Chris@55: /** @file paex_ocean_shore.c 
Chris@55: 	@ingroup examples_src
Chris@55: 	@brief Generate Pink Noise using Gardner method, and make "waves". Provides an example of how to
Chris@55:            post stuff to/from the audio callback using lock-free FIFOs implemented by the PA ringbuffer.
Chris@55: 
Chris@55: 	Optimization suggested by James McCartney uses a tree
Chris@55: 	to select which random value to replace.
Chris@55: <pre>
Chris@55: 	x x x x x x x x x x x x x x x x 
Chris@55: 	x   x   x   x   x   x   x   x   
Chris@55: 	x       x       x       x       
Chris@55: 	 x               x               
Chris@55: 	   x   
Chris@55: </pre>                            
Chris@55: 	Tree is generated by counting trailing zeros in an increasing index.
Chris@55: 	When the index is zero, no random number is selected.
Chris@55: 
Chris@55: 	@author Phil Burk  http://www.softsynth.com
Chris@55:             Robert Bielik
Chris@55: */
Chris@55: /*
Chris@55:  * $Id$
Chris@55:  *
Chris@55:  * This program uses the PortAudio Portable Audio Library.
Chris@55:  * For more information see: http://www.portaudio.com
Chris@55:  * Copyright (c) 1999-2000 Ross Bencina and Phil Burk
Chris@55:  *
Chris@55:  * Permission is hereby granted, free of charge, to any person obtaining
Chris@55:  * a copy of this software and associated documentation files
Chris@55:  * (the "Software"), to deal in the Software without restriction,
Chris@55:  * including without limitation the rights to use, copy, modify, merge,
Chris@55:  * publish, distribute, sublicense, and/or sell copies of the Software,
Chris@55:  * and to permit persons to whom the Software is furnished to do so,
Chris@55:  * subject to the following conditions:
Chris@55:  *
Chris@55:  * The above copyright notice and this permission notice shall be
Chris@55:  * included in all copies or substantial portions of the Software.
Chris@55:  *
Chris@55:  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
Chris@55:  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
Chris@55:  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
Chris@55:  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
Chris@55:  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
Chris@55:  * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
Chris@55:  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Chris@55:  */
Chris@55: 
Chris@55: /*
Chris@55:  * The text above constitutes the entire PortAudio license; however, 
Chris@55:  * the PortAudio community also makes the following non-binding requests:
Chris@55:  *
Chris@55:  * Any person wishing to distribute modifications to the Software is
Chris@55:  * requested to send the modifications to the original developer so that
Chris@55:  * they can be incorporated into the canonical version. It is also 
Chris@55:  * requested that these non-binding requests be included along with the 
Chris@55:  * license above.
Chris@55:  */
Chris@55: 
Chris@55: #include <stdio.h>
Chris@55: #include <stdlib.h>
Chris@55: #include <string.h>
Chris@55: #include <math.h>
Chris@55: #include <time.h>
Chris@55: 
Chris@55: #include "portaudio.h"
Chris@55: #include "pa_ringbuffer.h"
Chris@55: #include "pa_util.h"
Chris@55: 
Chris@55: #define PINK_MAX_RANDOM_ROWS   (30)
Chris@55: #define PINK_RANDOM_BITS       (24)
Chris@55: #define PINK_RANDOM_SHIFT      ((sizeof(long)*8)-PINK_RANDOM_BITS)
Chris@55: 
Chris@55: typedef struct
Chris@55: {
Chris@55:     long      pink_Rows[PINK_MAX_RANDOM_ROWS];
Chris@55:     long      pink_RunningSum;   /* Used to optimize summing of generators. */
Chris@55:     int       pink_Index;        /* Incremented each sample. */
