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OpenGL gvbam graphics corruption on load scaled

Posted: Mon Oct 20, 2008 11:09 pm
by nathan

Hi,

 

I'm running gvbam svn 773 on Linux/KDE. I set the default window size to x4. When I load an image, the graphics are all corrupted (glitched.png) [attachment=110].

 

When I go to the Video menu and select a different size, then go back to x4, the graphics are magically better (good.png) [attachment=111].

 

This goes away when I select Cairo instead of ogl. However, I prefer ogl graphics. I have an ATI radeon graphics card. lspci reports it as "01:00.0 VGA compatible controller: ATI Technologies Inc Device 9442".

 

Thanks.


OpenGL gvbam graphics corruption on load scaled

Posted: Tue Oct 21, 2008 12:07 am
by Squall Leonhart

I have an ATI radeon graphics card. lspci reports it as "01:00.0 VGA compatible controller: ATI Technologies Inc Device 9442".

 

Theres your problem.


OpenGL gvbam graphics corruption on load scaled

Posted: Tue Oct 21, 2008 3:21 am
by spacy51

Ehm... your screenshot shows that you use a pirated ROM :angel:

 

I recommend checking your ROMs with the no-intro datset.


OpenGL gvbam graphics corruption on load scaled

Posted: Tue Oct 21, 2008 8:34 am
by nathan

Theres your problem.

 

Elaborate further?

 

Ehm... your screenshot shows that you use a pirated ROM

I don't have the equipment to dump ROMs myself; ethically, I don't have a problem with downloading someone else's dump for games I already own. I apologize if I violated board policy by pasting this screenshot.

 

I also see this behavior on clean dumps of other images.


OpenGL gvbam graphics corruption on load scaled

Posted: Tue Oct 21, 2008 3:05 pm
by Squall Leonhart

ATI graphics chips are bad at opengl, even worse is that they are worse under Linux.

 

anyway, as we are hosted off of ngemu, we take on their no piracy, no warez rules.


OpenGL gvbam graphics corruption on load scaled

Posted: Tue Oct 21, 2008 8:15 pm
by nathan

Well, there's a difference between being bad at OpenGL and displaying a corrupted screen. I used VBA under Windows for years with no graphical corruption and an ATI Radeon 9800 Pro.


OpenGL gvbam graphics corruption on load scaled

Posted: Tue Oct 21, 2008 8:40 pm
by KunaiTeam

Just to be clear on this, and after looking at the OpenGL code, there is no bug that should cause this to happen in the VBA-M code. As long as this is working on other video cards on Linux, it is definitely a card-specific issue.

 

ATI cards have notoriously poor Linux support. So even if that card works for VBA-M in Windows, there's no guarantee it will work in Linux. No video card manufacturer has perfect Linux support, but You're going to have a much better experience in Linux if you have an Nvidia card (or even an Intel card, though you won't get the same kind of performance as ATI or Nvidia).

 

This is because the ATI drivers on Linux are pretty poor. Both ATI and Nvidia refuse to release the specs for most of their cards because they fear that if they do so, the other company will steal their trade secrets. That means that it has been up to the Linux community to reverse-engineer the cards and write their own drivers. Since it's mostly volunteers doing this, some cards have solid Linux drivers and others don't. Currently the reality is that Nvidia cards tend to have better Linux drivers than ATI cards.


OpenGL gvbam graphics corruption on load scaled

Posted: Wed Oct 22, 2008 1:01 am
by mudlord

anyway, as we are hosted off of ngemu, we take on their no piracy, no warez rules.

 

Correct.