Get angle with cos and sin

[twixman]

Hello ! I made a function that draw a circle with the mouse. In this function, I have an argument that is the angle where the circle is starting drawn.

With another function, I click on the screen a first time to point where the circle will start to be drawn, and a second time to point the center of my circle.

My problem is I don't manage to calculate the angle with this two points.

Here is my code :

expandcollapse popup

Func ask_circle()
    $angle = InputBox("Angle", "Please type in the angle in degrees you want it draws (360 is a full rotation).Click on OK and then, click one time on your screen for where the circle will start to be drawn, and a second time for the center.", 90)
    If @error = 1 Then
        MsgBox(64, "Cancelled", "Action cancelled")
        Exit
    EndIf
    Sleep(300)
    While 1
        If _IsPressed("01") Then
            $start_pos = MouseGetPos()
            ExitLoop
        EndIf
    WEnd
    Sleep(300)
    While 1
        If _IsPressed("01") Then
            $ctr_pos = MouseGetPos()
            ExitLoop
        EndIf
    WEnd
    $diam = Sqrt( ( $ctr_pos[1] - $start_pos[1] ) * ( $ctr_pos[1] - $start_pos[1] ) +  ( $ctr_pos[0] - $start_pos[0] ) * ( $ctr_pos[0] - $start_pos[0] ) )
    $sinus = ( $start_pos[1] - $ctr_pos[1] ) / $diam
    $cosinus = ( $start_pos[0] - $ctr_pos[0] ) / $diam
    $angle_init = _Degree(ACos($cosinus))
;~  If $cosinus >= 0 Then
;~      If $sinus >= 0 Then
;~          $angle_init = $angle_init
;~      Else
;~          $angle_init = 270 + $angle_init
;~      EndIf
;~  Else
;~      If $sinus >= 0 Then
;~          $angle_init = 270 - $angle_init
;~      Else
;~          $angle_init = 180 - $angle_init
;~      EndIf
;~  EndIf
    Sleep(300)
    Circle($ctr_pos[0], $ctr_pos[1], $diam, $angle_init, $angle)
EndFunc

$angle_init should be the angle between the horizontal line of the center and the line formed with the two points (center, and starting point)

$ctr_pos is [x,y] coords of the center

$start_pos is [x,y] coords of the starting point

$diam is the diameter

This code :

;~  If $cosinus >= 0 Then
;~      If $sinus >= 0 Then
;~          $angle_init = $angle_init
;~      Else
;~          $angle_init = 270 + $angle_init
;~      EndIf
;~  Else
;~      If $sinus >= 0 Then
;~          $angle_init = 270 - $angle_init
;~      Else
;~          $angle_init = 180 - $angle_init
;~      EndIf
;~  EndIf

is the way I wanted to do calculate the angle, but it does not work.

Need your help !

Thank you, cya

Edited December 26, 2006 by twixman

[twixman]

I made many test that I found logical and I had always problem in my tests....

So I checked everything and I found the problem came from the function _Degree() that sometime returned nothing

My new code is :

$diam = Sqrt( ( $ctr_pos[1] - $start_pos[1] ) * ( $ctr_pos[1] - $start_pos[1] ) +  ( $ctr_pos[0] - $start_pos[0] ) * ( $ctr_pos[0] - $start_pos[0] ) )
$radtodeg = 57.2957795130823
$angle_init = ACos(($start_pos[0] - $ctr_pos[0]) / $diam) * $radtodeg
If $start_pos[1] > $ctr_pos[1] Then $angle_init = - $angle_init