mesa3d-users

Re: [Mesa3d-users] silly question :-)

[Dmitry S. <sin...@ac...>]

Wolfram Wiesemann wrote:
> sorry to dizz you with this - for you maybe - silly question, but I need to know how to use Mesa in fullscreen mode. I haven't seen any example program dealing with this problem so I would be pleased if somebody could tell.
> thank you.
I think you must look at this page: http://www.devolution.com/~slouken/SDL/.
Good luck.

[Mesa3d-users] silly question :-)

[Wolfram W. <wie...@we...>]

sorry to dizz you with this - for you maybe - silly question, but I need to know how to use Mesa in fullscreen mode. I haven't seen any example program dealing with this problem so I would be pleased if somebody could tell.
thank you.
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Re: [Mesa3d-users] Shimmering Problems with Large Textured Polygon.

[Stephen J B. <sj...@ht...>]

On Tue, 25 Apr 2000 sh...@pl... wrote:

> I posted this message a couple of weeks ago in comp.graphics.api.opengl,
> but only got one barely relevant response. 
 
I've given up reading that news group - it's a mess.

> In a simulation that I'm developing, the ground is a very large polygon
> that's textured using a series of Mipmaps generated from a 64 X 64 rgb
> image using gluBuild2dMipmaps(). Both GL_WRAP_T and GL_WRAP_S are set to
> GL_REPEAT.
> 
>  The problem is that as the "eye" moves, the ground appears to be very shaky,
>  almost as if looking down on a large tray with thousands of wriggling worms.
 
>   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
>   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL,  5);

This is OK - but is there any special reason for doing this?  For a
64x64 map, it isn't necessary.  Is it possible that you may be cutting
off some of the lower level MIPmaps elsewhere in the code?  That would
certainly make the texture aliasing much worse.

>    glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_NEAREST );

       So it looks like you are seeing aliasing due to this ^^^^^^^^^^^^^^^^^^^^^^^^^

 Try GL_LINEAR_MIPMAP_LINEAR

> Yes, I'm aware that with the LINEAR_MIPMAP_LINEAR option, I can reduce the
> shimmering effect, but it slows down the simulation considerably.
 
Well, you get what you pay for!

With most modern hardware, there is no additional penalty for GL_LINEAR* over
GL_NEAREST* - but if you are rendering in software, you are screwed - the
extra load in reading 8 times the number of pixels and doing trilinear
interpolation is gonna hurt.

You could try GL_LINEAR_MIPMAP_NEAREST - that should be faster (with a software
only renderer) because it only has to read 4 times the number of pixels and
do bilinear blending. The crawling artifact should still be improved - although
you'll see abrupt changes in MIPmap level still.

>  Any suggestions and fixes would be deeply appreciated and gratefully acknowledged in the
>  (non-commercial) application that I'm trying to develop.
 
Well, you are seeing aliasing - and that's inevitable without doing some
filtering - which is what GL_LINEAR* does for you.

If you absolutely cannot do any better then go to a higher resolution map - but
filter it heavily in your paint program. Also try to keep the contrast in the map
as low as possible and avoid high frequency information.

Steve Baker                      (817)619-2657 (Vox/Vox-Mail)
L3Com/Link Simulation & Training (817)619-2466 (Fax)
Work: sj...@ht...            http://www.hti.com
Home: sjb...@ai...       http://web2.airmail.net/sjbaker1

[Mesa3d-users] Shimmering Problems with Large Textured Polygon.

[<sh...@pl...>]

I posted this message a couple of weeks ago in comp.graphics.api.opengl, but only got one barely relevant response. 

So, if anyone here would like to give it a shot,l I'd be very grateful.

_________________________________________
In a simulation that I'm developing, the ground is a very large polygon
that's textured using a series of Mipmaps generated from a 64 X 64 rgb
image using gluBuild2dMipmaps(). Both GL_WRAP_T and GL_WRAP_S are set to
GL_REPEAT.

 The problem is that as the "eye" moves, the ground appears to be very shaky,
 almost as if looking down on a large tray with thousands of wriggling worms.

