Club Amiga de Montreal - CAM/CAM_CD_1.iso/files/256.lha/GhostScript_v1.2/ReadMe.Amiga

Text File | 1989-06-14 | 7KB | 181 lines

Amiga Version of GhostScript 1.2

Changes to this version were preformed by Stephen Vermeulen, complete
source code for this version is available by writing

         Stephen Vermeulen
         Apt. 6 - 2312 - 22 St. N.W.
         Calgary, Alberta,
         Canada, T2M 3W4.

And including either a check for $10.00 or a $5.00 check and 2 disks.
Source code may be further redistributed under the terms of the
GNU License.

Memory Requirements:

This version of GhostScript requires around 1Meg to run, and may need
even more depending on the complexity of the page and the printer
resolution being used.  If you are using a 24 pin printer you may need
as much as 1.3Megs more to run it in the higher density modes.  It
is recommended that you first try using GhostScript in the screen
preview (-s) mode (this needs the least memory) and then try using
it with Preferences set to the LOWEST density setting (1) in the
Graphics 2 screen of preferences.

you might also need to use a 10,000 byte stack.  This is what I
normally use so I don't know if you can get away with less.

Use:

To use the files in this zoo file, put all the files in the same
directory and then assign T: to a directory where GhostScript
can write a small temporary file.

On the Amiga you run GhostScript with a command simliar to

     GS

which will just print the source code source message, or

     GS -s

which will start GhostScript and send output to a custom screen
and will await PostScript commands from the user. Or,

     GS input.ps -s

****
****  Note: it is normal to get a cannot find GS.MAP error, ignore it.
****

Where "input.ps" is the name of a file containing a PostScript
language document to be printed or displayed.  You may have a number
of files on the command line separated by spaces.  The "-s" switch
on the end of the line specifies the output device and is mandetory.
The following output devices are supported:

    -s   A custom screen that is interlaced and sized to the max
         display dimensions.  To see the actual dimensions employed
         take a look at the t:ghost_init.ps file that is created
         after the program has run.

         Since this is a preview mode the quality will be VERY poor.
         Also the output will pause at the end of each page until
         you click the mouse somewhere in the preview screen.

         This mode is most useful when learning how to program
         in PostScript since it gives you nearly immediate, paperless,
         feedback.  Remember to issue the "stroke" command to get
         your work actually painted on the display...

    -p   Use the Amiga's printer device for printing the result.
         GhostScript will read the current preferences graphics settings
         and determine the correct bitmap size to use.  GhostScript
         will then render to that bitmap and every time a "showpage"
         command is found will dump the bitmap to the printer. You can
         control the page size by changing the "Density"
         (1/2/3/4/5/6/7) settings and the "Limits"
         (Ignore/Bounded/Absolute/Pixels) settings in the "Graphics 2"
         screen of Preferences.

         Avoid settings where the pixel aspect ratio is extreme
         (probably over 2), as is the case with EpsonX and Density 3,
         these will cause GhostScript to toss its cookies... (luckily
         it does not seem to GURU in these cases)

The following switches apply to anyone who has a LazerXpress printer
from CLtd, or who has a copy of Express Paint 3.0.  For these to
work you need to have the VirtualPage.Library installed in your LIBS:
drawer.  In this case there is an extended syntax, for example:

  GS file.ps [-xNNNN] [-yMMMM] -vn

The -x and -y switches are optional, they must each be immediately
followed by a number, and if present they must PRECEED the mode
selection switch (-vn, -vp, -wn, or -wp) and follow any file names
or regular GhostScript switches.  Only one mode selection switch
is allowed, and it must be the LAST item on the command line.  If
a mode selection switch does not appear an error message will result.

   -xNNNN  specifies the width of the virtual page in pixels.
           If it is not present then a default of 2448 will
           be used (ie. -x2448).  This number should be a
           multiple of 16 (hardware reasons) and GhostScript
           will make it so by masking off the lower 4 bits
           (this rounds down the number).

   -yMMMM  specifies the height of the virtual page in pixels
           If it is not present the default value of 3204 will
           be used.

The following mode selection switches are used for virtual page printing
control:

   -vn  Render the output to a virtual page, but do NOT print it
        or erase the page when a "showpage" command is issued.
        This is useful for using GhostScript as a front end to
        Express Paint (or another virtual page supporting program).
        In this mode you can fire up GhostScript, print a page
        and then edit that page further in Express Paint 3.0 by
        starting Express Paint after GhostScript has started and
        selecting GhostScript's virtual page from Express Paint's
        startup window.  To print the virtual page you can use
        Express Paint's printer tool, and you can save the result
        as an IFF picture file if you wish.

   -vp  This renders the output and prints it using the virtual
        page library's printer support function.  When a "showpage"
        command is reached this mode will print the page (this will
        take about 10 seconds for a LazerXpress system) and it
        will then erase the page and start rendering the next page.
        Note: the current LazerXpress will probably print a white on
        BLACK (negative) image with this switch.

   -wn  Render the output to a virtual page and then invert it
        (flip all the bits) but do not print it.  This is the companion
        to -vn, except it will flip the bits resulting in a negative
        of what -vn produces, depending on your normal editing
        colours this negative may actually be a positive...

   -wp  Render the output, invert it (make a negative) and then
        print it using the virtual page library's printer function.
        This is the companion to -vp but on a LazerXpress system is
        the correct mode to use since it will produce black on white
        pages.

Examples:

This zoo distribution contains two example files, both of which were
derived from my thesis:

    mesh2.ps   is a single page PostScript file containing text
               and graphics.

    mesh.ps    is a six page PostScript file containing text and
               graphics, mesh2.ps is the second page of this file

both files were created with AmigaTeX on the Amiga and the graphics
were imported from FrameMaker on the SUN.  As such they give
GhostScript a pretty good workout and show some of its flaws.

Exiting:

When GhostScript is done you will be looking at a "GS>" prompt,
at this point you can issue PostScript commands or can return to
the CLI by typing

       quit

You might also try typing the following at the prompt:

        100 100 moveto
        600 600 lineto
        stroke
        showpage

and see what happens...

Have fun... Stephen Vermeulen May 1989.