Wt::SDLMixer Class Reference

Wrapper class around the audio mixer. More...

#include <sdlmixer.h>

Inheritance diagram for Wt::SDLMixer:

[legend]Collaboration diagram for Wt::SDLMixer:

[legend]List of all members.

Public Types
typedef BaseFactory< Audio >	AudioBaseFactory
Public Member Functions
virtual Audio::Chunk *	loadChunk (const std::string &filename) const
virtual int	allocateChannels (int channels)
virtual void	pause ()
	pause all channels
virtual void	resume ()
	resume all channels
virtual void	stop (int ms=0)
	stop all channels
virtual void	fadeOut (int ms)
virtual int	playingChannels () const
virtual int	pausedChannels () const
virtual bool	isAvailable () const
virtual Audio::Music *	loadMusic (const std::string &filename)
virtual void	playMusic (Audio::Music &)
	it blocks until any previously music fading out is done
virtual void	fadeInMusic (Audio::Music &, int ms)
virtual void	fadeOutMusic (int ms)
virtual void	setMusicVolume (int volume)
virtual void	pauseMusic ()
virtual void	rewindMusic ()
virtual bool	setMusicPosition (double start_sec)
virtual void	stopMusic ()
virtual bool	playingMusic () const
virtual bool	pausedMusic () const
virtual int	musicFading () const
int	numChannels () const
Channel *	operator[] (int i) const
Static Public Member Functions
static DERIVED *	instance ()
template<class GRANDCHILD>
static DERIVED *	instance ()
	instantiates the pointer compatible child of DERIVED aka grandchild
static DERIVED *	existingInstance ()
static void	init ()
static void	quit ()
Public Attributes
Signal01< void, Channel * >	finished
WVar< int >	musicLoops
sigc::signal< void >	musicFinished
Static Public Attributes
static Factory< Audio, SDLMixer >	factory
Protected Member Functions
	~SDLMixer ()
	SDLMixer ()
virtual int	minHWVolume () const
virtual int	maxHWVolume () const
int	HWVolume (int volume) const
template<typename CHILD>
void	adjustAllocatedChannels (int oldnum, int newnum)
Static Protected Member Functions
static Audio *	load ()
	try to load the instance
static void	onChannelFinish (int channel)
	callback called when a channel finishes
static void	onMusicFinish ()
static void	handleAudioEvent (const SDL_Event *event)
	SDLEvent::Audio handler.
Protected Attributes
std::vector< Channel * >	channels
Static Protected Attributes
static const int	minVolume = 0
static const int	maxVolume = 1000
static DERIVED *	instance_ = 0
Static Private Attributes
static FlagMap	fadingTypeMap
static FlagMap	musicTypeMap
Friends
class	Singleton< Audio >
Classes
class	Channel
class	Chunk
	SDLMixer::Chunk implementation class. More...
class	Music

---

Detailed Description

Wrapper class around the audio mixer.

Definition at line 37 of file sdlmixer.h.

---

Member Typedef Documentation

typedef BaseFactory<Audio> Wt::Audio::AudioBaseFactory [inherited]

Definition at line 86 of file audio.h.

---

Constructor & Destructor Documentation

Wt::SDLMixer::~SDLMixer

(

)

[protected]

Definition at line 60 of file sdlmixer.cpp.

References allocateChannels(), and trace.

                    {
    trace("sdlmixer", "Entering Destructor for SDLMixer\n");
    allocateChannels(0);
    Mix_CloseAudio();
}

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Wt::SDLMixer::SDLMixer

(

)

[protected]

Definition at line 35 of file sdlmixer.cpp.

References fadingTypeMap, musicTypeMap, onChannelFinish(), and Wt::Audio::onMusicFinish().

Referenced by load().

        : Audio() {

    // we can't reliably initialize staticly since we have to make
    // sure the enumeration is initialized first and this depends
    // from the linking order (static initialization fiasco)
    fadingTypeMap = boost::assign::map_list_of
                    (MIX_NO_FADING, FadingType::None)
                    (MIX_FADING_OUT, FadingType::Out)
                    (MIX_FADING_IN, FadingType::In);

    musicTypeMap = boost::assign::map_list_of
                   (MUS_NONE, MusicType::None)
                   (MUS_CMD, MusicType::Cmd)
                   (MUS_WAV, MusicType::WAV)
                   (MUS_MOD, MusicType::MOD)
                   (MUS_MID, MusicType::MID)
                   (MUS_OGG, MusicType::OGG)
                   (MUS_MP3, MusicType::MP3);

    adjustAllocatedChannels<SDLMixer>(0, Mix_AllocateChannels(-1));
    Mix_ChannelFinished(onChannelFinish);
    Mix_HookMusicFinished(onMusicFinish);
}

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---

Member Function Documentation

template<typename CHILD>

void Wt::Audio::adjustAllocatedChannels	(	int	oldnum,
		int	newnum
	)			[inline, protected, inherited]

Definition at line 241 of file audio.h.

