Comments on: Exploring iPhone Graphics Part 2

By: Christian Beer » Blog Archive » Core Graphics Introduction - iPhone Software Engineer

Sat, 19 Sep 2009 16:58:46 +0000

[...] Exploring iPhone Graphics Part 2 [...]

By: 6 Resources For Learning Core Graphics | iPhone Development Tutorials and Tips

Sat, 12 Sep 2009 06:33:12 +0000

[...] Basic shapes tutorial repeated all over the place, this is the best one that I’ve seen. Exploring iPhone Graphics Part 2 – Very good beginners animation tutorial with Core [...]

By: GNull

GNull — Sat, 14 Mar 2009 09:52:00 +0000

I can’t seem to get this Tutorial working either. Would it be possible if someone provided the XCode project in compressed format?

I keep getting the following error. It compiles fun but when it actually launches the simulator (or on the iPhone) it just crashes. The report mentions the following:

Application Specific Information:
iPhone Simulator 2.2 (77.4.9), iPhone OS 2.2.1 (5H11)
*** Terminating app due to uncaught exception ‘NSUnknownKeyException’, reason: ‘[ setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key viewController.’

By: david

david — Sun, 19 Oct 2008 02:41:01 +0000

Great tutorial! Reminds me of animating with actionscript book I read last year. Similar topics, but what I don’t understand is why you allocate memory for position and vector (point2d and vector2 classes) in the init method of Object2d, and then again another alloc in the Graphics View class where point2d and vector2d are allocated again in the initwithframe method?

I commented out the two allocs in the object2d init method and the animation still ran with out errors. Do you really need to allocate two separate copies of point2d and vector2d?

For what its worth memory management has allways confused me…

Thanks.

By: iamdavehi

iamdavehi — Wed, 02 Jul 2008 12:15:08 +0000

Do you know if this works on the Beta 8 SDK?
i keep getting an exception error.

*** Terminating app due to uncaught exception ‘NSUnknownKeyException’, reason: ‘[ setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key window.”

any ideas?

thanks
-Dave

By: i42sasoi

i42sasoi — Thu, 26 Jun 2008 11:28:58 +0000

The problem is that the context is always null.Do you know any way to fix it?

By: i42sasoi

i42sasoi — Wed, 25 Jun 2008 16:32:55 +0000

Hi,

first thanks a lot for your work. I think you make easy.

Reading this second part, inspired me with a problem I have drawing images.
I receive some images from a socket, and I´ve tried to display on the screen,I tried with [self setNeedsDisplay] but It is not call when a frame is received, It just show the last frame received.
I tried to make a function like:

- (void) draw:(CGRect) rect {


   CGContextRef context = UIGraphicsGetCurrentContext();

   CGContextClearRect(context, rect);
   [self drawImage:context];

}

-(void) drawImage:(CGContextRef)ctx { CGContextDrawImage(ctx, CGRectMake(0.0, 0.0,320,480), imageFrame.CGImage); }

imageFrame is the image i´ve received throught the socket.
Then i call draw every time a frame is received, but I received the next error:

CGContextClearRect: invalid context
CGContextDrawImage: invalid context

Do you know what I mean?

Sorry If It is offtopic, but I dont know anybody to ask.
Sorry for my poor English too.
Thanks.