PostScript Utilities


This document summarizes the PostScript utilities on the accompanying disk:

     PPEPSF    which converts an AutoCAD PostScript plot file to an
               Encapsulated PostScript file.

     SLD2PS    which converts an AutoCAD/AutoSketch slide file to
               a PostScript file. Optional encapsulation & color output
               flags are provided.

     ADI2PS    which processes a Binary ADI plot file to produce a
               PostScript file. Line widths can be assigned to "logical" pen
               numbers. Optional encapsulation is also provided for.

These utilities are primarily meant for use while interfacing desktop
publishing packages to Autodesk products like AutoCAD Release 9 & 10 and
AutoSketch 1.04 & 2.0 and AutoShade 1.1.

These utilities are designed to work under MS-DOS. Consequently, the input
files for these utilities should also be created by an Autodesk product running
under MS-DOS.

BACKGROUND

PostScript is a page description language developed by Adobe Systems Inc. It
serves as the basic page layout language of several laser printers and is a
natural output medium for the desktop publishing packages seeking to merge
text & graphics and to provide WYSIWYG output.

AutoCAD, AutoShade & AutoSketch are graphic design tools. While each of
these can provide generic PostScript output, certain extensions to this
output can be made in order to enhance their usefulness as PostScript data.

DEVELOPEMENT

These utilities are not very ambitious in their scope. In all 3 cases,
Encapsulated PostScript output is provided for. The major intent behind SLD2PS
was to provide a "screen dump" capability while that behind ADI2PS was to
provide for line-width assignment to logical PostScript pens. SLD2PS
additionally provides for full 256 color output (commercial color PostScript
printers have begun emerging in the hardcopy marketplace). PPEPSF is a pure
PostScript --> Encapsulated PostScript output utility.

The major reason for the development of these utilities was the fact that
I heard about AutoCAD users asking for them. Please feel free to comment on
these routines, suggest enhancements, reportproblems etc. For the more
adventerous users, the full C source code is available should you desire to make
any modifications or bug fixes. Splicing code from these utilities into commercial
or shareware utilities is an absolute no-no in my mind, modifying them for
personal use is perfectly ok.

PPEPSF

This utility takes a standard AutoCAD/AutoSketch/AutoShade PostScript file
and post-processes it into a format accepted as Encapsulated PostScript.

The calling syntax is :

     PPEPSF <input .plt file> <output .eps file>

Example:
           PPEPSF mpart
           PPEPSF mpart mpart2

The file extensions .plt and .eps are automatically tagged on. The output
file name is optional. If it is not provided, the input file name is assumed
as the default.

Both AutoCAD & AutoSketch plot files are output with .plt file extensions.

This utility essentially constructs a header in the PostScript file that
looks like:
          %!PS-Adobe-2.0 EPSF-1.2
          %%Bounding Box: llx lly urx ury
          %%EndComments

AutoCAD & AutoSketch files output Bounding Box information but this is done
at the end of the file. AutoShade 1.0 files are similar in this respect but
AutoShade 1.1 files are output in Encapsulated form.

The algorithm used is simple: make two passes on the input file, finding and
storing the Bounding Box string the first time. On the second pass, replace
the Header with this new EPSF type header. No other changes are made. This
utility was tested successfully with Xerox's Ventura Publisher and Aldus'
PageMaker.


SLD2PS

This utility process an AutoCAD Slide file to produce a PostScript or
Encapsulated PostScript file. It treats the PostScript device
akin to a display device, supporting hardware fill. It also supports
the full 256 color AutoCAD palette.  Both the "old" and the new Release 9 style
slide file formats are supported and SLD2PS automatically detects and adapts to
each.

An important point to note is that the resolution of the PostScript output
is strongly affected by the resolution of the graphics area in which the
slide was created. Thus, a slide file created on a 8514 display will look
infinitely better (but take longer to process) than one created on a EGA
display.

It's primary use is to provide a "Screen dump" type facility and to provide
full 256 color PostScript output.

The output is automatically scaled to fit a 8.5 x 11 sheet. The default
orientation is potrait which may be altered to landscape using the "Rotate
plots" switch.

