By Zevan | November 27, 2009
Actionscript:
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egyptianMultiply(12, 99);
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// trace(12 * 99) // test to make sure it works
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/* outputs:
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/64 768
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/32 384
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16 192
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8 96
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4 48
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/2 24
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/1 12
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---
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1188
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*/
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function egyptianMultiply(valueA:Number, valueB:Number):void {
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var left:Array = [];
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var right:Array = []
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// swap if valueB is smaller than value A
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if (valueB <valueA){
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var swap:int = valueB;
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valueB = valueA;
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valueA = swap;
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}
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// create left and right columns
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var currentLeft:int = 1;
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var currentRight:int = valueA;
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while (currentLeft <valueB){
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left.push(currentLeft);
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right.push(currentRight);
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currentRight += currentRight;
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currentLeft += currentLeft;
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}
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// add up the right column based on the left
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currentLeft = 0;
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var rightSum:int;
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var leftSum:int;
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var i:int = left.length - 1;
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while (currentLeft != valueB){
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leftSum = currentLeft + left[i];
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// if the next number causes the sum
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// to go above valueB, skip it
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if (leftSum <= valueB){
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currentLeft = leftSum;
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rightSum += right[i];
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trace("/" + left[i] + " " + right[i]);
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} else {
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trace(" " + left[i] + " " + right[i]);
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}
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i--;
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}
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trace("---");
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trace(rightSum);
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}
Someone mentioned egyptian multiplication to me yesterday... So read a little about it here and whipped up this example. For some reason I decided to do it in processing ... once it worked I ported it to ActionScript.
The above link describing the technique I used is from http://www.jimloy.com/... I haven't spent much time digging around the site, but it appears to have some pretty nice stuff on it...
If you're curious, here is the original processing version:
JAVA:
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int valueA = 10;
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int valueB = 8;
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if (valueB <valueA){
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int swap = valueB;
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valueB = valueA;
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valueA = swap;
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}
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int currentLeft = 1;
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int currentRight = valueA;
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while (currentLeft <valueB){
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left.add(currentLeft);
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right.add(currentRight);
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currentRight += currentRight;
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currentLeft += currentLeft;
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}
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currentLeft = 0;
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int result = 0;
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int i = left.size() - 1;
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while (currentLeft != valueB){
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int temp
= currentLeft
+ (Integer) left.
get(i
);
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if (temp <= valueB){
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currentLeft = temp;
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println("/" + left.get(i) + " " + right.get(i));
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} else {
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println(" " + left.get(i) + " " + right.get(i));
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}
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i--;
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}
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println("---");
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println(result);
After writing, this I took a look at the wikipedia entry... I also found myself on this short page about a scribe called Ahmes. (I recommend reading this if you are interested in PI)
By Zevan | November 25, 2009
Actionscript:
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var container:Sprite = new Sprite();
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container.x = stage.stageWidth / 2;
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container.y = stage.stageHeight / 2;
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addChild(container);
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var redBox:Sprite = new Sprite();
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redBox.graphics.beginFill(0xFF0000);
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redBox.graphics.drawRect(-50,-250,100,500);
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redBox.rotationZ = 10;
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container.addChild(redBox);
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var logos:Array = []
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var elements:Array = [];
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elements.push({element:redBox, z:0});
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// add the logos
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for (var i:int = 0; i<6; i++){
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var logoContainer:MovieClip = new MovieClip();
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var logoText:TextField = new TextField();
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logoText.defaultTextFormat = new TextFormat("_sans", 50);
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logoText.text = "LOGO";
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logoText.autoSize = "left";
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logoText.selectable= false;
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logoText.x = -logoText.width / 2;
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logoText.y = -logoText.height / 2;
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logoContainer.addChild(logoText);
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logoText.backgroundColor = 0xFFFFFF;
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container.addChild(logoContainer);
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logos.push(logoContainer);
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elements.push({element:logoContainer, z:0});
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}
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var ang:Number = -Math.PI / 2;
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var rotationSpeed:Number = 0.05;
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addEventListener(Event.ENTER_FRAME, onLoop);
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function onLoop(evt:Event):void {
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var dx:Number = (mouseY - stage.stageHeight / 2) / 10;
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var dy:Number = (mouseX - stage.stageWidth / 2) / 10;
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container.rotationX += (dx - container.rotationX) / 4;
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container.rotationY += (dy - container.rotationY) / 4;
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ang += rotationSpeed;
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for (var i:int = 0; i<logos.length; i++){
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var logo:Sprite = logos[i];
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logo.x = 150 * Math.cos(ang + i);
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logo.z = 150 * Math.sin(ang + i);
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logo.alpha = 1 - logo.z / 200;
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logo.rotationY = -Math.atan2(logo.z, logo.x) / Math.PI * 180 - 90;
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}
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// z-sort
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for (i = 0; i<elements.length; i++){
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elements[i].z = elements[i].element.transform.getRelativeMatrix3D(this).position.z;
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}
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elements.sortOn("z", Array.NUMERIC | Array.DESCENDING);
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for (i = 0; i<elements.length; i++) {
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container.addChild(elements[i].element);
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}
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}
A student of mine was having trouble creating a 3D logo for a client. I created this snippet to help explain how some of the fp10 3D stuff works.... z-sorting etc... The code could be optimized a bit... but it works nicely...
Have a look at the swf...
Also posted in 3D, motion | Tagged actionscript, as3, flash, fp10 |
By Zevan | November 23, 2009
Actionscript:
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var connect:Function = function(xp:Number, yp:Number, col:uint=0):Function{
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graphics.lineStyle(0,col);
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graphics.moveTo(xp, yp);
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var line:Function = function(xp:Number, yp:Number):Function{
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graphics.lineTo(xp, yp);
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return line;
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}
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return line;
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}
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// draw a triangle
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connect(200,100)(300,300)(100,300)(200, 100);
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// draw a box
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connect(100,100, 0xFF0000)(150,100)(150,150)(100, 150)(100,100);
This is one of those techniques that I never really get tired of. It's pretty useless, but fun to play around with every now and then. This draws the somewhat boring looking picture below:
[EDIT]
A few people pointed out that this could be simplified with arguments.callee... So here is an example... it does the same thing as the original code...
Actionscript:
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var connect:Function = function(xp:Number, yp:Number, col:uint=0):Function{
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graphics.lineStyle(0,col);
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graphics.moveTo(xp, yp);
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return function(xp:Number, yp:Number):Function{
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graphics.lineTo(xp, yp);
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return arguments.callee;
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}
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}
Also posted in functions | Tagged actionscript, as3, flash |
The other judge for the contest was Rich Shupe. We just reviewed the entries together and have decided on a winner....
The winner is Petri Leskinen (piXelero)
Have a look at the winning snippet if you haven't seen it already.
Rich and I thought that Kyle Phillips deserved honorable mention for his google analytics snippet.
Thanks to everyone who sent in snippets. Even though there were only a handful of submissions I had a good deal of fun reviewing and judging. I still have two more entries that I have yet to publish... so stay tuned...