Question

I have a CATiledLayer into which I render content in the following method

- (void)drawLayer:(CALayer *)layer inContext:(CGContextRef)ctx

I used the QuartzDemo code to draw a pattern. This works very well until I apply a rotation transform to the layer’s parentLayer (a UIView):

rotated:

These zigzag artefacts become worse when I start drawing lines and texts into the CATiledLayer.

I applied the transform as follows (I also tried using an affine transform on the view itself):

self.containerView.layer.transform = CATransform3DMakeRotation(angleRadians, 0.0f, 0.0f, 1.0f);

I transform the containerView rather than the layer itself, as I have several layers in that view that I would like to rotate at the same time without changing the relative positions.

I did not have problems when rotating UIImageViews in the past.

Is there a way that I can rotate the CATiledLayer without these problems?

Any help would be greatly appreciated.

Yours,

Felix

Answer 1

The only way of fixing this issue I found was this:

1. Draw the layer into a bitmap context
2. Set the CGImageRef of that context as the layer contents