quartz-graphics

I'm trying to create a shadow around a simple UIView object which is added on top of a UIViewController's view. what's the most straight forward way of doing this? Ned First, be sure to import the Quartz Core library: #import <QuartzCore/QuartzCore.h> Next, add the following lines to set up the shadow's properties: someView.layer.shadowColor = [[UIColor blackColor] CGColor]; someView.layer.shadowOffset = CGSizeMake(10.0f,10.0f); someView.layer.shadowOpacity = .5f; someView.layer.shadowRadius = 10.0f; Keep in mind that if you have that view's clipsToBounds property set to YES, the shadow won't

I have a sequence of images that I want to animate ( UIImageView supports some basic animation but it's not sufficient for my needs). My first approach was to use UIImageView and set the image property when the image. This was too slow. The reason for the poor speed was due to the drawing of the images (which surprised me; I assumed the bottle neck would be loading the image). My second approach was to use a generic UIView and set view.layer.contents = image.CGImage . This gave no noticeable improvement. Both of these approaches must be performed on the main thread. I think the poor speed is

I'm writing an application that uses your finger to draw simple diagrams. I have it working for the most part but now I'm trying to optimize its performance. When the user swipes their finger fast, I can't capture enough touch events to draw a smooth path. Here's my current approach: 1) I subclassed a UIView and added a poroperty to a CGLayer (gets created lazily and is the same size as my UIView). 2) My UIView subclass responds to touch events by storing the current and last touch points in instance variables. 3) My view's setNeedsDisplay is called and in the draw rect , do the following: -

I have a CALayer to animate a change in its image contents. Now, how can I change how long it takes for this animation to take place? papr It's more or less simple. You have an ivar CALayer *yourLayer . Then you set the delegate and implement the delegate method -(id<CAAction>)actionForLayer:forKey: - (void)awakeFromNib { yourLayer.delegate = self; yourLayer.name = @"yourLayer"; } - (id <CAAction>)actionForLayer:(CALayer *)layer forKey:(NSString *)event { if([layer.name isEqualToString yourLayer.name]) { // Check for right layer CABasicAnimation *ani = [CABasicAnimation animationWithKeyPath

I'm trying to learn how to use and implement CALayer in a Mac Objective-C application, but I can't seem to probably do the most basic thing - add a new layer and set its background colour/frame size. Can anyone see what is wrong with my code? CALayer *layer = [CALayer layer]; [layer setFrame:CGRectMake(0, 0, 100, 100)]; [layer setBackgroundColor:CGColorCreateGenericRGB(1.0, 0.0, 0.0, 1.0)]; [self.layer addSublayer:layer]; [layer display]; I put this in the - (void)drawRect:(NSRect)rect method of my custom NSView subclass, but when I run the application, it just shows a blank view, with no

Trying to figure out what I'm doing wrong here. Have tried several things, but I never see that elusive rectangle on the screen. Right now, that's all I want to do -- just draw a single rectangle on the screen. I'm getting an "invalid context" on everything but the CGContextSetRGBFillColor(). Getting the context after that seems kinda wrong to me, but I'm not at home looking at the examples I was using last night. Have I messed up something else as well? I really would like to get at least this much done tonight... - (id)initWithCoder:(NSCoder *)coder { CGRect myRect; CGPoint myPoint; CGSize

I'm trying to develop a complex painting application on the iPhone. I'm currently drawing using Quartz (e.g. CGContext ...). Unfortunately the Quartz overhead is just too slow for the type of drawing I'm doing, and I'm porting to OpenGL calls using the GLPaint example as a reference point. Is there a way to get a UIImage/CGImage from the EAGLview class (the equivalent of Quartz's UIGraphicsGetImageFromCurrentImageContext )? Basically I need to save the pictures drawn by the GLPaint application. -(UIImage *) saveImageFromGLView { NSInteger myDataLength = 320 * 480 * 4; // allocate array and

I'm creating a simple app where when the user presses a button, a series of lines will be drawn on the screen and the user will be able to see these lines drawn in real time (almost like an animation). My code looks something like this (has been simplified): UIGraphicsBeginImageContext(CGSizeMake(300,300)); CGContextRef context = UIGraphicsGetCurrentContext(); for (int i = 0; i < 100; i++ ) { CGContextMoveToPoint(context, i, i); CGContextAddLineToPoint(context, i+20, i+20); CGContextSetStrokeColorWithColor(context, [[UIColor blackColor] CGColor]); CGContextStrokePath(context); } UIImage