Re: Clipping a CAGradientLayer with a duplicated CAShapeLayer (don't)
On Thu, Feb 9, 2012 at 11:09 AM, Fritz Anderson fri...@manoverboard.org wrote: * Create a duplicate CAShapeLayer (maskL) with [[CAShapeLayer alloc] initWithLayer: shapeL]. - Adjust the fill color to blackColor, because masking goes by alpha. The CALayer documentation makes it quite clear that you should never, ever do this: Note: Invoking this method in any other situation will produce undefined behavior. Do not use this method to initialize a new layer with an existing layer’s content. https://developer.apple.com/library/ios/#documentation/GraphicsImaging/Reference/CALayer_class/Introduction/Introduction.html --Kyle Sluder ___ 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
Re: Clipping a CAGradientLayer with a duplicated CAShapeLayer (don't)
On Feb 9, 2012, at 11:09 AM, Fritz Anderson wrote: The trick was that -initWithLayer: did not produce a usable mask layer. Applications should not call -initWithLayer:. Its purpose of existence is so that if you have a CALayer subclass that has additional ivars that need copying, you can implement it and CoreAnimation can call it to do the right thing. The layers produced in this way are not expected to be useful as 'model' layers. If I created maskL as a new mask layer ([CAShapeLayer layer]), and initialized it to match shapeL (except for the fill), gradL was drawn as expected. http://stackoverflow.com/questions/4733966/applying-a-gradient-to-cashapelayer got me most of the way, but didn't extend to how to re-use the mask layer. Did you add the stroke shape layer as a sublayer of the gradient layer? If so, that may explain why you didn't get your stroke – the mask applies to a layer and all of its sublayers. As such, the shape layer would have at least partially masked the stroke (its possible Core Animation simply rejected rendering the shape layer entirely, as its path rendering emphasizes speed over accuracy). -- David Duncan ___ 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
Re: Clipping a CAGradientLayer with a duplicated CAShapeLayer (don't)
On 9 Feb 2012, at 1:25 PM, Kyle Sluder wrote: The CALayer documentation makes it quite clear that you should never, ever do this: Hence the last word of the subject of this thread. — F ___ 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
Re: Clipping a CAGradientLayer with a duplicated CAShapeLayer (don't)
On Feb 9, 2012, at 1:37 PM, Fritz Anderson wrote: On 9 Feb 2012, at 1:25 PM, Kyle Sluder wrote: The CALayer documentation makes it quite clear that you should never, ever do this: Hence the last word of the subject of this thread. Perhaps, but I believe that our point is that -initWithLayer: is not a method to use to duplicate a layer, its a method to create a shadow layer (which is something strictly for Core Animation's usage). If you duplicated a layer (by calling -init and setting all the appropriate properties) then there is no reason why it shouldn't work. -- David Duncan ___ 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
Re: Clipping a CAGradientLayer with a duplicated CAShapeLayer (don't)
On 9 Feb 2012, at 4:30 PM, David Duncan wrote: Perhaps, but I believe that our point is that -initWithLayer: is not a method to use to duplicate a layer, its a method to create a shadow layer (which is something strictly for Core Animation's usage). If you duplicated a layer (by calling -init and setting all the appropriate properties) then there is no reason why it shouldn't work. Absolutely. On 9 Feb 2012, at 1:09 PM, Fritz Anderson wrote: The trick was that -initWithLayer: did not produce a usable mask layer. If I created maskL as a new mask layer ([CAShapeLayer layer]), and initialized it to match shapeL (except for the fill), gradL was drawn as expected. I assume this is what you just said — or are you getting at a different way to duplicate the layer? — F ___ 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
Re: Clipping a CAGradientLayer with a duplicated CAShapeLayer (don't)
On Feb 9, 2012, at 2:36 PM, Fritz Anderson wrote: On 9 Feb 2012, at 1:09 PM, Fritz Anderson wrote: The trick was that -initWithLayer: did not produce a usable mask layer. If I created maskL as a new mask layer ([CAShapeLayer layer]), and initialized it to match shapeL (except for the fill), gradL was drawn as expected. I assume this is what you just said — or are you getting at a different way to duplicate the layer? Nope, using +layer or -init and copying appropriate properties is an appropriately acceptable way to duplicate a layer. -- David Duncan ___ 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
