CATransform3D transform = CATransform3DIdentity;
transform = CATransform3DTranslate(transform, rotationPoint.x-center.x, rotationPoint.y-center.y, 0.0);
transform = CATransform3DRotate(transform, rotationAngle, 0.0, 0.0, -1.0);
transform = CATransform3DTranslate(transform, center.x-rotationPoint.x, center.y-rotationPoint.y, 0.0);
Where center is the center of your layer, rotationAngle is in radians (positive is counterclockwise), and rotationPoint is the point about which you wish to rotate. center and rotationPoint are in the coordinate space of the containing view.
与恶龙缠斗过久,自身亦成为恶龙；凝视深渊过久,深渊将回以凝视…
