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I am using the RotateImage Component for my program. It is useful and powerful component for dealing with a picture. But a problem occured in these days. I don't know how to find the status of the rotation (CW or CCW) when the picture is operated. Can you give me some advice about it?

- Donnie
- Member
**Posts:**2**Joined:**September 10th, 2006, 1:22 pm

I think it is difficult to know the direction if you just compare the original angle to the new angle (refer to below programe). You know the minus and plus value will be occured. Maybe, I don't understand your meaning very well. Could you explain it in detail for me. Thanks a lot.

if Dragging then

begin

if X = RotateImage1.Width / 2 then

if Y < RotateImage1.Height / 2 then

Theta := Pi / 2

else

Theta := -Pi / 2

else

Theta := ArcTan2(Y - RotateImage1.Height / 2, X - RotateImage1.Width / 2);

Angle := StartAngle + 180 * (StartTheta - Theta) / Pi;

TrackBar1.Position := Trunc(Angle * 10) mod 3600;

TrackBar1Change(Self);

end;

if Dragging then

begin

if X = RotateImage1.Width / 2 then

if Y < RotateImage1.Height / 2 then

Theta := Pi / 2

else

Theta := -Pi / 2

else

Theta := ArcTan2(Y - RotateImage1.Height / 2, X - RotateImage1.Width / 2);

Angle := StartAngle + 180 * (StartTheta - Theta) / Pi;

TrackBar1.Position := Trunc(Angle * 10) mod 3600;

TrackBar1Change(Self);

end;

- Donnie
- Member
**Posts:**2**Joined:**September 10th, 2006, 1:22 pm

3 posts
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