VOGONS


First post, by gaula92

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Hello there

Dosbox for OSX runs great, but it has that annoying tearing effect in demos/games with horizontal scrolling.
Since we have that great SDL/Opengl backend, we could have a tear-free version! You just have to set AGL_SWAP_INTERVAL to 1 on the OpenGL init.

Could the Mac OSX developer add that, please?

Thanks!

[EDIT] should the enviroment variable __GL_SYNC_TO_VBLANK work on Mac OSX? I know it's a nvidia variable for Linux systems, but...what about OSX nvidia drivers? do they use the same enviroment variables as their Linux counterparts?

[EDIT] It seems it's possible to alter some settinsg in NVidia cards under MAC OSX without a control panel. However, we've to hack our way...
From macosxhints:

<quote>
Install Apple's Xcode Developer Tools, and run OpenGL Profiler.app, which you'll find in /Developer -> Applications -> Graphics Tools. Add the application that you would like FSAA in to the top section of OpenGL Profiler. Check Use custom pixel format and press Edit...

Add a kCGLPFASampleBuffer attribute with a value of 1. Then add a kCGLPFASamples attribute with a value of 2 or 4, depending on how much anti-aliasing you want in that app. Consider how much VRAM you have before choosing a higher value. Make sure you launch the chosen app with the Launch button in OpenGL Profiler or this won't work.
</quote>

It's only clear for FSAA: do you guys know about any other kCGL* variable for vsync? kDisableVerticalSyncBit = 0 sounds like should work but it doesn't....

Reply 1 of 1, by rhoenie

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Tried to add it but it didn't work (that doesn't mean much, though - I didn't try hard!).

I then googled a bit and it seems like libSDL 1.2.x for OSX is missing essential code to make it work. 🙁

An old posting of Sam Lantinga was proposing it for 1.3.x:
http://lists.libsdl.org/pipermail/sdl-libsdl. … ary/054407.html