To rotate a DIV we can add some CSS that, well, rotates the DIV using CSS transform rotate. To toggle the rotation we can keep a flag, a simple variable with a boolean value that tells us what way to rotate. var rotated = false; document.getElementById(‘button’).onclick = function() { var div = document.getElementById(‘div’), deg = … Read more
RollingFileAppender does this. You just need to set maxBackupIndex to the highest value for the backup file.
I avoid using macros unless necessary. This works perfectly well float degrees = 20; //the value in degrees view.transform = CGAffineTransformMakeRotation(degrees * M_PI/180);
The viewWillTransitionToSize delegate method gets called with a UIViewControllerTransitionCoordinator conforming object. A method that protocol declares is animateAlongsideTransition(_:animation, completion:). You can use that to have code execute after the transition is complete. override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) { super.viewWillTransition(to: size, with: coordinator) coordinator.animate(alongsideTransition: nil) { _ in // Your code here } … Read more
Precedence matters… In your second example, you’re apply a rotation AFTER you’ve drawn everything. This is not how graphics works. You need to apply the transformation first, then everything that follows will use that transformation. public class TestRotateImage { public static void main(String[] args) { new TestRotateImage(); } public TestRotateImage() { EventQueue.invokeLater(new Runnable() { @Override … Read more
A rotated vector can be described as a product of a rotation matrix with that vector. The German Wikipedia page on pitch, roll and yaw describes the rotation matrix for given Euler rotation angles. With that information, the rotation of all points with the same angles can be written as JavaScript function, where the points … Read more
OK – at last I seem to have done it. Any comments on the correctness would be useful… needed a translate, a rotate, a scale and an offset from the drawing rect position to make it work. Code is here: CGAffineTransform transform = CGAffineTransformIdentity; transform = CGAffineTransformTranslate(transform, boundingRect.size.width/2, boundingRect.size.height/2); transform = CGAffineTransformRotate(transform, angle); transform = … Read more
The answer depends on your coordinate system. Computer graphics coordinate system, with (0,0) at Top left If you are using a computer graphics vector implementation where (0,0) is the top left corner and you are rotating around the point (dx, dy), then the rotation calculation, including the translation back into the original coordinate system, would … Read more
Solution Given bounding box dimensions bx by by and t being the anticlockwise rotation of rectangle sized x by y: x = (1/(cos(t)^2-sin(t)^2)) * ( bx * cos(t) – by * sin(t)) y = (1/(cos(t)^2-sin(t)^2)) * (- bx * sin(t) + by * cos(t)) Derivation Why is this? First, consider that the length bx is … Read more
Hope this can be helpful to you, that’s how I usually implement gesture recognizers: UIRotationGestureRecognizer *rotationGesture = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotatePiece:)]; [piece addGestureRecognizer:rotationGesture]; [rotationGesture release]; UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(scalePiece:)]; [pinchGesture setDelegate:self]; [piece addGestureRecognizer:pinchGesture]; [pinchGesture release]; Rotate method: Reset the gesture recognizer’s rotation to 0 after applying so the next callback is a … Read more