Re: [LIBART] Working on new canvas item...

"James K. Wiggs" wrote:

>     Ahh, excellent.  My impression from the documentation and the
> source code I studied was that the vector paths had to be "closed"
> in the sense that you can't "lift the pen" once you start drawing.
> But it *is* possible to mix MOVETOs and LINETOs.  OK, made these
> changes *and* put the art_vpath_perturb() call back in.  I still
> get a few of these:
> x_order_2: colinear!
>    But only about 10 of them for ~430 pricebars.  I suspect that
> I'm getting them on pricebars where the open/close tics are at
> the same value.  And also, there are no *visible* plotting
> artifacts like "blocks" or tics that extend halfway across the
> graph.

Thanks, Lauris, for providing such useful help!

Here's a suggestion that may reduce the colinear warnings. Lauris

> MOVETO_OPEN (opening tic) LINETO (bar)
> MOVETO_OPEN (bottom of bar) LINETO (top of bar)
> MOVETO_OPEN (bar) LINETO (closing tic)

I'd suggest checking to see if opening and closing tics are equal to the
top or bottom of the bar, and keeping the pen down in those cases.

It's a little more code (it looks like you have to check all four cases
of opening or closing tics matching top or bottom), but you should run
quite a bit more stably.

Hope this helps,


Raph Levien <raph artofcode com>  |  artofcode LLC  |

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