[GRASS5] NVIZ updates

[Bob Covill]

Hello,

I have just applied a few changes for NVIZ to CVS. These changes are 
found in the ogsf and NVIZ2.2 directories.

These changes include the following:

1. Added colorbar (legend) support. The colorbar for the currently 
selected surface (color overlay) can be drawn from the Label panel. All 
features are working with the exception of "use list". Simply set your 
features and select the "Legend" button and mark the legend corners in 
the NVIZ window. Use the left mouse button to set the first corner and 
the right button to mark the second corner. If the selected points are 
wider than high, a horizontal bar will be drawn. The font for the legend 
is controled by the Font options in the label panel. A visible 
rubberband box is on the todo list for this feature.

2. Added Label support. Labels may now be drawn in the NVIZ window by 
first setting the label font options (color size, weight, etc), entering 
the label text in the "Label Text" entry box. Select the "Place Label" 
button and choose a position in the NVIZ window. The text will be drawn 
centered and above the selcted point.

3. Added font support. Font are now supported in NVIZ. This option is 
used in the above legend and labels. Note that the options available 
create an X compatible font. It is possible to set the options to a font 
that is not available on your system. You can use glxinfo to view 
available fonts. An error is printed to stderr if a font is not 
available. A generic default font should probably be defined in future 
updates.

4. Added North arrow support. A North arrow can now be drawn by 
selecting the Scale panel. Select the Place Arrow checkbutton and then 
the Place Arrow button. Select a location in the NVIZ window. The arrow 
is drawn originating from the selected point. The arrow can be drawn on 
a surface or beside a surface. The scaling option for the North arrow 
still needs some work in ogsf. You may end up with overly large or small 
arrows.

5. Added height options for vectors. I have cleaned up the vector panel 
to hopefully be a bit more intuitive. I have also added a height slider 
to the panel. The user may now draw the selected vector at a set height 
above the surface(s). This can help portions of the vector from being 
obscured in the surface(s). The vector can also be drawn flat (Display 
Flat) at a height set by the slider. Note that if the vector is being 
drawn flat, a surface must be associated with the vector. If there is no 
association, nothing will be drawn. This is something that still needs 
cleaning up. The vector panel should work a bit better now in the case 
where multiple vectors and surfaces are being drawn.

6. Set the lights to refresh every time a key frame is advanced. When 
creating a key frame animation output images did not seem to reflect the 
  users light positions (shading). This fix should correct that.

If you have any questions, problems, or comments about any of the 
changes 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