Free e-book by Charles Petzold

Check this out. It’s a book. It’s about programming Windows Phone using Silverlight and XNA. It’s by a hero of mine. And it’s a free download!  


Channel 9 Live at PDC

As if live streaming of my upcoming PDC talk was not enough, I’ll be doing a Q&A on Channel 9.  Friday October 29th, 10:00 AM PST. If you have questions you’d like me to address, tweet them @ch9live, or submit a question into the PDC10 Session Q&A panel on the right hand side of the…


PDC sneak preview #2

A screenshot of the demo from my upcoming PDC talk:   Cats are of course to be expected from me, but this year there are dogs too! Day after tomorrow, live streaming from


Sneak preview of my PDC talk

When I read the Swallows and Amazons books as a kid, I loved the "this is what it looked like at night" illustration, which was a page colored solid black. Years later, I finally found an excuse to use this classic image in a PowerPoint deck:   Would you believe this actually makes sense in…


See Shawn talk at PDC

Who:  Me! What:  Things You Need to Know Before Building XNA Games for Windows Phone.  "So you have a cool idea for a game. This session covers some of the less obvious things you will need to know to turn your idea into reality using XNA Game Studio for Windows Phone. Topics include how to…


XNA Game Studio 4.0, Xbox 360, and Indie Games

News from the XNA team blog: Game Studio 4.0 for Xbox will be released "later this fall"  (yes, that is deliberately vague 🙂 At that time we will start accepting 4.0 games into peer review There will be a 90 day window when you can submit both 3.1 and 4.0 games After 90 days, only…


Guide.IsTrialMode on Windows Phone

Kluch posts important info about the performance of Guide.IsTrialMode on Windows Phone: Can take ~60 milliseconds to query while in trial mode So don’t call it every frame! This delay only occurs when downloaded from Marketplace, not when testing with SimulateTrialMode Consider checking it once on startup, then again whenever the Game.Activated event fires


Doing stuff is always more expensive than doing nothing

I sometimes get performance questions that go something like "I want to frobnicate my kaboodle, and am considering doing this by flibitzing the wazoo, but I’m worried this might be too expensive". The only way I know to answer such a question is, mu. The problem is the phrase "too expensive". It is impossible to…


Iterator state machines

In my talk at MIX earlier this year, I mentioned that C# iterators can be useful for building state machines. Some of you asked for more detail about this idea, so, late but not never, here ya go. Let’s say we are building a game with an AI that can choose between five possible actions:…