 The sequence of operations is as follows:

 First, I generate the texture with :
 /*__________________________________________________________*/
 static void initex( void )
 { GLboolean verdad;

   glDisable( GL_DITHER );
   glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL );
   glHint( GL_PERSPECTIVE_CORRECTION_HINT, GL_FASTEST );
   glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

   glGenTextures( Ntex, TexObj ); /* Texture Object IDs */

 /* Ground is TexObj[0] */

   glBindTexture( GL_TEXTURE_2D, TexObj[0] );
   verdad=LoadRGBMipmaps(ImageFile[0],GL_RGB); /* Load Mipmaps */
   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL,  5);
   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_NEAREST );
   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT ); }
 /*_____________________________________________________________*/

 Then I bind the texture to the ground, broken up into a 100 sub-quads
 according to:
 /*_____________________________________________________________*/
   Depth=50000.0;
   Npatches=10;
   TerraFirma = glGenLists(1);
   Patch=Depth/(GLfloat)Npatches;
   glNewList(TerraFirma, GL_COMPILE);
   glBindTexture( GL_TEXTURE_2D, TexObj[0] );
   glEnable(GL_CLAMP_TO_EDGE);
   for(x=-Depth;x<Depth;x+=Patch){
   for(z=-Depth;z<Depth;z+=Patch){
   glBegin(GL_QUADS);
   glTexCoord2f( 0.0, 0.0 );  glVertex3f(x,0.0,z);
   glTexCoord2f( 1.0, 0.0 );  glVertex3f(x+Patch,0.0,z);
   glTexCoord2f( 1.0, 1.0 );  glVertex3f(x+Patch,0.0, z+Patch);
   glTexCoord2f( 0.0, 1.0 );  glVertex3f(x,0.0, z+Patch);
   glEnd();}}
   glEndList();
 /*_____________________________________________________________*/

 Finally, I render the ground with
 /*_____________________________________________________________*/
 glPushMatrix();
         glEnable(GL_TEXTURE_2D);
         glCallList(TerraFirma);
         glDisable(GL_TEXTURE_2D);
 glPopMatrix();
 /*_____________________________________________________________*/

Yes, I'm aware that with the LINEAR_MIPMAP_LINEAR option, I can reduce the
shimmering effect, but it slows down the simulation considerably.

 I've deleted what I believe to be the other non-pertinent lines of code.

 As I said above, the ground looks like its a very large tray of          
 wriggling worms.

 If I use just one large polygon for the ground and bind the texture to it, the wriggling
 is marginally reduced, but the texture image is very coarse.

 I've also tried using 128 x 128, 256 x 256 and 512 x 512 rgb images for the ground texture,
 but that dosent really solve the problem.

 Any suggestions and fixes would be deeply appreciated and gratefully acknowledged in the
 (non-commercial) application that I'm trying to develop.

 thanks                                                   
 -Sharat



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[Mesa3d-users] Mesa 3.2 released

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

I've released Mesa 3.2.  You can download it from
http://sourceforge.net/project/filelist.php?group_id=3

or

ftp://ftp.mesa3d.org/mesa/

Here's what's new since the 3.2 beta release:

    Bug fixes:
	- fixed memcpy bugs in span.c
	- fixed missing glEnd problem in demos/tessdemo.c
	- fixed bug when clearing 24bpp Ximages
	- fixed clipping problem found in Unreal Tournament
	- fixed Loki's "ice bug" and "crazy triangles" seen in Heretic2
	- fixed Loki's 3dfx RGB vs BGR bug
	- fixed Loki's 3dfx smooth/flat shading bug in SoF
    Changes:
	- updated docs/README file
	- use bcopy() optimizations on FreeBSD
	- re-enabled the optimized persp_textured_triangle() function


-Brian

Re: [Mesa3d-users] problems compiling Mesa..... please help.

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

Lock Heed wrote:
> 
> I'm trying to build for linux-glide.  I have the glide drivers installed
> propely, and i've updated mklib.gilde to point to the correct files, but
> when i try to make linux-glide, i get the following errors:  for every
> function (i.e., blend alpha texture) i get
> blend.c:586:warning: passing arg 5 from incompatable pointer type.

