How is CATransform3DMakeRotation used?
I can not figure out how to use CATransform3DMakeRotation开发者_StackOverflow中文版()
. Can somebody please tell me how to use it?
I think the first parameter is the angle, right? But what are the other three?
The first is the angle in radians the other 3 parameters are the axis (x, y, z). So for example if you want to rotate 180 degrees around the z axis just call the function like this:
myView.layer.transform = CATransform3DMakeRotation(M_PI, 0.0, 0.0, 1.0);
and apply the result to the transform property of the view you want to rotate.
You'll probably find these useful when using radians:
CGFloat DegreesToRadians(CGFloat degrees)
{
return degrees * M_PI / 180;
};
CGFloat RadiansToDegrees(CGFloat radians)
{
return radians * 180 / M_PI;
};
They represent the axis about which you want to rotate. Use 0,0,1 to rotate in the plane of the screen.
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