References Wt::Audio::Audio(), and Wt::Audio::channels.

                                                         {
        if (oldnum < newnum) {
            for (int i = oldnum; i < newnum; i++) {
                channels.push_back(new typename CHILD::Channel(i));
            }
        } else { // newnum < oldnum
            Audio& self = *this;
            for (int i = newnum; i < oldnum; i++) {
                delete self[i];
            }
            self.channels.resize(newnum);
        }
    }

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int Wt::SDLMixer::allocateChannels

(

int

channels

)

[virtual]

Reimplemented from Wt::Audio.

Definition at line 112 of file sdlmixer.cpp.

References Wt::Audio::numChannels().

Referenced by ~SDLMixer().

                                               {
    const int oldnum = numChannels();
    assert(Mix_AllocateChannels(-1) == oldnum);

    if (num_channels == oldnum || num_channels < 0)
        return oldnum;

    adjustAllocatedChannels<SDLMixer>(oldnum,
                                      Mix_AllocateChannels(num_channels));

    return numChannels();
}

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template<class DERIVED>

static DERIVED* Wt::Singleton< DERIVED >::existingInstance

(

)

[inline, static, inherited]

Definition at line 36 of file singleton.h.

Referenced by Wt::Application::exit(), Wt::Application::postEvent(), Wt::Application::sendEvent(), and Wt::Application::sendPostedEvents().

                                       {
        return instance_;
    }

void Wt::SDLMixer::fadeInMusic	(	Audio::Music &	,
		int	ms
	)			[virtual]

Reimplemented from Wt::Audio.

Definition at line 177 of file sdlmixer.cpp.

References Wt::Audio::musicLoops.

                                                    {
    SDLMixer::Music& m = * static_cast<SDLMixer::Music *>(&music);
    Mix_FadeInMusic(m, musicLoops - 1, ms);
}

void Wt::SDLMixer::fadeOut

(

int

ms

)

[virtual]

Reimplemented from Wt::Audio.

Definition at line 138 of file sdlmixer.cpp.

                             {
    Mix_FadeOutChannel(-1, ms);
}

void Wt::SDLMixer::fadeOutMusic

(

int

ms

)

[virtual]

Reimplemented from Wt::Audio.

Definition at line 182 of file sdlmixer.cpp.

                                  {
    Mix_FadeOutMusic(ms);
}

void Wt::Audio::handleAudioEvent

(

const SDL_Event *

event

)

[static, protected, inherited]

SDLEvent::Audio handler.

it emits the required signal to all interested parties

Definition at line 213 of file audio.cpp.

References Wt::Audio::Event::channel(), Wt::Audio::Event::chunk(), Wt::Audio::Channel::finished, Wt::Singleton< DERIVED >::instance(), and trace.

Referenced by Wt::Audio::Audio().

                                                   {
    trace("audio", "audio event delivered\n");
    Event *sdl_audio_event = static_cast<Event *>(event->user.data1);
    Chunk *chunk = sdl_audio_event->chunk();
    Channel *channel = sdl_audio_event->channel();
    if (chunk && channel) {
        chunk->finished(chunk);
        channel->finished(channel);
        instance()->finished(channel);
    } else {
        instance()->musicFinished();
    }
    delete sdl_audio_event;
}

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int Wt::Audio::HWVolume

(

int

volume

)

const [protected, inherited]

Definition at line 169 of file audio.cpp.

References Wt::Audio::maxHWVolume(), Wt::Audio::maxVolume, Wt::Audio::minHWVolume(), and Wt::Audio::minVolume.

                                    {
    return (maxHWVolume() - minHWVolume()) *  volume /
           (maxVolume - minVolume);
}

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template<class DERIVED>

static void Wt::Singleton< DERIVED >::init

(

)

[inline, static, inherited]

Note:

cannot fail

Reimplemented in Wt::Application.

Definition at line 49 of file singleton.h.

Referenced by Wt::Application::Application().

                       {
        if (!instance()) {
            assert(0);
        }
    }

template<class DERIVED>

template<class GRANDCHILD>

static DERIVED* Wt::Singleton< DERIVED >::instance

(

)

[inline, static, inherited]

instantiates the pointer compatible child of DERIVED aka grandchild

it is handy in driver like situations

Definition at line 43 of file singleton.h.

