Fwd: Re: Proposal: Saving graphs from Qt and wxt terminals

[Hans-Bernhard B. <HBB...@t-...>]

[Ooops, forgot to CC the list...]

Am 25.10.2014 um 23:18 schrieb Ethan Merritt:
> On Saturday, 25 October 2014 01:26:53 PM Philipp K. Janert wrote:
>  > On Sat, 25 Oct 2014 16:09:49 -0400 (EDT)
>  > Allin Cottrell <cot...@wf...> wrote:

>  > I guess the question then becomes: in what form is
>  > the graph information is available "when the button
>  > is pressed".

> The internal representation of the plot gradually built up
> by calls into the cairo library is in some I-dont-know-what
> vector format. The conversion to a specific output format,
> whether it's bitmap display on the screen or
> pdf for writing into a file, is done on request as the
> very last step.

That sounds like it's essentially the same way the Windows terminal
implemented both copy-to-clipboard and the "screendump" command.

The outboard driver (it used to be a DLL, back in 16-bit days) stores
the graphics commands it received from win.trm (function GraphOp()) as
struct GWOP in a linked list of arrays (struct GWOPBLK).  This entire
sequence then gets "played" by function win/wgraph.c::drawgraph() onto a
"context", which can be a screen window, a printer device, or a WMF to
be handed over to the clipboard.

Good to see the "modern" drivers catching up --- about 20 years later ;-P