Re: maximing/resizing multiple x11: change of palette

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

Petr,


Daniel J Sebald wrote:

> My thought was as follows:  PaletteMake creates a cmap structure:
>
>
>
> typedef struct cmap_t {
>    Colormap colormap;
>    unsigned long colors[Ncolors];    /* line colors */
> #ifdef             PM3D
>    unsigned long xorpixel;    /* line colors */
>    int total;
>    int allocated;
>    unsigned long *pixels;    /* pm3d colors */
> #endif
> } cmap_t;


I'm thinking that in the case that a palette comes across the pipe and 
it is different from that of the current_plot, the palette code should 
also search the linked list for a colormap that matches the one sent 
across the pipe.  It doesn't seem too far-fetched to me that someone 
experimenting with color maps would go back and forth between maps a lot 
of times.  The result could be, similar to the previous discussion, the 
same color map stored in memory many, many times.

So does it seem worthwhile including inside the above structure an 
instance of t_sm_palette, so that we may have quick comparisons in the 
case of palettes that are a color formula as opposed to user-defined 
gradients?  (Of course, I wouldn't store the gradient colors *and* the 
color map pixels because that would be real bloat.)  Or should we just 
stick to what I described previously, and if someone has a lot of varied 
palettes of very large size visible and is switching back and forth 
between them they will just have to live with it.

In some sense, for harmony or parsimony, or whatever you want to call 
it, between gnuplot_x11 and gnuplot, the frequency of sending the 
palette over the link should match how often gnuplot_x11 really needs 
it.  As Ethan pointed out, there are couple schemes:

The basic layout of gnuplot_x11 is that commands are read from the input
stream and either
	(a) executed immediately (e.g. "close window #5")
or	(b) stored in a list to be executed every time the current plot is redrawn.


In the former case, gnuplot should only be sending over the palette when 
it changes.  In the latter, gnuplot should send every time so that it 
goes into the plot buffer.  Right now, gnuplot_x11 is set up for (a), 
but gnuplot sends the palette every time a plot is done.  That would 
prevent gnuplot_x11 from testing every plot if the palette changed. 
 Just nit-picking I guess.

Dan