Chris@55:     int       pink_IndexMask;    /* Index wrapped by ANDing with this mask. */
Chris@55:     float     pink_Scalar;       /* Used to scale within range of -1.0 to +1.0 */
Chris@55: }
Chris@55: PinkNoise;
Chris@55: 
Chris@55: typedef struct 
Chris@55: {
Chris@55:     float       bq_b0;
Chris@55:     float       bq_b1;
Chris@55:     float       bq_b2;
Chris@55:     float       bq_a1;
Chris@55:     float       bq_a2;
Chris@55: } BiQuad;
Chris@55: 
Chris@55: typedef enum
Chris@55: {
Chris@55:     State_kAttack,
Chris@55:     State_kPreDecay,
Chris@55:     State_kDecay,
Chris@55:     State_kCnt,
Chris@55: } EnvState;
Chris@55: 
Chris@55: typedef struct
Chris@55: {
Chris@55:     PinkNoise   wave_left;
Chris@55:     PinkNoise   wave_right;
Chris@55: 
Chris@55:     BiQuad      wave_bq_coeffs;
Chris@55:     float       wave_bq_left[2];
Chris@55:     float       wave_bq_right[2];
Chris@55: 
Chris@55:     EnvState    wave_envelope_state;
Chris@55:     float       wave_envelope_level;
Chris@55:     float       wave_envelope_max_level;
Chris@55:     float       wave_pan_left;
Chris@55:     float       wave_pan_right;
Chris@55:     float       wave_attack_incr;
Chris@55:     float       wave_decay_incr;
Chris@55: 
Chris@55: } OceanWave;
Chris@55: 
Chris@55: /* Prototypes */
Chris@55: static unsigned long GenerateRandomNumber( void );
Chris@55: void InitializePinkNoise( PinkNoise *pink, int numRows );
Chris@55: float GeneratePinkNoise( PinkNoise *pink );
Chris@55: unsigned GenerateWave( OceanWave* wave, float* output, unsigned noOfFrames);
Chris@55: 
Chris@55: /************************************************************/
Chris@55: /* Calculate pseudo-random 32 bit number based on linear congruential method. */
Chris@55: static unsigned long GenerateRandomNumber( void )
Chris@55: {
Chris@55:     /* Change this seed for different random sequences. */
Chris@55:     static unsigned long randSeed = 22222;
Chris@55:     randSeed = (randSeed * 196314165) + 907633515;
Chris@55:     return randSeed;
Chris@55: }
Chris@55: 
Chris@55: /************************************************************/
Chris@55: /* Setup PinkNoise structure for N rows of generators. */
Chris@55: void InitializePinkNoise( PinkNoise *pink, int numRows )
Chris@55: {
Chris@55:     int i;
Chris@55:     long pmax;
Chris@55:     pink->pink_Index = 0;
Chris@55:     pink->pink_IndexMask = (1<<numRows) - 1;
Chris@55:     /* Calculate maximum possible signed random value. Extra 1 for white noise always added. */
Chris@55:     pmax = (numRows + 1) * (1<<(PINK_RANDOM_BITS-1));
Chris@55:     pink->pink_Scalar = 1.0f / pmax;
Chris@55:     /* Initialize rows. */
Chris@55:     for( i=0; i<numRows; i++ ) pink->pink_Rows[i] = 0;
Chris@55:     pink->pink_RunningSum = 0;
Chris@55: }
Chris@55: 
Chris@55: /* Generate Pink noise values between -1.0 and +1.0 */
Chris@55: float GeneratePinkNoise( PinkNoise *pink )
Chris@55: {
Chris@55:     long newRandom;
Chris@55:     long sum;
Chris@55:     float output;
Chris@55:     /* Increment and mask index. */
Chris@55:     pink->pink_Index = (pink->pink_Index + 1) & pink->pink_IndexMask;
Chris@55:     /* If index is zero, don't update any random values. */
Chris@55:     if( pink->pink_Index != 0 )
Chris@55:     {
Chris@55:         /* Determine how many trailing zeros in PinkIndex. */
Chris@55:         /* This algorithm will hang if n==0 so test first. */
Chris@55:         int numZeros = 0;
Chris@55:         int n = pink->pink_Index;
Chris@55:         while( (n & 1) == 0 )
Chris@55:         {
Chris@55:             n = n >> 1;
Chris@55:             numZeros++;
Chris@55:         }
Chris@55:         /* Replace the indexed ROWS random value.
