Class Audio

Namespace

GB

Assembly

GBSharp.Framework.dll

The sound hardware, at register level.

public static class Audio

Inheritance

object

Audio

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Remarks

This is deliberately not a music engine. It writes the APU registers and stops there: a note plays until something stops it, nothing is sequenced, and there is no mixing. A game that wants music wants a tracker driver, and that is a library rather than a framework concern.

Methods

Disable()

Powers down the APU, silencing everything and clearing its registers.

[Native("gbs_audio_off")]
public static void Disable()

Enable()

Powers up the APU and enables all channels on both speakers.

[Native("gbs_audio_on")]
public static void Enable()

Remarks

The sound hardware ignores every other register while it is off, so this has to come first.

PlayNoise(byte, byte)

Starts noise on channel 4.

[Native("gbs_audio_noise")]
public static void PlayNoise(byte volume, byte period)

Parameters

volume byte

period byte

Remarks

period is the raw polynomial-counter byte: lower values are brighter. Useful for hits and explosions.

PlayTone(Channel, Note, byte, Duty)

Starts a note on a square-wave channel.

[Native("gbs_audio_tone")]
public static void PlayTone(Channel channel, Note note, byte volume, Duty duty)

Parameters

channel Channel

note Note

volume byte

duty Duty

Remarks

channel is a runtime value, so this costs a branch in the shim on top of the register writes. Only Pulse1 and Pulse2 do anything; the note plays until Stop(Channel).

SetMasterVolume(byte, byte)

Sets the master volume for each speaker, 0-7.

[Native("gbs_audio_master_volume")]
public static void SetMasterVolume(byte left, byte right)

Parameters

left byte

right byte

SetRouting(byte)

Sets which channels reach which speaker.

[Native("gbs_audio_routing")]
public static void SetRouting(byte mask)

Parameters

mask byte

Remarks

The low nibble routes channels 1-4 to the right speaker, the high nibble to the left. 0xFF is everything on both.

Stop(Channel)

Silences one channel by dropping its envelope to zero.

[Native("gbs_audio_stop")]
public static void Stop(Channel channel)

Parameters

channel Channel