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copied!<p>Answer to title: Yes, CGAffineTransform can rotate more than 360 degrees just fine.<br> Answer to question: Yes, but you cannot animate it because there is nothing to animate.</p> <p>Remember that <a href="http://tinyurl.com/bp2e8x" rel="nofollow noreferrer">the affine transformation is a matrix</a>, and that a rotation matrix contains the sine and cosine numbers <em>precomputed</em>. It's as if you said:</p> <pre><code>CGFloat angle = 4.0 * M_PI; NSAffineTransformStruct matrix = { .m11 = cos(angle), .m12 = sin(angle), .m21 = -sin(angle), .m22 = cos(angle), .tx = 0.0, .ty = 0.0 }; NSAffineTransform *transform = [NSAffineTransform transform]; [transform setTransformStruct:matrix]; </code></pre> <p>Now, let's review some sample values for <code>cos</code> and <code>sin</code>:</p> <ul> <li><code>cos(0π)</code> = 1</li> <li><code>sin(0π)</code> = 0</li> <li><code>cos(2π)</code> = 1</li> <li><code>sin(2π)</code> = 0</li> <li><code>cos(4π)</code> = 1</li> <li><code>sin(4π)</code> = 0</li> </ul> <p>Remember, <strong>the matrix doesn't contain the angle -- it only contains the cosine and sine</strong>. And those values don't change from one multiple of a circle to another. Therefore, there is nothing to animate.</p> <p>(Note that Calculator.app gives wrong results for cos(xπ) and sin(xπ). Try Grapher, <a href="http://isthe.com/chongo/tech/comp/calc/" rel="nofollow noreferrer">calc</a>, or <a href="http://tinyurl.com/aztfkw" rel="nofollow noreferrer">Google</a>.) </p> <p>You will need to split the animation into fractions of a circle. The half-circles Brad Larson suggested will do just fine.</p>

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