Which version of Mesa?  Can you include the exact warnings?

-Brian

[Mesa3d-users] problems compiling Mesa..... please help.

[Lock H. <loc...@ho...>]

I'm trying to build for linux-glide.  I have the glide drivers installed 
propely, and i've updated mklib.gilde to point to the correct files, but 
when i try to make linux-glide, i get the following errors:  for every 
function (i.e., blend alpha texture) i get
blend.c:586:warning: passing arg 5 from incompatable pointer type.

i get that for every function.  please help.
loc...@ho...
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Re: [Mesa3d-users] Mesa/OGL extensions

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

Antonio Campos wrote:
> 
> Hello,
> where can I find documentation for the OpenGl/Mesa 1.2 extensions?

http://oss.sgi.com/projects/ogl-sample/registry/

-Brian

[Mesa3d-users] Mesa/OGL extensions

[Antonio C. <ac...@ex...>]

Hello,
where can I find documentation for the OpenGl/Mesa 1.2 extensions?

Re: [Mesa3d-users] Where or where have my polygons gone?

[Evan M. C. <le...@ca...>]

Aaron Joen wrote:

> How about trying this,
>
> before you render the map, scale up the size of your polygons by a factor
> large enough such that it will be displayed, you will know the size to scale
> from the smallest value in your dataset...
>
> Aaron

Thanks for the suggestion.

In my application I have to render terrain data from a radar simulation.  The
data from the radar is continually dumped into a 2d array of return values.
This 2d array of values is used to shade a set of polygons that are of fixed
shape.  The smallest being within the first 10% or so of the apex of the radial
scan.  Regardless of the range of terrain I'm presenting all the polygons have
a fixed relation to the size of the window (I.E. the number of elements in a
row to the number of pixels horizontally or vertically across the drawing
area).

My ortho projection changes with the range of the radar's data (in feet) and
the polygons are scaled to fit the resultant ortho projection.

Bottom line is whether I'm rendering 40, 80, or 160 nm of return data the same
set of polygons close to the apex of the scan will always be used and they will
always be small and they must always be drawn.

I've been playing with the predicate (area * area < .0025):

a (area * area <= 0)  embarrassingly incorrect; won't ever be negative...dooh
b (area <= 0 )  not good; after thinking about it it becomes obvious why it was
being squared...duh
c (area * area < .0001)  not enough
d (area == 0)  works fine for my combination of OS and hardware but there is
the nagging concern about dividing by a very small number.
e (area * area < .000000001) this value was not found experimentally, just
picked; it seems to work so I'll stick with it for now.

Since "d" wasn't giving me problems I'm sure e won't either.

Anyway, for the record "d" works on my Linux v2.2.12 box (and a v2.0.36 box for
that matter).  I've nominated "a" for Steve Baker's "Cruel Code" page but he
hasn't replied yet.  Admittedly it isn't in any official piece of released
code.  Only my edited copy of one and only for a short time.

Thanks for the help guys,

--
//  Evan M. Carey                       Camber Corp.
//  ev...@ca...                   4885 Alpha Road, Suite 110
//  972-991-5322 x145                   Dallas, TX  75244-4633
//  972-991-5352 fax.                   www.cambertx.com

Re: [Mesa3d-users] Where or where have my polygons gone?

[Aaron J. <jaj...@ho...>]

How about trying this,

before you render the map, scale up the size of your polygons by a factor 
large enough such that it will be displayed, you will know the size to scale 
from the smallest value in your dataset...



Aaron

>
>On Wed, 12 Apr 2000, Evan M. Carey wrote:
>
> > I'm making a 2D map.  Some of the polygons in this map are very very
> > small.  It appears that if a polygon is sufficiently small Mesa throws
> > it out.  I've got sections of my map which are always going to be
> > composed of _lots_ of little polygons and when they are not rendered I
> > end up with a big hole in the map.  If I change my orthographic
> > projection to look closer in at the hole I see that the geometry for the
> > polygons is valid cause they'll show up at close inspection.
>
>I agree that Mesa should not throw out polygons no matter how
>small - for precisely the reason you say...and the OpenGL specification
>does not permit such a thing to be done.  However, I'm pretty sure I
>heard of such an "optimisation" being added to Mesa (and I protested at
>the time).