                               {
        return (instance_) ? instance_ : GRANDCHILD::load();
    }

template<class DERIVED>

static DERIVED* Wt::Singleton< DERIVED >::instance

(

)

[inline, static, inherited]

Definition at line 32 of file singleton.h.

Referenced by Wt::Audio::Audio(), Wt::Sound::available(), Wt::SDLMixer::Chunk::channel(), Wt::NullAudio::Chunk::channel(), Wt::SDLSurface::defaultDepth(), Wt::SDLInput::EventInfo::EventInfo(), Wt::Dialog::exec(), Wt::Widget::grabKeyboard(), Wt::Widget::grabMouse(), Wt::Audio::handleAudioEvent(), Wt::SDLInput::handleKeyEvent(), Wt::Singleton< Wt::Audio >::init(), Wt::SDLTimer::init(), Wt::Sound::isAvailable(), Wt::Widget::keyboardGrabber(), Wt::Audio::load(), Wt::Widget::mouseGrabber(), onChannelFinish(), Wt::Audio::onChannelFinish(), Wt::Sound::play(), Wt::Singleton< Wt::Audio >::quit(), Wt::Widget::releaseKeyboard(), Wt::Widget::releaseMouse(), Wt::SDLInput::SDLInput(), setMusicVolume(), Wt::SDLMixer::Channel::setVolume(), and Wt::SDLMixer::Chunk::setVolume().

                               {
        return (instance_) ? instance_ : DERIVED::load();
    }

bool Wt::SDLMixer::isAvailable

(

)

const [virtual]

Reimplemented from Wt::Audio.

Definition at line 150 of file sdlmixer.cpp.

                                 {
    return true;
}

Audio * Wt::SDLMixer::load

(

)

[static, protected]

try to load the instance

if it fails return NULL if it succeeds must return the newly created object

Reimplemented from Wt::Audio.

Definition at line 66 of file sdlmixer.cpp.

References SDLMixer(), and trace.

                      {
    trace("sdlmixer", "Initializing SDL audio...\n");
    if (SDL_InitSubSystem(SDL_INIT_AUDIO) < 0) {
        trace("sdlmixer", "Initialize SDL audio: %s\n", SDL_GetError());
        goto fail;
    }

    int audio_rate, audio_channels;
    Uint16 audio_format;
    int chunksize;

    audio_format = MIX_DEFAULT_FORMAT;
    audio_channels = MIX_DEFAULT_CHANNELS;

    //undef this (HIFI) to reduce CPU by a 5%
    audio_rate = MIX_DEFAULT_FREQUENCY;
    chunksize = 1024;
    //audio_rate = 44100;
    //chunksize = 2048;

    /* Open the audio device */
    if (Mix_OpenAudio(audio_rate, audio_format,
                      audio_channels, chunksize) < 0) {
        trace("sdlmixer", "Initializing SDLMixer failed: %s\n", SDL_GetError());
        SDL_QuitSubSystem(SDL_INIT_AUDIO);
        goto fail;
    }

    Mix_QuerySpec(&audio_rate, &audio_format, &audio_channels);
    trace("sdlmixer") << "Opened audio at "<< audio_rate <<
    " Hz " << (audio_format & 0xFF) << "bit " <<
    ((audio_channels > 1) ? "stereo" : "mono") << std::endl;

    trace("audio", "SDLMixer initialization...ok\n");
    return new SDLMixer();

fail:
    trace("audio", "SDLMixer initialization...fail\n");
    return 0;
}

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Audio::Chunk * Wt::SDLMixer::loadChunk

(

const std::string &

filename

)

const [virtual]

Reimplemented from Wt::Audio.

Definition at line 107 of file sdlmixer.cpp.

                                                               {
    Mix_Chunk *chunk = Mix_LoadWAV(filename.c_str());
    return (chunk) ? new SDLMixer::Chunk(chunk) : 0;
}

Audio::Music * Wt::SDLMixer::loadMusic

(

const std::string &

filename

)

[virtual]

Reimplemented from Wt::Audio.

Definition at line 155 of file sdlmixer.cpp.

                                                         {
    Mix_Music *m = Mix_LoadMUS(filename.c_str());
    return (m) ? new Music(m) : 0;
}

int Wt::SDLMixer::maxHWVolume

(

)

const [protected, virtual]

Reimplemented from Wt::Audio.

