Kalifescope

Found here in the appstore

The free Lite version is here

Kalifescope is an interactive pattern generator based on a cellular automaton. These patterns are alive, they evolve in successive generations. The shape and color of a generation is determined by simple rules applied on the previous generation. A pattern consist of cells, each pixel on your iPhone represents a single cell.

A cell has a state; it is either alive or dead. A living cell has a color; this color is drawn as a pixel on the screen of your iPhone. The pixels of the full pattern consist of a grid of cells; each cell is surrounded by a number of neighbors. This grid wraps around like a donut: the neighbors of the right border are in the left border, the neighbors of the bottom are in the top. The state of a cell in the next generation is determined by considering its own state, is it alive or dead, and by counting the number of neighbor cells alive. Which state and neighbors to consider and which count leads to life or death leads to different rules. Kalifescope implements three different variations, including the rule known as “Conway’s game of life”.

Kalifescope implements a large number of rules to determine the color of a newborn cell. It can be simple like a random or fixed color; it can be complex like blending into the color of its living neighbors; or even more complex like blending into its neighbors colors with a preference for red, blue, green or white.

Kalifescope is, in contrast to other implementations of the game of life, interactive. With your finger you draw over an evolving pattern. There are two modes of drawing. Color only recolors living cells, in full mode your finger creates new living cells. The default mode is color only.

Live Step Hibernate

Swipe two fingers over the screen of your iPhone to pause the pattern; the bottom toolbar shows three options.

• Live: Continue
• Next step: Calculate the next generation and pause
• Hibernate: Pause the evolution

You can continue to draw and color on a paused pattern.

In the full version of Kalifescope, not in the Lite one, swiping will also open the settings menu to influence and set the rules for the pattern.

Drawing

Drawing mode is set in the drawing menu

When drawing three different pens shapes are available: circle, diamond and square. The thickness of the pen is determined by your drawing speed; moving your finger slowly over the screen results in a thin pen; moving it fast in a thick one.

Pen shape is also set in the drawing menu. The default shape is rounded.

The color rule for the new or recolored cells is also selected here.

Birth

Every generation new cells are born. The color of a new cell is determined by the color rule in the birth menu.

When blending the color of the neighbor cells influences the color of the new cell.

Which new cells are born is determined by the birth rule.

These rules deal with one or more of these aspects

• The state of the cell itself
• The state of the cells neighbors
• The position of the neighbors. Each cell has 8 neighbors. Different rules consider different neighbors.

Kalifescope implements three different rules.

• Ka-Life 1 : A cell will be alive in the next generation when it has 1 or 3 orthogonal living neighbors.
• Ka-Life 2 : A cell will be alive in the next generation when it has 1 or 3 diagonal living neighbors.
• Conway’s game of life : A living cell will stay alive in the next generation when it has 2 or 3 neighbors. A dead cell will become alive when it has 3 neighbors.

Start new life

There are several ways to start a new pattern

Blank. Draw a starting pattern with your finger.

Bull’s eye. A group of concentric lines is drawn. The shape of the line is determined by the current pen shape. These patterns evolve in a fascinating way.

Elifent. A small elephant starts the pattern. This is homage to dr Paulien Hogeweg who, way back in 1978, demonstrated the principles behind Kalifescope using an elephant as pattern and got me hooked to IT forever. See what happens.

Picture / photo. Pick an image or take a photo as starting pattern. All colored pixels in the image will become a live cell. When taking a photo the threshold for a live cell is determined by the threshold value in the settings.

Settings

These settings are saved on your iPhone

• Birth rate. This is the animation speed and determines how often the pattern is updated.
• Photo threshold. When taking a photo almost every pixel has some color. This setting determines the amount required to initialize a living cell.
• Welcome message. Show welcome message at startup.

Recommended

There are many combinations possible; each leading to different results. Some recommendations to get an idea of the possibilities:

• Just watch the default starting pattern for a couple of hundred of generations. Will the original pattern ever come back ?
• Switch the rule to Conway’s game of life. Start with a “Bull’s eye”. Do you notice the difference between Ka-Life and Conway ?
• Switch the rule after several generations. Start with Ka-Life, wait for a pattern to appear which you like and switch to Conway. Will the pattern ever become stable ?
• Draw new cells in an evolving Ka-Life pattern. Start with a “Bull’s eye”. After several generations draw your own cells over a part of the pattern. See how the parts of the pattern evolve.
• Draw new cells in an evolving Conway pattern. Can you produce gliders or pulsars ?

Known Issues

• Drawing in blend mode will not work when the pattern is empty. Blending black with black leads to black.
• Battery life. Computing a new generation in an evolving pattern is processor intensive. Watch your battery.
• Having picked a custom color this color might automagically turn to black after reentering the menu.