NAME

SYNTAX

lifeconv -ACDIMPRSpv? [-l pattern-lib] [-g n] file

DESCRIPTION

By default Xlife will run in a window taking up 4/5ths of your screen; you can use your window manager's Zoom or Resize feature to make it fill the whole screen. This window is a viewport on a universe which is effectively unbounded (4.2 billion on a side). Exactly the universe is a big torus.

If an initial pattern is specified, it will be loaded on startup, before Xlife accepts commands.

The -geometry option sets the Xlife window size and position as per usual for X applications. The -display option sets the display to use; overrides the DISPLAY environment variable. The -l option allows you to specify a pattern list library-file for name matching (default is `named-patterns').

lifeconv is a format-conversion utility that translates between several different file formats for saving patterns. It takes a pattern file argument and writes the conversion to standard output. Conversion options are described in the LOAD FILE FORMAT section below. The -g option permits you to evolve a loaded pattern for a given number of generations before saving. The -l option is the same as above. The -? option shows the usage summary. The -v option outputs version information and exits.

A utility table2r may convert table-format file with rules to r-format. This utility is written in awk.

COMMANDS

Tab

Change state 1 cells of tentative pattern to active state. It is useful for the creation of multirules pattern.

!

Place random cells on the area of the universe on the screen.

#

Change tentative-display mode. By default the tentative-pattern cells are displayed in normal state colors but with a bounding box. In the alternate (`wireframe') mode, tentative-pattern cells are displayed as open rectangles in the load-box color, but with no bounding box. Wireframe mode is useful when you are trying to match a loadscript to a template active pattern. It is also useful to compare two patterns.

$

Toggle running display of changed-cell count in per-generation status line. This count makes evolution slightly slower.

%

Set a percentage density for a randomly filled area. Default is 90%.

( [ {

Set a marker at current mouse position. There are three markers, one for each of these characters.

) ] }

Go to a marker (make it the current mouse position). The marker jumped to by each closing bracket is that set by the corresponding open-bracket command.

*,=

Toggle showing of speed in the number of generations per second.

+,=

Zoom the view in, magnifying the area around the mouse cursor. At zoom scale N, cells are two to the power N pixels wide; the default cell size is scale 4, 16 pixels on a side. Scale range is -10 to 6; at scales -1, -2 and -3 a single pixel represents the logical or of a square sample of 4, 16, and 64 pixels respectively. The same effect has the movement of mouse wheel up.

<

Slow down evolution; increase delay by 10 msec.

>

Speed up evolution; decrease delay by 10 msec.

-

Zoom the view out. The same effect has the movement of mouse wheel down.

.

Center the universe view on the cursor (also Button 3 in normal mode).

/

Show quantity of cells of different kinds (colors).

0

Center the median position of the live boxes.

1,End

Move your view of the universe diagonally down and left.

2,Down

Move your view of the universe down.

3,PageDown

Move your view of the universe diagonally down and right.

4,Left

Move your view of the universe left.

5

Center the universe on the screen (based on average position of the cells).

6,Right

Move your view of the universe right.

7,Home

Move your view of the universe diagonally up and left.

8,Up

Move your view of the universe up.

9,PageUp

Move your view of the universe diagonally up and right.

?

Help for xlife. This help may be used as a menu.

@

Toggle 2-state automata history. The history provided by addition of 5 new states: the new cell state 2 means that this cell is dead but was alive earlier, the new states 3 and 4 mean marked ON and OFF respectively (they may be changed to each other so they will always remain marked), the new state 5 means `start ON' (becomes normal marked OFF cell, the state 3, when it dies), the new state 6 means `boundary OFF' (can never turn ON). The history may be also activated by addition of `+' suffix to the string determinating rules.

A

Add comments.

B

Benchmark. Enter number of generations and get time. This is also the fastest mode of the evolution.

C

Clear the universe and discard current load script. If there is a boxed pattern, clear that instead.

D

Discard current load script, including any tentative pattern, but leave cell population intact. (Helpful for using an old pattern as a template to construct a load script).

E

Rotate pseudocolor display modes for 2-state automaton. In display mode 0 (the default) all live cells are displayed normally. In display mode 1, new cells are shown in state 2 color. In display mode 2, new cells are shown in state 2 color and dying ones in state 3 color. In display mode 3, dying cells are shown in state 3 color. In display mode 3, only cells changed from the previous generation are shown (whether alive or dead). Has no effect on N-state automata or a tentative pattern. It has also no effect when scale is below 8:1.

