Top "Core-graphics" questions

Core Graphics is Apple's framework for low-level drawing operations on Mac OS X and iOS.

How do I draw a shadow under a UIView?

I'm trying to draw a shadow under the bottom edge of a UIView in Cocoa Touch. I understand that I …

iphone objective-c ios cocoa-touch core-graphics
How to Rotate a UIImage 90 degrees?

I have a UIImage that is UIImageOrientationUp (portrait) that I would like to rotate counter-clockwise by 90 degrees (to landscape). I …

ios objective-c uiimage uikit core-graphics
How to get pixel data from a UIImage (Cocoa Touch) or CGImage (Core Graphics)?

I have a UIImage (Cocoa Touch). From that, I'm happy to get a CGImage or anything else you'd like that's …

cocoa cocoa-touch core-graphics
UIImage: Resize, then Crop

I've been bashing my face into this one for literally days now and even though I feel constantly that I …

iphone ios image-processing core-graphics
CGContextDrawImage draws image upside down when passed UIImage.CGImage

Does anyone know why CGContextDrawImage would be drawing my image upside down? I am loading an image in from my …

ios cocoa-touch core-graphics cgcontextdrawimage
invalid context 0x0 under iOS 7.0 and system degradation

I've read as many search results I could find on this dreaded problem, unfortunatelly, each one seems to focus on …

objective-c ios7 core-graphics
Inner shadow effect on UIView layer?

I have the following CALayer: CAGradientLayer *gradient = [CAGradientLayer layer]; gradient.frame = CGRectMake(8, 57, 296, 30); gradient.cornerRadius = 3.0f; gradient.colors = [NSArray arrayWithObjects:(id)[…

iphone core-graphics calayer
How can I set CG_CONTEXT_SHOW_BACKTRACE environmental variable?

I have three buttons in my view. After setting the cornerRadus in the viewDidLoad() : button.layer.cornerRadius = 20 I get the …

ios xcode swift core-graphics
How do I make UILabel display outlined text?

All I want is a one pixel black border around my white UILabel text. I got as far as subclassing …

ios objective-c iphone cocoa-touch core-graphics
iOS 7 style Blur view

Does anybody know of any controls that will replicate the iOS7 style blur views. I'm assumming there can be some …

ios objective-c core-graphics