gnuplot-beta

cairopng terminal

[Peter D. <pc...@wi...>]

I finally got around to implementing a quick and dirty cairopng hack
that Timothée intimated in March:*

diff -ru gnuplot-orig/term/cairo.trm gnuplot/term/cairo.trm
--- gnuplot-orig/term/cairo.trm 2007-09-13 23:12:53.000000000 -0700
+++ gnuplot/term/cairo.trm      2007-09-13 23:15:01.000000000 -0700
@@ -374,6 +374,7 @@

        /* finish the page - cairo_destroy still has to be called for the whole documentation
         * to be written */
+        cairo_surface_write_to_png(cairo_get_target(plot.cr), outstr);
        cairo_show_page(plot.cr);

        FPRINTF((stderr,"status =
        %s\n",cairo_status_to_string(cairo_status(plot.cr))));


Problem is, it still produces a redundant PDF which gets truncated by
the PNG; how to go about suppressing the PDF output?

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  * http://sourceforge.net/mailarchive/message.php?msg_name=45F1A71F.6010506%40ens.fr

Re: cairopng terminal

[Peter D. <pc...@wi...>]

> I finally got around to implementing a quick and dirty cairopng hack
> that Timothée intimated in March[.]

It turns out that hack was insufficient, among other things, for
multiplots; the attached patch implements multiplots as a successive
sequence of PNGs in the form <filename>-#.png.

The resultant PNGs can be composed with something like:

    convert plot-0.png plot-1.png -composite plot-2.png -composite plot.png

Is there any advantage over the simple `convert plot.pdf plot.png'?
The image quality, above all, seems to be superior to the naive
conversion.

Re: cairopng terminal

[Peter D. <pc...@wi...>]

> It turns out that hack was insufficient, among other things, for
> multiplots[.]

The attached patch works for multiplots without requiring
post-processing; it still piggybacks, however, on the cairopdf
terminal.

Re: cairopng terminal [submitted]

[Peter D. <pc...@wi...>]

> [I]t still piggybacks, however, on the cairopdf terminal.

I broke down and created a bona fide cairopng terminal based on
Timothee's cairopdf with trivial enhancements; it can be used with:

    set terminal cairopng

I also submitted it to sourceforge.*

-----------
  * http://sourceforge.net/tracker/index.php?func=detail&aid=1795644&group_id=2055&atid=302055

Re: cairopng terminal [submitted]

[<tim...@en...>]

Peter Danenberg wrote:
>> [I]t still piggybacks, however, on the cairopdf terminal.
>>     
>
> I broke down and created a bona fide cairopng terminal based on
> Timothee's cairopdf with trivial enhancements; it can be used with:
>
>     set terminal cairopng
>
> I also submitted it to sourceforge.*
>
>   
Hi Peter !

I'm happy to see you working on this, and having success in adapting 
cairopdf to write png. It's a good proof that the cairopdf terminal is 
to some extent understandable ;) and that cairo itself is well designed 
since few modifications were required.

Here are a few remarks:
- first, if it is agreed to included this cairopng terminal, we should 
make our best to share the code between the various cairo* terminals 
(pdf and png currently, but it could be svg and ps too). At least the 
help text, which is also shared with wxt, and maybe more of the code.
- second, the most obvious advantage of this terminal is its 
antialiasing, which gd doesn't have at the same level. Does this mean 
that cairopng could be made the default 'png' terminal ?
- third, maybe it's time to talk with gd people, who have been talking 
about interfacing gd and cairo, so that we could draw with cairo and 
export to as many format as gd supports.

Best regards,

Timothée

Re: cairopng terminal [submitted]

[Peter D. <pc...@wi...>]

> [W]e should make our best to share the code between the various cairo*
> terminals . . .

That occured to me, too; it should be possible to abstract a set of
utilities that accept, say, a cairo_surface_t and a render-function
(like cairo_surface_write_to_png).

> Does this mean that cairopng could be made the default 'png'
> terminal?

Ideally, it will act as a drop-in replacement.

> [M]aybe it's time to talk with gd people, who have been
> talking about interfacing gd and cairo . . .

Do you have a link, by any chance?