Mode-X 320x240 graphics issues in Q2DOS

[Maraakate]

Recently, we switched our code in Q2DOS to default to 320x240 Mode-X. The reasons were that the original ports expected the game to be in a 4:3 resolution and the canonical resolution was 320x240. In any case, this change worked OK in real DOS, Win9x Dos Box, and in the DOSBox emulator itself.

Someone brought to my attention that it does not work in pcem showing a graphics corruption issue similar to NTVDM.



You can verify the issue by downloading https://bitbucket.org/neozeed/q2dos/dow ... _SWonly.7z and you can check it against our current video code at
https://bitbucket.org/neozeed/q2dos/src ... ?at=master
https://bitbucket.org/neozeed/q2dos/src ... ?at=master

We are using Quake 1's video code for rendering Planar modes and it's possible we may have implemented something incorrectly, but considering it works on real hardware just fine it's rather hard to say.

To test out the resolution go to the video menu and select VGA-X 320x240 (should be sw_mode 1).

[ppgrainbow]

Recently, we switched our code in Q2DOS to default to 320x240 Mode-X. The reasons were that the original ports expected the game to be in a 4:3 resolution and the canonical resolution was 320x240. In any case, this change worked OK in real DOS, Win9x Dos Box, and in the DOSBox emulator itself.

Someone brought to my attention that it does not work in pcem showing a graphics corruption issue similar to NTVDM.



You can verify the issue by downloading https://bitbucket.org/neozeed/q2dos/dow ... _SWonly.7z and you can check it against our current video code at
https://bitbucket.org/neozeed/q2dos/src ... ?at=master
https://bitbucket.org/neozeed/q2dos/src ... ?at=master

We are using Quake 1's video code for rendering Planar modes and it's possible we may have implemented something incorrectly, but considering it works on real hardware just fine it's rather hard to say.

To test out the resolution go to the video menu and select VGA-X 320x240 (should be sw_mode 1).

That doesn't sound so good. I sure hope that it gets fixed.

Maraakate, what emulated video card were you using to try to run Quake II for DOS that does not work properly in VGA-X 320x240 mode?

[leilei]

It seems to work fine for me on ATI Mach64 GX, ATI-18800, ATI-28800 OAK OTI-067 S3 Trio 64, S3 Vision 864, S3 ViRGE, Tseng ET4000/W32p, Tseng ET4000AX,. It even works on the plain VGA



it DOES NOT work on the Trident TGUI9440 and the Trident TVGA8900D (which is what that screenshot seems to represent)

[Maraakate]

I don't know what the video card was the user choose. He reported the issue to us and in turn we reverted back to 320x200 as default startup resolution and I posted the issue here.

I will find out more though.

[leilei]

It might be a bug in Q2DOS as 320x240 ModeX seems to work in Quake on the TGUI9440 and TVGA

[Maraakate]

It's quite possible as the way the video works is slightly different in Quake 2. I am wondering if someone where in the init routines there was some test for some non-compliant cards and they added such things. I saw there was some kind of specific hack in there some ATI cards that didn't report the number of pages properly.

[Maraakate]

Huge necropost, but this issue should now be fixed in Q2DOS. I had problems with it on some real hardware and fixed it there. Let me know if it's still not working.