Re: [Plplot-devel] plinit, plend, plinit sequence now works, but I am having second thoughts

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

I can't tell you the specific answer to your questions due to how maniacally
busy I am these days (having just joined Lightspeed Semiconductor), but I can
elucidate some of the plplot design ideas that have historically been
un-documented.  And, I can give it in an object-oriented context, which
(because it is "canonical") is a lot nicer than the "this is the way it should
work" approach I've used historically. :)

This also includes proposals for change to how we do it now -- i.e. the
behavior of plinit().  I've always been somewhat bothered by the way stream 0
vs stream N is handled (this bugged me back in '94 but I wasn't exactly
swimming in free time then either).

When plplot starts, you have the statically pre-allocated stream, stream 0.
Yes the stream 0 that I hate b/c it's not allocated on the heap like a proper
data-structure/object (in the plframe widget I automatically start from stream
1).  

So stream 0 is like a class definition and an instance rolled into one.  What
I think we need to do is get rid of the "instance" part of this and leave
stream 0 as a "class definition" only.  In this case all the command line
arguments and initial pls...() calls (before plinit) serve to override the
default initializion of the class variables, i.e. set stream 0 parameters only

In other words, stream 0 becomes the template for all plplot streams.  You can
use it, but once you've called plinit() you have your own "instance" of the
plplot "object" -- i.e. you have a new stream with all the relevant state info
copied from stream 0.  If you change it, it dies when your stream dies with
plend1().

If you really want to change stream 0 (i.e. the "plplot object" "class data")
you can always set your stream number to 0 and fire away.

To summarize:

plinit() creates a new stream, copied from stream 0
plend1() deletes that stream
plend() deletes all streams, except of course stream 0 which is "class data"

Let me know if any of this helps.

-- 
Maurice LeBrun    mj...@ga...
Research Organization for Information Science and Technology of Japan (RIST)