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Re: arrows sometimes flipped
From: |
David O'Toole |
Subject: |
Re: arrows sometimes flipped |
Date: |
Wed Feb 28 17:06:02 2001 |
I'd noticed that once or twice, but forgotten about it... thanks for
pointing it out (and finding a bugfix too! :-). This is very helpful.
-dave
> I noticed when a machine is connected to another machine,
> such that the arrow should point -->--, it sometimes
> faces the wrong way. It only happens when the line
> is completely horizontal (dy == 0). I found the bug,
> and here's a cleaned up version of the code in
> engine_view.c:
> -----------------------------------------------------
> if (dy == 0) theta = ((dx<=0)?0:PI);
> else {
> theta = atan(((double)dx)/((double)dy));
> theta = (PI/2.0) - theta; // we want the complementary angle
> if (sy < ky)
> theta += PI;
> }
>
> if(theta)
> poly_rotate(poly, 3, theta);
>
> // now we can draw....
> ---------------------------------------------------
>
> It fixes the flipping problem, and also combines the two
> potential calls to poly_rotate() into one.
>
> Nice to see the project picking up steam!
>
> Richard Todd
>
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> Octal-dev mailing list
> address@hidden
> http://mail.gnu.org/mailman/listinfo/octal-dev
>
--
@@@ david o'toole
@@@ address@hidden
@@@ www.gnu.org/software/octal