OS/2 Professional/OS2PRO194.ISO/os2/prgramer/mirrors/pmlife.hlp

OS/2 Help File | 1993-01-18 | 21KB | 425 lines

ΓòÉΓòÉΓòÉ 1. Help Index ΓòÉΓòÉΓòÉ

Help Index


General Information
Life's Rules
File
Import
Export
Edit
Copy
Cut
Paste
Move
Delete
Options
Clear
Dimensions
Toggle
Alive
Dead
Step
Start
Stop


ΓòÉΓòÉΓòÉ 2. General Information ΓòÉΓòÉΓòÉ

General Information

The Life game was created by John Horton Conway.  Conway was a mathematician at
Gonville and Caius College of the University of Cambridge.  One of the first
publications of the rules for this algorithm was made in the Mathematical Games
feature of Scientific American some years ago.

Written well before the era of personal computers, the Scientific American
article suggests using a checkerboard and checkers or poker chips to represent
the Life universe.  There have been some advances since then, but Life's rules
are still the same.  This present application is an elaborate adaptation of
Conway's idea.

This adaptation of the Life game was written originally by Steve Emmons at
Micrografx.  Michael Harrison made substantial modifications.  David M. Wilson
enhanced the performance.  This on-line information was written by Derrel R.
Blain.

For a complete description of how the Life game works see Life's Rules.


ΓòÉΓòÉΓòÉ 3. Life's Rules ΓòÉΓòÉΓòÉ

Life's Rules

The Life universe, consists of a starting pattern of cell or organisms within a
framework of adjacent squares.  These cells are born, die, or survive for each
step or generation according to a set of simple rules.

Conway's original rules, to which this application conforms, are as follows:

    Survivals

    Every cell with two or three neighboring cells survives until the next
    generation.

    Deaths

    Cells with four or more cells adjacent to them, in any single generation,
    die from overpopulation.  Every cell with one or fewer neighbors dies from
    isolation.

    Births

    Each empty cell which is next to exactly three neighbors will experience a
    birth in the next cycle.


How The Game Proceeds

The game begins with an initial population or pattern which you create using
the mouse by clicking on cells in the Life universe.  At each step or
generation, all births and deaths within the Life universe occur simultaneously
according to the rules listed above.  The cycles or generations continue until
there is no change in the pattern.


Example

In the example pattern below, you can see three succsesive generations of three
different cell groups.

    First Generation

    Our example begins with a pattern of three isolated groups of cells.  Each
    of the cells is colored red to signify that it is a new cell.



    Second Generation

    Notice the changes in this second generation.  Each of the cells that
    remain from the preceding generation are colored blue.  Cells that were
    born in this generation are colored red.  Two cells in the left group have
    died from isolation.  In the middle group, a new cell has been born.  In
    the right group two cells died and two others were born.



    Third Generation

    In this third generation, all the cells in the left hand group have
    expired.  The group in the middle has reached a stable condition and will
    remain in this state as long as the Life universe continues.  You can see
    that the cells at the right are now at the same state in which they were
    prior to this generation.  This particular pattern will continue to
    oscillate with a period of two steps for as long as the Life universe
    continues to cycle.



Other Patterns

The files distributed with this application include other examples of both
stable and oscillating patterns.  Some patterns oscillate with a long period of
several steps.  Others, named "Walkers" or "Gliders", actually move across the
Life universe by replicating and shifting themselves using several steps.


ΓòÉΓòÉΓòÉ 4. File ΓòÉΓòÉΓòÉ

File


The commands in this menu enable you to import and export patterns as files.
Export will write a cell pattern to disk.  Import will read a pattern file from
disk.

The command available in this menu are :

Import
Export


ΓòÉΓòÉΓòÉ 5. Import ΓòÉΓòÉΓòÉ

Import

Use import to read a cell pattern file from disk.

To Import a pattern:

1.  Select Import in the File menu.
2.  Either select a pattern file name with the mouse or enter the valid name of
a pattern file in the dialog box.
3.  Move the cursor to the upper left corner of the area in which you want the
imported pattern to be pasted.
3.  Click the mouse button.


ΓòÉΓòÉΓòÉ 6. Export ΓòÉΓòÉΓòÉ

Export

Use Export to save a portion of Life's cell pattern as a file.

To Export a pattern to a file:

1.  Select Export.
2.  Place the cursor at one corner of the area to be saved.
3.  Click and drag the cursor to the opposite corner of the pattern area.  The
Life game will display a square around the selected area as you click and drag.
4.  Release the mouse button.


ΓòÉΓòÉΓòÉ 7. Edit ΓòÉΓòÉΓòÉ

Edit

The commands in this menu enable you to modify the displayed pattern.  Changes
may be made to the displayed pattern at any time when the Life universe is not
cycling though successive generations.

They are:

Copy
Cut
Paste
Move
Delete


ΓòÉΓòÉΓòÉ 8. Copy ΓòÉΓòÉΓòÉ

Copy

Use Copy to copy an area of the displayed cell pattern to the Clipboard.  The
pattern on the display is not changed.  The cell pattern is saved to the in a
binary format intelligible only to the Life application.  You will not be able
to view the pattern in the Clipboard with another application.

To Copy a pattern:

1.  Select Copy in the File menu.
2.  Place the cursor at one corner of the pattern area to be copied.  This may
be only a portion of the complete Life universe displayed.
3.  Click and drag the cursor to the opposite corner of the pattern area.  The
Life game will display a square around the selected area as you click and drag.
4.  Release the mouse button.


ΓòÉΓòÉΓòÉ 9. Cut ΓòÉΓòÉΓòÉ

Cut

Moves a pattern to the Clipboard, replacing the previous Clipboard contents.
The pattern on the display is removed.

