CALayer Antialiasing not as good as UIView antialiasing

Question

I've been trying to animate circle drawing using CALayer. It all works well, but the problem is - drawn circle is not antialiased enough. It has a bit too rough borders, (or blurred if rasterize is used). (AntiAliasing is enabled) Tried also: edgeAntialiasingMask = kCALayerLeftEdge | kCALayerRightEdge | kCALayerBottomEdge | kCALayerTopEdge; to no avail. Here is an example how it looks like without rasterization: And here is an example with rasterization: (tried values from 1.0 till 4.0 (just to be sure. Result - the same.)) And here is the same circle, but drawn inside UIView drawrect: You can see, that circle drawn using UIView drawrect is looking much better. The reason I cannot use UIView is because I need to animate circle filling. Using CALayer it is really easy, but to do the same on UIView, I don't really know if it is even possible. (I could try to launch drawrect: every 1/60 seconds, but I think it will get laggy, as it is not intended that way). So - does anyone have any sol…

Accepted Answer

I've had issues with pixelated drawing in a `CALayer` on retina devices before. (I'm assuming you're seeing the issue on retina devices) Doing the following fixed the issue I was experiencing:

```
layer.contentsScale = [[UIScreen mainScreen] scale];
```

You shouldn't need to deal with rasterization or antialiasing. In my own code, I had initially implemented drawing something to a `UIView` that I later changed to be drawn in a `CALayer`, and simply setting the `contentsScale` property made both draw identically.

CALayer Antialiasing not as good as UIView antialiasing

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