Definition at line 228 of file sdlmixer.cpp.

                                {
    return MIX_MAX_VOLUME;
}

int Wt::SDLMixer::minHWVolume

(

)

const [protected, virtual]

Reimplemented from Wt::Audio.

Definition at line 224 of file sdlmixer.cpp.

                                {
    return 0;
}

int Wt::SDLMixer::musicFading

(

)

const [virtual]

Reimplemented from Wt::Audio.

Definition at line 216 of file sdlmixer.cpp.

References fadingTypeMap.

                                {
    return fadingTypeMap[Mix_FadingMusic()];
}

int Wt::Audio::numChannels

(

)

const [inherited]

Definition at line 82 of file audio.cpp.

References Wt::Audio::channels.

Referenced by allocateChannels().

                             {
    return channels.size();
}

void Wt::SDLMixer::onChannelFinish

(

int

channel

)

[static, protected]

callback called when a channel finishes

Reimplemented from Wt::Audio.

Definition at line 232 of file sdlmixer.cpp.

References Wt::Singleton< DERIVED >::instance(), and Wt::Audio::onChannelFinish().

Referenced by SDLMixer().

                                             {
    Audio::onChannelFinish(channel_id);
    // if this function is called  SDLMixer is running
    // so all static casts are safe
    SDLMixer& self = * static_cast<SDLMixer *>(instance());
    SDLMixer::Channel *channel =
        static_cast<SDLMixer::Channel *>(self.channels[channel_id]);
    SDLMixer::Chunk *chunk = static_cast<SDLMixer::Chunk *>(channel->chunk());
    channel->chunk_p = 0;
    chunk->channel_id = -1;
}

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void Wt::Audio::onMusicFinish

(

)

[static, protected, inherited]

posts a SDL type event (SDLEvent::Audio) in the SDL event queue. By the time the event it is dispatched all SDL actions are allowed.

Definition at line 198 of file audio.cpp.

References Wt::SDLEvent::Audio, Wt::SDLEvent::push(), and trace.

Referenced by Wt::NullAudio::fadeInMusic(), Wt::NullAudio::playMusic(), and SDLMixer().

                          {
    SDL_Event event;

    event.type = SDLEvent::Audio;
    event.user.code = 0;
    event.user.data1 = new Event(0, 0);
    event.user.data2 = 0;

    trace("audio", "musicFinished callback called\n");

    SDLEvent::push(&event);
}

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Audio::Channel * Wt::Audio::operator[]

(

int

i

)

const [inherited]

Definition at line 86 of file audio.cpp.

References Wt::Audio::channels.

                                           {
    return channels[i];
}

void Wt::SDLMixer::pause

(

)

[virtual]

pause all channels

Reimplemented from Wt::Audio.

Definition at line 125 of file sdlmixer.cpp.

                     {
    Mix_Pause(-1);
}

int Wt::SDLMixer::pausedChannels

(

)

const [virtual]

Reimplemented from Wt::Audio.

Definition at line 146 of file sdlmixer.cpp.

                                   {
    return Mix_Paused(-1);
}

bool Wt::SDLMixer::pausedMusic

(

)

const [virtual]

Reimplemented from Wt::Audio.

Definition at line 212 of file sdlmixer.cpp.

                                 {
    return Mix_PausedMusic();
}

void Wt::SDLMixer::pauseMusic

(

)

[virtual]

Reimplemented from Wt::Audio.

Definition at line 192 of file sdlmixer.cpp.

                          {
    Mix_PauseMusic();
}

int Wt::SDLMixer::playingChannels

(

)

const [virtual]

Reimplemented from Wt::Audio.

Definition at line 142 of file sdlmixer.cpp.

                                    {
    return Mix_Playing(-1);
}

bool Wt::SDLMixer::playingMusic

(

)

const [virtual]

Reimplemented from Wt::Audio.

Definition at line 208 of file sdlmixer.cpp.

                                  {
    return Mix_PlayingMusic();
}

void Wt::SDLMixer::playMusic

(

Audio::Music &

)

[virtual]

it blocks until any previously music fading out is done

Reimplemented from Wt::Audio.

Definition at line 171 of file sdlmixer.cpp.

References Wt::Audio::musicLoops, and trace.

                                          {
    SDLMixer::Music& m = * static_cast<SDLMixer::Music *>(&music);
    trace("sdlmixer", "SDLMixer::playMusic() called\n");
    Mix_PlayMusic(m, musicLoops - 1);
}

template<class DERIVED>

static void Wt::Singleton< DERIVED >::quit

(

)

[inline, static, inherited]

Reimplemented in Wt::Application.

