Rotate iOS Image Clockwise

Question

I am trying to animate my image by having it rotate clockwise, and shrink down. So far, it is only going counter-clockwise. I have tried both positive and negative values for the value/Key path of rotating along Z, but it changed nothing.

[window addSubview:splashView];
    [window bringSubviewToFront:splashView];
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:2.0];

    [UIView setAnimationDelegate:self];
    [UIView setAnimationDidStopSelector:@selector(startupAnimationDone:finished:context:)];
    splashView.frame = CGRectMake(160, 284, 0, 0);
    [splashView.layer setValue:[NSNumber numberWithInt:-360]
                       forKeyPath:@"transform.rotation.z"];

    [UIView commitAnimations];

I'm toying around with exactly how much, but am thinking make it spin completely around at least twice while it is shrinking. — user717452, Mar 15 '13 at 16:54

calimarkus · Answer 1 · 2013-03-16T00:26:18.077

1

Or just use M_PI directly.

M_PI_4 = 45 degrees
M_PI_2 = 90 degrees
M_PI = 180 degrees
M_PI*2 = 360 degrees

You can also set your transform more easily.

// set transform
splashView.layer.transform = CATransform3DMakeRotation(-M_PI*2, 0, 0, 1);

instead of

[splashView.layer setValue:[NSNumber numberWithInt:-360] 
                forKeyPath:@"transform.rotation.z"];

edited Mar 16 '13 at 00:26

answered Mar 15 '13 at 16:48

calimarkus

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That line of code just made the view shrink without doing any rotation. – user717452 Mar 15 '13 at 16:52

score 1 · Accepted Answer · answered Mar 15 '13 at 16:58

To rotate in specific direction more than 360°use CAKeyframeAnimation. There you can set not only the final value, but also some intermediate values.

// consider this to be pseudo code
keyFrameAnimation.values = @[ 90, 180, 270, 360, 450, 540, ... ];

I don't have any code to show you, but this is defnitely the way to do it.

Mick MacCallum · Answer 3 · 2013-03-15T16:49:04.500

0

That's because you're passing degrees to the animation when it wants radians. Here's an example of how to make the conversion.

float degrees = 90.0f;
float radians = degrees * (180.0f / M_PI);

edited Mar 15 '13 at 16:49

answered Mar 15 '13 at 16:43

Mick MacCallum

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Ok...........so where do I put that and what do I set for the setValue in my code? – user717452 Mar 15 '13 at 16:45
@user717452 Are you serious? – Mick MacCallum Mar 15 '13 at 16:50
I asked how to make something spin clockwise and you gave me two float values with nothing else at all. – user717452 Mar 15 '13 at 16:51

Rotate iOS Image Clockwise

3 Answers3