X/Y (Calculating angle, problem)

[cili1]

Hello!

I'm making a program that calculates the angle to a position on the X/Y axis.

The problem is that as soon as I input a negative position (for example. -2, -2) it resets at 180° and "starts all over again".

I want to be able to get the angles above 180° as I illustrate in the picture below.

The blue text shows what values it shows at the moment.

Green text is what I want it to show.

#include <GUIConstants.au3>
#include <Math.au3>

$Form1 = GUICreate("Angle?", 180, 60, 500, 400)
GUISetState(@SW_SHOW)
GUICtrlCreateLabel("Y", 5, 5, 15, 20)
GUICtrlCreateLabel("X", 5, 30, 15, 20)
$GUI_a = GUICtrlCreateInput("", 20, 5, 150, 20)
$GUI_c = GUICtrlCreateInput("", 20, 30, 150, 20)

HotKeySet("{F1}", "Calc")
HotKeySet("{ESC}", "Terminate")

While 1
WEnd

Func Calc()
    $a = GUICtrlRead($GUI_a)
    $c = GUICtrlRead($GUI_c)

    $b = Sqrt($a*$a+$c*$c)
    
    $calc1 = $b*$b + $c*$c
    $calc2 = -2*$b*$c
    $calc3 = $a*$a - $calc1
    $calc4 = $calc3/$calc2
    
    $cos = ACos($calc4)
    $test = Round(_Degree($cos), 2)
    MsgBox(0, "", $test & "%")
EndFunc

Func Terminate()
    Exit 0
EndFunc

[Yashied]

Returns the angle relative the center of your screen.

MsgBox(0, '', _Angle(@DesktopWidth / 2 + 100, @DesktopHeight / 2 + 100))

Func _Angle($X, $Y)

    Local $CX = @DesktopWidth / 2, $CY = @DesktopHeight / 2

    If ($CX = $X) And ($CY = $Y) Then
        Return SetError(1, 0, -1)
    EndIf

    Local $Grad = ($Y <= $CY) * 180 - ATan(($CX - $X) / ($CY - $Y)) * 180 / 3.1415926535897932384626 + 90

    If $Grad = 360 Then
        $Grad = 0
    EndIf
    Return $Grad
EndFunc   ;==>_Angle

Edited May 23, 2009 by Yashied

[cili1]

Returns the angle relative the center of your screen.

Thank you!

Problem solved.