quartz-graphics

Scenario: I have a set of CGPath s. They are mostly just lines (i.e. not closed shapes). They are drawn on the screen in a UIView 's draw method. How can I check if the user tapped near one of the paths? Here's what I had working: UIGraphincsBeginImageContext(CGPathGetBoundingBox(path)); CGContextRef g = UIGraphicsGetCurrentContext(); CGContextAddPath(g,path); CGContextSetLineWidth(g,15); CGContextReplacePathWithStrokedPath(g); CGPath clickArea = CGContextCopyPath(g); //Not documented UIGraphicsEndImageContext(); So what I'm doing is creating an image context, because it has the functions I

Dipping my feet into some more Core Graphics drawing, I'm attempting to recreate a wicked looking metallic knob, and I've landed on what is probably a show-stopping issue. There doesn't seem to be any way to draw angle gradients in Core Graphics. I see there's CGContextDrawRadialGradient() and CGContextDrawLinearGradient() , but there's nothing that I see that would allow me to draw an angle gradient. Does anyone know of a workaround, or a bit of framework hidden away somewhere to accomplish this without pre-rendering the knob into an image file? AngleGradientKnob http://dl.dropbox.com/u

I'm using the following code to simulate a click of the mouse: void PostMouseEvent(CGMouseButton button, CGEventType type, const CGPoint point) { CGEventRef theEvent = CGEventCreateMouseEvent(NULL, type, point, button); CGEventSetType(theEvent, type); CGEventPost(kCGHIDEventTap, theEvent); CFRelease(theEvent); } void LeftClick(const CGPoint point) { PostMouseEvent(kCGMouseButtonLeft, kCGEventMouseMoved, point); NSLog(@"Click!"); PostMouseEvent(kCGMouseButtonLeft, kCGEventLeftMouseDown, point); PostMouseEvent(kCGMouseButtonLeft, kCGEventLeftMouseUp, point); } I can use basically the same code

I'm using UIImageWriteToSavedPhotosAlbum to save a UIImage to the user's photo album. The problem is that the image doesn't have transparency and is a JPG. I've got the pixel data set correctly to have transparency, but there doesn't seem to be a way to save in a transparency-supported format. Ideas? EDIT: There is no way to accomplish this, however there are other ways to deliver PNG images to the user. One of which is to save the image in the Documents directory (as detailed below). Once you've done that, you can email it, save it in a database, etc. You just can't get it into the photo