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Re: [Mesa3d-users] Where or where have my polygons gone?

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

"Evan M. Carey" wrote:
> 
> Brian Paul wrote:
> 
> >       if (area * bf < 0 || area * area < .0025)
> >          return;
> >
> > Try replacing the .0025 with a smaller value, or zero.
> >
> > -Brian
> 
> Brian,
> 
> I made the predicate like so:
> 
>     if (area * bf < 0 || area * area <= 0)
>         return;
> 
> I realize there might still be problems with excessively small areas but for my
> app this seems to work OK...so far.  Thanks for the reply.  I _really_
> appreciate the quick solution.  If I do end up having problems I know where to
> go to play with the limit.

Great.

Understand that I'm still hesitant to put this change into Mesa
by default.  I distinctly remember problems with FP over/underflow
and tiny triangles.  I don't have time right now to reexamine this
problem in any detail now.

-Brian

Re: [Mesa3d-users] Linking

[Stephen J B. <sj...@ht...>]

On Thu, 13 Apr 2000, Filipe Bonjour wrote:

> Dear Steve and Mesa users,
> 
> > It's unfortunate that Mesa sometimes gets dumped into /usr/X11R6/lib,
> > instead of /usr/lib where is belongs.  The simplest, most pragmatic
> > solution is:
> 
> Wel, if you want to install it the wasy way like me, with RPMs,
> apparently you have to face the consequences!
> 
> In any case that wasn't the problem. The problem (thanks physic) was
> that the RPM didn't create a file libGL.so, but only files
> libGL.so.version (such as libGL.so.1.2.0). So I just created a link
> libGL.so to libGL.so.1.2.0 and it linked.
 
You'll find there are still some programs out there that won't link.


Steve Baker                      (817)619-2657 (Vox/Vox-Mail)
L3Com/Link Simulation & Training (817)619-2466 (Fax)
Work: sj...@ht...            http://www.hti.com
Home: sjb...@ai...       http://web2.airmail.net/sjbaker1

Re: [Mesa3d-users] Linking

[Filipe B. <bo...@im...>]

Dear Steve and Mesa users,

> It's unfortunate that Mesa sometimes gets dumped into /usr/X11R6/lib,
> instead of /usr/lib where is belongs.  The simplest, most pragmatic
> solution is:

Wel, if you want to install it the wasy way like me, with RPMs,
apparently you have to face the consequences!

In any case that wasn't the problem. The problem (thanks physic) was
that the RPM didn't create a file libGL.so, but only files
libGL.so.version (such as libGL.so.1.2.0). So I just created a link
libGL.so to libGL.so.1.2.0 and it linked.

Thanks for the help,

Fil

+-----------------------------------------------------------------------+
| Fil Bonjour                      | Home address:                      |
| UNICAMP, IMECC, DMA - Room 328   | Rua Alberto de Salvo 53            |
| 13081-970 Campinas SP Brazil     | 13084-290 Campinas SP Brazil       |
| Phone: (++55.19) 788.60.44       | Phone: (+55.19) 289.77.84          |
| Fax:   (++55.19) 289.14.66       |                                    |
| Email: bo...@im...    | Email: fbo...@uo...         |
| http://ime.unicamp.br/~bonjour   | http://sites.uol.com.br/fbonjour   |
+-----------------------------------------------------------------------+

Re: [Mesa3d-users] Linking

[Stephen J B. <sj...@ht...>]

On Thu, 13 Apr 2000, Filipe Bonjour wrote:

