Creating a Sound Demo

Now we need to add in another Windows game project to our XELibrary solution. We can
call this new project SoundDemo. We can also set up our solution for our Xbox 360
project if we want to test it on the console. Now we need to make sure our game is referencing
the XELibrary project.
Once we have our XELibrary referenced correctly, we can start writing code to test out our
new sound class (and updated input class). We need to use the library’s namespace at the
top of our game class as follows:
using XELibrary;
We should also add a folder called Content with a Sounds subfolder to our solution. We
can then paste our XACT project file into our Sounds folder. The wave files should be put
in the folder, but do not need to be included in the project. When we compile our code
later, the Content Pipeline will find all of the waves from the wave bank and wrap them
into a wave bank .xwb file. It also creates a sound bank .xsb file while the audio engine is
stored in Chapter7.xgs (as that is what we had as our XACT project name).
We will now add in our InputHandler game component so we can kick off sound events
based on our input. We need to declare our private member field to hold the component
as well as adding it to our game’s components collection:
Creating a Sound Demo 147
7
private InputHandler input;
private SoundManager sound;
public Game1()
{
graphics = new GraphicsDeviceManager(this);
content = new ContentManager(Services);
input = new InputHandler(this);
Components.Add(input);
sound = new SoundManager(this, “Chapter7”);
Components.Add(sound);
}
We passed in “Chapter7” to our constructor because that is what we called our XACT
project. The next thing we need to do is set up our playlist. We can do this inside of our
Initialize method because we added the sound component in our constructor:
string[] playList = { “Song1”, “Song2”, “Song3” };
sound.StartPlayList(playList);
The code tells our sound manager we will be playing three different songs. The library
will keep checking to see if they are playing. If not, it will automatically play the next
one, looping back to the beginning song when it reaches the end of the list.
Now we can actually populate our Update method to check for our input to play all of the
sounds and songs we set up in XACT. We need to add the following code to our Update
method:
if (input.KeyboardState.WasKeyPressed(Keys.D1) ||
input.ButtonHandler.WasButtonPressed(0, InputHandler.ButtonType.A))
sound.Play(“gunshot”);
if (input.KeyboardState.WasKeyPressed(Keys.D2) ||
input.ButtonHandler.WasButtonPressed(0, InputHandler.ButtonType.B))
sound.Play(“hit”);
if (input.KeyboardState.WasKeyPressed(Keys.D3) ||
input.ButtonHandler.WasButtonPressed(0,
InputHandler.ButtonType.LeftShoulder))
sound.Play(“attention”);
if (input.KeyboardState.WasKeyPressed(Keys.D4) ||
input.ButtonHandler.WasButtonPressed(0,
InputHandler.ButtonType.LeftStick))
sound.Play(“explosion”);
if (input.KeyboardState.WasKeyPressed(Keys.D5) ||
input.ButtonHandler.WasButtonPressed(0,
InputHandler.ButtonType.RightShoulder))
148 CHAPTER 7 Sounds and Music
sound.Play(“bullet”);
if (input.KeyboardState.WasKeyPressed(Keys.D6) ||
input.ButtonHandler.WasButtonPressed(0,
InputHandler.ButtonType.RightStick))
sound.Play(“crash”);
if (input.KeyboardState.WasKeyPressed(Keys.D7) ||
input.ButtonHandler.WasButtonPressed(0, InputHandler.ButtonType.X))
sound.Play(“complex”);
if (input.KeyboardState.WasKeyPressed(Keys.D8) ||
input.ButtonHandler.WasButtonPressed(0, InputHandler.ButtonType.Y))
sound.Toggle(“CoolLoop”);
if (input.KeyboardState.WasKeyPressed(Keys.D9) ||
input.ButtonHandler.WasButtonPressed(0,
InputHandler.ButtonType.LeftShoulder))
sound.Toggle(“CoolLoop 2”);
if (input.KeyboardState.WasKeyPressed(Keys.P) ||
input.ButtonHandler.WasButtonPressed(0, InputHandler.ButtonType.Start))
{
sound.Toggle(“CoolLoop”);
}
if (input.KeyboardState.WasKeyPressed(Keys.S) ||
(input.GamePads[0].Triggers.Right > 0))
sound.StopPlayList();
We are simply checking to see if different keys were pressed or different buttons were
pushed. Based on those results we play different cues that we set up in the XACT project.
