Re: maximing/resizing multiple x11: change of palette

[Daniel J S. <dan...@ie...>]

Ethan Merritt wrote:

>On Monday 16 August 2004 01:50 am, Petr Mikulik <mi...@ph...> wrote:
>  
>
>>There is a bug in the color palette treatment in the X11 terminal: when
>>using multiple X11 terminals, window redraw (requested e.g. by a window
>>manager) will change its palette.
>>
>>Is it possible to fix it?
>>    
>>
>
>I am not very familiar with this, and I may have it wrong.
>But It looks to me that the PM3D code would have to be re-written.
>
>As it is, gnuplot_x11 only maintains two GC (= "Graphics Context")
>structures. One of these is used for PM3D operations, and the other
>is used for everything else.   There is not currently any notion of
>keeping a separate GC for each plot window.  So if you redefine
>the PM3D GC to use a different palette, it affects all PM3D operations
>in all windows.
>
>I imagine it would be possible to create a new GC for each window,
>but I am not sure what pitfalls that would expose.
>
>I believe that Johannes Zellner wrote this code, so maybe he has
>some insight into the issue.
>
>Otherwise, maintaining per-window information is related to code
>that Daniel Sebald added recently, so he might be interested in 
>experimenting with this.
>

I didn't look at the code, but as soon as I tried Petr's example it 
struck me that what Ethan's describing is the case.

I'll have a look this evening to assess how much it would involve.  But 
it seems logical that since an X11 plot keeps all information about the 
plotting primitives so that it can be redrawn, it should also keep track 
of the palette.  If things are organized as I suspect, that palette 
should be a separate entity in the plot structure, not go into the list 
of graphics primitives.  That's easy enough to add.  Then, when 
reactivated, just install the palette.

What this means, I think, is that when you issue a palette command to a 
certain X11 plot, the graphics primitives can still be used to draw 
under that new palette.  The X11 code could certainly be redrawn upon 
getting that palette command.  Do you want that?  I.e., for X11 do you 
want to have to have to do "set palette; replot"?  Or should the "set 
palette" change the X11 plot right away?  Note, that for non-GUI 
terminals you would always have to do a "set palette; replot" to affect 
a change.

Dan