mesa3d-dev

[Mesa3d-dev] bugs

[<jo...@hr...>]

Hi all,

Since some time (around the same time all the software rastering was put
in separate directories) I observe the following 2 problems which may or may
not be related:
   To test I use the program xlockmore (see ftp://ftp.tux.org./pub/tux/bagleyd/xlockmore/

 problems :
    -in mode moebius a part of the edge is not drawn resulting in a zig-zag
      line. Mesa3.4 draws it correct
    -Occasional xlock crashes in the GL modes due to invalid floats and
     access violation. I have no idea where to look for the error since
     normal error messages are not given. So probably a memory leak overwrites
     the program.


          Jouk


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  Jouk Jansen
		 
  jo...@hr...

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Re: [Mesa3d-dev] bugs

[Brian P. <br...@va...>]

"Jacob (=Jouk) Jansen" wrote:
> 
> Hi all,
> 
> Since some time (around the same time all the software rastering was put
> in separate directories) I observe the following 2 problems which may or may
> not be related:
>    To test I use the program xlockmore (see ftp://ftp.tux.org./pub/tux/bagleyd/xlockmore/
> 
>  problems :
>     -in mode moebius a part of the edge is not drawn resulting in a zig-zag
>       line. Mesa3.4 draws it correct

This looks like a glPolygonMode() bug.  The interior edges in the quad
strip shouldn't be rendered.  Keith could probably find this pretty
quickly.


>     -Occasional xlock crashes in the GL modes due to invalid floats and
>      access violation. I have no idea where to look for the error since
>      normal error messages are not given. So probably a memory leak overwrites
>      the program.

Which modes or programs in particular cause this?

-Brian

Re: [Mesa3d-dev] bugs

[Brian P. <br...@va...>]

Brian Paul wrote:
> 
> "Jacob (=Jouk) Jansen" wrote:
> >
> > Hi all,
> >
> > Since some time (around the same time all the software rastering was put
> > in separate directories) I observe the following 2 problems which may or may
> > not be related:
> >    To test I use the program xlockmore (see ftp://ftp.tux.org./pub/tux/bagleyd/xlockmore/
> >
> >  problems :
> >     -in mode moebius a part of the edge is not drawn resulting in a zig-zag
> >       line. Mesa3.4 draws it correct
> 
> This looks like a glPolygonMode() bug.  The interior edges in the quad
> strip shouldn't be rendered.  Keith could probably find this pretty
> quickly.
> 
> >     -Occasional xlock crashes in the GL modes due to invalid floats and
> >      access violation. I have no idea where to look for the error since
> >      normal error messages are not given. So probably a memory leak overwrites
> >      the program.
> 
> Which modes or programs in particular cause this?


I found the problem.

gloss has an FP exception if I run with "setenv MESA_DEBUG FP".

The problem is in the texgen code.  In the template function
for texgen_sphere_map() the VB->tmp_f array is NULL and being
allocated on the spot.  However, its contents are undefined.

Below is a simple patch which just changes the MALLOC to a CALLOC
so the array is initialized to zero.

I know Keith's been changing the vertex buffer code so I'll
wait for him to comment before committing this.

-Brian



*** t_texgen_tmp.h      2000/11/16 21:05:42     1.1
--- t_texgen_tmp.h      2000/12/15 22:57:19
***************
*** 291,297 ****
     GLfloat (*f)[3], *m;
  
     if (!VB->tmp_f) 
!       VB->tmp_f = (GLfloat (*)[3]) MALLOC(VB->Size * sizeof(GLfloat) * 3);
  
     if (!VB->tmp_m) 
        VB->tmp_m = (GLfloat *) MALLOC(VB->Size * sizeof(GLfloat));
--- 291,297 ----
     GLfloat (*f)[3], *m;
  
     if (!VB->tmp_f) 
!       VB->tmp_f = (GLfloat (*)[3]) CALLOC(VB->Size * sizeof(GLfloat) * 3);
  
     if (!VB->tmp_m) 
        VB->tmp_m = (GLfloat *) MALLOC(VB->Size * sizeof(GLfloat));

Re: [Mesa3d-dev] bugs

[Keith W. <ke...@va...>]

Brian Paul wrote:
> 
> Brian Paul wrote:
> >
> > "Jacob (=Jouk) Jansen" wrote:
> > >
> > > Hi all,
> > >
> > > Since some time (around the same time all the software rastering was put
> > > in separate directories) I observe the following 2 problems which may or may
> > > not be related:
> > >    To test I use the program xlockmore (see ftp://ftp.tux.org./pub/tux/bagleyd/xlockmore/
> > >
> > >  problems :
> > >     -in mode moebius a part of the edge is not drawn resulting in a zig-zag
> > >       line. Mesa3.4 draws it correct
> >
> > This looks like a glPolygonMode() bug.  The interior edges in the quad
> > strip shouldn't be rendered.  Keith could probably find this pretty
> > quickly.
> >
> > >     -Occasional xlock crashes in the GL modes due to invalid floats and
> > >      access violation. I have no idea where to look for the error since
> > >      normal error messages are not given. So probably a memory leak overwrites
> > >      the program.
> >
> > Which modes or programs in particular cause this?
> 
> I found the problem.
> 
> gloss has an FP exception if I run with "setenv MESA_DEBUG FP".
> 
> The problem is in the texgen code.  In the template function
> for texgen_sphere_map() the VB->tmp_f array is NULL and being
> allocated on the spot.  However, its contents are undefined.
> 
> Below is a simple patch which just changes the MALLOC to a CALLOC
> so the array is initialized to zero.
> 
> I know Keith's been changing the vertex buffer code so I'll
> wait for him to comment before committing this.

I'll check this change into my codebase.  The name of that file has changed
(there's no need for a _tmp file any longer).  Don't worry about committing
it.

In fact, I'd be happiest if people held off all commits to the tnl/ directory
until I get this code in.

Keith

Re: [Mesa3d-dev] bugs

[Keith W. <ke...@va...>]

Brian Paul wrote:
> 
> "Jacob (=Jouk) Jansen" wrote:
> >
> > Hi all,
> >
> > Since some time (around the same time all the software rastering was put
> > in separate directories) I observe the following 2 problems which may or may
> > not be related:
> >    To test I use the program xlockmore (see ftp://ftp.tux.org./pub/tux/bagleyd/xlockmore/
> >
> >  problems :
> >     -in mode moebius a part of the edge is not drawn resulting in a zig-zag
> >       line. Mesa3.4 draws it correct
> 
> This looks like a glPolygonMode() bug.  The interior edges in the quad
> strip shouldn't be rendered.  Keith could probably find this pretty
> quickly.

I'm reworking the edgeflag/polygon-mode code to be transparent and robust. 
Don't bother too much about bugs in the existing code.

Keith