
GFORGE  -   Graphical Fractal Forgery                   v1.2   jpb 12/16/95

Generates 16-bit heightfields for POV-Ray, using a high-quality algorithm:
the IFFT of 1/f noise.  Several parameters give you control over the
appearance of the output, which can range from sand to hills to mountains.
Run the "sample" script to see examples of the output possible.

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COMPILING:
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The program is not fancy and should compile easily under GNU C (gcc)*.  Type
"make big" if your machine stores floating point numbers in IEEE big-endian
format (SPARC, SGI, Motorola, etc.) or "make little" if your floats are in
little-endian format (Intel 80x86/Linux, DEC Ultrix). By the way, this only
makes a difference if you're using the "MAT" Matlab binary format output,
if you never use that format it doesn't matter which you select; the
program will otherwise work fine either way.

* NOTE: The zlib v0.93 code will compile incorrectly at the moment using
gcc 2.6.3 under DEC's OSF/1 (You'll get a segmentation fault when saving a
PNG image). If you are running OSF/1, use DEC's "cc" instead to compile the
code in the zlib directory. This seems unique to OSF; I have compiled
everything with no trouble using gcc 2.6.3 under Sun SunOS 4.1.3, DEC
Ultrix v4.2A, SGI Irix v.4, HP-UX A.09.05, IBM AIX v3.2.5, and MSDOS 5.0
(djgpp 1.12maint4), and also gcc 2.5.8 under Linux 1.1.95.

Once the compile is complete, try running the "gen-tga" script to generate
some example TGA heightfields ready for rendering in POV-Ray, or the
"gen-pgm" or "gen-png" scripts to generate files for viewing directly.  If
you have Tcl7.4/Tk4.0 running on X-Windows, try xforge.tcl for a
rudimentary graphical front-end (work in progress- I just started learning
Tcl/TK this week).

New in version 1.1 is the ability to add craters- thanks Heiko.  New in
v1.1f is PNG output- thanks to G.E. Schalnat at Group 42 Inc. for PNGLIB,
and J-l Gailly and Mark Adler for ZLIB. Also, there are new
frequency-domain filtering options. For more details, see the man page
gforge.1. This is freely redistributable software under the terms of the
GNU Public License; see the enclosed GPL for details.

Updates: at the moment, the very latest version of gforge and also the
quite-possibly-useful "hutil" heightfield utilities package, is available
from  http://jumpjibe.stanford.edu:8080/gforge/  (though this may change).

Authors:
	John Beale                      Heiko Eissfeldt
	P.O Box 8188                    <heiko@colossus.escape.de>
	Stanford CA 94309-8188
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  email: beale@jumpjibe.stanford.edu
<http://www-leland.stanford.edu/~beale>