To Cut a pattern:

1.  Select Cut.
2.  Place the cursor at one corner of the pattern area to be Cut.
3.  Click and drag the cursor to the opposite corner of the pattern area.  The
Life game will display a square around the selected area as you click and drag.
4.  Release the mouse button.


ΓòÉΓòÉΓòÉ 10. Paste ΓòÉΓòÉΓòÉ

Paste

Inserts the pattern from the Clipboard at the cursor.  A pattern must have been
cut or copied to the Clipboard previously.

To paste a pattern from the Clipboard:

1.  Select Paste from the Edit menu.
2.  Place the cursor in the Life universe where the upper left corner of the
pasted pattern should begin.
3.  Click the mouse.

How the cells from the Clipboard are pasted into the displayed pattern depends
on the options Toggle, Alive, and Dead.

If Toggle is currently selected, then any place where one cell would be pasted
over another, the cell is dead after the paste.  Any place where only one cell
is pasted, the cell remains alive.  Dead cells are not changed.

If Alive is currently selected, then any place where a cell is to be pasted is
marked as alive.  Alive cells from  the previous pattern are not changed.

If Dead is currently selected, any place where one cell is pasted over another
is marked as dead.  Other cells are not changed.  No new cells are made alive.


ΓòÉΓòÉΓòÉ 11. Move ΓòÉΓòÉΓòÉ

Move

Move enables you to select a portion of the displayed to be moved within the
display.  The moved pattern is also copied to the Clipboard.

To Move a pattern:

1.  Select Move from the Edit menu.
2.  Place the cursor at one corner of the area to be moved.
3.  Click and drag to the opposite corner of the pattern to be moved.
4.  Release the mouse button.
5.  Move the cursor inside the box bounding the selected area.
5.  Click and drag the box to the area where the moved pattern should be
pasted.
6.  Release the mouse button.


ΓòÉΓòÉΓòÉ 12. Delete ΓòÉΓòÉΓòÉ

Delete

Deletes a portion of the displayed pattern.  The contents of the Clipboard are
not changed.

To Delete a pattern:

1.  Select Delete from the Edit menu.
2.  Place the cursor at one corner of the pattern area to be deleted.
3.  Click and drag the cursor to the opposite corner of the pattern area.  The
Life game will display a square around the selected area as you click and drag.
4.  Release the mouse button.


ΓòÉΓòÉΓòÉ 13. Options ΓòÉΓòÉΓòÉ

Options

The menu selection available under the Options menu enable you to customize
some of the operations of the Life game.

Clear
Dimensions
Toggle
Alive
Dead


ΓòÉΓòÉΓòÉ 14. Clear ΓòÉΓòÉΓòÉ

Clear

Use Clear to eliminate all living cells from the displayed pattern.


ΓòÉΓòÉΓòÉ 15. Dimensions ΓòÉΓòÉΓòÉ

Dimensions

Use Dimensions to change the size of the Life universe.

To use Dimensions:

1.  Select Dimensions in the Options Menu.
2.  Enter a new number for the horizontal cells.
3.  Enter a new number for the vertical cells.
4.  Select OK or Cancel

If there are any living cells in the Life universe before the dimensions are
changed, these will be eliminated.


ΓòÉΓòÉΓòÉ 16. Toggle ΓòÉΓòÉΓòÉ

Toggle

Use the Toggle option to change the manner in which cells clicked on with the
mouse behave.  If the Toggle option is selected, clicking on a living cell will
cause it to die and clicking on a dead cell will cause it to be marked as
alive.


ΓòÉΓòÉΓòÉ 17. Alive ΓòÉΓòÉΓòÉ


 Alive

Use the Alive option to change the manner in which cells selected with the
mouse behave.  If the Alive option is selected, clicking on any cell, living or
dead, will cause that cell to be marked as alive.


ΓòÉΓòÉΓòÉ 18. Dead ΓòÉΓòÉΓòÉ

Dead

Use the Dead option to change the manner in which cells selected with the mouse
behave.  If the Dead option is selected, clicking on any cell, living or dead,
will cause that cell to be marked as dead.



ΓòÉΓòÉΓòÉ 19. Step ΓòÉΓòÉΓòÉ

Step

Use Step to cause one cycle or generation of the Life universe.


ΓòÉΓòÉΓòÉ 20. Start ΓòÉΓòÉΓòÉ

Start

Use Start to cause the Life universe to cycle through successive generations
automatically.


ΓòÉΓòÉΓòÉ 21. Stop ΓòÉΓòÉΓòÉ

Stop

Use Stop to cause the Life universe to discontinue its generation.


ΓòÉΓòÉΓòÉ 22. Click and Drag ΓòÉΓòÉΓòÉ

Click and Drag


To Click and Drag means to place the cursor at some beginning position, hold
down a mouse button (usually the left button), then move the cursor to a new
position while holding the mouse button down.


ΓòÉΓòÉΓòÉ <hidden>  ΓòÉΓòÉΓòÉ

Cell


A cell is one of the spaces within the life universe.  Cells may be either
alive or dead.  Dead cells are not displayed.


ΓòÉΓòÉΓòÉ <hidden>  ΓòÉΓòÉΓòÉ

Clipboard


The Clipboard is a temporary storage area.


ΓòÉΓòÉΓòÉ <hidden>  ΓòÉΓòÉΓòÉ

Pattern


A pattern is a collection of living cells.


ΓòÉΓòÉΓòÉ <hidden>  ΓòÉΓòÉΓòÉ

Generation


A generation or step occurs when all the rules for birth, life, and death are
applied to all cells within the Life universe simultaneously.