## [Fun] Spiral animation

Markus Gaelli gaelli at emergent.de
Sun Jun 20 12:34:41 UTC 2004

```Hi folks,

I thought some of you might like it...
I stole the formula at the bottom from Wolframs New Kind of Science:
http://www.wolframscience.com/nksonline/page-411?firstview=1

For an online version of the spirals see:
http://www.squeakland.org/project.jsp?http://www.emergent.de/pub/
smalltalk/squeak/projects/galaxies.001.pr

I find it amazing, that sunflowers (anAngle =  137.5 = 360*(1-phi)),
yin-yang, and lots of other interesting :-/ symbols can be made out of
this simple formula (which I made a bit more complex for aesthetic
reasons).

| backgroundColor  leafSize anExtent aCanvas numbersOfLeafs someColors
aPoint |
backgroundColor _ Color blue muchDarker.
leafSize _ 60 @ 60.
anExtent _ Display extent y @ Display extent y.
aCanvas _ BalloonCanvas extent: anExtent.
numbersOfLeafs _ 200.
someColors _ Color wheel: numbersOfLeafs.
[Display fillColor: backgroundColor.
0
to: 360
by: 0.1
do: [:anAngle |
(1 to: numbersOfLeafs)
do: [:anInt |
aPoint _ (anInt sqrt * ((anInt * anAngle degreesToRadians) cos @
(anInt * anAngle degreesToRadians) sin) * (anExtent - leafSize /
numbersOfLeafs sqrt) + (anExtent - leafSize) / 2) rounded.
aCanvas
fillOval: (aPoint extent: (leafSize * (numbersOfLeafs - anInt) /
numbersOfLeafs) rounded)
color: (someColors at: anInt)].
aCanvas showAt: (Display center - (anExtent / 2)) rounded.
aCanvas fillColor: backgroundColor].
[Sensor anyButtonPressed] whileFalse.
nil]
ensure: [Display restore]

Enjoy,

Markus

```