RE: [Flightgear-devel] A Crash.

[Curtis L. O. <cu...@fl...>]

I did a little diagnostics on this problem and here's what's
happening.

There was a typo in the $fgbase/materials file where an alias was
pointing to a non-existant material name.  (This has been fixed.)

The alias code didn't check to see if this condition would occur so it
was putting a 'NULL' entry in the material library which was causing
the crash.  It now checks for and skips bad aliases and prints a
warning message.

Curt.


Norman Vine writes:
> Erik Hofman writes:
> >
> >Alex Perry wrote:
> >>
> >> > slot.get_state() returns 0xcccccccc.
> >> > Does slot.get_state() return valid values on Linux/CygWin?
> >> > The first time its called, the value is good, the second time it is
> >> > bad.
> >>
> >> F9 works find under Linux.  The terrain textures go away, to bright
> green,
> >> but the sky and panel continue to be textured.
> 
> F9 is broken for me on Cygwin also :-(
> 
> >I've found the problem.
> >When a texture is an alias it's not initialized properly.
> 
> Good Catch !!
> 
> >Change FlightGear/src/Objects/matlib.cxx
> >
> >if ( material_name == "alias" ) {
> >   string src_mat, dst_mat;
> >  in >> dst_mat >> src_mat;
> >  SG_LOG( SG_GENERAL, SG_INFO, "  Material alias: " << dst_mat <<
> >          " mapped to " << src_mat );
> >  FGNewMat m = matlib[src_mat];
> >
> >  // ADD THIS LINE
> >  m.build_ssg_state( GL_FLAT, fgGetBool("/sim/rendering/textures"),
> >false );
> >
> >  matlib[dst_mat] = m;
> >} else
> >
> >This seems to be the same problem as i had with :
> >material_lib.load_next_deferred();
> >
> >Where the slot.get_texture_name_c_str() hasn't been initialized to
> >something like "".
> 
> Almost ......
> 
> It looks like we have a problem with class FGMaterialLib
> 
> currently this is
> 
> // Material management class
> class FGMaterialLib {
> 
> private:
> 
>     // associative array of materials
>     typedef map < string, FGNewMat, less<string> > material_map;
> 
> I think inorder for aliases to work we want
> 
>     typedef FGNewMatPtr FGNewMat *
>     typedef map < string, FGNewMatPtr, less<string> > material_map;
> 
> or some such
> 
> This will require a bit of thought and code restructuring
> but it looks like a showstopper to me the way it is :-((
> 
> Curt ???
> 
> Norman
> 
> 
> _______________________________________________
> Flightgear-devel mailing list
> Fli...@li...
> http://lists.sourceforge.net/lists/listinfo/flightgear-devel

-- 
Curtis Olson   Human Factors Research Lab       FlightGear Project
Twin Cities    cu...@hf...                cu...@fl...
Minnesota      http://www.menet.umn.edu/~curt   http://www.flightgear.org