forked from: forked from: Perfect Shuffle Visualization
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Perfect Shuffle Visualization
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How many times does it requires for 15 cards to
go back to where one started?
inspired by:
http://d.hatena.ne.jp/nishiohirokazu/20100107/1262835414
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The Perfect Shuffle resets order when ...
cards = (1<<(n>>1))-((n&1)<<1);
steps = (n&~1)>>(n&1);
Press left or right arrow to change the n value.
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/**
* Copyright xor ( http://wonderfl.net/user/xor )
* MIT License ( http://www.opensource.org/licenses/mit-license.php )
* Downloaded from: http://wonderfl.net/c/y215
*/
// forked from keim_at_Si's forked from: Perfect Shuffle Visualization
// forked from nitoyon's Perfect Shuffle Visualization
//------------------------------------------------------
// Perfect Shuffle Visualization
//------------------------------------------------------
// How many times does it requires for 15 cards to
// go back to where one started?
//
// inspired by:
// http://d.hatena.ne.jp/nishiohirokazu/20100107/1262835414
//
//------------------------------------------------------------
// The Perfect Shuffle resets order when ...
// cards = (1<<(n>>1))-((n&1)<<1);
// steps = (n&~1)>>(n&1);
// Press left or right arrow to change the n value.
//------------------------------------------------------------
package {
import flash.events.*;
import flash.display.*;
import flash.text.*;
import flash.filters.BlurFilter;
import frocessing.color.ColorHSV;
[SWF(width="465",height="465",backgroundColor="0x000000")]
public class main extends Sprite {
private const RADIUS:Number = 230;
private const HOLE:Number = 40;
private var index:int = 12;
private var canvas:Shape = new Shape();
private var textField:TextField = new TextField();
public function main() {
addEventListener(Event.ADDED_TO_STAGE, init);
if(null != stage) init();
}
public function init():void {
stage.scaleMode = "noScale";
graphics.beginFill(0x000000);
graphics.drawRect(0, 0, 475, 475);
graphics.endFill();
with (addChild(canvas)) {
filters = [new BlurFilter(2, 2)];
y = x = 232;
}
addChild(textField);
stage.addEventListener("keyDown", function(e:KeyboardEvent):void {
index += (e.keyCode == 37) ? -1 : (e.keyCode == 39) ? 1 : 0;
if (index == 0) index = 1;
drawPerfectShuffle(canvas.graphics);
});
drawPerfectShuffle(canvas.graphics);
function drawPerfectShuffle(g:Graphics) : void {
var size:int = (1<<(index>>1))-((index&1)<<1);
var step:int = (index&~1)>>(index&1);
var angleStep:Number = 6.283185307179586/step;
var thickness:Number = 16/index;
var num:int, i:int, j:int;
g.clear();
for (i=0; i<size; i++) {
num = i;
g.lineStyle(thickness, new ColorHSV(i * 270 / size, .7).value, .7);
g.moveTo(0, num*(RADIUS-HOLE)/size+HOLE);
var th:Number = angleStep, cth:Number, dist:Number;
for (j=0; j<step; j++, th+=angleStep) {
num <<= 1;
num += (num < size) ? 1 : -size;
dist = num*(RADIUS-HOLE)/size+HOLE;
cth = th - angleStep*0.3;
g.curveTo(Math.sin(cth) * dist, Math.cos(cth) * dist, Math.sin(th) * dist, Math.cos(th) * dist);
}
}
textField.htmlText = "<font color='#ffffff'>n=" + String(index) + "</font>";
}
}
}
}