Spinning Wheel Game: Trouble with rotation image

Question

Possible Duplicate:
Can I use CGAffineTransformMakeRotation to rotate a view more than 360 degrees?

I'm trying to create a game where pushing a button spins an dial image, having trouble with the rotation code. Goal is to spin the image from its current position by a % of 360, i.e .4 * 360, spin the image 144 degrees. Thanks Guys!

-(IBAction)spin:(id)sender
{

    float strenght = DEGREES_TO_RADIANS(.5 * 360);

    [UIView animateWithDuration:0.5f delay:0.0f options:UIViewAnimationCurveEaseOut animations:^
    {
        [spinner_iv setTransform:CGAffineTransformRotate([spinner_iv transform],strenght)];
    } 
    completion:^(BOOL finished) 
    {
        //done
    }];
}

just gives unexpected results, it works if rotating by <179 degrees at a time, anything over doesn't work. Noticed when NSLogging my spinner_iv rotation it goes from 0-180,-180-0... i'm lost. oh and thank you for responding. — Nicholas L. Eby, Feb 21 '12 at 10:56

score 1 · Answer 1 · edited May 23 '17 at 12:11

1

UIView animations using CGAffineTransform take the 'shortest path', so if you request a clockwise rotation of 270 degrees, it will animate anticlockwise by 90 degrees.

You can get any number of spins if you instead rotate the view layer using CATransform3D - yes, use this even if you are rotating in 2D. See Can I use CGAffineTransformMakeRotation to rotate a view more than 360 degrees?

edited May 23 '17 at 12:11

Community

1
1

answered Apr 12 '12 at 22:59

Cowirrie

7,218
1
29
42

score 0 · Answer 2 · answered Feb 21 '12 at 11:52

0

Converting degrees to radians is

Radians = Degrees * (PI/180)

answered Feb 21 '12 at 11:52

Nick Bull

4,276
1
18
25

I couldn't see your code, so I'm guessing this might be what's wrong. – Nick Bull Feb 21 '12 at 11:55

Spinning Wheel Game: Trouble with rotation image

2 Answers2