The DPS client side consists of four libraries and a number of basic tools for programming and configuration; these are all included with X11R6.8.2.
The libpsres
library is a library for management of
PostScript resources, on-disk files representing PostScript data
structures such as fonts, font encodings, procsets, etc. It is
closely related to the makepsres
tool (see
client-side tools later in this document).
The basic DPS client library is libdps
. This library contains a
number of functions for connection establishment, resource management,
as well as stubs for all standard PostScript operators. Normally, all
DPS clients should link with libdps
; in addition, libdps
may
be used for printing by non-DPS clients (this is done, for example, by
Sun's JDK). This library is documented in [CLRM] and [CLSX].
The libdpstk
library contains a number of additional utilities
for managing DPS contexts, user paths and user objects, and for
previewing EPS files. It is documented in [DPTX].
The libdpstkXm
library contains four Motif widgets. The DPS
Scrolling Widget is a DPS drawing area that automatically manages
issues such as scrolling, scaling, client-side backing store,
incremental redisplay, etc. The Font Selection Box, and its
associated Font Preview, present a convenient and powerful
interface for choosing scalable fonts. Finally, the Color Picker
presents an interface for choosing colours using either of the RGB or
HSV spaces. The latter three widgets are documented in [DPTX]; some
summary Scrolling Widget documentation is available in the doc
subdirectory of the DPS.tar.gz
file, available from urlnam.
The source code for libdpstkXm
is included with X11R6.8.2; however,
as it depends on Motif, this library is not built by default.
A GTK-based library providing some of the functionality of
libdpstkXm
is available from
the gtkDPS site.
In X11R5, libdps
did not depend on libXt
. In X11R6,
however, code was added to make the Xt main loop dispatch to sundry
code on DPS events; with this addition, all programs that link with
libdps
need to link with libXt
, whether they use Xt or not.
This state of affairs is unfortunately true of the version of
libdps
included with X11R6.8.2. We are currently considering
various solutions to this problem (including the use of weak linker
symbols or splitting off the guilty functions into a separate
library).
In addition to the libraries, the client side of DPS consists of two utilities.
The makepsres
utility is used for managing PostScript resources.
Its basic operation consists in walking recursively a filesystem tree,
noting all resources, and then writing out a ``Unix PostScript
Resources,'' file, basically a directory of all the resources found.
This utility is documented in the makepsres(1) manual page.
The pswrap
utility is a stub generator for PostScript clients.
Roughly speaking, it takes as its input textual PostScript code, and
generates a collection of C functions that transmit that code in
pre-tokenised form to the DPS extension. Pswrap
is documented in
[PSWRAP].
X11R6.8.2 contains three sample DPS clients, dpsinfo
,
dpsexec
and texteroids
. They are documented in their
respective manual pages.
A number of sample clients that depend on Motif are available in urlnam. Additional sample clients can be found as part of GtkDPS (see above).
The GNUstep environment can be compiled to use DPS for all rendering; for more information, please see the GNUstep site.