Hero of Allacrost: hoa_audio::GameAudio Class Reference

Public Member Functions

uint32

CheckErrors ()

Returns a set of error codes and also clears the error code to a no-error state.

void

DEBUG_PrintInfo ()

Prints information related to the system's audio capabilities as reported by SDL_mixer.

void

PlaySound (std::string filename)

Plays a sound once.

bool

SingletonInitialize ()

A method for the inheriting class to implement, which initializes the class.

void

Update ()

Periodically removes any temporarily loaded sounds that have finished playing.

~GameAudio ()

Volume Member Access Functions

Used for reading and modifying the volume of music/sound in the game.

These volume changes have a global effect (they modify the volume of all music/sound sources). There is currently no support to change the volume levels of individual sound or music sources. However, one can achieve the same effect by modifying the source properties and (in the case of single-channel audio) manipulating distance attenuation.

Note:: In OpenAL, the gain property of sources is essentially the volume.
In addition to these functions, you can also change the gain (volume) of the listener, which will effect the volume level of all audio heard in the game.

float

GetMusicVolume ()

float

GetSoundVolume ()

void

SetMusicVolume (float vol)

void

SetSoundVolume (float vol)

Global Music Manipulation Functions

Performs specified operation on all active music.

Since there is only one music source, these functions only affect that source. They are equivalent to calling the {Pause/Resume/Stop/Rewind}Music functions on the MusicDescriptor which currently has posession of the source.

void

void

void

void

Global Sound Manipulation Functions

Performs specified operation on all active sounds.

void

PauseAllSounds ()

void

ResumeAllSounds ()

void

StopAllSounds ()

Global Audio Manipulation Functions

Performs specified operation on all active sounds and music.

These functions will only effect audio data that is in the state(s) specified below: PauseAudio() <==> playing state ResumeAudio() <==> paused state StopAudio() <==> playing state RewindAudio() <==> playing state, paused state

void

PauseAudio ()

void

ResumeAudio ()

void

RewindAudio ()

void

StopAudio ()

Private Member Functions

GameAudio ()

Audio Data Retrieval Functions

Creates and loads new audio data if the data is not already loaded.

Parameters:

filename

The filename of the file data to search for (not including the pathname or file extension).

Returns:: A pointer to the class object holding the new data. NULL may also be returned, indicating an error.

These functions are critical to ensuring efficient memory usage in the audio engine (in other words: making sure no more than one copy of audio data is loaded into the engine at any given time). When these functions are called, first the map of audio data objects is searched to see if the data is already found in there. If it is, a pointer to that object is returned. Otherwise, the function will attempt to create a new object and store that into the appropriate data object map. If that fails for some reason, the function will return NULL.

private_audio::MusicData *

_AcquireMusicData (std::string filename)

private_audio::SoundData *

_AcquireSoundData (std::string filename)

Private Attributes

uint32

_audio_errors

Retains all the errors that have occured on audio-related function calls, except for loading errors.

float

_music_volume

The volume level for music playback. Valid range is between 0.0f and 1.0f.

float

_sound_volume

The volume level for sound playback. Valid range is between 0.0f and 1.0f.

std::list< SoundDescriptor * >

_temp_sounds

Holds sounds which are temporarily loaded and played This vector holds any sounds loaded via a call to AudioManager::PlaySound. It will play the sound once to completion. The AudioManager::Update call periodically reviews this list and removes any sounds which have finished playing.

Audio Data Containers

Sound (WAV) and music (OGG) data are stored in these container classes and referenced by the SoundDescriptor and MusicDescriptor classes. They are stored in this manner to allow for optimized memory usage (in other words, only one instance of .wav and .ogg data can be loaded in the application at any point in time). The sound or music filename string serves as the map key for determining if the data is loaded or not. The key is a reference to the filename string (which is stored in the SoundData or MusicData class itself).

std::map< std::string, private_audio::MusicData * >

_music_data

std::map< std::string, private_audio::SoundData * >

_sound_data

Friends

class

hoa_utils::Singleton< GameAudio >

class

MusicDescriptor

class

private_audio::MusicData

class

private_audio::SoundData

class

SoundDescriptor

This class manages all audio data allocation and manipulation. The OpenAL sources are wrapped inside this class and OpenAL buffers (which are represented by the SoundDescriptor and MusicObject classes) grab these sources as they need them. The buffers are stored in map structures so that audio data is not loaded when it already exists.

hoa_audio::GameAudio Class Reference

Public Member Functions

Private Member Functions

Private Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation