Re: Getting the color of a pixel

[Bryan Brown <bbrown saltmine radix net>]

I was able to do what I needed using the gdk_image* functions, retrieving
only the necessary portions of the drawing area into an image from which
to get the pixel colors.  I then converted the image corrdinates back to
the drawing area coordinates.

Of course, it's vitally necessary to limit the amount of data retrieved
via each call to gdk_image_get because the performance can really suffer
if you overdo it.  As a first cut I tried retrieving the entire drawing
area image with each call, and the resulting performance was
a-g-o-n-i-z-i-n-g-l-y s-l-o-w.  Performace was peppy, however, when I just
retrieved the pieces I actually needed.

Havoc's book was really helpful for this.

Regards,

Bryan


*---------------------------------------------------------------
* Bryan Brown      <*>              bbrown radix net
* http://www.radix.net/~bbrown
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