[Re: PICT format]

Joseph J. Strout jstrout at ucsd.edu
Thu Sep 18 22:58:25 EST 1997


In article <341E7F51.4A36 at ibsm.cnrs-mrs.fr>, athel at ir2cbm.cnrs-mrs.fr wrote:

>I didn't realize when I asked the question that this
>was a vector format, in fact I still find it rather puzzling, given that
>my scanner software seems to like writing in PICT and it's not obvious
>to me that what a scnner sees is vectorial.

PICT stores pixel maps *as well as* vector information.  Basically, it
stores any series of QuickDraw commands, including the drawing of lines,
ovals, polygons, and yes, CopyBits on pixel maps.

>even the PICT file must be pretty
>bloated given that expressing a bit map as vectors presumably means
>storing the instructions for drawing 10000 lines of zero length.

Nope, if you're using the CopyBits call, then it's just thaht one call,
plus a big stream of data -- a compact (though not compressed) format.

>(In
>case you're wondering, yes, that's how I draw a pixel in Quickdraw:
>MoveTo(x,y); LineTo(x,y);  It's obviously inefficient, but it works).

Ack -- the standard method is to directly stuff the pixel map of an
offscreen GWorld, then copy this GWorld to the screen.  But whatever works
for you...

,------------------------------------------------------------------.
|    Joseph J. Strout           Department of Neuroscience, UCSD   |
|    jstrout at ucsd.edu           http://www-acs.ucsd.edu/~jstrout/  |
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