FRACTAL FROLICS

by The Fractal Farm



Possibly the most devastating response to my recent fractal request

came from the appropriately-named Fractal Farm, an outfit consisting

of Thomas Rushton who handles algorithms and Jonathan Scott who does

the coding. They sent in a C90 packed with stuff, a selection of which

is printed below. The first three are pretty short, but the fourth

will take a little effort. And look - no hex!



Chaos

This produces randomly generated fractal patterns, the shapes of which

depend on three numbers which are entered when the program is run.

These should be between -2 and +2. The guys at the Farm recommend

trying phone numbers. For example, 0.01, 0.631 and 0.1433. As with all

fractal programs, it takes ages to run but pretty patterns start

appearing almost straight away.



Crystals

This program demonstrates the growth of a crystal using a highly

scientific technique which I won't go into now, and it shows (it sez

ere) how small imperfections can go on to trigger larger ones. Knock

it in and see what happens.



Fern

A classic example of a naturally occurring fractal is a fern. Each leaf

is a replica of the main plant, and branching off from the stem of the

leaf are lots of even smaller copies. This means that realistic ferns

can be easily drawn on the Speccy, and here's a program to do it.



All you have to do is type in a couple of branch angles (0-90 degrees

would be sensible) and then wait.



Landscapes

This is the longest program, probably because it gives the most

elaborate results. It draws 3D wire-frame landscapes which can be

shaped by altering a range of probabilities.



On running the program, a short menu pops up. Pressing 1 or 2 draws a

landscape (mini or full) and 3 lets you alter the probabilities.

What's happening here is that each x and y value on the grid on which

the landscapes are drawn is assigned a probability - the higher the

value, the more likely a piece of land will appear on it. There are

two screens, one for x values and one for y, which can be swopped

between by pressing X and Y. The cursor keys are used to increase or

decrease the values at each position up to a maximum limit. The amount

of unused probability, as it were, is shown on the right of the screen

- it must all be used up before this section can be left.



Sounds a bit fiddly, I know, but the results are excellent.



The Fractal Farm boys have announced the impending arrival of a second

tape-full, so watch this space. All right, you can stop now.