Apple did me a favor as a writer by delaying the release of Mac OS X 10.5 from June to October. With a June release I would have had a difficult decision to make: delay updating Xcode Tools Sensei until I finished the OpenGL book, or delay development on the OpenGL book to update the Xcode book. Apple gave me another four months to finish the OpenGL book.

All updates for Xcode 3 and Leopard will come in a new edition of Xcode Tools Sensei. Xcode and Interface Builder are going to have major updates. Trying to juggle Xcode 1.x, 2.x, and 3 in one text would be difficult for me to write and you to read. I also will have to take a bunch of new screenshots so it makes sense to have two versions of the book: the current version that supports Xcode 1.x and 2.x, and a new version specifically for Xcode 3. The electronic edition of the Xcode 3 version would be available at a discount for everyone who has the current version of the book.

Skim is a free, open-source PDF viewer for Mac OS X. Mac OS X comes with Preview, which views PDF files, and Adobe Acrobat Reader is freely available so what makes Skim special? Skim has features that make reading technical articles and academic papers easier.

The first of these features is the ability to add notes to a PDF document. It’s the electronic equivalent of adding sticky notes to a paper document. When you’re reading difficult material, being able to make notes to yourself helps in understanding the material.

A second useful feature is the ability to highlight areas of text by putting a circle or box around it. A third feature is snapshots, which let you keep important pieces of a document in easy reach.

Skim is at version 0.2, which means it’s far from a finished product. But if you read a lot of PDF technical articles, you should give Skim a test drive.

I haven’t posted anything about the OpenGL book for a while, but I am writing to let you know I am still working on it. Progress has been excruciatingly slow, which has been very frustrating to me. On the code front, I’ve been working on the physics code. On the writing front, I have a lot of material written on several chapters, but I still don’t have a finished chapter. Whenever I write about something, it brings up several additional topics I have to write about. When I write about those topics, it brings up more things to write about, which makes finishing difficult.

I have started moving the Me and Mark Publishing website to a new host. Everything should be transferred within the next 1-2 days. Hopefully there won’t be any problems. I will add an item to the Latest News section about the switch. If you see the item on the Me and Mark Publishing home page, you’re viewing the site with the new host.

TextWrangler is a free text editor for Mac OS X. It also happens to be a nice development environment for interpreted languages, especially for Perl, Python, and Ruby programming.

TextWrangler’s Advantage over Xcode for Interpreted Languages

Xcode is designed for compiled languages like C++ and Java, not interpreted languages like Python and Ruby. You can create an external build system project in Xcode, but it is not very useful for interpreted languages because there is nothing to build for interpreted languages. You have to run the Terminal application and launch your program from the command line using your language’s interpreter.

TextWrangler’s shebang (#!) menu allows you to run Unix scripts from TextWrangler so you don’t have to launch Terminal. TextWrangler has built-in support for Perl, Python, and Ruby, which means you can run and debug Perl, Python, and Ruby programs from TextWrangler. You can use TextWrangler to run programs in other interpreted languages, but you can’t debug them using TextWrangler’s Run in Debugger menu item.

Creating and Running a Program with TextWrangler

Writing and running code in interpreted languages is easy in TextWrangler. The following steps show you how to write a simple Ruby program with TextWrangler:

1. Choose File > New Text Document.
2. At the bottom of the document window are three pop-up menus. The left menu should say (none). Choose Ruby from the left pop-up menu. This tells TextWrangler that you are writing a Ruby program, which turns on Ruby syntax highlighting and enables the Run in Debugger menu item.
3. Write your code. For a Hello World program, enter puts “Hello World”.
4. Choose #! > Run to run the program.

The instructions for Perl and Python are similar. For Step 2 you would choose either Perl or Python from the pop-up menu and write Perl or Python code instead of Ruby.

If you are using another interpreted language, the first line of code must specify the path to the interpreter.

#!/path/to/interpreter

The #! sequence is the start of a Unix script.

Using TextWrangler with Xcode

Although you don’t need Xcode for small projects if you use TextWrangler, Xcode has its place for larger projects. You would use Xcode for project organization and version control and use TextWrangler to write the code and run the program. The Xcode Tools Tips page has a tip on using external editors with Xcode.