Definition at line 55 of file singleton.h.

Referenced by Wt::Application::~Application().

                       {
        delete instance();
    }

void Wt::SDLMixer::resume

(

)

[virtual]

resume all channels

Reimplemented from Wt::Audio.

Definition at line 129 of file sdlmixer.cpp.

                      {
    Mix_Resume(-1);
}

void Wt::SDLMixer::rewindMusic

(

)

[virtual]

Reimplemented from Wt::Audio.

Definition at line 196 of file sdlmixer.cpp.

                           {
    Mix_RewindMusic();
}

bool Wt::SDLMixer::setMusicPosition

(

double

start_sec

)

[virtual]

Reimplemented from Wt::Audio.

Definition at line 200 of file sdlmixer.cpp.

                                                {
    return !Mix_SetMusicPosition(start_sec);
}

void Wt::SDLMixer::setMusicVolume

(

int

volume

)

[virtual]

Reimplemented from Wt::Audio.

Definition at line 186 of file sdlmixer.cpp.

References Wt::Singleton< DERIVED >::instance().

                                        {
    SDLMixer& self = * static_cast<SDLMixer *>(instance());
    int hwvol = self.HWVolume(volume);
    Mix_VolumeMusic(hwvol);
}

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void Wt::SDLMixer::stop

(

int

ms = 0

)

[virtual]

stop all channels

Reimplemented from Wt::Audio.

Definition at line 133 of file sdlmixer.cpp.

                          {
    (ms) ? Mix_ExpireChannel(-1, ms) :
    Mix_HaltChannel(-1);
}

void Wt::SDLMixer::stopMusic

(

)

[virtual]

Reimplemented from Wt::Audio.

Definition at line 204 of file sdlmixer.cpp.

                         {
    Mix_HaltMusic();
}

---

Friends And Related Function Documentation

friend class Singleton< Audio > [friend]

Reimplemented from Wt::Audio.

Definition at line 38 of file sdlmixer.h.

---

Member Data Documentation

std::vector<Channel *> Wt::Audio::channels [protected, inherited]

Definition at line 260 of file audio.h.

Referenced by Wt::Audio::adjustAllocatedChannels(), Wt::Audio::allocateChannels(), Wt::Audio::numChannels(), and Wt::Audio::operator[]().

Factory< Audio, SDLMixer > Wt::SDLMixer::factory [static]

Reimplemented from Wt::Audio.

Definition at line 40 of file sdlmixer.h.

FlagMap Wt::SDLMixer::fadingTypeMap [static, private]

Definition at line 183 of file sdlmixer.h.

Referenced by Wt::SDLMixer::Channel::fading(), musicFading(), and SDLMixer().

Signal01<void, Channel *> Wt::Audio::finished [inherited]

Definition at line 198 of file audio.h.

template<class DERIVED>

DERIVED * Wt::Singleton< DERIVED >::instance_ = 0 [static, protected, inherited]

Definition at line 91 of file singleton.h.

Referenced by Wt::Singleton< Wt::Audio >::existingInstance(), Wt::Singleton< Wt::Audio >::instance(), Wt::Singleton< Wt::Audio >::load(), Wt::SDLDisplay::load(), Wt::Audio::load(), Wt::Singleton< Wt::Audio >::Singleton(), and Wt::Singleton< Wt::Audio >::~Singleton().

const int Wt::Audio::maxVolume = 1000 [static, protected, inherited]

Definition at line 238 of file audio.h.

Referenced by Wt::SDLMixer::Chunk::Chunk(), and Wt::Audio::HWVolume().

const int Wt::Audio::minVolume = 0 [static, protected, inherited]

Definition at line 237 of file audio.h.

Referenced by Wt::Audio::HWVolume().

sigc::signal<void> Wt::Audio::musicFinished [inherited]

Definition at line 226 of file audio.h.

WVar<int> Wt::Audio::musicLoops [inherited]

Definition at line 224 of file audio.h.

Referenced by fadeInMusic(), and playMusic().

FlagMap Wt::SDLMixer::musicTypeMap [static, private]

Definition at line 184 of file sdlmixer.h.

Referenced by SDLMixer(), and Wt::SDLMixer::Music::type().

---

The documentation for this class was generated from the following files:

• sdlmixer.h
• sdlmixer.cpp

---

Generated Fri Jul 28 19:32:39 2006.
Copyright © 1998-2003 by the respective authors.

This document is licensed under the terms of the GNU Free Documentation License and may be freely distributed under the conditions given by this license.