path: root/doc/ghostpcl.txt

GhostPCL

This document discusses configuration, compilation and running of the GhostPCL family of products:
PCL5E [1], PCL5C [2], PCLXL [3], and HPGL/2 with RTL [5], additionally a scaled down PJL [4] inter-
preter is provided. All of the PCL products use the Ghostscript Graphic Library for graphics, imaging and
driver support. A brief tour of the Ghostscript documentation www.ghostscript.com/doc/ will be helpful to
understand this document. The relevant ghostscript version used by PCL can be found in gs/src/version.mak.

GhostPCL is PCL technology; it is not intended to be a finished software application but a collection of
software components that will ultimately be included in a software application or a real time embedded
system. Generally the GhostPCL languages are compliant with the Genoa (now QualityLogic) Functional
Test Suite and the Genoa Application Test suite. Also each language should run the corresponding Genoa
Comprehensive Evaluation Test (CET) without egregious errors.

For printer customers we have GhostSwitch. GhostSwitch integrates Ghostscript's Postscript and PDF
interpreter with GhostPCL in a language switching environment with auto language sensing and PJL job
control as found on many modern printers.

In this document and the software, PCL6 refers to technology that supports both PCL5 and PCLXL lan-
guages.


Quick Start For Unix environment with GCC.

tar zxvf ghostpcl-xxx.tar.gz; cd ghostpcl-xxx # unpack the release and go to the release directory 1
make fonts                                           # install the fonts. 2
make product                                         # compile and link pcl6
.make test                                           # test pcl6 (optional).
make install                                         # install it





Supported development environments

    Windows NT and '95 with Microsoft Visual C/C++

    Linux with gcc

    Unix environments without GCC


Unpacking the source

The source code will either be on CD-ROM (without any archiving or compression) or in a archived com-
pressed format. Zip is used for Windows environments and compressed tar format for Unix environments.
If you have a CD-ROM release you will want to replicate the directory structure from the CD-ROM to a
development directory on a hard drive. The compile process does not require a special directory name. If
you have obtained the archived compressed version use:

For Windows:

pkunzip -d <archive name>


For Unix::

  1If tar "z"' option is not supported: gunzip ghostpcl-xxx.tar.gz; tar xvf ghostpcl-xxx.tar.
  2See Fonts to configure this differently.





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gunzip <archive name.gz>
tar xvf <archive name>

After unpacking the result should be a directory hierarchy which is briefly described next.


Brief Overview of Directory Hierarchy

pcl Source code for the PCL interpreter. Files beginning with "pc" handle pcl state, text and rules. "rt"
     files implement pcl's raster language RTL and the "pg" source code files are for HPGL/2.

pxl Source code for the PCL-XL interpreter. This is an entirely different language than PCL; all files in
     this subdirectory are prefixed with "px"

pl This subdirectory contains code that can be shared by PCL and PXL. In particular font scaling code,
     the printer job language (PJL) and the language switching machinery are in this subdirectory. All files
     in this directory are prefixed with pl.

common PCL and PXL shared makefiles. The subdirectory is an historical artifact from when PCL and
     PXL had separate makefiles. It does contain the makefile to build the ghostscript graphics library.

tools miscellaneous tools and test files.

tools/GOT GOT means graphical object tagging. The system is able to classify high level graphical objects
     (text, images and vectors) and store this information in the framebuffer along with the output data.
     The tools in these directories are used to unpack a framebuffer that has been tagged for display in a
     viewable format.

tools/viewer The Java pcl viewer is a sample graphical user interface for the GhostPCL system.

language switch top level makefiles for building a share language environment. This is where the shared
     language environment which includes PostScript and PDF can be built.

gs Ghostscript branch, refer to the documentation at www.ghostscript.com/doc/ for more information
     about ghostscript.

main The "workhorse" makefiles of the system. These are also most likely to need modification to add/remove
     devices, choose a font scaler, and set directory locations.

urwfonts 80 URW TrueType fonts.


This directory structure is the default, but the directories can be rearranged with minor modifications to
the makefiles.


Building with Microsoft Visual C/C++

The PCL tools are known to build with Visual C/C++ 4.0, 5.0 and 6.0. There are 2 ways of building the PCL
components with Microsoft Visual C/C++: Convert the current makefile environment to a Visual C/C++
project; or compile the source directly using nmake. The following steps take you through converting the
supplied makefile environment to a Visual C++ project:


    Unpack the source code, see Unpacking the source.

    Start MSVC++.

    Open main/pcl6 msvc.mak and MSVC++ should wrap the makefile automatically and create an MSVC
     project.