F

Load n-state rules from a given file (see the N-STATE SUPPORT section below). The file with rules may be given by absolute path or just by name of the rules. In the latter case all subdirectories of the default directories will be searched.

G

Generate tentative loaded or active pattern for one or more steps.

H

Toggle history record mode. It is fast mode for any type of automaton. Use `h', These colors maybe changed by `X' command.

I

Force tentative pattern to be incorporated into main pattern (automatic with g, h, o, l, and W commands).

J

Jump to (x,y) location - make it the current mouse position.

K

Discard comments associates with current pattern. It also clears #K line.

L

Immediately reload, at the cursor, a copy of the last pattern loaded.

M

Toggle display of a grid mesh overlaying the board.

N

Change the file's internal name.

O

Set current mouse position to be the origin of displayed coordinates.

P

Toggle the oscillation check mode. The `g' command evolution stops whenever it detects an oscilator in this mode. This command compares the starting pattern with the next patterns. So it just checks whether a given pattern is an oscillator.

Q

Quit

R

Change the (2-state) rules in "stays alive on"/"born on" or B0..8/S0..8 format. The standard rules are 23/3 (alive on two or three neighbors, birth on three neighbors for an empty cell) or B3/S23 or S23/B3. Its possible to use third component which must be number between 3 and 256. This number sets age limit for the cells. So /2/3 establishes Brian's Brain rules and 345/2/4 - Star Wars'. Alternatively, enable a payoff matrix with the syntax <float>$<float> as described in the PRISONER'S DILEMMA section. It is possible to use named rules. The words "life", "seeds", "wireworld", "lifehistory", "life+", and "brian" (for "brian's brain") are recognized.

S

Save the universe to a file adding extension `.l', along with any comments created via `A'. If there is currently a boxed pattern, only the boxed pattern is saved. It is possible to select a format for the saved pattern. See section MAIN LOAD FILE FORMAT for the details.

T

Set up the topology. It is possible to select the rectangular area with connected edges (anchor ring, tore) or the rectangular plain. The letter `Q' (quasiplain) means very big torus - this is the default mode. The letter `T' means limited torus and the letter `P' means limited plain. You should enter rectangle's width and height in the latter cases. The sizes of the rectangle will be rounded up to the multiples of 8. The size 0 means pseudoinfinity. The bounded area center is the initial origin of coordinates. For example, `T16,0', `T8x8', `P0,64', `T4096,4096', `T8X512', `P400*400', `Q' may be used to set up the topology. It is possible to use previous setup. If `T512,512' topology is used then the set `64x' will set `T64*512'. You may set bordered plain with any form for the 2-state automata in the history mode - you should draw borders with 6th color.

U

Undo load of tentative pattern.

V

View comments.

W

Write (and flush from memory) script of loaded patterns into a file with `.l' extension. When loaded, this script corresponds the earliest ancestor of current pattern that can be reconstructed from loaded patterns (it does not include changes made with mouse: flips, rotates, and moves).

X

Load palette from a file with extension .colors (default). This file consists of lines of text. Any blank lines or lines starting with `#' are ignored. The specification of the RGB colors for one or more states should use the lines like these:
color=1 0 0 255 #0000ff
color=2 255 0 0
color=4 255 255 0 cyan
color=5 255 0 255

Y

Yank out active pattern. If tentative one exists then move tentative pattern to the universe.

Z

Restore default palette.

^

Set seed for random number generator.

a

Add n-state transition - 6 digits (one old state, one for each orthogonal neighborhood cell, and one new state) or filled S(N*C)R form. The new rule will be logged to the file new.transitions (this requires write permission for the directory with last loaded pattern).

b

Display the xmin/xmax and ymin/ymax values of the live cells.

c

Toggle showing of cell count. Active cell count makes evolution a bit slower.

d

Duplicate tentative pattern. Allows to create multiple copies of the same object interactively. Just press `d' and then mouse button 1.

f

Set evolution speed for `g' to high (no delay between evolutions), the default.

g

Toggle running the game. Evolve/Stop. Incorporate any tentative pattern. Then step through generations until something exceptional happens, like still life or stability or a key pressed or possible oscillation detection (the last only if a `P' period check is set) or like an `i' timer running out.

