[Plplot-devel] wish list for the colour palettes

[Alan W. I. <ir...@be...>]

Maurice, could you please find a way to display the entire cmap0 colour
palette GUI? Right now, the 16 default colour buttons overlap at the end,
and I believe one of them is entirely covered up.  Also, sure as anything
you will have some user wanting to use more or less than 16 cmap0 colours so
would you be willing to put in a user-selectable number of colours?  Perhaps
the solution is a slider which lets you look at various parts of cmap0 if
there are more than say 12 colours.

Similarly, I think the number of cmap1 control points should be user
selectable with a slider for display so the number of control points could
be much greater than 16 if the user desired. For example, the gray scale in
example 8 is done with 256 cmap1 control points.  It would be nice to be
able to display and manipulate that palette or any colour image palette
(with typically 256 colours) that you might run into when working with
images.

Finally, I noticed when checking example 8 that no attempt (as far as I
could tell) was made to display the working palette.  Instead when the cmap1
palette was pressed, immediately the gray scale was turned into the default
colour scheme.

For now, even if your GUI won't support anything other than cmap1's with 6
control points, it would still be worthwhile to be able to display and edit
the current working palette (assuming it has the same number of control
points as your default one).  I could use that capability immediately to
diagnose troubles with 6-control point palettes that are set up under
programme control like restore_cmap1 in x08.tcl.  In that case, my eyes tell
me it is not quite restoring the default colours (I am trying to match your
6 points with my local copy of x08.tcl before I check in the results). It
would be great to actually see the cmap1 numbers produced by restore_cmap1
using your palette GUI, but right now it always just gives me the default
regardless of what I do under programme control.

So here is the wishlist summary:

(1) User selectable number of colours for cmap0

(2) User selectable number of control points for cmap1

(3) If GUI would be too large use a slider to display parts of it

(4) cmap1 colour palette displays the actual colour map when it starts
and not the default colour map.

(5) Make sure actual colour map is also used for cmap0 palette when it starts
(I haven't played with it so I don't know the score there.)

I will settle for (4) with number of control points fixed at 6, but I
hope you do the rest as well.

Alan

email: ir...@be...
phone: 250-727-2902	FAX: 250-721-7715
snail-mail:
Dr. Alan W. Irwin
Department of Physics and Astronomy,
University of Victoria, P.O. Box 3055,
Victoria, British Columbia, Canada, V8W 3P6
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