Re: [Plplot-general] C++ interface and windows redraw

[Maurice L. <mj...@ga...>]

Did anyone respond to this?  I am getting caught up with email after letting
it slide for a few weeks.

Victor Munoz writes:
 > 
 >   I've been using plplot for some weeks. Since I prefer C++, I'm using
 > that interface, but I noticed I couldn't easily ask for the postscript
 > driver and then specify the output file name so that my program does not
 > expect an answer from the keyboard. The problem seemed to be that plstream
 > constructors call plinit(), so when, after the plstream object is created,
 > I intended to set the filename, I got a segfault. My program was:
 > 
 > #include "plstream.h"
 > int main(){
 >   plstream pls(1,1,"psc");
 >   pls.sfnam("tres.ps");
 > }
 > 
 > I decided to add a constructor to the plstream class, so that something
 > like plstream pls(1,1,"psc","tres.ps") works, and consequently
 > automatically opens an output file. I had to recompile the libraries, but
 > it worked. If someone knows of a better or easier solution, or if someone
 > thinks this is a good feature to include in future versions, I'd be glad
 > to know.

Sounds like a good constructor to have.  If you supply a patch, it will be
included.

 > Second. I noticed that if I create two plstream objects, and the second
 > window is put over the first one in my screen, the first one is erased, so
 > I cannot see both windows simultaneously (that's why I had to worry about
 > writing files, by the way). Is that a common problem with the xwin driver,
 > or there's something in my distribution I could change to fix this?

That's because the xwin driver is part of the same process and is single
threaded.  It'd be nice to add a threaded capability to it to handle the
event loop, but there are too many worthwhile projects, not enough time.
You can also try the tk driver, which lives in a separate process so doesn't
suffer from this problem.

-- 
Maurice LeBrun    mj...@ga...