Table of contents

Copyright information
Introduction
Features
System requirements
Usage
Notes
Thanks to
How to reach the author
Revision history


Copyright information

PosterBrot 1.6 - A Mandelbrot set poster generator
Copyright © 1994 George Leonidas Coulouris

        The  author  is not responsible for any damage, whether direct
or consequential, resulting from the use of this program.

        This  program is free software; you can redistribute it and/or
modify  it under the terms of the GNU General Public License Version 2
as published by the Free Software Foundation.

        This  program  is  distributed  in  the  hope  that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY  or  FITNESS  FOR  A  PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

        You  should  have  received  a  copy of the GNU General Public
License  along  with  this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.


Introduction

        PosterBrot is a greyscale Mandelbrot set poster generator.  It
will  generate  a  set of PGM image files, which, when printed, can be
combined into a poster.


Features

        -  Portable.   PosterBrot is written in ANSI C, and can ported
to any platform which supports the standard.

        -  FPU support.  Directly uses the MC6888x, if available.

        -  Smooth.  PosterBrot colors by escape radius, rather than by
escape  iteration.   This  method  produces extremely smooth gradients
with fewer iterations per pixel.


System requirements

        - AmigaDOS 2.0
        - Software suitable for printing PGM images


Usage

        PosterBrot  takes  one  command  line  argument, the file name
under which to store the images.

        PosterBrot  will  then  prompt  for some information about the
poster that you wish to generate.

Mandelbrot attributes:

        xmin :
                Real minimum (left edge) of the poster.

        xmax :
                Real maximum (right edge) of the poster.

        ymin :
                Imaginary minimum (bottom) of the poster.

        ymax :
                Imaginary maximum (top) of the poster.

        Maximum iterations/pixel :
                Maximum number of iterations per pixel.


Poster attributes:

        Width  (pages) :
                Width of the poster, in pages.

        Height (pages) :
                Height of the poster, in pages.


Page attributes:

        Width  (pixels) :
                Width of each page, in pixels.

        Height (pixels) :
                Height of each page, in pixels.

PosterBrot  will  then generate the image files.  PosterBrot will keep
you informed about its progress.

        The  naming  convention  is  filename.x.y,  where  x and y are
two-digit page indices.

Example:

        A 3 x 3 poster would be laid out like this:

        +-------+-------+-------+
        |       |       |       |
        |  0,0  |  1,0  |  2,0  |
        |       |       |       |
        +-------+-------+-------+
        |       |       |       |
        |  0,1  |  1,1  |  2,1  |
        |       |       |       |
        +-------+-------+-------+
        |       |       |       |
        |  0,2  |  1,2  |  2,2  |
        |       |       |       |
        +-------+-------+-------+

Such a poster would produce files like filename.00.00, filename.00.01,
etc.


Notes

        Keep in mind that PosterBrot is not a Mandelbrot set explorer.
I  reccomend  that  you  find  your  coordinates  with  a program like
MandelMania 4.1 (good) or Mand2000 (better).

        There  are a wealth of image processing tools which will allow
you  to  print  the  PGM  images  that  PosterBrot generates.  ImageFX
immediately  comes  to mind, but there are plenty of programs floating
around which will do the job.

        To recompile PosterBrot (using SAS/C 6.3 or later)

on vanilla (non-FPU) systems:

        sc PosterBrot.c link

on MC6888x-equipped systems:

        sc DEF=USEFPU PosterBrot.c iteratec.a link


Thanks to

        · Bill Talkiewicz
        · Don Schmalberger

        · Bob Livingston - Rest in peace, my friend.


How to reach the author

Send feedback, suggestions, flames, etc. to:

        deltax@hermes.acm.rpi.edu


Help to put me through college! Send donations to:

        George L. Coulouris
        Box 4499 Route 32
        Catskill, NY 12414
        USA


Revision history

1.0 - 1.2       Internal revisions.

1.3             15 Jan 93.  First public release.

1.4             21 May 94.  Removed progress report buffering.

1.5             31 May 94.  Rewrote iteration function in
floating-point assembler ( ~17% speed gain ).

1.6             9 June 94.  Tightened assembler code, made PC-relative.
Removed percentage indicator.