> I have just installed Mesa 3.1-2 on my Linux Redhat 6.1 and I can't
> compile any of my old OpenGL programs. (I used OpenGL on Sun computers,
> and I have never used Mesa under Linux.) The problen is in the linking
> stage, actually. I installed the RPM file, didn't compile the library
> myself, so maybe I didn't do something crucial.
> 
> The directory /usr/X11R6/lib contains, apart the non-GL stuff, the
> libraries/files
> 
> libGL.la	libGL.so.1	libGL.so.1.0	libGL.so.1.2.0
> libGLU.la	libGLU.so.1	libGLU.so.1.2.0	libGLU.so.3
> libGLU.so.3.1.2	libglut.la	libglut.so.3	libglut.so.3.7
> libglut.so.3.7.0
> 
> Although I include -L/usr/X11R6/lib in my compile-line I get the
> message:
> 
> /usr/bin/ld: cannot open -lGL: No such file or directory
> collect2: ld returned 1 exit status
> make: *** [visu_3D] Error 1
 
It's unfortunate that Mesa sometimes gets dumped into /usr/X11R6/lib,
instead of /usr/lib where is belongs.  The simplest, most pragmatic
solution is:

  ln -s /usr/X11R6/lib/libGL.so.1 /usr/lib/libGL.so
  ln -s /usr/X11R6/lib/libGLU.so.1 /usr/lib/libGLU.so
  ln -s /usr/X11R6/lib/libglut.so.3 /usr/lib/libglut.so

...which is where Mesa is *supposed* to install.

Steve Baker                      (817)619-2657 (Vox/Vox-Mail)
L3Com/Link Simulation & Training (817)619-2466 (Fax)
Work: sj...@ht...            http://www.hti.com
Home: sjb...@ai...       http://web2.airmail.net/sjbaker1

Re: [Mesa3d-users] Where or where have my polygons gone?

[Evan M. C. <le...@ca...>]

Stephen J Baker wrote:

> On Thu, 13 Apr 2000, Evan M. Carey wrote:
>
> > I made the predicate like so:
> >
> >     if (area * bf < 0 || area * area <= 0)
>                            ^^^^^^^^^^^^^^^^
>                           A number times itself can't be
>                           less than zero, so '== 0' might
>                           be better...then you might as
>                           well save the multiply and go
>                           with 'area==0'.
>
> Steve Baker                      (817)619-2657 (Vox/Vox-Mail)
> L3Com/Link Simulation & Training (817)619-2466 (Fax)
> Work: sj...@ht...           http://www.hti.com
> Home: sjb...@ai...       http://web2.airmail.net/sjbaker1

Duh.  What was i thinking.  Your right.  Save that one for you stupid
code page Steve.

--
//  Evan M. Carey                       Camber Corp.
//  ev...@ca...                   4885 Alpha Road, Suite 110
//  972-991-5322 x145                   Dallas, TX  75244-4633
//  972-991-5352 fax.                   www.cambertx.com

Re: [Mesa3d-users] Where or where have my polygons gone?

[Stephen J B. <sj...@ht...>]

On Thu, 13 Apr 2000, Evan M. Carey wrote:

> I made the predicate like so:
> 
>     if (area * bf < 0 || area * area <= 0)
                           ^^^^^^^^^^^^^^^^
                          A number times itself can't be
                          less than zero, so '== 0' might
                          be better...then you might as
                          well save the multiply and go
                          with 'area==0'.

Steve Baker                      (817)619-2657 (Vox/Vox-Mail)
L3Com/Link Simulation & Training (817)619-2466 (Fax)
Work: sj...@ht...            http://www.hti.com
Home: sjb...@ai...       http://web2.airmail.net/sjbaker1

Re: [Mesa3d-users] Linking

[physic <ph...@te...>]

> The directory /usr/X11R6/lib contains, apart the non-GL stuff, the
> libraries/files

To link to mesa the you need the command that looks something like this:
  -L/usr/X11R6/lib -lGL

which presumably you have.  It's possible that the rpm installed your
libs elsewhere.  In particular, they are suppsoed to go in /usr/lib.
So the first thing is to check to make sure that libGL.so.whatever
actually points to a real lib.  They should all be symbolic links to
libGL.so.1.2.0 I think.  Next, make sure there aren't other libGL.so
links laying aroung that your link might pick up first.  If that
doesnt work, give us more information.  Like the actual link command
and an 'ls -l' of libGL.so and whatever it links too.  Be doublely sure
about not having multiple versions around.  That tends to bite alot of
people.

