Re: pngcairo: suggestion for additional option

[Ethan A M. <merritt@u.washington.edu>]

Allin:

I attach a revised version of your patch.
The changes are:
- Export pre-calculated values for TERM_XMIN etc taken from the axis
  structures
- Initialize term->tscale to 1.0 for all terminals that do not provide
  an explicit value
- Initialize term->tscale for SVG terminal

Please give it a look-over.  Also please help me figure out which other
terminals need an explicit scale, and whether the exported variables need
to be of type double rather than integer. For instance, I think "post eps"
needs a scale factor of 20, but PostScript coordinates are not limited to
integers.  A test plot gave
        TERM_XMIN = 546
        TERM_XMAX = 6990
        TERM_YMIN = 280
        TERM_YMAX = 4872
and dividing back by 20 will give non-integral values.  I am also worried
that to actually use these values we would also need to have the offset
of the coordinate origin relative to the origin of the PostScript page.
On the other hand, the necessary information is already in the output
PostScript file, so perhaps it is not necessary to export it as a user
variable inside gnuplot.  What do you think?


-- 
Ethan A Merritt