The calling syntax is :

     SLD2PS <options> <input .SLD file>

The options available are:

                         -E: Generate Encapsulated PostScript file
                         -C: Output Full color Postscript
                         -R: Rotate plots to landscape orientation
                         -?: Print help message

These may be input in any order & combination and must be separated by
spaces.

Examples:

     SLD2PS chroma        ... Dump CHROMA.SLD to PostScript
     SLD2PS -R chroma     ... Rotate plot to landscape orientation
     SLD2PS -C chroma     ... Output full PostScript color information
     SLD2PS -E -R chroma  ... Encapsulated PostScript output, rotate plots



ADI2PS

This utility postprocesses a Binary ADI plot file into a PostScript or
Encapsulated PostScript file.

Its primary use is to output line width information to a PostScript file.
AutoCAD & AutoSketch currently treat a PostScript device as a single pen
plotting device, and as a consequence one cannot assign line widths to a
"logical" pen number. ADI2PS overcomes this limitation.

The calling syntax is:

     ADI2PS <options> <input ADI binary .plt file>

Valid options are:
                      -R for Reconfiguring
                      -C to output a C size Bounding Box
                      -E for Encapsulated PostScript output
                      -? to print help message

When ADI2PS is fired up, it looks for a file called PEN.CFG in the current
directory. If this file is not found, the program leads you through the full
configuration process which involves assigning a pen width to each of the 16
pens. This configuration information may be updated at any time by using the
"-R" switch to reconfigure the program.

In order to use this program, configure AutoCAD for an ADI plotter,
outputting a Binary ADI plot file. The number of steps in the X & Y
direction should be 300 [which is the resolution of most PostScript devices].

This may be done by following these steps:

     Select Configure AutoCAD from AutoCAD's Main Menu
     Select Configure plotter from the Configuration menu
     Select Autodesk Device Interface from the list of available plotters
     Select Binary file from the list of output formats available
     Answer Y to the question "Does your plotter have multiple pens? "
     Answer 16 to the question "How many pens does it have: "
     Answer N to the question "Does it have multiple dashed line styles? "
     Answer N to the question "Is the plotter variable speed"
     Answer N to the question "Specify plot size in millimeters"
     Enter a value to the question "Maximum horizontal (X) plot size" eg. 11
     Answer 300 to the question "Plotter steps per inch in the (X) direction"
     Enter a value to the question "Maximum vertical (Y) plot size" eg. 8.5
     Answer 300 to the question "Plotter steps per inch in the (Y) direction"

     The rest of the dialogue is the standard AutoCAD plot dialogue. Select
     the desired size units, plot origin, paper size, rotating plots option,
     adjust area fill option, removal of hidden lines option, and plot
     scale.

     Configure ADI2PS by simply running it if the PEN.CFG file is not
     present, or by using the -R switch to reconfigure it. The dialog issued
     during configuration is self-explanatory. Remember that the pen width
     is specified in PostScript Units !!! Thus the value selected specifies
     the width of a vector drawn using that pen number in multiples of 1/72
     inch.

     Use the AutoCAD PLOT command to create a .plt file. Shell out to DOS and
     run ADI2PS. This step creates either a .ps or a .eps file. Copy this file to the
     printer by using the DOS COPY command to the port to which the PostScript
     device is connected e.g. copy test.ps lpt1:



I hope you find these utilities useful. Some of the "features" not
implemented and mentioned in the documentation above are rather interesting
but one has run out of time for now.

An important note: This is NOT an Autodesk product and the company itself has
little to do with these utilities beyond providing the inspiration for the same.

You can reach me by sending a message to Hans c/o "*SYSOP" on Autodesk's
CompuServe Forum (GO ADESK) or by sending mail over UUCP {sun!acad!hans}.
You cannot reach me over the phone unless you are an Authorized Autodesk
dealer in which case you can call the Autodesk Dealer Support number.


                                        .... Amar Hanspal, Jan '89.
                                             ("The Code Cutter of Calcutta")

                                             Autodesk Inc.
                                             2320 Marinship Way
                                             Sausalito, CA 94965