The latest Zelda game came out for Gamecube today at 5:00 PM, and I got to wait in line for it. My mother heard there were shortages so she asked my father to go to Target to get a copy. She needed two copies as Christmas presents, and purchases were limited to one per person so I ended up going to be the second person.

We got to Target a little after 4:30 PM. Fortunately, there were only two people in line when we got there. A couple in their 60′s got in line behind us a few minutes later to buy a copy for their grandson, and another person got in line a few minutes before 5. Seven people in line. I felt a little foolish waiting in such a short line.

Then 5:00 came, and I saw the store had only 6 copies of the game. Those of us in line were the only people to get a copy of the game. I was shocked at how few copies were available. I figured at least 20 would be available, but I felt a lot less foolish waiting in line. It’s going to be hard to find a copy of Zelda by Christmas.

I’ve come to the conclusion there is no way I’m going to be able to finish the OpenGL book by the end of the year, as I had hoped. I would like to have the book finished in the first quarter of 2007.

Writing has progressed slower than I thought. I have my facts correct, but I’m having a hard time making the material interesting to read and making clear explanations. I’m frustrated by the slow progress I’m making, but I prefer taking the time to write a good book that helps people instead of rushing a crappy book that doesn’t help anyone.

By play the same stuff I mean play the same part of a level repeatedly. This problem occurs more with console games than computer games because console games have less flexibility in game saving.

Example: Metroid Prime

I’m going to use the game Metroid Prime to describe the problem of playing the same part of a level repeatedly for two reasons. One, it’s the game I’m currently playing so it is fresh in my mind. Two, it’s a really good game. I want to show that even good games can have minor problems.

If you’re wondering why I’m playing a 4 year old game, I’ll explain it now. I got Metroid Prime about 3 years ago and I got stuck early and quit playing it. I started playing it recently because my brother needed my Playstation 2 to play DVDs because his DVD player broke and I finished my other GameCube games.

Repetition Can Turn Something Fun Into a Chore

Metroid Prime features a lot of boss enemies to fight, and they can be very difficult to defeat. To reach a boss involves fighting lesser enemies, running, jumping, maneuvering the morph ball through tight areas, and problem solving. Sometimes it can take 5-10 minutes of gameplay to reach the boss, and when you die, you have to go back to the last save point and play those 5-10 minutes again.

Because some of the boss enemies are tough to defeat, you can die dozens of times, and replaying the same 5-10 minutes of gameplay to reach the boss gets old fast. Playing those 5-10 minutes to reach the boss is fun the first time. You’re making progress in the game and exploring new areas. Playing to reach the boss a few more times lets you perfect your technique. But after dying 25-50 times, playing the same sequence to reach the boss becomes a chore instead of being fun.

Solutions

One solution to the problem of having to play the same area of a level repeatedly is to provide more save points. In the case of Metroid Prime, having a save point before reaching a boss would prevent the player from having to play the same sequence over and over again. But more save points could make the game too easy. Metroid Prime replenishes your energy (health) to 100% when you save the game.

Another solution would be to continue the game where you died. In the case of Metroid Prime, being able to fight the boss right away after dying would eliminate a lot of frustration. The time spent getting to the boss could be spent on the real challenge, defeating the boss.

The good news for most of the game developers reading this is you’re developing computer games, not console games. Computer games can let the player save the game whenever they want so you can keep the player from playing the same sequence over and over again.

I got an email last night from a customer. He tried to download the updated version of Xcode Tools Sensei and got an error message saying the file was not found on the server. The error message is not surprising because I pulled the file from the server two months ago.

I wanted people who had bought the electronic version of the book to be able to download the new version. For obvious business reasons I didn’t want the new version to be on the site permanently. My solution was to post the updated version on my site for a week and send an email to every customer who wanted to be contacted about updates. I figured a week was enough time for the customers I emailed to download the new version. I apparently was wrong.

I did send the customer the new version. If any of you bought an old electronic version (before September 2006) and want the new version, send me an email and I’ll send you the new version.

I switched the blog from Lulu to Blogger. The old blog did not handle large posts (over a page) well, eliminating text in the middle of the post. I did a test post of a 7 page article, and there were no problems so I decided to switch. Blogger’s spell checking is an added bonus. I included a link to the old blog entries to ease the transition.