[hardy] xournal does not give smooth lines

[Andrew Frank]

Binary package hint: xournal

xournal 0.4.1 (same as in 7.10) gives jagged lines, not smooth. the difference is clearly visible between 7.10 and 8.04. the problem must be in one of the packages used for rendering.

with use xinput and discard core events (which works for 7.10)
it gives bad jagged edges and occasionally fine horizontal black lines across the writing.

makes xournal unusable!

[Ryan Sinn (ryan-sinn)]

I have some jagged lines on my Xournal too

[Ryan Sinn (ryan-sinn)]

My issue related to my bug #199999 has been resolved by unchecking "Use XInput" under the "Options" menu in Xournal.

[Ryan Sinn (ryan-sinn)]

Looks like this issue could be related to an upstream bug between Wacom drivers and XOrg 7.3

Here's the upstream bug:
http://sourceforge.net/tracker/index.php?func=detail&aid=1891727&group_id=163434&atid=827733

Here's how it specifically related to this issue:

There are a few additional issues which cause Xournal to be further
confused:

1) the order in which the XInput and Core events are sent has been reversed
(now it's Core first, XInput second); this causes Xournal to fail to
discard
the Core events when "Enable XInput" is checked and "Discard Core Events"
is unchecked. Thus in that case it tries to process both types of events
(the source code modification I'm giving above fixes this). In principle
that wouldn't be a problem, except for some reason the XInput events are
shifted from the Core events by 1 pixel along each axis... thus resulting
in interesting zigzag stroke shapes.

2) in addition, the 1-pixel zigzags caused by the above issue trigger a bug
in the GnomeCanvas library (or the rendering library it relies on, I'm not
sure); this slows down considerably the graphics processing, and
the resulting lag is what causes strokes to sometimes only appear after the
pen's been lifted, with extra horizontal segments, etc. As far as I can
tell, there's no lag, zigzags, and extra line segments in the other
situations. Avoiding those is the main objective of the fixes I suggest
above.