Have a layer that displays an image and has some animations attached. The animations modify layer.bounds (just the size changes) and layer.position .
Everything works fine, EXCEPT when the image's orientation EXIF flag is set. So, I am also setting the layer.transform to a transformation that brings the image into its correct, upright orientation. This works, EXCEPT that the animations are now off. They still do some animations , but the bounds and positions are not correct any more. Below are some code excerpts to make this more concrete and to show how I attempted to deal with the orientation flag of the images. My main questions are: Does anyone have experience with this case, i.e., animations of layers that show images that have a non-upright EXIF orientation? Is there a better/different way of handling non-upright EXIF orientation flags of images, something other than setting the transformation of the layer (layer.transform) ? All hints and insights will be highly appreciated. Best regards, Gabriel Encl: Here are more details. Here is a code excerpt: CALayer * imgLayer = [CALayer layer]; imgLayer.contents = (__bridge id) imageRef; imgLayer.anchorPoint = CGPointMake( 0.0, 0.0 ); CGAffineTransform img_trf = ... compute a CGAffineTransform based on the EXIF orientation flag (in [1,8]) (*) imgLayer.transform = CATransform3DMakeAffineTransform( img_trf ); CABasicAnimation * anim = ... set up the animation(s) ... compute NSRect from_rect, to_rect that will be used to set up the animations of the layer ... from_rect = CGRectApplyAffineTransform( from_rect, img_trf ); anim.fromValue = [NSValue valueWithRect: from_rect ]; to_rect = CGRectApplyAffineTransform( to_rect, img_trf ); anim.toValue = [NSValue valueWithRect: to_rect ]; NSPoint fromPos = NSMakePoint( ... ); fromPos = CGPointApplyAffineTransform( fromPos, img_trf ); anim.fromValue = [NSValue valueWithPoint: fromPos]; ... similarly for anim.toValue ... So, for instance, if orientation==2, this means that the image is horizontally flipped. So, the transformation img_trf I compute is img_trf = CGAffineTransformMake(-1.0, 0.0, 0.0, 1.0, 0.0, 0.0); i.e., the x-coord is flipped. The CGRectApplyAffineTransform() call does not change the rectangles, which is reasonable. The x-coord of fromPos and toPos are flipped (sign is inverted), as expected. BUT the animation does not do what it should , the image is way off the screen. I have, of course, also tried without any transformations on the bounds (from_rect, to_rect) and without transforming anim.fromValue, anim.toValue. But then the (oriented) image was completely invisible , maybe way off the screen. So, it seems that the CALayer's transformation machinery does not take care of adjusting bounds/position when a layer's transform is set.
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