Thank you for the report.
The code can be improved to work better with external patches, but the existance of those patches is no reason to disable the code.

I'll check with the patches, but VGA_SetOverride() has this:

1			vga.draw.width=0; // change it so the output window gets updated
2			VGA_SetupDrawing(0);

Probably should force update in SDL_SetVideoMode_Wrap() as well? Or maybe GFX_ResetScreen() can force update?

Both gulikoza's glide wrapper and kekko's voodoo1 emulation are so valuable to DOSBox. Both are cross platform compatible, at least I have tested Windows and Linux builds. In fact, both of them can exist at the same time and enabled at the same time in single build. For games that run significantly better with glide wrapper, all I do is to put the wrapper's version of guest GLIDE2X.DLL at the game folder. Oops, that's for Win9x 😊 . For DOS games, such as TR1, I just use the %PATH% env to force which copy of GLIDE2X.OVL I would like the game to see. For slow machines such as thin-and-light laptops (I have AMD C-60 and Celeron 847), glide wrapper really shines.

I am currently maintaining a 2-in-1 clean patch against latest DOSBox SVN. I am eagerly looking forward for these 2 significant enhancements to be accepted into DOSBox mainline. Until they are accepted in the DOSBox mainline, I think devs should seriously consider checking every changes in the mainline code against the two 3Dfx/Glide mechanism.

I don't mean to be pushy, but I really want to know what the devs are still waiting for before committing these 2 changes into mainline code. I can provide the 2-in-1 clean patch to facilitate testing for DOSBox mainline changes.

One more note, with dgVoodoo and DOSBox output=openglnb, TR1 crashed right away on 3Dfx activation on latest SVN with glide pass-through patch. I used to think that this may be incompatibility for Direct3D wrapper rendering into SDL OpenGL surface from DOSBox, but I was wrong. By disabling the SETMODE_SAVES, it works.

The fact that I was looking into this is because voodoo1 emulation requires output=opengl/openglnb to be accelerated. I thought I was only able to make both 3Dfx/Glide mechanism co-exist with OpenGlide. Now, it looks like it was mainly due to the faulty code.