Re: [Groff] Re: ESC/P2 printer driver

[Roger Leigh]

Werner LEMBERG <address@hidden> writes:

> Sorry for the late reply.  For stupid reasons I haven't received mail
> from the groff mailing list for some months.

No problem!  I've been quite busy, so I've not done much up until now.

>> The ESC/P driver would be quite a simple driver.  All I want in this
>> case is an 80 col x 60 line extended ASCII output with bold, italics
>> etc.  This could probably be based on grotty.
>
> Yes, this seems a natural choice.

So far, I've taken tty.cpp and stripped out:
* All colour handling
* Inverse video and other terminal-specific code
* All of the old_drawing_scheme stuff

I've then replaced the SGR escape formatting codes with ESC/P codes.
All it now needs is some device set-up/clean-up stuff, and it should
work.

What is the project policy WRT the C++ Standard Library, templates and
namespaces?  Is it OK to use std::string, std::vector etc?  I noticed
ptable.h uses macros where templates could be used to make the code
cleaner (you might even be able to use std::map internally), i.e.:

template<typename T>
class ptable {
  std::map<std::string, typename T> m_table;
};

>> I've had a look in detail at the grotty driver, and I'm now starting
>> to look at the grolj4 driver.  AFAICT I need to write a DESC file,
>> font metrics for each supported font (I'm trying to get these from
>> Epson for their proportional typefaces) and possibly a roff file in
>> addition.
>
> Right.

A question here:

In the font file (font/devescp/R.proto) I have specified the numeric
codes for a whole set of characters, including accented chars,
symbols, Greek and mathematical symbols using the two-letter symbol
code, for example:

~n      24      0       0244

Do I also need to specify an additional line, like this:

ñ       "

for the latin-1 equivalent, or will groff convert automatically?  What
happens with utf-8 input?

Another thing the printer provides is a whole set of line drawing
characters.  I should be able to use those by replacing the unicode
line drawing chars in crossings[] etc.

One thing I'm unsure how to implement are some of the special
character sets the printer supports.  By loading selecting different
country codes in the printer, a series of ASCII codes become different
characters (e.g. # -> £, ] -> Å).  They have the same number, however,
so I can't put them in the DESC file.  To access one of these chars
means selecting a non-US country, printing the code, and then
selecting US again.  What is the best way to accomplish this?  Some
printers also have multiple selectable [entire] character sets.


tty.tmac contains a some macros I want, but it also has some I need to
redefine or unset.  If I create an escp.tmac and include tty.tmac in
this, will this get loaded automatically when I use -Tescp as the
output device?


I've attached a preliminary copy of what I've done so far.  Does this
look OK WRT the Makefile changes etc.?

Many thanks,
Roger

-- 
Roger Leigh

                Printing on GNU/Linux?  http://gimp-print.sourceforge.net/
                GPG Public Key: 0x25BFB848.  Please sign and encrypt your mail.

groff-groescp-preliminary.diff.bz2
Description: groescp driver (incomplete preliminary version)