GWorld is a Apple 1986? technology for defining a bitmap and characteristics. The bytes can exist either in RAM or VRAM (depends). 
Technically it's been replaced by a BitMap Graphics Context, but every mcintosh app written since the 1984 worked with gworlds, 

Mmm ok well mm it HAS been nearly 5 years since I wrote all that, in checking I see that I *cheat* and take the GWorld pointer from QuickTime and 
register it via stQuicktimeSetSurfacewidthheightrowBytesdepthmovie  as the bitmap for the Surface Plugin api. Therefore for macintosh we have quicktime actually write bits into the bitmap that is registered  with the surface plugin. 

The downside is that for the windows platform (anyone want to build the quicktimeplugin?) it somewhere must copy the bits out of the gworld bitmap 
back into a Squeak Form bitmap oops via a memory copy all of some sort. This means moving MB of data every frame that we don't do on the macintosh. 


On 2010-12-29, at 3:52 PM, Chris Cunnington wrote:

> Thanks for that rundown, John.
> It definitely uses GWorld. For sure:
> 
> SophieQuickTimeMovieViaPlugin>>gWorldPtr
> SophieQuickTimeInterface>>setGWorldPtrOntoSurface:width:height:rowBytes:depth:movie:
> 
> I guess you're saying that's somewhat different than the SurfacePlugin.
> Cool stuff.
> 
> Chris
> 
> 

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