Tuesday, August 11, 2009

sfxr - A Great Free Sound Effect Generator



One of the problems I always have when I'm working on a game project is sourcing sound effects. Recently, I came across sfxr, a very nice program for creating sound effects. It was a great help when I was working on Saucer Pilots.

It is basically a little software synth with a bunch of variables you can tweak to generate a wide variety of sounds. A helpful set of presets are provided for generating commonly needed classes of video game sounds.

Once you find something you like, export it to a WAV file and you are good to go. Very handy little utility.

Thursday, August 6, 2009

Saucer Pilots - XNA Dream Build Play 2009



Whew! I just squeaked an entry in under tonight's deadline for the 2009 XNA Dream Build Play competition.

Last Monday, I was messing around with a new "flying saucer" game prototype idea. It seemed like it had promise, so I kicked into high gear to try to get something submittable for the competition. I initially got the submission date wrong, and thought I had until this Sunday. A few days ago, I realized my error and really had to step things up.

The competition was a good impetus to get me to actually finish something. I'm generally much more fond of starting things than completing them...

Anyway, the game is "Saucer Pilots" - a 1-4 player saucer flying game with five different gameplay modes. Xbox LIVE avatars are used for saucer pilot models (avatars do not appear in this video, as they are not visible on the PC). The physics implementation I'm using is Farseer.

Overall, I think it turned out pretty well for a week-and-a-half effort. The only thing that made that timeline possible was the framework on top of XNA that I've developed over the past year. And help from Sherry.

Oh, and did I mention that it has fishing?

Tuesday, March 24, 2009

Creating Playlists With Linq - Another Great Use For CodeDomProvider



I recently found a new use for dynamically-compiled assemblies using CodeDomProvider. Combined with Linq, it enables the ultimate flexibility in music playlist generation.

My "Code Playlists", are snippets of code that can do whatever they want as long as they return an enumerable collection of song objects. As you can see above, simple Linq expressions make it really easy to generate pretty much any collection of songs that my music metadata can support.

Thursday, March 12, 2009

WPF Progress Bars Revisited

Because some people were having trouble understanding how to use my original WPF progress bar code, I thought I'd post an updated, easier to use version.

The problems people were having pretty much all centered around not understanding how to run their code in a background thread. My updated version handles this for you.

First, please have a look at the original post, as you will need some of the code from there:

WPF Progress Bars

The XAML and IProgressContext code is still the same, but here is an updated partial class for the progress dialog, along with a delegate definition that it requires:

public delegate void ProgressWorkerDelegate(IProgressContext progressContext);

public partial class ProgressDialog : Window, IProgressContext
{
private bool canceled = false;
private ProgressWorkerDelegate workDelegate = null;

public bool Canceled
{
get { return canceled; }
}

public ProgressDialog() : this(null)
{            
}

public ProgressDialog(ProgressWorkerDelegate workDelegate)
: this(workDelegate, false)
{
}

public ProgressDialog(ProgressWorkerDelegate workDelegate, bool startInBackground)
{
this.workDelegate = workDelegate;

InitializeComponent();

CancelButton.Click += new RoutedEventHandler(CancelButton_Click);

if (workDelegate != null)
{
if (startInBackground)
{
new Thread(new ThreadStart(StartWork)).Start();
}
else
{
StartWork();
}
}
}

private void StartWork()
{
workDelegate(this);
}

void CancelButton_Click(object sender, RoutedEventArgs e)
{
canceled = true;
CancelButton.IsEnabled = false;
}

public void UpdateProgress(double progress)
{
Dispatcher.BeginInvoke(DispatcherPriority.Background,
(SendOrPostCallback)delegate { Progress.SetValue(ProgressBar.ValueProperty, progress); }, null);
}

public void UpdateStatus(string status)
{
Dispatcher.BeginInvoke(DispatcherPriority.Background,
(SendOrPostCallback)delegate { StatusText.SetValue(TextBlock.TextProperty, status); }, null);
}

public void Finish()
{
Dispatcher.BeginInvoke(DispatcherPriority.Background,
(SendOrPostCallback)delegate { Close(); }, null);
}
}


The key difference is that you can now pass the dialog a delegate that will be used to do your work, and can have it automatically get run in the background.

To use it, do something like this:

ProgressDialog progressDialog = new ProgressDialog(MyWorkFunction, true);
progressDialog.ShowDialog();


Note that I am using ShowDialog() above to keep the operation modal. If you want the rest of your UI to still accept input, use Show() instead.

Your function to actually do the work would look something like this:

void MyWorkFunction(IProgressContext progressContext)
{
for (int i = 0; i < 100; i++)
{
if (myProgressContext.Canceled)
break;

progressContext.UpdateProgress((double)i / 100.0);
progressContext.UpdateStatus("Doing Step " + i);
}

progressContext.Finish();
}

Wednesday, March 4, 2009

Gravity Game

Gravity Game

My latest hobby project is a gravity-based game in the tradition of old classics like Lunar Lander, Gravitar and Thrust. Currently, the mechanics are pretty simple. Shoot things, avoid being shot, crashing, or being hit by an asteroid, and use your tractor beam to move around colored balls that act as keys to remove barriers.

I've also been playing with water dynamics.

Gravity Game

The game is XNA-based, and I'm using Farseer as my physics engine.

Monday, January 19, 2009

More FM Synth Progress



Ok, my "little" FM synthesizer project is now officially a bit out of control. It has grown to include a drum pattern editor, chord progressions and a mini song sequencer. WPF, with its clean separation between the UI and the underlying code is perfect for doing audio interface work. Too bad the digital audio world is still mired in C++...

Monday, January 12, 2009

WPF Layout Woes - MeasureOverride killed Schrödinger's Cat

A struggle I'm currently having with layout in WPF reminds me of the Observer Effect in physics. It turns out that calling Measure() on a child object has side effects. You would think that the measuring phase of layout would simply involve asking the child how big it wants to be. Instead, you need to pass it a size constraint.

Normally, that would not be a problem, but what if you want to size a set of children based on their relative desired sizes? Catch-22. You can't call Measure() on a child without knowing the maximum size you want it to be. And, in my situation, I don't know what size I want it to be without first measuring it. And, once you have measured an objected, its size "sticks" - changing it when you do Arrange() only alters the size of the clip rectangle (an important distinction if the child actually can be variably sized - such as content within a ScrollViewer).

Very frustrating.

I have found a fairly complicated way of working around the isue, but it seems like a fundamental (if not often encountered) flaw in the way WPF layout works.