Tag Archives: actionscript

Odd Even Classic

Actionscript:
  1. // from http://www.bit-101.com/blog/?p=729
  2. var number:Number = 10.5;
  3.  
  4. // for numbers
  5. var isEven:Boolean = (number % 2) == 0;
  6. trace(isEven);
  7.  
  8. // for ints
  9. var integer:int = 10;
  10. isEven = (integer & 1) == 0;
  11. trace(isEven);

This is a classic that I've seen all over the place online... found myself needing it today and figured I should post it. It just an easy way to determine if a number is odd or even... I remember originally reading it over at Bit-101.com a few years back...

Two posts today because I think I missed a post recently...

Posted in Math, Operators | Also tagged | Leave a comment

Difference Between Two Angles

Actionscript:
  1. // from http://codebase.dbp-site.com/code/find-difference-between-two-angles-25
  2. function angleDifference(angle0:Number, angle1:Number):Number{
  3.     return Math.abs((angle0 + 180 -  angle1) % 360 - 180);
  4. }
  5.  
  6. trace("get the angle between:");
  7. trace("350 and 10 =", angleDifference(350, 10));
  8. trace("180 and -1 =", angleDifference(180, -1));
  9. trace("-10 and 5 =", angleDifference(-10, 5));
  10. trace("725 and -45 =", angleDifference(725, -45));
  11. /* outputs:
  12. get the angle between:
  13. 350 and 10 =  20
  14. 180 and -1 =  179
  15. -10 and 5 =  15
  16. 725 and -45 =  50
  17. */

This snippet shows an easy way to find the difference between two angles. The tricky part about doing this is finding the difference between something like 350 and 1 (which should be 11).

Over the years I have done this a few different ways - I needed it for something today and realized that my way was a tad clunky (had a little redundant logic) - So with a quick google search I found a more elegant solution.

Posted in Math, misc, motion | Also tagged | 9 Comments

Mouse.cursor

Actionscript:
  1. var count:int = 0;
  2. var cursors:Array = [MouseCursor.ARROW, MouseCursor.BUTTON, MouseCursor.HAND, MouseCursor.IBEAM];
  3. setInterval(changeMouse, 100);
  4. function changeMouse():void{
  5.     Mouse.cursor = cursors[count % cursors.length];
  6.     count++;
  7. }

This is a small snippet that shows the cursor property of the Mouse class. This is fp10 only...

Posted in UI | Also tagged | Leave a comment

QuickBox2D Play

Actionscript:
  1. import com.actionsnippet.qbox.*;
  2. import Box2D.Common.Math.*;
  3.  
  4. [SWF (backgroundColor=0xaa0000, width=700, height=600)]
  5.  
  6. const TWO_PI:Number = Math.PI * 2;
  7.  
  8. var sim:QuickBox2D = new QuickBox2D(this,{gravityY:20, debug:false});
  9.  
  10. var i:int = 0;
  11.  
  12. // add some circles
  13. var circles:Array = [];
  14. var circleNum:int = 20;
  15. for (i = 0; i<circleNum; i++){
  16.     circles[i] = sim.addCircle({x: 8, y:-2 - i, radius:0.1 + Math.random()*0.4, fillColor:0x000000});
  17. }
  18.  
  19. // add some boxes
  20. var boxes:Array = [];
  21. var boxNum:int = 20;
  22. for (i= 0; i<boxNum; i++){
  23.     var rx:Number = 4 + (i % 5) * 4;
  24.     var ry:Number =  4 + int(i / 5) * 4;
  25.     var ra:Number = Math.random() * TWO_PI;
  26.     boxes[i] = sim.addBox({x:rx, y:ry, width:3, height:0.4, angle:ra, density:0,fillColor:0xFF2200});
  27. }
  28.  
  29. // vector(0,0) used to reset velocity
  30. var resetVec:b2Vec2 = new b2Vec2();
  31.  
  32. sim.start();
  33. sim.mouseDrag();
  34.  
  35. addEventListener(Event.ENTER_FRAME, onLoop);
  36. function onLoop(evt:Event):void {
  37.      // rotate all boxes
  38.      for (i= 0; i<boxNum; i++){
  39.         boxes[i].angle += .05;
  40.      }
  41.      // move circles to top of sceen after they fall off bottom
  42.       for (i= 0; i<circleNum; i++){
  43.         if (circles[i].y> 20){
  44.             circles[i].y = -1;
  45.             circles[i].x = Math.random()*(stage.stageWidth / 30 - 9) + 4;
  46.             // access to Box2D b2Body methods
  47.             circles[i].body.SetLinearVelocity(resetVec);
  48.         }
  49.      }
  50. }

This is another QuickBox2D experiment. If you don't know what QuickBox2D is ... read about it here.

Take a look at the swf here

Posted in Box2D, QuickBox2D, motion | Also tagged , | 1 Comment