> So ld doesn't find the libGL file. I suspect it's because it looks for
> an archive file (presumably libGL.a) which doesn't exist.

It should actually want libGL.so

> Fil

--physic
ph...@te...

[Mesa3d-users] Linking

[Filipe B. <bo...@im...>]

Hi,

I have just installed Mesa 3.1-2 on my Linux Redhat 6.1 and I can't
compile any of my old OpenGL programs. (I used OpenGL on Sun computers,
and I have never used Mesa under Linux.) The problen is in the linking
stage, actually. I installed the RPM file, didn't compile the library
myself, so maybe I didn't do something crucial.

The directory /usr/X11R6/lib contains, apart the non-GL stuff, the
libraries/files

libGL.la	libGL.so.1	libGL.so.1.0	libGL.so.1.2.0
libGLU.la	libGLU.so.1	libGLU.so.1.2.0	libGLU.so.3
libGLU.so.3.1.2	libglut.la	libglut.so.3	libglut.so.3.7
libglut.so.3.7.0

Although I include -L/usr/X11R6/lib in my compile-line I get the
message:

/usr/bin/ld: cannot open -lGL: No such file or directory
collect2: ld returned 1 exit status
make: *** [visu_3D] Error 1

So ld doesn't find the libGL file. I suspect it's because it looks for
an archive file (presumably libGL.a) which doesn't exist.

Reading the README files from the Mesa WWW page, I tried (as root) to
run "ldconfig -v" but that didn't solve it. I restarted Linux with no
more success.

Can anyone tell me how I can compile my programs? Do I have to create
the archive with ar? Is there some compile-lne option I forgot?

Thanks,

Fil

+-----------------------------------------------------------------------+
| Fil Bonjour                      | Home address:                      |
| UNICAMP, IMECC, DMA - Room 328   | Rua Alberto de Salvo 53            |
| 13081-970 Campinas SP Brazil     | 13084-290 Campinas SP Brazil       |
| Phone: (++55.19) 788.60.44       | Phone: (+55.19) 289.77.84          |
| Fax:   (++55.19) 289.14.66       |                                    |
| Email: bo...@im...    | Email: fbo...@uo...         |
| http://ime.unicamp.br/~bonjour   | http://sites.uol.com.br/fbonjour   |
+-----------------------------------------------------------------------+

Re: [Mesa3d-users] Where or where have my polygons gone?

[Evan M. C. <le...@ca...>]

Brian Paul wrote:

>       if (area * bf < 0 || area * area < .0025)
>          return;
>
> Try replacing the .0025 with a smaller value, or zero.
>
> -Brian

Brian,

I made the predicate like so:

    if (area * bf < 0 || area * area <= 0)
        return;

I realize there might still be problems with excessively small areas but for my
app this seems to work OK...so far.  Thanks for the reply.  I _really_
appreciate the quick solution.  If I do end up having problems I know where to
go to play with the limit.

Thanks,

--
//  Evan M. Carey                       Camber Corp.
//  ev...@ca...                   4885 Alpha Road, Suite 110
//  972-991-5322 x145                   Dallas, TX  75244-4633
//  972-991-5352 fax.                   www.cambertx.com

[Mesa3d-users] Mesa-3.2 demos building

[DAANEN V. <VD...@CH...>]

Hi, 
I compiled mesa-3.2 with mingw32 compiler. When I try to buid some demos
examples ( eg : isosurf.c ) this what I get ?

	D:\Mesa-3.2\demos>gcc -o isosurf.exe isosurf.c -lglut -lglut32
-lglu32 -lopengl32
	isosurf.c:99: warning: `CLIP_MASK' redefined
	
D:\IDE\MINGW32\BIN\..\lib\gcc-lib\i386-mingw32\2.95.2\..\..\..\..\include\wi
ngdi.h:343: warning: this is the location of the 	previous definition
	C:\TEMP\ccP48Xfb.o(.text+0x18de):isosurf.c: undefined reference to
`glDrawArraysEXT'
	C:\TEMP\ccP48Xfb.o(.text+0x253c):isosurf.c: undefined reference to
`glVertexPointerEXT'
	C:\TEMP\ccP48Xfb.o(.text+0x2556):isosurf.c: undefined reference to
`glNormalPointerEXT'
	C:\TEMP\ccP48Xfb.o(.text+0x2578):isosurf.c: undefined reference to
`glVertexPointerEXT'
	C:\TEMP\ccP48Xfb.o(.text+0x2592):isosurf.c: undefined reference to
`glNormalPointerEXT'

	Which library (libraries) should I link with to 'find' references to
those 3 gl? functions ?

