Rotation problems: Howto calculate shortest way?

[zutto]

yap, i fail, i cant figure out howto make it think thats shortest way, it always fails with the 0.00 angle :/

i am not going with 360, i am going with radians[i am pretty sure ;? fix me if i am wrong.] {2*pi but that shouldnt matter.}

.. i think pics will tell you more.

and here how it should be

give me some ideas

PS. My paint skills, ftw!

[monoceres]

Could it be so easy that you've missed the fact that the yellow dot is not at angle 0 but rather 90° (or π/2 if you want). That's how the unit circle works anyway.

[Alek]

some old function I used once for this, not sure if it works or not.

It returns an array, where [0] is direction and [1] is angle difference.

[0] can be 1 or -1 (-1 for left and 1 for right I think)

Func _Between($s_Next_Rot, $s_Cur_Rot)
    Local $Array[2]

    If $s_Cur_Rot > $s_Next_Rot Then
        If ($s_Cur_Rot - $s_Next_Rot) < 181 Then
            $Array[0] = 1
            $Array[1] = $s_Cur_Rot - $s_Next_Rot
        Else
            $Array[0] = -1
            $Array[1] = (($s_Next_Rot + 360) - $s_Cur_Rot)
        EndIf
    Else
        If ($s_Next_Rot - $s_Cur_Rot) < 181 Then
            $Array[0] = -1
            $Array[1] = $s_Next_Rot - $s_Cur_Rot
        Else
            $Array[0] = 1
            $Array[1] = (($s_Cur_Rot + 360) - $s_Next_Rot)
        EndIf
    EndIf

    Return $Array
EndFunc

[zutto]

some old function I used once for this, not sure if it works or not.

It returns an array, where [0] is direction and [1] is angle difference.

[0] can be 1 or -1 (-1 for left and 1 for right I think)

Func _Between($s_Next_Rot, $s_Cur_Rot)
    Local $Array[2]

    If $s_Cur_Rot > $s_Next_Rot Then
        If ($s_Cur_Rot - $s_Next_Rot) < 181 Then
            $Array[0] = 1
            $Array[1] = $s_Cur_Rot - $s_Next_Rot
        Else
            $Array[0] = -1
            $Array[1] = (($s_Next_Rot + 360) - $s_Cur_Rot)
        EndIf
    Else
        If ($s_Next_Rot - $s_Cur_Rot) < 181 Then
            $Array[0] = -1
            $Array[1] = $s_Next_Rot - $s_Cur_Rot
        Else
            $Array[0] = 1
            $Array[1] = (($s_Cur_Rot + 360) - $s_Next_Rot)
        EndIf
    EndIf

    Return $Array
EndFunc

going to try that

EDIT: fails like my method i used earlier, if your rotation is like.. 5.20 and target is 0.89 it will go right, instead of going left :/

Could it be so easy that you've missed the fact that the yellow dot is not at angle 0 but rather 90° (or π/2 if you want). That's how the unit circle works anyway.

wasnt the point that it wasnt on exactly 0, was just example Edited April 7, 2009 by zutto

[TerarinK]

http://math2.org/math/geometry/circles.htm