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Hi,
is it possible to set a minimal time between sounds of the same group?
I play a sound when a collision occourse, but this can happen very often and with only minimal time inbetween.
Currently I have a timer running which toggles a variable. I check this to see if I should play the sound or not. But this is not build into the soundsystem and I need it a several places.
I ssomething like this possible already with CocosDenshion?
zombie
Steve Oldmeadow
Administrator
All CocosDenshion offers is the ability to specify a channel group is non-interruptible. This means any sound playing in that group will play to completion. This prevents the problem of sounds getting clipped when many sounds are triggered. If a non-interruptible channel group only has a single channel then basically only one sound will be heard at a time.
Someone ask me to share the code I hacked in for a delay between sounds. Here it is:
typedef struct _channelGroup {
int startIndex;
int endIndex;
int currentIndex;
bool mute;
////// added
uint64_t minimalPause;
uint64_t lastTimeStamp;
//////
} channelGroup;
////// added
- (void) setPauseTime:(int64_t)pause forChannelGroup:(int)channel
{
_channelGroups[channel].minimalPause = pause;
}
//////
- (ALuint)playSound:(int) soundId channelGroupId:(int)channelGroupId pitch:(float) pitch pan:(float) pan gain:(float) gain loop:(BOOL) loop {
#ifdef DEBUG
//Sanity check parameters - only in DEBUG
NSAssert(soundId >= 0, @"soundId can not be negative");
NSAssert(soundId < CD_MAX_BUFFERS, @"soundId exceeds limit");
NSAssert(channelGroupId >= 0, @"channelGroupId can not be negative");
NSAssert(channelGroupId < _channelGroupTotal, @"channelGroupId exceeds limit");
NSAssert(pitch > 0, @"pitch must be greater than zero");
NSAssert(pan >= -1 && pan <= 1, @"pan must be between -1 and 1");
NSAssert(gain >= 0, @"gain can not be negative");
#endif
uint64_t timeStamp;
channelGroup *cGroup = &_channelGroups[channelGroupId];
//If mute or initialisation has failed or buffer is not loaded then do nothing
if (_mute || !functioning || _bufferStates[soundId] != CD_BS_LOADED || cGroup->mute) {
#ifdef DEBUG
if (!functioning) {
CCLOG(@"Denshion: sound playback aborted because sound engine is not functioning");
} else if (_bufferStates[soundId] != CD_BS_LOADED) {
CCLOG(@"Denshion: sound playback aborted because buffer %i is not loaded", soundId);
}
#endif
return CD_MUTE;
}
//Work out which channel we can use
int channel = cGroup->currentIndex;
if (channel != CD_CHANNEL_GROUP_NON_INTERRUPTIBLE) {
if (cGroup->startIndex != cGroup->endIndex) {
cGroup->currentIndex++;
if(cGroup->currentIndex > cGroup->endIndex) {
cGroup->currentIndex = cGroup->startIndex;
}
}
////// added
if(cGroup->minimalPause > 0)
{
timeStamp = getTimeStampInMiliseconds();
if((timeStamp - cGroup->lastTimeStamp) < cGroup->minimalPause)
return CD_NO_SOURCE;
cGroup->lastTimeStamp = timeStamp;
}
//////
return [self _startSound:soundId channelId:channel pitchVal:pitch*scheduler.timeScale panVal:pan gainVal:gain looping:loop checkState:TRUE];
} else {
//Channel group is non interruptible therefore we must search for the first non playing channel/source if there are any
int checkingIndex = cGroup->startIndex;
ALint state = 0;
while ((checkingIndex <= cGroup->endIndex) && (channel == CD_CHANNEL_GROUP_NON_INTERRUPTIBLE)) {
//Check if source is playing
alGetSourcei(_sources[checkingIndex], AL_SOURCE_STATE, &state);
if (state != AL_PLAYING) {
channel = checkingIndex;
}
checkingIndex++;
}
if (channel != CD_CHANNEL_GROUP_NON_INTERRUPTIBLE) {
//Found a free channel
////// added
if(cGroup->minimalPause > 0)
{
timeStamp = getTimeStampInMiliseconds();
if((timeStamp - cGroup->lastTimeStamp) < cGroup->minimalPause)
return CD_NO_SOURCE;
cGroup->lastTimeStamp = timeStamp;
}
//////
return [self _startSound:soundId channelId:channel pitchVal:pitch*scheduler.timeScale panVal:pan gainVal:gain looping:loop checkState:FALSE];
} else {
//Didn't find a free channel
return CD_NO_SOURCE;
}
}
}Zombie, I'd like to ask you, where does the getTimeStampInMiliseconds() function come from?
I think my version of cocos might be pre-0.8.2.
Example, cGroup->currentIndex = cGroup->startIndex; is `_channelGroups[channelGroupId].currentIndex = _channelGroups[channelGroupId].startIndex;
` in my copy of CocosDenshion.m.
Thank you.
Steve Oldmeadow
Administrator
I have to agree with nsxdavid. What I do is create a GameSoundManager class that handles all the specifics for my game such as setting up the channel groups, declaring all the sound id constants, managing the volume levels etc.
This sort of minimal pause functionality could easily be handled in a wrapper. The problem with modifying the source is when updates come out. I am working on some big changes to CocosDenshion and when they are released you will then have to either reintegrate your code or stick with an older version of CocosDenshion.
Steve Oldmeadow
Administrator
@zombie - what I said wasn't intended to be a criticism of you, I've done my fair share of hacks in the past and I know how much time pressure you must be under. It was more a warning to people that may pick up your hack. You have already given them the algorithm - it would be nice to see someone who wants this functionality step up and refactor your code into a 'nicer' implementation that gets fed back to the community.
papapete
Member
I was wondering if this issue has been addressed recently? I've been looking in the forums. I need to write something that requires a minimum delay between sounds, and I don't know how to write a wrapper. Actually, even if I try to use this hack, some of the playsound algorithm (variable names, conditional statements, etc.) seems to have changed in the files, so I can't easily determine where to adapt/insert these lines. Can anyone point me in the right direction? Surely this is a common need? I have several objects colliding at once, and rather than have a mess of sound, I just need to limit the number playing.
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