I do not know how to modify any OpenGL file, i just searched and collected them for Rage3 based cards, i like ATi RagePro/LT/XL!
1. In OpenGL you just need do use 16bit, not more, 32bit does not work for these cards. Even some D3D games need 16bit only, like Moto Racer.
2. Rage XL has improved bilinear filtering on transparent textures compared to the Rage Pro. Rage XL is A die shrink of the Rage Pro that runs with lower power consumption, higher frequencies and has image quality fixes. Newer Rage XL PCI (4752) cards have compatibility issues for older PCs PCI slots and 3DCIF, Rage XL AGP works well.
3. I do not have played those GL games, but maybe you can try all OpenGL versions out, latest OpenGL 4.12.1107 should have most bug fixes? Rage3 cards are somehow limited, but these are first ATi 3D cards, that you could play 3D games at playable speed, not like S3 Virge or ATi Rage1/2. Rage3 chipset is quite capable. You can use RagePro-Tweaker and disable OpenGL Bi-linear filtering if you like, it speeds up performance and try Rage XL out.
Maybe OpenGL Switcher (for OpenGL) helps:
4. ATi Rage XL has improvements that you may like, it has Fog Table integration. I love my Rage XL 8MB AGP (Compaq), it has also sharper 2D and 3D output quality, better than other RagePro/LT/XL i have. D3D, OpenGL, 3DCIF APIs in Win9x and most DOS games work well, what more you want, oh yes, it can accelerate DVD playback.
Look for: 3.11.3 Function Support Differences between RAGE XL and RAGE PRO
http://old.vgamuseum.info/images/stories/doc/ … tions_dec03.pdf