Hello, dear Performers:

I have got a problem to solve, and I am sure that somebody must know about it.

I am developing a flying simulator, with Performer 2.0, and an Indigo2 High
IMPACT. This machine has Open/GL native graphics hardware.

I already have developed the terrain database to fly over, and it works fine.

Now I need to create a sort of binocular with a graduated grid, to look
trough and see the database terrain augmented. The problem is that I don't
exactly know how to do it.

I guess that I must use some sort of Pre-Draw or Post-Draw Callback function,
and whithin that function use Open/GL commands to draw the grid and a black
area to simulate the binocular shape. In fact I am using a Post-Draw Callback.

To draw the grid, I am using the ovelay plane, in a similar way as Performer does
with the stats channel. To draw the binocular shape, I am trying to use the stencil 
buffer., but it is not working as I expected. Therefore, I am in need of a source C
example program or some documentation related to the use of the stencil buffer
within Performer.

I have been searching in all the Performer directories in my disk, for source
programs that do this, but I have found nothing.

I would appreciate very much if anybody could tell me where to find any source
C programs, or any printed documents, that would allow me to achieve this goal.

Thanks in advance to everybody. Suggestions are wellcome.

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Rafael Garcia
ELCO Sistemas
Madrid - Spain
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