Re: [matplotlib-devel] cairo patch #4: Fix draw_arc

[Steve C. <ste...@ya...>]

Carl,
I've not been following the matplotlib mailing lists recently, but I
came across your blog and had a look at the cairo patches. It looks like
all the cairo patches are against some old version of matplotlib.

patch #2 enable clipping
I enabled clipping in Jan-2007.

patch #1 for 'snapping'
The patch did not reach the mailing list (?). But in a later mail you
mention that snapping smooth, curved user data is a really bad idea. So
the patch should probably not be applied.

patch #3 snap dash lengths, relies on patch #1.
I think this patch has the problems of patch #1 - if the dashes are
being used to draw axes or gridlines then snapping is OK. But if the
dashes are for user data then snapping is not necessarily what you want.

I think the real problem highlighted by patches #1 and #3 is that
matplotlib (the frontend) does not tell the backends when it is drawing
the plot axes and gridlines to enable the backends to switch on pixel
aligned drawing.

patch #4 for arcs
Looks good, applied it today.

Regards,
Steve.