Chris@55:          * Subtract and add back to RunningSum instead of adding all the random
Chris@55:          * values together. Only one changes each time.
Chris@55:          */
Chris@55:         pink->pink_RunningSum -= pink->pink_Rows[numZeros];
Chris@55:         newRandom = ((long)GenerateRandomNumber()) >> PINK_RANDOM_SHIFT;
Chris@55:         pink->pink_RunningSum += newRandom;
Chris@55:         pink->pink_Rows[numZeros] = newRandom;
Chris@55:     }
Chris@55: 
Chris@55:     /* Add extra white noise value. */
Chris@55:     newRandom = ((long)GenerateRandomNumber()) >> PINK_RANDOM_SHIFT;
Chris@55:     sum = pink->pink_RunningSum + newRandom;
Chris@55:     /* Scale to range of -1.0 to 0.9999. */
Chris@55:     output = pink->pink_Scalar * sum;
Chris@55:     return output;
Chris@55: }
Chris@55: 
Chris@55: float ProcessBiquad(const BiQuad* coeffs, float* memory, float input)
Chris@55: {
Chris@55:     float w = input - coeffs->bq_a1 * memory[0] - coeffs->bq_a2 * memory[1];
Chris@55:     float out = coeffs->bq_b1 * memory[0] + coeffs->bq_b2 * memory[1] + coeffs->bq_b0 * w;
Chris@55:     memory[1] = memory[0];
Chris@55:     memory[0] = w;
Chris@55:     return out;
Chris@55: }
Chris@55: 
Chris@55: static const float one_over_2Q_LP = 0.3f;
Chris@55: static const float one_over_2Q_HP = 1.0f;
Chris@55: 
Chris@55: unsigned GenerateWave( OceanWave* wave, float* output, unsigned noOfFrames )
Chris@55: {
Chris@55:     unsigned retval=0,i;
Chris@55:     float targetLevel, levelIncr, currentLevel;
Chris@55:     switch (wave->wave_envelope_state)
Chris@55:     {
Chris@55:     case State_kAttack:
Chris@55:         targetLevel = noOfFrames * wave->wave_attack_incr + wave->wave_envelope_level;
Chris@55:         if (targetLevel >= wave->wave_envelope_max_level)
Chris@55:         {
Chris@55:             /* Go to decay state */
Chris@55:             wave->wave_envelope_state = State_kPreDecay;
Chris@55:             targetLevel = wave->wave_envelope_max_level;
Chris@55:         }
Chris@55:         /* Calculate lowpass biquad coeffs
Chris@55:         
Chris@55:             alpha = sin(w0)/(2*Q)
Chris@55: 
Chris@55:                 b0 =  (1 - cos(w0))/2
Chris@55:                 b1 =   1 - cos(w0)
Chris@55:                 b2 =  (1 - cos(w0))/2
Chris@55:                 a0 =   1 + alpha
Chris@55:                 a1 =  -2*cos(w0)
Chris@55:                 a2 =   1 - alpha
Chris@55: 
Chris@55:             w0 = [0 - pi[
Chris@55:         */
Chris@55:         {
Chris@55:             const float w0 = 3.141592654f * targetLevel / wave->wave_envelope_max_level;
Chris@55:             const float alpha = sinf(w0) * one_over_2Q_LP;
Chris@55:             const float cosw0 = cosf(w0);
Chris@55:             const float a0_fact = 1.0f / (1.0f + alpha);
Chris@55:             wave->wave_bq_coeffs.bq_b1 = (1.0f - cosw0) * a0_fact;
Chris@55:             wave->wave_bq_coeffs.bq_b0 = wave->wave_bq_coeffs.bq_b1 * 0.5f;
Chris@55:             wave->wave_bq_coeffs.bq_b2 = wave->wave_bq_coeffs.bq_b0;
Chris@55:             wave->wave_bq_coeffs.bq_a2 = (1.0f - alpha) * a0_fact;
Chris@55:             wave->wave_bq_coeffs.bq_a1 = -2.0f * cosw0 * a0_fact;
Chris@55:         }
Chris@55:         break;
Chris@55: 
Chris@55:     case State_kPreDecay:
Chris@55:         /* Reset biquad state */
Chris@55:         memset(wave->wave_bq_left, 0, 2 * sizeof(float));
