Re: [Plplot-general] Some notes on PLplot implementation and Ada binding

[<hba...@ma...>]

On Aug 16, 2006, at 5:40 AM, Jerry wrote:
> I have made an option to exchange Black and White in Color Map 0
> (color 0 and color 15) because it is customary to work on a white
> canvas on Macintosh. This works fine using the excellent AquaTerm
> graphics terminal emulator on OS X. However, on X-windows (also
> running on OS X), when black and white are switched, only the first
> plot appears on a white background, and all others (in a particular
> run) appear on a black background. However, the line color remains
> switched, so that what were supposed to be black lines drawn on a
> white background are instead (after the first plot) black lines drawn
> on a black background, thus invisible.

Did you setup the color table (with, for example, plscmap0n) prior to  
calling plinit()? Not all of the drivers support changing the color  
table "on the fly".

> Another difference between running with AquaTerm and X-windows is
> that AquaTerm plots all the plots of a particular run one after the
> other in different windows, but X-windows (same binary) pauses after
> each plot until Return is pressed, then re-draws the next plot in the
> same window. There is a mention in the plplot.h about multiplot mode
> with respect to plenv and plenv0--maybe that is relevant, but I
> haven't been able to see any difference in behavior when using either
> plenv or plenv0 on either windowing system.

I believe that the difficulty here is that X-windows doesn't (at  
least easily) support "orphaned" windows. Since every window must  
have a running process associated with it, the X-windows driver was  
written to pause at plend()/pleop() so that the user would have a  
chance to see the graph before it was destroyed when the process  
ended, as would happen when you run one of the PLplot examples. This  
is also why all the plots are drawn in the same window.

-Hazen