The book covers all the important basics and shows you how to build an iPhone UI and wire up the buttons, etc. In fact it’s the book I used to figure out how to write the touch handlers in the previous example. Besides basic interaction (taps, touches, gestures), the book also covers what’s known in the iPhone as “views” (think of them as pages of your application). It also covers things like how to design for rotation, acceleration, location, table views, tab bars, pickers, etc. It even covers the basics of using SQLite3 to save data locally.

Once you are done reading the book, you may realize just how simple it is to recreate many of the apps that you see in the App Store and in the Apple commercials using ready made components supplied by the iPhone SDK.

Even if you decide to just build an OpenGL ES app – you will probably still end up using views to create opening and configuration screens for your app. So no matter what approach you take to developing iPhone apps, you will probably find the information in this book essential.

Besides Amazon – you can buy a PDF version of the book here: http://www.apress.com/book/view/1430216263

Since the book is heavy in Objective-C code, you may also want to pick yourself up a copy of Programming in Objective-C 2.0 (2nd Edition) (Developer’s Library).

When you port C++ to the iPhone you will probably want to just add your code to an Objective-C project.

Here are some of the issues that may lead to compiler warnings and errors:

• You need to change the extension of your C++ source files from *.cpp to *.mm
• If you reference your C++ *.h file from a *.m file you will get weird syntax errors around your class definition. The reason is because ANY file in your project that references a C++ *.h file must end in *.mm. So if your Objective-C code references a C++ file, change the extension to *.mm.
• You will get warnings that Objective-C ignores constructors and destructors. So you will have to break out that code and call it after defining your object.
• You will get a weird syntax error if you forget to put a semi-colon after your class definition ( class MyClass { … } ; ). This fixes the error “error: new types may not be defined in a return type“. Xcode generates the brackets but doesn’t put the semi-colon in automatically. So be on the lookout for that. You won’t get this error until you add a method that returns something. If you started out with a bunch of void methods – then wonder why it suddenly broke – that’s why.
• The virtual keyword isn’t allowed. In Objective-C all methods are virtual. If your derived class has a matching method, it will be called instead of the one in the base class – as if you did declare it virtual.

See also: Using C++ With Objective-C (developer.apple.com)

OpenGL and Mobile Devices: Round 2 – OpenGL ES for the iPhone and iPod Touch

If you know basic OpenGL and are trying to get started on the iPhone, this may be a good place to start.

UPDATE: Be forewarned – I have yet to successfully port the application listed in the article to the iPhone. For suggestions see my next post about mixing C++.

I’ve decided to teach myself Open GL first – then go through the pain of learning OpenGL ES – which means when I scale back to ES, some features I’m going to learn about may be missing.  

Even though I’m more comfortable in Windows, I’m going to make life even more complicated by learning OpenGL on the Mac first.

OpenGL on the Mac

To get started developing for OpenGL on the Mac you are going to need Xcode.  See my previous post for information on that.  I’m assuming you are using the latest version of Mac OS X.

Then what you need to do is visit this link:

http://blog.onesadcookie.com/2007/12/xcodeglut-tutorial.html

At this point you could be done.  What I’m doing here is taking my notes from that article and compressing them.  In a few places I did things a little differently.  But in each case the goal was met:  have a working project that will compile OpenGL and GLUT code.