Chris@55:         memset(wave->wave_bq_right, 0, 2 * sizeof(float));
Chris@55:         wave->wave_envelope_state = State_kDecay;
Chris@55: 
Chris@55:         /* Deliberate fall-through */
Chris@55: 
Chris@55:     case State_kDecay:
Chris@55:         targetLevel = noOfFrames * wave->wave_decay_incr + wave->wave_envelope_level;
Chris@55:         if (targetLevel < 0.001f)
Chris@55:         {
Chris@55:             /* < -60 dB, we're done */
Chris@55:             wave->wave_envelope_state = 3;
Chris@55:             retval = 1;
Chris@55:         }
Chris@55:         /* Calculate highpass biquad coeffs
Chris@55: 
Chris@55:             alpha = sin(w0)/(2*Q)
Chris@55: 
Chris@55:             b0 =  (1 + cos(w0))/2
Chris@55:             b1 = -(1 + cos(w0))
Chris@55:             b2 =  (1 + cos(w0))/2
Chris@55:             a0 =   1 + alpha
Chris@55:             a1 =  -2*cos(w0)
Chris@55:             a2 =   1 - alpha
Chris@55: 
Chris@55:             w0 = [0 - pi/2[
Chris@55:         */
Chris@55:         {
Chris@55:             const float v = targetLevel / wave->wave_envelope_max_level;
Chris@55:             const float w0 = 1.5707963f * (1.0f - (v*v));
Chris@55:             const float alpha = sinf(w0) * one_over_2Q_HP;
Chris@55:             const float cosw0 = cosf(w0);
Chris@55:             const float a0_fact = 1.0f / (1.0f + alpha);
Chris@55:             wave->wave_bq_coeffs.bq_b1 = (float)(- (1 + cosw0) * a0_fact);
Chris@55:             wave->wave_bq_coeffs.bq_b0 = -wave->wave_bq_coeffs.bq_b1 * 0.5f;
Chris@55:             wave->wave_bq_coeffs.bq_b2 = wave->wave_bq_coeffs.bq_b0;
Chris@55:             wave->wave_bq_coeffs.bq_a2 = (float)((1.0 - alpha) * a0_fact);
Chris@55:             wave->wave_bq_coeffs.bq_a1 = (float)(-2.0 * cosw0 * a0_fact);
Chris@55:         }
Chris@55:         break;
Chris@55: 
Chris@55:     default:
Chris@55:         break;
Chris@55:     }
Chris@55: 
Chris@55:     currentLevel = wave->wave_envelope_level;
Chris@55:     wave->wave_envelope_level = targetLevel;
Chris@55:     levelIncr = (targetLevel - currentLevel) / noOfFrames;
Chris@55: 
Chris@55:     for (i = 0; i < noOfFrames; ++i, currentLevel += levelIncr)
Chris@55:     {
Chris@55:         (*output++) += ProcessBiquad(&wave->wave_bq_coeffs, wave->wave_bq_left, (GeneratePinkNoise(&wave->wave_left))) * currentLevel * wave->wave_pan_left;
Chris@55:         (*output++) += ProcessBiquad(&wave->wave_bq_coeffs, wave->wave_bq_right, (GeneratePinkNoise(&wave->wave_right))) * currentLevel * wave->wave_pan_right;
Chris@55:     }
Chris@55: 
Chris@55:     return retval;
Chris@55: }
Chris@55: 
Chris@55: 
Chris@55: /*******************************************************************/
Chris@55: 
Chris@55: /* Context for callback routine. */
Chris@55: typedef struct
Chris@55: {
Chris@55:     OceanWave*          waves[16];      /* Maximum 16 waves */
Chris@55:     unsigned            noOfActiveWaves;
Chris@55: 
Chris@55:     /* Ring buffer (FIFO) for "communicating" towards audio callback */
Chris@55:     PaUtilRingBuffer    rBufToRT;
Chris@55:     void*               rBufToRTData;
Chris@55: 
Chris@55:     /* Ring buffer (FIFO) for "communicating" from audio callback */
Chris@55:     PaUtilRingBuffer    rBufFromRT;
Chris@55:     void*               rBufFromRTData;
Chris@55: }
Chris@55: paTestData;
Chris@55: 
Chris@55: /* This routine will be called by the PortAudio engine when audio is needed.