h

(Hide) stop displaying after each generation, does not iconify. This mode maybe up to several times faster than established by g-command. However j-command with proper step gives faster speed and more comfortable output.

i

Set up timer. Set the maximum number of generations to perform for following `g' or other evolution commands. A zero value (the default) is interpreted as "never stop". This command is very similar to 'G'.

j

Set jump length (step) for the command `g'. The value 0 or 1 means no jump. The greater value means faster speed.

k

Pick up color from the pattern's cell.

l

Load (actually add) pattern to the universe from a file with extension `.l' (default), `.life', `.rle', `.mcl', `.lif', or `.cells'. This lets you overlay multiple saved states to make for some interesting effects. Loaded pattern is (default) initially considered tentative, and may be manipulated in various ways before incorporating it into main pattern. (To indicate this, it's surrounded by a bounding box.) Clear the universe if you want to start from scratch. It is possible either to select pattern at the widget list directly or to enter pattern name - this will start the search for the requested pattern at current and library directories. There are two modes to load patterns. The first mode is direct. It directly place pattern to the active pattern space. Directly loaded pattern isn't added to the save script. The second mode is tentative. It allows pattern manipulations before its addition to the pattern space.

m

Set evolution speed for `g' to medium (250 msec delay).

n

Goto next object. This command allows to find far ships, etc.

o

Incorporate any tentative pattern, then forward one generation.

p

Toggle running display of mouse position. Position is only for reference during a session, and does not effect coordinates of saved points.

r

Redraw the screen.

s

Set evolution speed for `g' to slow speed (500 msec delay).

t

Test n-state transition. Enter 5 digits (start state and 4 neighbors states), get result state.

u

Undo manipulations of the tentative pattern, but not the load (tentative pattern is restored to the original position and indentation).

v

View internal variable values and other information.

x

Change pivot position of the tentative points to the current position of the mouse.

COMMANDS IN SHIFT MODE

COMMANDS FOR WIDGET

MOUSE WHEEL

BUTTON BINDINGS IN NORMAL MODE

1

Activate a cell at the cursor, giving it the currently selected state. In a 2-state automaton cells are always activated with state 1. In an N-state automaton, you pick your current color as described in N-STATE SUPPORT below.

2

Delete a cell at the cursor (force it to state 0). To clear a region select it by mouse and press C.

3

Erase any previous selection box. If you drag the cursor with button 3 held down, then release it, the rectangle between the press and release points is boxed and made tentative (as though it had just been loaded and not yet incorporated). The tentative pattern can then be moved, flipped, and rotated before re-incorporating it. If you've just clicked at a tile then this tile becomes the center of the screen.

BUTTON BINDINGS WITH TENTATIVE PATTERN LOADED

1

Move pattern to current position.

2

Flip pattern about its x-axis.

3

Rotate pattern clockwise about its origin.

BUTTON BINDINGS WITH STATE WINDOW

1

Select state.

2

Set color for the state.

WIDGET OPTIONS

MAIN LOAD FILE FORMAT

Some format directives may use the offsets which are useful with direct load mode and with I-format. These offsets are ignored in the tentative load mode.

Each image section is interpreted according to the format letter following its section line #. The format letters are:

PATTERN INCLUSION

#I <pattern> <x> <y> <rotate> <flip> <delay>

Any prefix of fields that includes a pattern name is acceptable, with the natural defaults (no delay, no flip, no rotate, no y or x offset).

In the above

<pattern>

is a pattern name (described below);

<x>,<y>

are integers representing horizontal and vertical offsets; and

<rotate>

is an integer that specifies the number of times the pattern is rotated 90 degrees clockwise around the origin. Any rotation value (positive or negative) is acceptable, as all are taken mod 4 (true mod, not "%").

<flip>

is a multiplier (1 or -1) for the y coordinate that specifies a flip about the x-axis. Other integers are accepted and silently mapped to 1.

<delay>

is an integer specifying the number of generations to perform before loading the pattern (negative values have same effect as 0).

Note that all of the transformations applied to an included pattern are taken relative to the pattern that includes it. Thus, loading an assemblage of included patterns works as one would expect.

A pattern name takes one of the following three forms:

<file>

include whole file <file> (like old format)

<file>:<name>

include pattern block <name> in <file>

:<name>

include pattern block <name> in current file

(Note that <file>: is not allowed.)

A file may also include literal or pattern blocks. A pattern block is a pattern given in any acceptable format between a line containing "#B <name>" and another line containing "#E". Pattern blocks are skipped when including a whole file.

