Hi all,I am a new iOS developer who is trying to translate my Android project into iOS.The app I am building is a drawing app. It shows users a uncolored image and let them to color it.Now I am facing a problem that when I draw an image onto a CALayer using my customed draw function. To support zoom and drag operation, I update drawRect according to user's touch event, but the image always get blurred because the drawing size is bigger than the actual size.override func draw(_ layer: CALayer, in ctx: CGContext) { ctx.draw(img, in: drawRect) }The blurred part has just two colors to highlight users which part is currently selected. Blur only happends at the boundary of two colors. I have noticed that changing the layer.magnificationFilter into nearest may help. But it seem that the filter works only if I set image to the layer with layer.contents, overriding draw function cannot benefit from the filter any more.How can I set a nearest filter for bitmap when drawing with context?Desperately waiting for tyhe answer...