Chris@55: ** It may called at interrupt level on some machines so don't do anything
Chris@55: ** that could mess up the system like calling malloc() or free().
Chris@55: */
Chris@55: static int patestCallback(const void*                     inputBuffer,
Chris@55:                           void*                           outputBuffer,
Chris@55:                           unsigned long                   framesPerBuffer,
Chris@55: 			              const PaStreamCallbackTimeInfo* timeInfo,
Chris@55: 			              PaStreamCallbackFlags           statusFlags,
Chris@55:                           void*                           userData)
Chris@55: {
Chris@55:     int i;
Chris@55:     paTestData *data = (paTestData*)userData;
Chris@55:     float *out = (float*)outputBuffer;
Chris@55:     (void) inputBuffer; /* Prevent "unused variable" warnings. */
Chris@55: 
Chris@55:     /* Reset output data first */
Chris@55:     memset(out, 0, framesPerBuffer * 2 * sizeof(float));
Chris@55: 
Chris@55:     for (i = 0; i < 16; ++i)
Chris@55:     {
Chris@55:         /* Consume the input queue */
Chris@55:         if (data->waves[i] == 0 && PaUtil_GetRingBufferReadAvailable(&data->rBufToRT))
Chris@55:         {
Chris@55:             OceanWave* ptr = 0;
Chris@55:             PaUtil_ReadRingBuffer(&data->rBufToRT, &ptr, 1);
Chris@55:             data->waves[i] = ptr;
Chris@55:         }
Chris@55: 
Chris@55:         if (data->waves[i] != 0)
Chris@55:         {
Chris@55:             if (GenerateWave(data->waves[i], out, framesPerBuffer))
Chris@55:             {
Chris@55:                 /* If wave is "done", post it back to the main thread for deletion */
Chris@55:                 PaUtil_WriteRingBuffer(&data->rBufFromRT, &data->waves[i], 1);
Chris@55:                 data->waves[i] = 0;
Chris@55:             }
Chris@55:         }
Chris@55:     }
Chris@55:     return paContinue;
Chris@55: }
Chris@55: 
Chris@55: #define NEW_ROW_SIZE (12 + (8*rand())/RAND_MAX)
Chris@55: 
Chris@55: OceanWave* InitializeWave(double SR, float attackInSeconds, float maxLevel, float positionLeftRight)
Chris@55: {
Chris@55:     OceanWave* wave = NULL;
Chris@55:     static unsigned lastNoOfRows = 12;
Chris@55:     unsigned newNoOfRows;
Chris@55: 
Chris@55:     wave = (OceanWave*)PaUtil_AllocateMemory(sizeof(OceanWave));
Chris@55:     if (wave != NULL)
Chris@55:     {
Chris@55:         InitializePinkNoise(&wave->wave_left, lastNoOfRows);
Chris@55:         while ((newNoOfRows = NEW_ROW_SIZE) == lastNoOfRows);
Chris@55:         InitializePinkNoise(&wave->wave_right, newNoOfRows);
Chris@55:         lastNoOfRows = newNoOfRows;
Chris@55: 
Chris@55:         wave->wave_envelope_state = State_kAttack;
Chris@55:         wave->wave_envelope_level = 0.f;
Chris@55:         wave->wave_envelope_max_level = maxLevel;
Chris@55:         wave->wave_attack_incr = wave->wave_envelope_max_level / (attackInSeconds * (float)SR);
Chris@55:         wave->wave_decay_incr = - wave->wave_envelope_max_level / (attackInSeconds * 4 * (float)SR);
Chris@55: 
Chris@55:         wave->wave_pan_left = sqrtf(1.0f - positionLeftRight);
Chris@55:         wave->wave_pan_right = sqrtf(positionLeftRight);
Chris@55:     }
Chris@55:     return wave;