A good exercise for us would be to run the demo and reread the section of this chapter
where we set up all of these sounds and see if they do what we expect when we press the
appropriate keys or buttons. In particular we can press the B button or number 2 key
repeatedly and see that the “hit” cue is queuing up as we told it to limit itself to only
playing once and to queue failed requests. We can also click down on our right thumb
stick or press the number 6 key to hear our crash. If the playlist is hindering our hearing
of the sounds we can stop it by pressing the S key or pushing on our right trigger.
The final piece of code for our sound demo is where we can set a global variable for the
RPC we set up as well as the volume of our default category cues. To start, we need to add
two more private member fields:
private float currentVolume = 0.5f;
private float value = 0;
Now we can finish up our Update method with the following code:
if (input.KeyboardState.IsHoldingKey(Keys.Up) ||
input.GamePads[0].DPad.Up == ButtonState.Pressed)
Creating a Sound Demo 149
7

Now we need to add in another Windows game project to our XELibrary solution. We can
call this new project SoundDemo. We can also set up our solution for our Xbox 360
project if we want to test it on the console. Now we need to make sure our game is referencing
the XELibrary project.
Once we have our XELibrary referenced correctly, we can start writing code to test out our
new sound class (and updated input class). We need to use the library’s namespace at the
top of our game class as follows:
using XELibrary;
We should also add a folder called Content with a Sounds subfolder to our solution. We
can then paste our XACT project file into our Sounds folder. The wave files should be put
in the folder, but do not need to be included in the project. When we compile our code
later, the Content Pipeline will find all of the waves from the wave bank and wrap them
into a wave bank .xwb file. It also creates a sound bank .xsb file while the audio engine is
stored in Chapter7.xgs (as that is what we had as our XACT project name).
We will now add in our InputHandler game component so we can kick off sound events
based on our input. We need to declare our private member field to hold the component
as well as adding it to our game’s components collection:
Creating a Sound Demo 147
7
private InputHandler input;
private SoundManager sound;
public Game1()
{
graphics = new GraphicsDeviceManager(this);
content = new ContentManager(Services);
input = new InputHandler(this);
Components.Add(input);
sound = new SoundManager(this, “Chapter7”);
Components.Add(sound);
}
We passed in “Chapter7” to our constructor because that is what we called our XACT
project. The next thing we need to do is set up our playlist. We can do this inside of our
Initialize method because we added the sound component in our constructor:
string[] playList = { “Song1”, “Song2”, “Song3” };
sound.StartPlayList(playList);
The code tells our sound manager we will be playing three different songs. The library
will keep checking to see if they are playing. If not, it will automatically play the next
one, looping back to the beginning song when it reaches the end of the list.
Now we can actually populate our Update method to check for our input to play all of the
sounds and songs we set up in XACT. We need to add the following code to our Update
method:
if (input.KeyboardState.WasKeyPressed(Keys.D1) ||
input.ButtonHandler.WasButtonPressed(0, InputHandler.ButtonType.A))
sound.Play(“gunshot”);
if (input.KeyboardState.WasKeyPressed(Keys.D2) ||
input.ButtonHandler.WasButtonPressed(0, InputHandler.ButtonType.B))
sound.Play(“hit”);
if (input.KeyboardState.WasKeyPressed(Keys.D3) ||
input.ButtonHandler.WasButtonPressed(0,
InputHandler.ButtonType.LeftShoulder))
sound.Play(“attention”);
if (input.KeyboardState.WasKeyPressed(Keys.D4) ||
input.ButtonHandler.WasButtonPressed(0,
InputHandler.ButtonType.LeftStick))
sound.Play(“explosion”);
if (input.KeyboardState.WasKeyPressed(Keys.D5) ||
input.ButtonHandler.WasButtonPressed(0,
InputHandler.ButtonType.RightShoulder))
148 CHAPTER 7 Sounds and Music
sound.Play(“bullet”);
if (input.KeyboardState.WasKeyPressed(Keys.D6) ||
input.ButtonHandler.WasButtonPressed(0,
InputHandler.ButtonType.RightStick))
sound.Play(“crash”);
if (input.KeyboardState.WasKeyPressed(Keys.D7) ||
input.ButtonHandler.WasButtonPressed(0, InputHandler.ButtonType.X))
sound.Play(“complex”);
if (input.KeyboardState.WasKeyPressed(Keys.D8) ||
input.ButtonHandler.WasButtonPressed(0, InputHandler.ButtonType.Y))
sound.Toggle(“CoolLoop”);
if (input.KeyboardState.WasKeyPressed(Keys.D9) ||
input.ButtonHandler.WasButtonPressed(0,
InputHandler.ButtonType.LeftShoulder))
sound.Toggle(“CoolLoop 2”);
if (input.KeyboardState.WasKeyPressed(Keys.P) ||
input.ButtonHandler.WasButtonPressed(0, InputHandler.ButtonType.Start))
{
sound.Toggle(“CoolLoop”);
}
if (input.KeyboardState.WasKeyPressed(Keys.S) ||
(input.GamePads[0].Triggers.Right > 0))
sound.StopPlayList();
We are simply checking to see if different keys were pressed or different buttons were
pushed. Based on those results we play different cues that we set up in the XACT project.
