GEInterfaces.cpp Example File

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 #include <memory.h>
 #include "GEInterfaces.h"

 using namespace GE;

 /**
  * CAudioSource
  * common functionality
  *
  */
 IAudioSource::IAudioSource() {
     m_next = 0;
 };

 IAudioSource::~IAudioSource() {

 };

 /**
  * CAudioMixer
  *
  */
 CAudioMixer::CAudioMixer() {
     m_sourceList = 0;
     m_mixingBuffer = 0;
     m_mixingBufferLength = 0;
     m_fixedGeneralVolume = 4096;
 };

 CAudioMixer::~CAudioMixer() {
     destroyList();
     if (m_mixingBuffer) {
         delete [] m_mixingBuffer;
         m_mixingBuffer = 0;
     };
 };

 void CAudioMixer::destroyList() {
     m_mutex.lock();
     IAudioSource *l = m_sourceList;
     while (l) {
         IAudioSource *n = l->m_next;
         delete l;
         l = n;
     };
     m_sourceList = 0;
     m_mutex.unlock();
 };

 IAudioSource* CAudioMixer::addAudioSource( IAudioSource *source ) {
     m_mutex.lock();
     source->m_next = 0;
     if (m_sourceList) {
         IAudioSource *l = m_sourceList;
         while (l->m_next) l = l->m_next;
         l->m_next = source;
     } else m_sourceList = source;
     m_mutex.unlock();
     return source;

 };

 bool CAudioMixer::removeAudioSource( IAudioSource *source ) {
     return true;
 };

 void CAudioMixer::setGeneralVolume( float vol ) {
     m_fixedGeneralVolume = (4096.0f*vol);
 };

 int CAudioMixer::pullAudio( AUDIO_SAMPLE_TYPE *target, int bufferLength ) {

     if (!m_sourceList) return 0;

     m_mutex.lock();

     if (m_mixingBufferLength<bufferLength) {
         if (m_mixingBuffer) delete [] m_mixingBuffer;
         m_mixingBufferLength = bufferLength;
         m_mixingBuffer = new AUDIO_SAMPLE_TYPE[ m_mixingBufferLength ];
     };

     memset( target, 0, sizeof( AUDIO_SAMPLE_TYPE ) * bufferLength );

     AUDIO_SAMPLE_TYPE *t;
     AUDIO_SAMPLE_TYPE *t_target;
     AUDIO_SAMPLE_TYPE *s;

     IAudioSource *prev = 0;
     IAudioSource *l = m_sourceList;
     while (l) {
         IAudioSource *next = l->m_next;

             // process l
         int mixed = l->pullAudio( m_mixingBuffer, bufferLength );
         if (mixed>0) {
             // mix to main..
             t = target;
             t_target = t+mixed;
             s = m_mixingBuffer;
             while (t!=t_target) {
                 *t +=(((*s)*m_fixedGeneralVolume)>>12);
                 t++;
                 s++;
             };
         };

         // autodestroy
         if (l->canBeDestroyed() == true) {          // NOTE, IS UNDER TESTING,... MIGHT CAUSE UNPREDICTABLE CRASHING WITH SOME USE CASES!!!
             if (!prev)
                 m_sourceList = next;
             else prev->m_next = next;
             delete l;
             l = 0;
         };

         prev = l;
         l = next;
     };
     m_mutex.unlock();
     return bufferLength;
 };