It’s going on seven months since my last post, which is kind of pathetic. When finishing a large project, like the WP7 port of Guardian, my brain tends to shut down for awhile for recharging. That, on top of starting a new job back in November, lead to a much longer blogging hiatus than intended. So, how about something simple to get back into the swing of things. And since we’re talking about time… Very often in video games there…
Spruced up the menus quite a bit with some floaty asteroids instead of just the raw text. Looks much nicer I think. The todo list is pretty much empty now. Mostly some final balancing and play testing left to go, and some art work for the various icons and other app store images. If all goes well over the next couple of days it’ll be complete and ready to test when I hopefully get my hardware on Monday.
Here is my attempt at using XNA to duplicate some of the UI functionality on WP7. Well, not really duplicate so much as “create a passing resemblance to”. The menu is pretty boring. I’ve been trying to come up with a good idea to make it interesting, and think I finally have something that will be worth the effort. That’ll probably be the next movie. The first WP7 phones are supposed to be released in the U.S. on November 8th…
In a previous post about texture modification, I mentioned the evils of transferring data from the GPU to the CPU, and then presented an example showing one way to avoid doing it. The post wasn’t really about deformable 2D terrain or collision detection, but was intended to help newer game programmers open up a new way of thinking when it comes to using the GPU to accomplish tasks.
Since that post, and the one showing a video of my WP7 game, I’ve received a couple of questions about how I do the collision detection in Guardian, which would seem to require the use of Texture2D.GetData.
Added some tough “boss” asteroids. This one just has a single kill point so it’s relatively simple. Later waves will require destroying multiple targets for the kill. Still need to add a destruction sequence when it’s destroyed, rather than just fading away like it currently does.
I’ve been working on a Windows Phone 7 port of Guardian and finally have something to show for it. All of the systems are in place now, just need to do a lot of tuning and game play tweaking. Of course, at this point I have no idea how it’s going to perform on an actual phone, but it should do fairly well. Hopefully there won’t be too much optimization required after I get my hands on some hardware. I…
I’ve had a couple of questions about what changes are needed to get the texture modification tutorial to work in XNA 3.1. So, here’s a 3.1 version of the project, and a quick overview of the major things that need to change. You need to create the depth/stencil buffer yourself, set it on the GraphicsDevice when setting the render target, and restore the previous buffer when you’re done. RenderTarget2D can’t be used directly as a texture, you must call RenderTarget2D.GetTexture…
Sometimes you need to modify a texture while your game is running, and there are a number of ways to do this. One of the first things newer game programmers often try to do is use Texture2D.GetData to copy the texture data from the GPU to an array on the CPU, modify the bytes, and then send it back to the GPU with Texture2D.SetData.
This is a bad idea on many, levels. Beyond issues with pipeline stalls, GetData and SetData can be slow, especially when working with a large texture. Any time you’re tempted grab data from the GPU for use on the CPU you should very carefully consider all of your options. There are often other solutions that let you keep the data entirely on the GPU and accomplish the same thing.
This tutorial will use an example that could be solved with GetData and SetData, and show you another alternative using render targets and the stencil buffer that will let you perform the same function entirely on the GPU.