Errata

Spotlight is not able to find the MobileSafari.app file on my computer. I have the latest sdk installed (3.1.2)

My mistake, I had thought the code on these pages was the same as the Example project but after finding the code crashes as soon as I try to run it in the simulator, I have taken a closer look. The Example project has no gsTest files, it has no mainLoop function in the appDelegate, and doesn't use the Render function, but drawRect instead. When the ActiveSDK is changed to 3.1.2 it does run in the simulator, which is more than the code in the book does.

There is no project called Test_Framework in the files downloaded from SourceForge, the project is called Chapter3_Framework. However, that project has no gsMain files or gsTest files either. When the active SDK is changed to 3.1.2 the code does compile, but with warnings. It still uses stringWithContentsOfFile in the Resource Manager DirectoryMasher function - this was deprecated with the release of version 3.0 (in June I believe).

In short, the code in the book between pages 71-77, does not seem to resemble any of the example projects downloaded from Sourceforge, whose code is out of date anyway. It has many small errors, and doesn't work, even when these are corrected. The gsMain view displays for a fraction of a second and then the app crashes.

Thanks for writing the book, so far so good. The theory is very helpful for me, and it seemed well written as a primer.

I'm confused about the implementation that starts on pg. 71. Is the code in the book correct? Or, should we reference the downloadable code at sourceforge.com, for the correct code, while using the book for the explanation of the process?

Also

step 1. you did not name the project but you reference it in step 5. (convoluted).
step 2. you can select the class type of subclass in the New File dialogue box, so there's no need to change it in the header file in step 4 (GameState.h UIView).

Thanks

The code in the Render method returns errors, telling me that the context in not correct.
<Error>: CGContextSetFillColorWithColor: invalid context
and many more

In general the code on these pages does not seem to be the same as the example project.

Hi my name is Lawrence,

If anyone wants to discuss the book, or work together to try and resolve some of the problems posted here, you may email me.

larsvmd@mac.com

www.zonesight.com
Visual Development
iPhone Beginner Developer

I typed following code, it doesn't work for me. the program compiles, displays a black screen, and kick out ... CGContext invalid errors to the console.

-(void) render {
CGContextRef g = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(g, [UIColor grayColor].CGColor);
CGContextFillRect(g, CGRectMake(0, 0, self.frame.size.width,
self.frame.size.height));
CGContextSetFillColorWithColor(g,[UIColor blackColor].CGColor);

[@"O'Reilly Rules!" drawAtPoint:CGPointMake(10.0, 20.0)
withFont:[UIFont systemFontOfSize:[UIFont systemFontSize]]];
}

When I replace the code with the following, it prints to console just fine.

{
NSLog(@"print this");
}

Adding code to the Update function, the first line refers to Test_FrameworkAppDelegate.
When the project is first created no project name is suggested; however, the code so far resembles the Example project downloaded from Sourceforge far more than the Chapter3Framework project.

Furthermore, in the text on page 71, at the beginning of the section on Implementation, instruction 5. refers to ExampleViewController.m which is a part of the Example project, but on Page 74 at the top of the page, it is the Test_FrameworkAppDelegate class which is referred to in both the text and the sample code below.

Some clarification would be helpful, especially for beginners in iPhone programming.

Once you get to this section it all starts to come right, and a great deal easier to follow. The book is now dealing with the same code as the Chapter3 Framework project, although it never actually names it, which is a pity as there are two projects in the download for Chapter 3..

I'm trying this on Simulator 4.2 or my iPhone 4. It's not working. There is only an orange background. The downloaded sample code does not work either. Does this have anything to do with my old book vs new xCode/SDK/device or maybe the opengles 1 is old or anything?

I get layer <CAEAGLLayer: 0x4be8370> in NSLog. No errors, but no textures (png or font) either.