(Note that pattern blocks cannot be nested.)

The -I and -C options of lifeconv may be useful for collecting inclusions from multiple files into a single self-contained file.

When you save a pattern in `I' mode, the program automatically does a pattern analysis to detect `blobs' (completely connected regions of live cells). Repeated blobs are recognized, even if they are rotated or reflected. If there is only one blob, the save output is identical to #P format. Otherwise the output is a list of blobs followed by #I lines that will recreate the saved pattern. This has two advantages: duplicate blobs are only written once, and common pattern elements are recognized and named (so the save file is also a census).

The elements container for this recognition is the file "named-patterns" (or file selected by -l option at startup). It specifies the name of a file containing the names of patterns to be recognized and named when doing I-format (structured) saves. A leading slash distinguishes an absolute pathname; otherwise the relative name is searched for beneath the LIFEPATH or default directories (as for a pattern file). Each line of this file contains up to three fields; a pattern name, a pattern file or file:block reference (as for the `l' command) and a cycle length. When the cycle length is 0, only one recognition template is generated from each entry; when it is nonzero, one is generated for each step in the cycle (with steps after 0 distinguished by a number suffix on the name). Thus, for example, an entry that reads

glider ss:glider 2

Will generate two recognition templates, one named `glider' and another named `glider2'. The cycle length is optional and defaults to 0; the second field is optional and defaults to the value of the first. Comments (led by #) and blank lines are ignored. This name container is only activated for the life rules.

The file "named-patterns" default content referes to the file "match.l" which contains named patterns list in the #B/#E-format.

N-STATE SUPPORT

Don't rotate or flip pattern with non-symmetrical rules!

When Xlife is used in this mode, the program uses color to indicate states. Pattern picture files may contain digits to specify the states of picture cells; `*' is interpreted as 1. Color-picker radio buttons are set up at the right-hand side of the input window; by clicking your cursor on a button, you set button 1 to paint with that color. You can return to 2-state mode with the `R' command.

Refer to the rule-set file `codd.r' for an example of transition definition syntax. Each line contains either a directive or 6 digits or letters arranged as

<old-state><neighbor><neighbor><neighbor><neighbor><new-state>

For <old-state> or <neighbor> you may also specify a state set; digits or letters enclosed in square brackets. This wild-cards the transition in the obvious way. You should use letters instead numbers for states above 9, so use A instead 10, B instead 11, and so on. The letter `a' means 36, `b' - 37, etc. The sign `@' means 62, `~' - 63. Comments (begun with `#') are permitted in the file.

You can arrange for rulesets to be loaded automatically by putting a `#U' directive in a pattern file. When you save a pattern, a #U is automatically generated into the save file giving the name of the current ruleset.

The directive

states <maxstates>

tells the code what the automaton's count of cell states is.

Rule tables usually don't specify every possible set of inputs. For those not listed, the central cell remains unchanged if `passive' declaration is not used.

The presence of `passive' declaration will require manual input of missed transition. So if, while evolving a pattern, the code finds a cell and neighborhood in a state for which no transition has been specified, the program queries the user for a new state, and the tuple implied is added to the database. A line of the form

passive <maxstate>

instructs the code that all combinations of cell and neighbor states up to and including <maxstate> for which there is no explicit rule leave the cell status unchanged. A `passive' declaration in a rules file can be partially overridden by later, explicit transition rules. The form `passive 0' is a way to say to use manual input for every missed transition.

The directive

nosymmetries

sets absence of symmetry in rules. It may be used with Langton Ants, Perrier loops, etc.

The directive

rotate4reflect

sets this type of symmetry. It may be used with Bank I, II, III, IV, etc.

The directive

Moore

sets this neighborhood. It may be used with Bank III, etc. The default symmetry is `rotate8'. This directive should precede state or symmetry declaration.

You can also specify rules depending on a neighbor count. A rule line of the form

S(N*C)R

with S, N, C, and R being digits, is interpreted to mean that if a cell has state S and exactly C neighbors of state N, the result state is R. For an example of usage, see the Wireworld-4 rules file. This doesn't works with `nosymmetries' or with `Moore'.

Rules are checked in the order given in the file - the first rule that matches is applied. If you want (`passive' should be set in this case), you can write rules in the form of general cases and exceptions, as long as the exceptions appear first in the file.

