xmartin(1) USER COMMANDS xmartin(1)
NAME
xmartin - set X root window to Martin hopalong pattern
SYNOPSIS
xmartin [options]
xmartin+ [-q] [-demo] [-n name] [-file file] [options]
DESCRIPTION
Xmartin sets the X root window to a hopalong pattern. Xmar-
tin+ is an optional front end. The hopalong algorithm was
attributed to Barry Martin of Aston University (Birmingham,
England) in A. K. Dewdney's Computer Recreations column in
the September 1986 Scientific American.
OPTIONS
-f { martin1 | martin2 | ejk1 | ejk2 }
Requests a specific hopalong function. Default: ran-
domly selected. The probability that a function will be
selected can be tailored with the xmartin+ front end
described below.
-a -b -c { r | r:r | r::r }
Sets the corresponding hopalong parameter to the real
value r or to a random value in the range r:r or r::r.
Two colons indicate a plus-or-minus range. For example,
-100:1e3 means a value between -100 and 1000, while
1::3 means a value between 1 and 3 or between -1 and
-3. By default, random values are assigned. The ranges
for default random values can be tailored with the
xmartin+ front end described below.
-p n -P n
Sets maximum points to calculate to n. -p sets the max-
imum for in-range (i.e. on display) points. -P sets the
total points to calculate. Defaults: -p: 25% of pixels
in server display (or tile). -P: 3 times the -p value.
-dynam [ nd ]
Requests dynamic display. That is, the pattern is
displayed as calculated instead of all at once when
complete. If present, nd sets the number of in-range
points to calculate before displaying them. Default:
1024 (128 if -tile).
-tile [ XxY ]
Requests that the root window be tiled with a pattern
smaller than the entire display. XxY, if present,
requests a specific tiling pattern. For example, -tile
3x4 requests a tile size of 1/3 the display width and
1/4 the display height. A random XxY is used if not
supplied. This option substantially reduces calcula-
tion time and memory requirements for the pattern.
Amiga Unix Last change: 29 March 1990 1
xmartin(1) USER COMMANDS xmartin(1)
-perturb [ n[,v] ]
Perturbs the calculation every n points by offsetting
the current x and y values by v. If v or n are not sup-
plied, random values are used.
-zoom z
Multiplies calculation coordinates by z before display.
Thus, z > 1 magnifies, and z < 1 reduces. Default: 1.0
(4.0 for martin2.)
-move d,p
Moves the pattern p pixels in the direction d. The
direction d is either a compass degree heading (0 =
north, 90 = east, 180 = south, etc), or the common
abbreviations ('n', 'sw', 'nnw', etc.) Thus, for exam-
ple, -move ne,300 moves the pattern 300 pixels toward
the upper right corner.
-recall
Recalls hopalong parameters (-f, -a, -b, -c, -zoom,
-move, -perturb) from the last pattern before process-
ing any other arguments. Thus, for example, -recall
-zoom 0.5 -perturb will zoom out and add random pertur-
bation to the previous pattern. The recall parameters
are saved in $HOME/.xmartin. A pattern generated with
-recall is not itself saved.
-nc n
For color or grayscale displays, sets the number of
points to calculate before changing colors. (Default:
1/16th of -P value.)
-nrc Non-random color sequence.
-mono
Forces white-on-black for a grayscale (or color)
display. You might try this if you don't care for the
automatic color-to-grayscale mapping.
-v Prints xmartin version and patch level.
FRONT END
On systems with perl installed, the xmartin+ front end may
be used to invoke xmartin with probabilities and parameters
tailored to your preferences, or to request interesting
parameter sets by name. Tailored parameters and recorded
values are stored in $HOME/.xmartin+. -n name requests a
parameter set by name, -q prints the names in the file, and
-file file uses a file other than $HOME/.xmartin+. -demo
executes (using -dynam) each entry once. All xmartin param-
eters (except -f or -recall) are accepted, so you can add to
or alter options generated by xmartin+.
Amiga Unix Last change: 29 March 1990 2
xmartin(1) USER COMMANDS xmartin(1)
If you don't have a .xmartin+ file, one with comments and
examples is created.
RESOURCES
For color or grayscale displays, xmartin honors these
resources (shown with default values):
xmartin*Color1: red
xmartin*Color2: green
xmartin*Color3: blue
xmartin*Color4: yellow
xmartin*Color5: magenta
xmartin*Color6: cyan
xmartin*Color7: coral
xmartin*Color8: slate blue
xmartin*Color9: orange red
xmartin*Color10: spring green
xmartin*Color11: orange
xmartin*Color12: steel blue
xmartin*Color13: pink
xmartin*Color14: violet
xmartin*Color15: firebrick
xmartin*Color16: gold
Colors are used in this order if -nrc is selected, otherwise
they are used in a random order. Color is changed every -nc
n points during the calculation.
BUGS
On some systems, certain parameter combinations cause xmar-
tin to abort with a floating point exception. (The neuron
pattern defined by xmartin+ is an example.) By using -dynam
you can at least see what was generated up to the point the
calculation exceeded your system's limits.
AUTHOR
Ed Kubaitis, Computing Services Office, University of Illi-
nois.
Amiga Unix Last change: 29 March 1990 3