 A Flash Developer Resource Site

# Thread: Simple problem, how to get angle between two points?

1. ## Simple problem, how to get angle between two points?

I tried to do:
Code:
`Math.abs(Math.atan2((y1-y2),(x1-x2)))*(180/Math.PI)`
but i am getting 1-180 and 180 to 1 as i go around the pivoted point, instead of 1-360, what am i doing wrong??  Reply With Quote

2. ok, i solved it myself!  Reply With Quote

Hi
I am facing the same problem.

my email is uzair@meragsm.com.

Thanks  Reply With Quote

4. Hi,
You can easily fix this by doing the small changes. This one really help

var angle=Math.atan2((y1-y2),(x1-x2))
if (angle<0) {
angle +=3
}
angle=angle*(180/Math.PI)  Reply With Quote

5. Originally Posted by bluemagica I tried to do:
Code:
`Math.abs(Math.atan2((y1-y2),(x1-x2)))*(180/Math.PI)`
but i am getting 1-180 and 180 to 1 as i go around the pivoted point, instead of 1-360, what am i doing wrong??
It would be better if you made two other varibles:

dy=y2-y1
dx=x2-x1

Your y's and x's are backwards. also. instead of having to do the 180/Math.PI you could use:

object.rotation= ATAN2(x,y)

this returns in degrees.

I will give you a free script that I used to make an Ipod dial:

var dial=element ("dial2");
var windowScroller=element ("window scroller");

function rot(evt:Event):void
{
var mx=(mouseX-dial.x);
var my=(mouseY-dial.y);
dial.rotation= ATAN2(mx,-my)

var y0= 5
var y1= dial.rotation/1.4

for(var i:Number = 0;i<=130;i++)
{
windowScroller.y= y1;
}
}

This makes a dial rotate to the position of the mouse (face it). It also makes the windowScroller change y position as you rotate the mouse around.  Reply With Quote

6. Suthers,

Welcome to flashkit, I see you've found all the old threads.

If you look at Adobe's documentation, the parameters for atan2 are actually (y,x).

It's supposed to look similar to the way they teach you to find the angle of vector <x,y> in math class:
atan(y/x) -- what normal people use
atan2(y,x) -- what programmers use  Reply With Quote

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•

 » Home » Movies » Tutorials » Submissions » Board » Links » Reviews » Feedback » Gallery » Fonts » The Lounge » Sound Loops » Sound FX » About FK » Sitemap 