ghost@aladdin.com (L. Peter Deutsch) (05/21/91)
The PostScript specification trivia question for today: If you ask a PostScript engine to draw a zero-degree arc and there is no current point, does the arc operator just do a moveto, or does it do a moveto and then draw a zero-length line? It makes a difference, because if you've selected non-round caps and round joins, 'stroke' will give no output if arc does the former, whereas the latter will draw a dot. Since this isn't culled out as a special case in the Red Book, I suspect the latter is the correct interpretation, but it would be nice to know for sure. L. Peter Deutsch :: Aladdin Enterprises :: P.O. box 60264, Palo Alto, CA 94306 ghost@aladdin.com ; ...decwrl!aladdin!ghost ; (415)322-0103 <<< new phone # "Implementation is the sincerest form of flattery."
Christopher Tate <CXT105@psuvm.psu.edu> (05/21/91)
If you ask it to draw an arc when there is no current point, shouldn't it
give you a 'nocurrentpoint' error?
Just two cents from the far corner....
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Christopher Tate |
Student-Type Person | Migratory lifeform with a
cxt105@psuvm.psu.edu | tropism for bookstores.
{...}!psuvax1!psuvm.bitnet!cxt105 |
cxt105@psuvm.bitnet |flar@bendenweyr.Eng.Sun.COM (Jim Graham) (05/22/91)
CXT105@psuvm.psu.edu (Christopher Tate) writes: |> If you ask it to draw an arc when there is no current point, shouldn't it |> give you a 'nocurrentpoint' error? From the redbook: If there is a current point, the arc operator includes a straight line segment from the current point to the first endpoint of this arc and then adds the arc itself into the current path. If the current path is empty, the arc operator does not produce the initial straight line segment. In any event, the second endpoint of the arc becomes the new current point. ...jim
flar@bendenweyr.Eng.Sun.COM (Jim Graham) (05/23/91)
ghost@aladdin.com (L. Peter Deutsch) writes: |> The PostScript specification trivia question for today: |> |> If you ask a PostScript engine to draw a zero-degree arc and there is |> no current point, does the arc operator just do a moveto, or does it |> do a moveto and then draw a zero-length line? It makes a difference, |> because if you've selected non-round caps and round joins, 'stroke' |> will give no output if arc does the former, whereas the latter will |> draw a dot. According to the Laserwriters, "newpath 50 50 20 0 0 arc" generates a single path element, "70 50 moveto". ...jim