I am looking for a way to work around the conflict between -[CALayer cornerRadius] and +[NSBezierPath bezierPathWithRoundedRect:xRadius:yRadius]. These days, NSBezierPath apparently uses a new algorithm to draw rounded corners on a rectangle, resulting in a smoother-appearing curve. However, various other classes apparently still use an older algorithm and draw rounded corners in a slightly different shape. This results in an unsightly graphical blemish when the two rounded rectangles are superimposed. The difference is illustrated and explained at <http://stackoverflow.com/questions/22453095/why-does-applying-a-bezierpathwithroundedrect-mask-yield-a-different-result-from> and the included links.
My OS X application has a transparent borderless window. The window's content view contains an NSVisualEffectView subview with dark material and a maskImage set to give it rounded corners using +[NSBezierPath bezierPathWithRoundedRect:xRadius:yRadius]. The NSVisualEffectView in turn contains a Core Animation layer-hosting subview whose root layer calls -setCornerRadius: before setting its background color. Because of the conflict between CALayer and NSBezierPath described above, all four corners of the window reveal a thin, curved arc in the dark color of the NSVisualEffectView material, because the curve drawn by the Core Animation layer's lighter background color has a little different shape. I have tried every strategy I can think of to eliminate this graphical glitch, without success. All of my strategies involve using the same methods to draw the corners both in the NSVisualEffectView and the CALayer, on the assumption that using a single method for both will result in identical corner shapes. For example, I have drawn the corners of the NSVisualEffectView's maskImage using CGPathCreateWithRoundedRect(), which, according to lots of Googling, apparently does not incorporate the improved NSBezierPath rounded corner algorithm. And I have tried adding a CAShapeLayer mask to the subview's root layer using either -bezierPathWithRoundRect or CGPathCreateWithRoundedRect() instead of -setCornerRadius to round the corners. Nothing has eliminated the unsightly sliver at each corner, although -bezierPathWithRoundedRect and CGPathCreateWithRoundedRect() both create a slimmer sliver. Can anyone suggest another approach? Apple's application switcher (Command-Tab), which I am trying to imitate, seems to solve the problem. Or maybe it takes a completely different approach. -- Bill Cheeseman - b...@cheeseman.name _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
