Comments on: Step by step AS3 translation of Flash game creation tutorial – part 2

By: escorpior

escorpior — Tue, 20 Apr 2010 09:07:06 +0000

Realy nice tutorial, thank you very much.

By: kyle_mantesso

kyle_mantesso — Fri, 26 Sep 2008 14:45:42 +0000

hey just wanted to thank you for all the tutorials! im writting a game in AS3 using the nintendo wiimote for uni and I have found these tutorials very useful, thank you!

By: ZealousZephyr

ZealousZephyr — Wed, 16 Jul 2008 20:50:52 +0000

I wrote a function for circle hit tests for a game before.

function circleHitTest(
circ1:MovieClip,
circ2:MovieClip,
extra:Number = 0):Boolean{
//get distances between two circles
var dx:Number = circ1.x – circ2.x;
var dy:Number = circ1.y – circ2.y;
//get “direct” distance
var td:Number = Math.sqrt(dx*dx + dy*dy);
//if the radius of both circles is
//larger than the distance, then hit
if(td < circ1.width/2 + circ2.width/2 + extra){
return true;
}
return false;
}

(I hope the code displays correctly.)
The “extra” parameter is if you want it to register as a hit if they are further away from eachother(I used it in my game to make sure that circles don’t spawn to close to each other).

By: sorby

sorby — Thu, 03 Jul 2008 16:38:55 +0000

@ Robin W
That has already been taken care of with this code:
coin.x = Math.random()*510+20; //Changes the x of the coin to a random number between 20 and 530.
coin.y = Math.random()*360+20; //Changes the y of the coin to a random number between 20 and 380.

The only problem is that the width of the stage is 500, so if your getting a random number between 510 and 20 there’s a chance the coin may appear off the screen.

By: Robin W.

Robin W. — Sat, 28 Jun 2008 21:16:08 +0000

@Alex L.
That has already been taken care of with this code:
coin.x = Math.random()*510+20; //Changes the x of the coin to a random number between 20 and 530.
coin.y = Math.random()*360+20; //Changes the y of the coin to a random number between 20 and 380.

By: Alex L.

Alex L. — Sat, 21 Jun 2008 15:37:31 +0000

One thing you may want to do is make it so the coin cannot appear in the black border, or else it is impossible to get.

By: Graham

Graham — Sat, 21 Jun 2008 12:35:19 +0000

I think, when using circles, you might want to do a radius+radius distance test fro a very accurate hittest.
For example:
var dx = ball.x-coin.x
var dy = ball.y-coin.y
var dis = Math.sqrt(dx*dx+dy*dy)
if (dis < (rad1 + rad2)) {
// it hit
}