1. In Xcode select: File / New Project …
2. Under Mac OS X select: Other
3. Click on: Empty Project
4. Click: Choose …
5. Select your development root directory
6. Click: New Folder
7. Give the folder the name of your project, like TestOpenGL
8. For Save As enter the name of your project, like TestOpenGL
9. Click: Save 
10. Under Groups & Files right-click on Targets
11. Select: Add / New Target …
12. Under Mac OS X select: Cocoa
13. Select: Application
14. Click: Next
15. Enter a Target Name, like TestOpenGL
16. Click: Finish
17. You’ll be presented with a Target “TestOpenGL” Info window
18. Scroll to the bottom and double click: GCC_PREFIX_HEADER
19. Clear the contents and click OK
20. Close the Info window
21. In the Groups & Files window of Xcode, right click on the Products folder
22. Select: Add / Existing Frameworks …
23. Expand: Frameworks
24. Select: GLUT.framework
25. Apple-key + click OpenGL.framework
26. Click: Add
27. You’ll see a dialog box, just use the defaults and click Add
28. In the Groups & Files window of Xcode, right click on the Products folder
29. Select: Add / New File …
30. Under Mac OS X select: C and C++
31. Select: C File
32. Click: Next
33. Name it main.c
34. Click: Finish

You Need a Mac

To develop for the iPhone and iPod Touch you need a Mac running Leopard (10.5). Earlier versions of the Mac OS won’t do. Bundled with Leopard is a free IDE called Xcode. Once you have Xcode up and running, you need to go to http://developer.apple.com/iphone/, create a login, and download the iPhone SDK on to your Mac.

Objective-C

Some of you may freak out at this point at the thought of learning another programming language. The de facto standard for programming for the iPhone is Objective-C. You can also do some coding in C++. But most everyone is working in Objective-C. The Apple site has tutorials on iPhone development and there are tutorials out there on Objective-C. So I’m not going to repeat that stuff here.

Simulation is Free, Distribution is $99

You can build your application on the Mac using Xcode and run it in an iPhone simulator for free. But if you actually want to try your code on your iPhone or iPod Touch, you are going to have to plunk down $99 and join the iPhone Developer Program (or more if you are part of a larger enterprise).

Once signed up you will find that when you login to http://developer.apple.com/iphone/ you have a new button that leads to the iPhone Developer Program Portal. This is where you go to manage certificates that you will need to develop for the device. The steps are laid out for the most part. So again I’m not going to repeat instructions that are available online. But I did run into a few issues that I will document here.

Issue #1: Unable to locate a suitable developer disk image

I own the latest iPod Touch that comes with 2.1.1 installed. When I tried to create my app in Xcode I got an error dialog that said “Unable to locate a suitable developer disk image.” I found a solution to my problem here. To quote from the thread:

You will need to create the following symlink:
…/iPhoneOS.platform/DeviceSupport/2.1.1/
pointing at:
…/iPhoneOS.platform/DeviceSupport/2.1/

To do that, open up a terminal window (command prompt) and enter the following:

cd /Developer/Platforms/iPhoneOS.platform/DeviceSupport
ln -s 2.1/ 2.1.1

Issue #2: Signing Your Name

Once you have access to the developer portal you will find instructions under the Provision / How To section that tell you to do this:

In the Project Info window select the ‘Build’ tab and enter “iPhone Developer: YourFirstName YourLastName” in the ‘Code Signing Identity’->’Any iPhone OS’ field setting. This is also the Common Name of your iPhone Development Certificate. (Note: Be sure to include the space between the ‘:’ and ‘YourFirstName’.)

So reading that, I entered “iPhone Developer: Mitch Allen” – it didn’t work. Why? Because when I signed up for the developer program I used my full name so it would match my credit card. What I needed to do was set this to “iPhone Developer: Mitchell Allen.”

Issue #3: Error 0xE800003A

When trying to load and run the application on the actual device you get this rather cryptic error: “Your mobile device has encountered an unexpected error (0xE800003A) during the install phase.”

The closest thing I found to a solution was here.

The instructions for creating certificates for your application tell you to create an identifier like this: com.yourcompany.yourapp. I was experimenting by creating an app based on Conways Game of Life. So my identifier was “com.mitchallen.life2.” To make the dreaded error code go away I almost followed the instructions in the thread. What I did was edit the Bundle Identifier in info.plist to be:

com.mitchallen.${PRODUCT_NAME:Identifier}

I hope this helps!

You may also want to read this article: The iPhone Development Story.