-screen pbuffers, thus
allowing rendering to be done undisturbed by screen savers, other
windows, etc. This routine is still fairly new and requires a bit more
work. For those wishing to try the off-screen rendering use a compile
flag #define OS_RENDER to build the ogsf library and nvwish. The version
is compatible with GLX v.1.3, earlier versions will probably not work.
To enable off-screen rendering use "Noff_screen 1". When finished use
"Noff_screen 0" to destroy the pbuffer visual. Note that the togl window
should be minimized before calling Noff_screen 1. This ensures that the
pbuffer remains the currently selected visual.

If you have any question, comments or problems with the above please let
me know.

Also, for those interested I have got a good portion of the 3dview stuff
working in nviz. This is the saving and loading of 3d views. If anyone
is interested in testing what I have so far, please let me know.

-- 
Bob Covill

Tekmap Consulting
P.O. Box 2016
Fall River, N.S.
B2T 1K6
Canada

E-Mail: bcovill at tekmap.ns.ca
Phone: 902-860-1496
Fax: 902-860-1498