Re: [Plplot-devel] plreplot and clearing the page (jim please read ifyou'e around)

[Alan W. I. <ir...@be...>]

Hi Phil:

On 2017-01-13 08:48-0000 p.d...@gm... wrote:

> Thanks Alan, I'll review those emails.

Good.

Here is my understanding from reviewing those e-mails and looking at
code.

I think the qt device driver is a good model for what has to be done.
So if you look at Jim's changes for it, via

git diff 5867959e^..5867959e drivers/qt.cpp

you will see no changes for any of the noninteractive devices, but for
the qtwidget device what happened previously in the eop code is now
split into an "eop" routine that only exercises "non-wait" code and a
"wait" routine that exercises all former eop code that waits.

Currently there is no such wait routine in drivers/wx*.cpp, but I
think you might need it since what is currently called
wxPLDevice::EndPage has logic that depends on pls->nopause. So it
appears that what you need to do is to follow what was done for qt and
split all such wait code that is currently exercised by the eop
routine into its own wait routine.

If you agree this is the right way to go, then please go ahead with
the implementation but also exercise extreme caution about pushing it,
i.e., wait until you, Pedro, and I have thoroughly tested it on all
platforms by building _both_ the test_c_wxwidgets (which exercises a
subset of the examples with -dev wxwidgets and the -np option) and
test_wxPLplotDemo targets on Linux and also by running one example
with -dev wxwidgets on that platform without the -np option, and by
doing the equivalent tests (running at least one example with -dev
wxwidgets with and without the -np option and running wxPLplotDemo)
for the MSVC case.  Given such testing, I would be happy to
see you push this in time for the 5.12.0 release because there
are no impacts of such wxwidgets driver changes on any other
part of PLplot.

However, the reason why I suggest extreme caution about pushing is
that Jim's equivalent change for cairo was a complete success for both
-dev xcairo and ext-cairo-test, but it appeared to have a side effect
of exposing a bug in extXdrawable_demo which we could not fix in a
timely manner for the release of 5.11.1.  Therefore, Jim and I made
the joint decision then to revert his change to cairo.c (see commit
d64d9c684) until someone could figure out that extXdrawable_demo
issue.  As of this date nobody has found such a solution so Jim's fix
for xcairo still remains reverted.  But if your equivalent change for
wxwidgets works, then post-release I plan to reinstate Jim's fix for
xcairo and simply drop extXdrawable_demo until someone can figure out
the issue with it.

In any case, in anticipation that you will be looking very carefully
at the eop versus wait distinction in plbuf, I suggest you document
that distinction clearly (in drivers/README.drivers or some other file
that document refers to) so no other interactive driver writers run
afoul of this issue.

Alan
__________________________
Alan W. Irwin

Astronomical research affiliation with Department of Physics and Astronomy,
University of Victoria (astrowww.phys.uvic.ca).

Programming affiliations with the FreeEOS equation-of-state
implementation for stellar interiors (freeeos.sf.net); the Time
Ephemerides project (timeephem.sf.net); PLplot scientific plotting
software package (plplot.sf.net); the libLASi project
(unifont.org/lasi); the Loads of Linux Links project (loll.sf.net);
and the Linux Brochure Project (lbproject.sf.net).
__________________________

Linux-powered Science
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