In article <chr### [at] netplexaussieorg> , 
Christopher James Huff <chr### [at] maccom>  wrote:

> I thought the PICT limit was 32768x32768...maybe I'm thinking of the
> QuickDraw API.

The limit is of Picts is that of PixMaps.  To be precise, the rowbytes field
uses a few of the upper bits to store other information.  This design
problem dates back to System 1 and the original QuickDraw.  While it is
fixed in Mac OS 9 and later, it has never been documented by Apple how to
access the 32 bit rowbyte field.  And the Pict image format would not be
able to handle it either.

So, while QuickDraw can handle 32k*32k pixels, one cannot create a single
bitmap of such a big image.  For this this reason since POV-Ray 3.1 Mac the
preview is split into tiles, which works around the problem to some extend.
However, doing the same for rendering to Pict images would require enormous
amounts of memory and such Pict images would not be supported by all
applications (also in theory it would be possible to create such a Pict
image) or System 7.x and earlier.

    Thorsten

____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

Visit POV-Ray on the web: http://mac.povray.org

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