[Plib-devel] Debug messages with 1.8.3 / ATI problems on Mac

[Jan R. <slo...@gm...>]

Hello!

I'm currently rewriting the graphics engine of the CRRCsim model airplane
flight simulator to use SSG (and some other parts of PLIB). Right now
we're running a mixture of "old" OpenGL code and "new" SSG code. The
sky dome and the airplane models are drawn by SSG but the scenery and some
parts of the 2D screen overlay are still using plain OpenGL.

Until now the conversion was quite easy and problem-free, but right now
we're facing three strange problems. I don't know if they are really
caused by PLIB, but maybe they are related to it and therefore I hope
that maybe someone on this list has an idea what goes wrong.

First problem: one developer reports strange debugging messages
when linking with plib-1.8.3 (from the Debian repository) on
Debian Sarge GNU/Linux:

[_ae_loopback_array_elt,759] aa->offset = 57
[_ae_loopback_array_elt,759] aa->offset = 137

This problem only arises when a special AC3D model is loaded into the
scenegraph. With other models the message does not appear. When
linking against plib-1.8.4 (this time built from source) the
messages are also gone. But grep-ing through the 1.8.3 source code did 
not reveal a line that could produce a message like this.

Any idea where this messages could come from?


Second problem, on the same computer: All untextured AC3D models
look plain white. This problem hasn't shown up on any other
computer yet. Textured models look o.k., and the problem only
arises with 1.8.4. With 1.8.3 (and after removing any "crease"
entries from the .ac files) all models look right.


Next problem: Some MacOSX-users are reporting a missing texture on
the sky dome. The dome (not using the ssgaSky class) simply
consists of some vertex arrays which form a half sphere. The vertices
don't have a color value but are assigned texture coordinates from one
256x256 pixel RGB texture. This looks alright on Linux machines
and on an iMac, but two users with ATI-powered-Macs reported a plain
white sky sphere.

I don't think that this problem is related to PLIB at all, but maybe 
other PLIB applications have this problem as well and maybe even
could provide a solution. Some details on one of the machines from
the CRRCsim log file:

Using the following rendering mode:
  Renderer:    ATi Rage 128 Pro OpenGL Engine
  Vendor:      ATI Technologies Inc.
  GL version:  1.1 ATI-1.4.4
  RGBA bpp:    8/8/8/8
  Depth bpp:   24
  Stencil bpp: 0

BTW, the OpenGL window is initialized using SDL. Don't know if this
could be related to any of these problems.

Kind regards,
Jan R.

-- 
Jan Reucker
email: jan dot reucker at web dot de
web:   http://www.reucker-online.de