Getting from point A to B in a circle

[=sinister=]

So you have a circle, 360 degrees around. Somewhere in that circle you have point A. This is where "you" are located. You have the X and Y coordinates for location A. You are facing a degree. You need to turn a certain amount of degrees to face point "B", which you also have the X and Y coordinate of.

Thats the problem, anyone know how to solve?

EXAMPLE:

POINT A X: 2

POINT A Y: 3

POINT B X: 5

POINT B Y: 7

RotationDegree (Which way you are facing): 39 (degrees)

My wild guess is it has to do something with the Tan() function in AutoIt (Or something like that I forgot the name). I'm only in Algebra right now, and I asked everyone I knew and they couldn't figure this out.

Edited January 6, 2008 by =sinister=

[DaleHohm]

What do you need to solve for?

[The Ape]

Maybe this could help?

[Nahuel]

Perhaps it's just me, but that problem is kinda confusing Coordinates are relative. So we need to know where the circle is centered.

The equation of a circumference centered at ( a , b ) is:

(x-a)^2 + (y-b)^2 = r^2

and this one is centered at (0,0)

x^2 + y^2 = r^2

Another thing I don't understand is what you mean by "You are facing a degree". Could you do some graphics?

If you have two points that belong to a circumference, it should be quite easy to make the mouse move from point A to B following the circle.

Edited January 6, 2008 by Nahuel

[=sinister=]

Not trying to do with mouse.

Lets say you are "facing" north, or looking directly north. This is the data I know:

-Degree i'm looking at, or facing.

-The XY Coordinates of where I am standing

-The XY Coordinates of where I need to go

I need to rotate x amount of degrees to face the coordinate I need to go to. Sorry for my bad explanation =P

So basically i'm solving the the x amount of degrees I need to face the B coordinates.

I'll try to make a graphic

--Edit--

Sorry for bad explanation

Edited January 6, 2008 by =sinister=

[GEOSoft]

I think I know what he wants but I forget the math to do it.

He is standing at the outer edge of a circle (at point A) facing the center of the circle. Point B is another point on the outside egde of the circle. How many degrees would he have to turn to be facing point B?

Look at a compass. If he is standing at south(180°) while facing north (0°) and point B is east(90°) then he would have to turn 45° to the right in order to face Point B.

[crzftx]

why do the points have to be on a circle, that fact changes nothing. There must [i assume] be some significance in that information.

Assuming that information was pointless, we have 2 points on the standard X,Y coordinate plane.

The location of A will be (x1, y1) and the location of B will be (x2, y2)

The rotation of A will be direction

If x1 > x2 Then
  Return 180 - direction + ATan((x1-x2)/(y1-y2))
Else x1 < x2
  Return direction + ATan((x1-x2)/(y1-y2))
EndIf

I'm not completely sure about the direction part of it, but finding the angle is correct. If you're going to use this, make sure to check if y1 = y2 (Divide by 0).

Edited January 6, 2008 by crzftx