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    Set the project setting (Alt F7). To create a debug:
      NMAKE /f pcl6 msvc.mak DEBUG=1 DEVSTUDIO=c:\progra 1\micros 31

      Now set the name of the executable for debuggging to .\obj\pcl6.exe, and set the program argument
      to be any pcl6 options wanted and the name of the pcl file.

    Now PCL6 is set to be compiled, debugged and use other features of the MSVC++ IDE.2

This will build both the PCL and XL language and supporting language switching code.


Building with Linux and GCC

The pcl tools have been compiled on Linux using GCC. It is easiest to simply use the instructions provided
in the section Quick Start For Unix environment with GCC.


Building on a generic UNIX platform

The PCL tools have been compiled on Solaris with the Sun Development Tools and SGI with the native SGI
C compiler. We only provide makefiles for the gcc tools and assume users can customize the gcc makefiles
such that they work with vendor's compilers. For the Sun Development tools the following workaround is
sufficient to build the software:


    change to the main subdirectory.

    make CC =cc CCLD=cc \ CCAUX=cc CFLAGS=-g CC NO WARN=cc GCFLAGS=

If you intend to do development using the software a dedicated makefile should be constructed.


Customizing the build process

The build process is completely configurable. Here is a list of things that are user will most like be interested
in customizing.    To change any of these see the appropriate makefile for your platform in the "main"
subdirectory


    Directory location of source directories.

    Directory location of objects, executables, and other compile time generated files.

    Selection of devices.

    Directory location of PJL filesystem volume 0 and 1

    The font scaling technology.

        ­ Defaults to /tmp/pjl0 and /tmp/pjl1

        ­ Edit pl/pl.mak PJL VOLUME 0 and PJL VOLUME 1 to match desired root


All of these can be configured in the top level makefile or can be specified on the make command line.

The following make targets are available:

  1DEBUG=1/0 on/off will require you manually clean; del main\obj\*.*
  2Dos hackers can start up a dos window, set the DEVSTUDIO environment variable, and use the same make com-
mands as above (the DEVSTUDIO variable should be set to the top level of the Microsoft Developer Studio, e gset
DEVSTUDIO=c:\progra 1\devstu 1" or NMAKE /f pcl6 msvc.mak DEBUG=1 DEVSTUDIO=c:\progra 1\micros 3)



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debug build tools with symbols and debugging information

product builds optimized code.

pg-fp builds profiling code for hardware with floating point.

pg-nofp builds profiling code for hardware with no floating point (ie 
                                                                         with floating point emulation software).


Building only one Language

PCL or PCL-XL can be built together in a language switching environment or each can be built alone
with the supporting PJL interpreter. The simplest way to implement one language is simply to remove the
unwanted implementation from the pdl implementation table located in pl/plimpl.c:

For example, this is the default table with two implementations: PCL and XL.



            /* Zero-terminated list of pointers to implementations */
            pl interp implementation t const * const pdl implementation[] = {
                    &pcl implementation,
                    &pxl implementation,
                    0
            };


If you only wish to use one interpreter remove the unwanted one and recompile the code.


Running the products.

      Few things are harder to put up with than a good example. Mark Twain


Most ghostscript options, as described in the Ghostscript documentation www.ghostscript.com/doc/, hav
similar effect in the GhostPCL system. Of course, options specific to the PostScript or PDF language are
not relevant and are ignored.

pcl6 mypcl.pcl

Interpret a pcl file called mypcl.pcl and render it to the default device. For now the default device on systems
with x11 is a full color x11 display, other system default to laserjet 4 output suitable for a monochrome laser
printer.

pcl6 -dTextAlphaBits=4 mypcltext.pcl

When rendering pcl text onn a low (screen) resolution display device, use the TextAlphaBits option to enable
anti-aliasing.

pcl6 -sDEVICE=x11 mypcl.pcl

Interpret a pcl file called mypcl.pcl and render to the x11 device.

pcl6 -sDEVICE=ljet4 -sOutputFile="| lpr" -dNOPAUSE mypcl.pcl

Interpret mypcl.pcl and send the Laserjet 4 formatted output to the command lpr.

pcl6 -sDEVICE=pcxcmyk -sOutputFile="pcxpage.%d" -dNOPAUSE mypcl.pcl

Interpret mypcl.pcl and generate CMYK output. Pages are to be put in files named pcxpage.1, pcxpage.2,
pcxpage.3, etc.

pcl6 -r72 -sDEVICE=x11mono mypcl.pcl -r100 -sDEVICE=x11 mypcl.pcl

Render a pcl file at 72dpi on the monochrome X11 device, then render the same file at 100 dpi on color X11
device. This demonstrates on-the-fly device switching.


