The "spacing" option of the warp tool used to be handled by the
gegl:warp op, and have little effect. Instead, implement it in the
warp tool directly, having the same effect as the other paint
tools.
Having a properly-working "spacing" option allows us to use EXACT
motion mode without cirppling down performance, which means that
the stroke now follows the pointer exactly, even when processing
takes a while.
Decrease the default "spacing" value to 10.
(cherry picked from commit e8a39d5c49)
... and to disable/control the rate of the periodic stroke.
The warp tool is now fast enough to enable stroking directly in
the motion handler, which gives better-quality response to motion
than stroking periodically. It's not quite fast enough to enable
exact motion, though :/
Allow individually enabling/disabling stroking during motion and
periodically, and allow controlling the rate of the periodical
stroke.
When using the MOVE behavior, don't append the current cursor
position to the stroke path in the timeout proc if the cursor
hasn't moved since last time. It has no effect, except for
requiring an unnecessary update.
and get the update extents from the signal's "roi" parameter. Should
be more correct but produces more artifacts for me. Either this patch
is broken, or (more likely) this triggers a bug.