Chris@55: }
Chris@55: 
Chris@55: static float GenerateFloatRandom(float minValue, float maxValue)
Chris@55: {
Chris@55:     return minValue + ((maxValue - minValue) * rand()) / RAND_MAX;
Chris@55: }
Chris@55: 
Chris@55: /*******************************************************************/
Chris@55: int main(void);
Chris@55: int main(void)
Chris@55: {
Chris@55:     PaStream*           stream;
Chris@55:     PaError             err;
Chris@55:     paTestData          data = {0};
Chris@55:     PaStreamParameters  outputParameters;
Chris@55:     double              tstamp;
Chris@55:     double              tstart;
Chris@55:     double              tdelta = 0;
Chris@55:     static const double SR  = 44100.0;
Chris@55:     static const int    FPB = 128; /* Frames per buffer: 2.9 ms buffers. */
Chris@55: 
Chris@55:     /* Initialize communication buffers (queues) */
Chris@55:     data.rBufToRTData = PaUtil_AllocateMemory(sizeof(OceanWave*) * 256);
Chris@55:     if (data.rBufToRTData == NULL)
Chris@55:     {
Chris@55:         return 1;
Chris@55:     }
Chris@55:     PaUtil_InitializeRingBuffer(&data.rBufToRT, sizeof(OceanWave*), 256, data.rBufToRTData);
Chris@55: 
Chris@55:     data.rBufFromRTData = PaUtil_AllocateMemory(sizeof(OceanWave*) * 256);
Chris@55:     if (data.rBufFromRTData == NULL)
Chris@55:     {
Chris@55:         return 1;
Chris@55:     }
Chris@55:     PaUtil_InitializeRingBuffer(&data.rBufFromRT, sizeof(OceanWave*), 256, data.rBufFromRTData);
Chris@55: 
Chris@55:     err = Pa_Initialize();
Chris@55:     if( err != paNoError ) goto error;
Chris@55: 
Chris@55:     /* Open a stereo PortAudio stream so we can hear the result. */
Chris@55:     outputParameters.device = Pa_GetDefaultOutputDevice(); /* Take the default output device. */
Chris@55:     if (outputParameters.device == paNoDevice) {
Chris@55:       fprintf(stderr,"Error: No default output device.\n");
Chris@55:       goto error;
Chris@55:     }
Chris@55:     outputParameters.channelCount = 2;                     /* Stereo output, most likely supported. */
Chris@55:     outputParameters.hostApiSpecificStreamInfo = NULL;
Chris@55:     outputParameters.sampleFormat = paFloat32;             /* 32 bit floating point output. */
Chris@55:     outputParameters.suggestedLatency = Pa_GetDeviceInfo(outputParameters.device)->defaultLowOutputLatency;
Chris@55:     err = Pa_OpenStream(&stream,
Chris@55:                         NULL,                              /* No input. */
Chris@55:                         &outputParameters,
Chris@55:                         SR,                                /* Sample rate. */
Chris@55:                         FPB,                               /* Frames per buffer. */
Chris@55:                         paDitherOff,                       /* Clip but don't dither */
Chris@55:                         patestCallback,
Chris@55:                         &data);
Chris@55:     if( err != paNoError ) goto error;
Chris@55: 
Chris@55:     err = Pa_StartStream( stream );
Chris@55:     if( err != paNoError ) goto error;
Chris@55: 
Chris@55:     printf("Stereo \"ocean waves\" for one minute...\n");
Chris@55: 
Chris@55:     tstart = PaUtil_GetTime();
Chris@55:     tstamp = tstart;