When the evolution function encounters a neighborhood for which there is no defined transition, it stops and boxes that neighborhood. You are prompted for a result state. Once you've entered it, the evolution function continues and the new transition rule is appended to a new-transitions file in the current directory. This feature can't be activated because all transitions are defined.

PRISONER'S DILEMMA MODELS

These are two-state automata. In Alun's implementation one state always cooperates, one always defects (higher states could model Tit-for-Tat, Generous Tit-for-Tat, or Pavlov). There is a payoff matrix of the following form:

To make the game interesting, b must be greater than 1. (Lloyd's simulation only considers the case a = 0.) On each round, each cell first plays the game with each of its neighbors in turn. Then, each cell looks at the payoffs of its neighbors (and its own payoff) and switches to the strategy with the highest payoff).

To set up such a game, use the `R' command in the following form:

R<b>$<a>

You may also use #T form in the pattern file.

For example, to set up Lloyd's simulation, do `R1.85$0'. In these simulations, use the following mapping between states and strategies:

0

Quiescent.

1

Live, always cooperates.

2

Live, always defects.

3

A transition, from cooperator to defector. It behaves like defector.

4

A transition, from defector to cooperator. It behaves like cooperator.

Interesting b values are in the range (1, 2]; Lloyd likes 1.85. Different values produce wide ranges of different behaviors, including stable end states, statistical equilibria and cycles with large swings. Initial clustering of cooperators is also important; a single cooperator will always be snuffed by surrounding defectors, but a block of 4 or more may be able to defend themselves and earn a high enough relative payoff to convert neighbors.

Lloyd included illustrations of a 1.85 game starting with one defector in a sea of cooperators. The resulting patterns look like Persian carpets or Koch snowflake curves.

OTHER FEATURES OF RULE FILES AND EDITING

debug NUMBER

is ignored.

Transition rules entered interactively are appended (commented with user ID and timestamp) to the file new.transitions in the current directory. This file can later be selectively merged with your original ruleset using a text editor.

STRUCTURED PATTERN EDITING

               ..*...
               .*.*..
               *...**
               *...**
               *...**
               .*.*..
               ..*...

ENVIRONMENT

If the the variable LIFEPATH is set to a colon-separated list of directories, these directories (and their first-level subdirectories) will be searched for pattern-file names and rulesets. The default list includes "." and LIFEDIR; that is, pattern files are searched for, by default, below the current directory and below the global pattern directory.

The recommended way to organize your pattern directories is to have one subdirectory per automaton. The distribution provides the following:

life

contains an extensive library of interesting Life patterns.

life-like

contains a library of interesting similar to Life patterns (seeds, life without death, highlife replicator, brian's brain, starwars, ...).

codd

contains transition rules and several demos.

devore

variation of the Codd self-replicating computer.

HPP

is the earliest lattice gas model.

perrier

this loop is a self-reproducing calculator.

wireworld

contains transition rules and a test pattern for the Wireworld automaton as described in the January 1990 issue of Scientific American (Computer Recreations, p. 146).

wireworld-4

contains transition rules and test patterns for the Wireworld-4 automata. Wireworld-4 is a variant of classical Wireworld at the von-Neumann-style rotationally symmetric neighborhood.

byl, chou-reggia

contain small n-state replicators.

langton

contains famous loop and ant(s).

evoloop, sexyloop, SDSR

contain evolutionary replicators.

pd

contains patterns for Lloyd's variant of Prisoner's Dilemma games.

These will be copied under LIFEDIR by a normal installation. The distribution may contain additional directories with more patterns.

EXPLORATION

23/3

the default, of course; Conway's "Life" rules.

1234/3

patterns "crystallize"

12345/45

patterns become contained

12345/4

same as above, but settles VERY quickly

5/12

floor tile patterns... Variations of this tend to be interesting as well.

1357/1357

replicators world...

/2

seeds - most patterns expand indefinitely, some interesting ones. Fast gliders.

012345678/3

life without death. Ladders.

AUTHORS

Original X code:
Chuck Silvers

Enhancements to #I format and user interface:
Paul Callahan

Auto-sizing, load format enhancements, 8-state support, all of the non-Life automata, still-life detection, boxing:
Eric S. Raymond

Many new commands, subpixel resolution, M format:
Achim Flammenkamp

A lot of fixes, improvements, and a save/load widget:
Vladimir Lidovski

SEE ALSO