Opened 21 years ago

Closed 21 years ago

Last modified 5 years ago

#615 closed defect (wontfix)

OSX: fullscreen mode VBL sync

Reported by: SF/arekkusu Owned by: fingolfin
Priority: normal Component: Port: Mac OS X
Version: Keywords:
Cc: Game:


ScummVM 0.3.0b Built on Dec 6 2002 12:15:06 English CD-talkie, Mac OSX

There is annoying tearing in fullscreen mode in OS X. SDL_GL should be syncing the context swaps to VBL.

Windows mode is okay since all window swaps are synced to VBL under OS X.

Ticket imported from: #650423. Ticket imported from: bugs/615.

Change History (7)

comment:1 by fingolfin, 21 years ago

As you noticed yourself, "SDL_GL should be syncing". Go and file a bugreport with SDL, please.

comment:2 by fingolfin, 21 years ago

Owner: set to fingolfin
Resolution: wontfix
Status: newclosed

comment:3 by SF/arekkusu, 21 years ago


libsdl doesn't appear to have a bug forum, so I asked on their mailing list. It appears that you can easily work around this with a few lines of platform-specific code:

Subject: Re: [SDL] OSX: fullscreen openGL vbl syncing? From: Andrew Straw <> To: Reply-To:

Give this a try. I think you need the Cocoa headers included.

CGLContextObj context; long params[] = {1};

context = CGLGetCurrentContext(); CGLSetParameter(context, kCGLCPSwapInterval, params);

On Tuesday, December 17, 2002, at 03:23 PM, arekkusu wrote:

I have a question about SDL's behavior on OSX. Apologies if this is a known issue... I can't see any bug reporting forum on the site... perhaps Max Horn / Darrell Walisser can clue me in??

Under Mac OS X, when creating a full screen double buffered context using openGL (for filtering and aspect scaling of 2D content, in my case) does SDL provide VBL synchronization?

I know that AGL can do what I want, but looking at SDL_dspvideo.c it appears DrawSprocket is being used and I am unsure how well this is supported on OS X. Also looking at some games that use SDL (GLTron, ScummVM) there is very apparent tearing in fullscreen mode.

comment:4 by SF/arekkusu, 21 years ago

Status: closednew

comment:5 by fingolfin, 21 years ago

Bo, I do not consider putting this into ScummVM, even assuming it works (I didn't try that code you pasted; it may or may not work). The GL mode in ScummVM is not really supported. I can not recommend to anybody to use it, simply because it looks extremly ugly due to the inferior scaler used (bilinear as opposed to the special scalers used in the normal ScummVM backend).

Note that I am the "Max Horn" refered to in your email <g>.

comment:6 by fingolfin, 21 years ago

Status: newclosed

comment:7 by digitall, 5 years ago

Component: --Unset--Port: Mac OS X
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