Chris@55:     srand( (unsigned)time(NULL) );
Chris@55: 
Chris@55:     while( ( err = Pa_IsStreamActive( stream ) ) == 1 )
Chris@55:     {
Chris@55:         const double tcurrent = PaUtil_GetTime();
Chris@55: 
Chris@55:         /* Delete "waves" that the callback is finished with */
Chris@55:         while (PaUtil_GetRingBufferReadAvailable(&data.rBufFromRT) > 0)
Chris@55:         {
Chris@55:             OceanWave* ptr = 0;
Chris@55:             PaUtil_ReadRingBuffer(&data.rBufFromRT, &ptr, 1);
Chris@55:             if (ptr != 0)
Chris@55:             {
Chris@55:                 printf("Wave is deleted...\n");
Chris@55:                 PaUtil_FreeMemory(ptr);
Chris@55:                 --data.noOfActiveWaves;
Chris@55:             }
Chris@55:         }
Chris@55: 
Chris@55:         if (tcurrent - tstart < 60.0) /* Only start new "waves" during one minute */
Chris@55:         {
Chris@55:             if (tcurrent >= tstamp)
Chris@55:             {
Chris@55:                 double tdelta = GenerateFloatRandom(1.0f, 4.0f);
Chris@55:                 tstamp += tdelta;
Chris@55: 
Chris@55:                 if (data.noOfActiveWaves<16)
Chris@55:                 {
Chris@55:                     const float attackTime = GenerateFloatRandom(2.0f, 6.0f);
Chris@55:                     const float level = GenerateFloatRandom(0.1f, 1.0f);
Chris@55:                     const float pos = GenerateFloatRandom(0.0f, 1.0f);
Chris@55:                     OceanWave* p = InitializeWave(SR, attackTime, level, pos);
Chris@55:                     if (p != NULL)
Chris@55:                     {
Chris@55:                         /* Post wave to audio callback */
Chris@55:                         PaUtil_WriteRingBuffer(&data.rBufToRT, &p, 1);
Chris@55:                         ++data.noOfActiveWaves;
Chris@55: 
Chris@55:                         printf("Starting wave at level = %.2f, attack = %.2lf, pos = %.2lf\n", level, attackTime, pos);
Chris@55:                     }
Chris@55:                 }
Chris@55:             }
Chris@55:         }
Chris@55:         else
Chris@55:         {
Chris@55:             if (data.noOfActiveWaves == 0)
Chris@55:             {
Chris@55:                 printf("All waves finished!\n");
Chris@55:                 break;
Chris@55:             }
Chris@55:         }
Chris@55: 
Chris@55:         Pa_Sleep(100);
Chris@55:     }
Chris@55:     if( err < 0 ) goto error;
Chris@55: 
Chris@55:     err = Pa_CloseStream( stream );
Chris@55:     if( err != paNoError ) goto error;
Chris@55: 
Chris@55:     if (data.rBufToRTData)
Chris@55:     {
Chris@55:         PaUtil_FreeMemory(data.rBufToRTData);
Chris@55:     }
Chris@55:     if (data.rBufFromRTData)
Chris@55:     {
Chris@55:         PaUtil_FreeMemory(data.rBufFromRTData);
Chris@55:     }
Chris@55:     
Chris@55:     Pa_Sleep(1000);
Chris@55: 
Chris@55:     Pa_Terminate();
Chris@55:     return 0;
Chris@55: 
Chris@55: error:
Chris@55:     Pa_Terminate();
Chris@55:     fprintf( stderr, "An error occured while using the portaudio stream\n" );
Chris@55:     fprintf( stderr, "Error number: %d\n", err );
Chris@55:     fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
Chris@55:     return 0;
Chris@55: }