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pcl6 -sDEVICE=bmpamono -sOutputFile=foo.bmp mypcl.pcl

The bmpamono (1 bit) and bmpa16m (full color) run asynchronously. In short, the language and graphics
library produce bands in one thread while the device renders the bands in a second thread.

pcl6 -sDEVICE=pdfwrite -sOutputFile=mypcl.pdf mypcl.pcl

Convert the pcl file mypcl.pcl to PDF with output written to mypcl.pdf.

pcl6

Simply running the interpreter should generate some useful information about the available options and
devices.


PCL Personality

The PCL emulation comes in three flavors: PCL5E, PCL5C, and RTL. The PCL5E personality thresholds
colors to black and white irrespective of the color parameters of the output device. PCL5C is the color
personality, used with a monochrome device it will grayscale colors. The RTL personality can be used to
print HPGL/2 RTL plot files.

pcl6 -PRTL myrtl.rtl

run the interpreter with the rtl personality.

pcl6 -PPCL5E -sDEVICE=ljet4 mypcl.pcl

run the interpreter with the pcl5e personality. This will threshold colors to black and white (ljet4 is a 1 bit
device).

pcl6 -PPCL5C -sDEVICE=ljet4 mypcl.pcl

run the interpreter with the pcl5c personality. This will grayscale colors on the 1 bit output device. If not
set on the command line the pcl interpreter personality will be set to PCL5E if the output device is 1 bit per
pixel otherwise it is set to PCL5C. RTL must be explicitly set on the command line. RTL always grayscales
and never thresholds colors to black and white.


Fonts

The release is packaged with 80 high quality URW TrueType fonts. For commercial use of the GhostPCL
technology these fonts can be licensed from Artifex. The fonts are searched for in either the fonts, /win-
dows/fonts, or a directory specified with the PCLFONTSOURCE environment variable.

Fonts and a font scaler from a third-party vendor such as Agfa or Bitstream may also be used. There is
an existing interface for integrating the AGFA Universal Font Scaler Technology, several Artifex customers
currently use this solution. The software can use Hewlett Packard FONTSMART version 1.5 or Windows
TrueType fonts, using either of these font solutions require minor PCL code modifications.


PCL Code changes required to use other TrueType fonts.

To use a new set of TrueType fonts requires modifying the C code in the file pl/plftable.c. The C structure
resident table contains a list of Windows TrueType font names. In the released package these names will
correspond with the Windows True Type font names in the URW font set. To use a different font set these
names must be replaced with the new font names and the code (at least the plftable.c module) should be
recompiled and linked. The file tools/fontpage.pcl can be run to display font samples and the pcl escape
sequences required to select the fonts in a pcl stream. This option is only recommended for advanced
developers. It is easiest to simply create a downloaded font and embed it in the PCL stream, see the PCL
Technical Reference Manual [1] for details.





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Using the language switching build

For printer and embedded device users we provide a complete language switching solution consisting of
PCL/HPGL2, PCLXL, PS, PDF, with Job Control. For host based user we strongly recommend that you
use GhostPCL and Ghostscript separately as the shared language has particular feature well suited to printer
environment but the same feature may produce unexpected results on host based environments.


Building the Language Switch Environment

At this time, we have makefile support for Microsoft Visual C and Linux with gcc. For the Microsoft Visual
C the use the instructions in the section Building with Microsoft Visual C, but this time you will wrap the
makefile pspcl6 gcc.mak which is located in the directory language switch. For Linux the makefile targets
for the language switch build are exactly the same except each target is prefixed with "ls ". So using the
pattern from the "Quick Start" section we have:


tar zxvf ghostpcl-xxx.tar.gz; cd ghostpcl-xxx # unpack the release and go to the release directory.
make ls fonts                                # install the fonts.
make ls product                              # compile and link pspcl6.
make ls test                                 # test pspcl6 (optional).
make ls install                              # install it.




Reporting bugs

If you find a bug or have comments about this documentation, please send mail to bug-pcl@ghostscript.com.


Trademark Credits

PostScript is a registered trademark of Adobe Systems Inc. PCL is a registered trademark of Hewlett-Packard
Company.



References

 [1] PCL 5 Printer Language Technical Reference Manual, HP Part No. 5961-0509, First Edition - October
    1992

 [2] PCL 5 Color Technical Reference Manual Copyright 1999, Hewlett-Packard Company.

 [3] PCL XL Feature Reference.

 [4] Printer Job Language Technical Reference Manual Edition 10, HP Part No. 5021-0380, October 1997.

 [5] The HP-GL/2 and HP RTL Reference Guide A Handbook for Program Developers, Addison Wesley
    Publishing Company, 1993.





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