A good exercise for us would be to run the demo and reread the section of this chapter
where we set up all of these sounds and see if they do what we expect when we press the
appropriate keys or buttons. In particular we can press the B button or number 2 key
repeatedly and see that the “hit” cue is queuing up as we told it to limit itself to only
playing once and to queue failed requests. We can also click down on our right thumb
stick or press the number 6 key to hear our crash. If the playlist is hindering our hearing
of the sounds we can stop it by pressing the S key or pushing on our right trigger.
The final piece of code for our sound demo is where we can set a global variable for the
RPC we set up as well as the volume of our default category cues. To start, we need to add
two more private member fields:
private float currentVolume = 0.5f;
private float value = 0;
Now we can finish up our Update method with the following code:
if (input.KeyboardState.IsHoldingKey(Keys.Up) ||
input.GamePads[0].DPad.Up == ButtonState.Pressed)
Creating a Sound Demo 149
7
currentVolume += 0.05f;
if (input.KeyboardState.IsHoldingKey(Keys.Down) ||
input.GamePads[0].DPad.Down == ButtonState.Pressed)
currentVolume -= 0.05f;
currentVolume = MathHelper.Clamp(currentVolume, 0.0f, 1.0f);
sound.SetVolume(“Default”, currentVolume);
if (input.KeyboardState.WasKeyPressed(Keys.NumPad1))
value = 5000;
if (input.KeyboardState.WasKeyPressed(Keys.NumPad2))
value = 25000;
if (input.KeyboardState.WasKeyPressed(Keys.NumPad3))
value = 30000;
if (input.KeyboardState.WasKeyPressed(Keys.NumPad4))
value = 40000;
if (input.KeyboardState.WasKeyPressed(Keys.NumPad5))
value = 50000;
if (input.KeyboardState.WasKeyPressed(Keys.NumPad6))
value = 60000;
if (input.KeyboardState.WasKeyPressed(Keys.NumPad7))
value = 70000;
if (input.KeyboardState.WasKeyPressed(Keys.NumPad8))
value = 80000;
if (input.KeyboardState.WasKeyPressed(Keys.NumPad9))
value = 90000;
if (input.KeyboardState.WasKeyPressed(Keys.NumPad0))
value = 100000;
if (input.GamePads[0].Triggers.Left > 0)
value = input.GamePads[0].Triggers.Left * 100000;
sound.SetGlobalVariable(“SpeedOfSound”, value);
This completes our sound demo code and now if we run it and press the Up and Down
arrow keys or on the Dpad we can hear the volume of the sounds associated with our
“Default” category go up and down. We clamp our value between 0 and 1 because that is
what the engine takes to set the volume. This is an example of how checking for the
input state without considering the previous state can get us into trouble. The code will
turn the volume up and down very quickly because it is getting back a true on every call
every frame. Feel free to add Dpad to the updated InputHandler code.
Not only does this code let us test the volume settings, it also lets us set a global variable.
In the XACT project, if we used SpeedOfSound as one of the parameters when setting up
our curve then we can actually modify the way the cue sounds here at runtime. That is
pretty powerful.