Re: [Mesa3d-users] Where or where have my polygons gone?

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

Stephen J Baker wrote:
> 
> On Wed, 12 Apr 2000, Evan M. Carey wrote:
> 
> > I'm making a 2D map.  Some of the polygons in this map are very very
> > small.  It appears that if a polygon is sufficiently small Mesa throws
> > it out.  I've got sections of my map which are always going to be
> > composed of _lots_ of little polygons and when they are not rendered I
> > end up with a big hole in the map.  If I change my orthographic
> > projection to look closer in at the hole I see that the geometry for the
> > polygons is valid cause they'll show up at close inspection.
> 
> I agree that Mesa should not throw out polygons no matter how
> small - for precisely the reason you say...and the OpenGL specification
> does not permit such a thing to be done.  However, I'm pretty sure I
> heard of such an "optimisation" being added to Mesa (and I protested at
> the time).

There was a problem with FP over/underflow when rendering very small
triangles.  It wasn't an optimization.

Evan, in src/tritemp.h you can try changing the area test for small
triangles and see what happens.  The code in question is:

      if (area * bf < 0 || area * area < .0025)
	 return;

Try replacing the .0025 with a smaller value, or zero.

-Brian

Re: [Mesa3d-users] Where or where have my polygons gone?

[Stephen J B. <sj...@ht...>]

On Wed, 12 Apr 2000, Evan M. Carey wrote:

> I'm making a 2D map.  Some of the polygons in this map are very very
> small.  It appears that if a polygon is sufficiently small Mesa throws
> it out.  I've got sections of my map which are always going to be
> composed of _lots_ of little polygons and when they are not rendered I
> end up with a big hole in the map.  If I change my orthographic
> projection to look closer in at the hole I see that the geometry for the
> polygons is valid cause they'll show up at close inspection.
 
I agree that Mesa should not throw out polygons no matter how
small - for precisely the reason you say...and the OpenGL specification
does not permit such a thing to be done.  However, I'm pretty sure I
heard of such an "optimisation" being added to Mesa (and I protested at
the time).

Steve Baker                      (817)619-2657 (Vox/Vox-Mail)
L3Com/Link Simulation & Training (817)619-2466 (Fax)
Work: sj...@ht...            http://www.hti.com
Home: sjb...@ai...       http://web2.airmail.net/sjbaker1

[Mesa3d-users] Oops sorry: My New Site

[Aaron J. <jaj...@ho...>]

Silly me, left out the address

http://home1.pacific.net.sg/~gishsh05/



Aaron
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com

[Mesa3d-users] Where or where have my polygons gone?

[Evan M. C. <le...@ca...>]

I tried looking in the archives and the FAQ but didn't find an answer to
my question so forgive me if this has been answered already.

I'm making a 2D map.  Some of the polygons in this map are very very
small.  It appears that if a polygon is sufficiently small Mesa throws
it out.  I've got sections of my map which are always going to be
composed of _lots_ of little polygons and when they are not rendered I
end up with a big hole in the map.  If I change my orthographic
projection to look closer in at the hole I see that the geometry for the
polygons is valid cause they'll show up at close inspection.

In my application I don't mind that while rendering these small polygons
that the pixel used to represent them will be repeatedly updated until
I've scanned over far enough to start in on a new pixel.  I.E. last
polygon rendered gets it.  That's actually desirable for my domain.

Any suggestions?

Thanks in advance!

--
//  Evan M. Carey                       Camber Corp.
//  ev...@ca...                   4885 Alpha Road, Suite 110
//  972-991-5322 x145                   Dallas, TX  75244-4633
//  972-991-5352 fax.                   www.cambertx.com