[Plib-devel] texture compression

[<tia...@sa...>]

Hello

I was wondering if i or someone else can add texture compression support 
to plib, which i believe can be done without disrupting the current plib 
behaviour and with few files being affected.

Below is my original post to the FlightGear devel list, with a quick 
hack patch.

Currently we're still discussing this, so no further details, but if we 
go ahead with it, is it alright regarding plib?


Thanks

Cheers,
Tiago


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Hello

I'm having a HW problem and i can't enable AGP in linux, which makes the
hunter, b1900d and the Nimitz lower FPSs dramatically, which i believe
is caused by the NVRAM filling up with textures thus forcing texture
transfers to the card (GF4 MX 440 64MB)

so after Surge mentioned texture compression, i added it in plib, with
amazing performance improvements in those situations, It also appears to
be improving FPS in general in other situations.

it doesn't check for the extension, **before trying**, check glxinfo for
the presence of "EXT_texture_compression_s3tc"
it's just an ugly hack, works for me and likely everyone else with s3tc, 
but it's bad code, i know,

a brief explanation: http://www.digit-life.com/articles/reviews3tcfxt1/
spec:
http://oss.sgi.com/projects/ogl-sample/registry/EXT/texture_compression_s3tc.txt


i have no experience with patches, but here it is, against plib
1.8.4,for those interested.
added one line, made one token change:

diff -cr plib-1.8.4/src/ssg/ssgLoadTexture.cxx
plib-1.8.4ext/src/ssg/ssgLoadTexture.cxx
*** plib-1.8.4/src/ssg/ssgLoadTexture.cxx    2003-06-27 08:15:15.000000000
+0000
--- plib-1.8.4ext/src/ssg/ssgLoadTexture.cxx    2006-01-07
16:44:17.000000000 +0000
***************
*** 24,29 ****
--- 24,30 ----

   #include "ssgLocal.h"

+ #define PROXY_TEXTURES_ARE_BROKEN

   struct _ssgTextureFormat
   {
***************
*** 161,167 ****
       total_texels_loaded += w * h ;

       glTexImage2D  ( GL_TEXTURE_2D,
!                      map_level, zsize, w, h, FALSE /* Border */,
                               (zsize==1)?GL_LUMINANCE:
                               (zsize==2)?GL_LUMINANCE_ALPHA:
                               (zsize==3)?GL_RGB:
--- 162,168 ----
       total_texels_loaded += w * h ;

       glTexImage2D  ( GL_TEXTURE_2D,
!                      map_level, /*zsize*/ 0x83F3, w, h, FALSE /*
Border */,
                               (zsize==1)?GL_LUMINANCE:
                               (zsize==2)?GL_LUMINANCE_ALPHA:
                               (zsize==3)?GL_RGB: