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Re: Circles in XOR mode [message #10570] Sat, 13 December 1997 00:00
wonko is currently offline  wonko
Messages: 22
Registered: March 1997
Junior Member
mat@thetis.pet.med.ubc.ca (Mat Wilson) wrote:

> I've made circles by generating a set of points for
> each circle and then use the PLOTS function. This
> works fine in regular graphics mode, but in mode 6
> (XOR mode) complete circles are not drawn. It seems
> as though certain pixels are written to twice and
> so do not appear in the final rendering of the
> circle.
>
> My question is, are there any circle-drawing routines
> out there which draw complete circles in XOR mode?

Try using fewer points for the circle. If the vector which you input to
PLOTS contains about as many elements as the circle will have points,
then the lines which PLOTS draws are about two pixels in length. The next
line starts with the second pixel of the first, so this pixel is drawn
twice, and so on.

Alex
--
Alex Schuster Wonko@weird.cologne.de PGP Key available
alex@pet.mpin-koeln.mpg.de
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