#1656 pstricks palatte colors not defined for SMPAL_COLOR_MODE_GRADIENT mode

[Dan Sebald]

The pstricks.trm palette support has fallen a bit behind. I've attached a small change to make the color definitions work for SMPAL_COLOR_MODE_GRADIENT mode the same as SMPAL_COLOR_MODE_RGB. Without the change the pstricks terminal will create a LaTeX file that uses the \polypmIIId{} definition as though the colors have been defined, but they are missing. Here's some LaTeX compilation errors:

No file oct-M5gQtq-sa.aux.
(/usr/share/texmf/tex/latex/base/omscmr.fd) (/tmp/oct-M5gQtq.tex

! Package xcolor Error: Undefined color `PST@COLOR57'.

See the xcolor package documentation for explanation.
Type H <return> for immediate help.
...</return>

l.440 \polypmIIId{57}(
0.7664,0.6868)(0.7628,0.6837)(0.76,0.6878)(0.7636,0.6909)

?

[Dan Sebald]

Here's an example. Type

load 'foo.gp'

at the gnuplot prompt.

[Dan Sebald]

Then place the attached file in the same directory as foo-inc.tex and type

latex foo

at the bash terminal prompt.

[Christoph Bersch]

The same issue appears with the filledcurves plotting style:

set terminal pstricks
set output 'foo.tex'
plot x with filledcurves y1

Back then, when the bug came up 7 years ago, I already had a closer look at the problem, see https://groups.google.com/forum/#!topic/comp.graphics.apps.gnuplot/8qUCHCW77X0 No, I never submitted the promised bug report ;)

I tried to rewrite larger parts of the pstricks terminal driver to fix this, and also make use of many other features. But seeing that the terminal is hardly ever used, since with the tikz terminal a much better LaTeX-based terminal is available, I didn't go on with the development.

[Dan Sebald]

I was trying a demo plot on all terminal types and pstricks failed. I figured if it is a simple issue/fix, then worth it, otherwise not. There are a couple other palette definition schemes that appear to not be addressed by the if/else clause but I didn't pursue those... Good memory though, 7 years.

[Ethan Merritt]

We don't really have a documented policy about ignoring, updating, or deprecating terminal drivers as they become obsoleted by newer ones. I don't really consider it a "bug" if a newish feature does not work on some old terminal type that never did support it. If there's an easy and obvious update, fine. But I worry that for anything nontrivial the risk of breaking ancient seldom-tested code paths outweighs the gain. Anyone who needs the new feature can use a newer terminal that does support it, probably lua/tikz in this case, while any ancient scripts that use the old terminal will continue to work as they always did since they obviously pre-date the feature in question.

[Bastian Märkisch]

Please note that the pstricksterminal was recently updated considerably [18d0e3] and now gives very reasonable results.