Top "Core-graphics" questions

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

How can I set the UINavigationbar with gradient color?

I want to set the UINavigationbar backgroundColor to a gradient color where I would like to set it via an …

ios uinavigationbar core-graphics
Getting a screenshot of a UIScrollView, including offscreen parts

I have a UIScrollView decendent that implements a takeScreenshot method that looks like this: -(void)takeScreenshot { CGRect contextRect = CGRectMake(0, 0, 768, 1004); …

ios iphone ipad core-graphics
Saving CGImageRef to a png file?

in my Cocoa application, I load a .jpg file from disk, manipulate it. Now it needs to be written to …

cocoa png core-graphics cgimage
Rotating an image context (CGContextRotateCTM) causing it to become blank. Why?

#define radians(degrees) (degrees * M_PI/180) UIImage *rotate(UIImage *image) { CGSize size = image.size;; UIGraphicsBeginImageContext(size); CGContextRef context = UIGraphicsGetCurrentContext(); // If …

iphone objective-c ios core-graphics
redraw a custom uiview when changing a device orientation

If I draw my chart inside - (void)drawRect:(CGRect)rect is just enough to set [_chartView setContentMode:UIViewContentModeRedraw] and …

ios uiview core-graphics quartz-core
Vertical flip of CGContext

I have a UIView that I am trying to render into a UIImage using [CALayer renderInContext:]. However, I find that …

iphone uikit core-graphics
Getting a CGImage from CIImage

I have a UIImage which is loaded from a CIImage with: tempImage = [UIImage imageWithCIImage:ciImage]; The problem is I need …

ios core-graphics core-image cgimage ciimage
How to store CGRect values in NSMutableArray?

How would I store CGRect objects in a NSMutableArray, and then later retrieve them?

iphone nsmutablearray core-graphics
Can I use CGAffineTransformMakeRotation to rotate a view more than 360 degrees?

I'm writing an iPhone app, and I've got an image which I'ld like to have swirl outwards. Currently my code …

iphone cocoa-touch core-animation core-graphics
How can I draw an arrow using Core Graphics?

I need to draw line with arrow on its end in my Draw app. I'm not good in trigonometry, so …

objective-c ios core-graphics quartz-2d