Version 0.99

RawLoop.cpp

@@ -0,0 +1,155 @@
+/*******************************************/
+/*  Raw Looped Soundfile Class,            */
+/*  by Perry R. Cook, 1995-96              */ 
+/*  This Object can open a raw 16bit data  */
+/*  (signed integers) file, and play back  */
+/*  the data, looping only, with linear    */
+/*  interpolation on playback.             */
+/*******************************************/
+
+#include "RawLoop.h"
+
+RawLoop :: RawLoop(char *fileName)
+{
+    long i;
+    short temp;
+    FILE *fd;
+    fd = fopen(fileName,"rb");
+    if (!fd)   {
+	printf("Couldn't find soundfile %s  !!!!!!!!\n",fileName);
+	exit(0);
+    }
+    i = 0;
+    while (fread(&temp,2,1,fd)) i++;
+    length = i;
+    fseek(fd,0,0);
+    data = (MY_FLOAT *) malloc(MY_FLOAT_SIZE * (length + 1));
+    i = 0;
+    while (fread(&temp,2,1,fd))   {
+	data[i] = temp;
+	i++;
+    }
+    data[length] = data[0];
+    fclose(fd);
+    time = 0.0;
+    phaseOffset = 0.0;
+    rate = 1.0;
+}
+
+RawLoop :: ~RawLoop()
+{
+    free(data);
+}
+
+void RawLoop :: reset()
+{
+    time = 0.0;
+    lastOutput = 0.0;
+}
+
+void RawLoop :: normalize()
+{
+    this->normalize(1.0);
+}
+
+void RawLoop :: normalize(MY_FLOAT newPeak)
+{
+    long i;
+    MY_FLOAT max = 0.0;
+    for (i=0;i<=length;i++)
+	if (fabs(data[i]) > max) 
+	    max = fabs(data[i]);
+    if (max > 0.0)       {
+	max = 1.0 / max;
+	max *= newPeak;
+	for (i=0;i<=length;i++)
+	    data[i] *= max;
+    }
+}
+
+void RawLoop :: setRate(MY_FLOAT aRate)
+{
+    rate = aRate;
+}
+
+void RawLoop :: setFreq(MY_FLOAT aFreq)
+{
+    rate = length * ONE_OVER_SRATE * aFreq;
+}
+
+void RawLoop :: addTime(MY_FLOAT aTime)    /* Add an absolute time */
+{                                          /* in samples           */
+    time += aTime;
+}
+
+void RawLoop :: addPhase(MY_FLOAT anAngle) /* Add a time in cycles */
+{                                          /* Cycles here means    */
+    time += length * anAngle;              /* 1.0 = length         */
+}
+
+void RawLoop :: addPhaseOffset(MY_FLOAT anAngle)
+{                                          /* Add a phase offset   */
+    phaseOffset = length * anAngle;        /* in cycles, where     */
+}                                          /* 1.0 = length         */
+
+MY_FLOAT RawLoop :: tick()
+{
+    long temp;
+    
+    MY_FLOAT temp_time, alpha;
+    
+    time += rate;                          /*  Update current time    */
+    
+    while (time >= length)                 /*  Check for end of sound */
+	time -= length;                    /*  loop back to beginning */
+    while (time < 0.0)                     /*  Check for end of sound */
+	time += length;                    /*  loop back to beginning */
+    
+    temp_time = time;
+    
+    if (phaseOffset != 0.0)       {
+	temp_time += phaseOffset;          /*  Add phase offset       */
+	while (temp_time >= length)        /*  Check for end of sound */
+	    temp_time -= length;           /*  loop back to beginning */
+	while (temp_time < 0.0)            /*  Check for end of sound */
+	    temp_time += length;           /*  loop back to beginning */
+    }
+
+    temp = (long) temp_time;               /*  Integer part of time address    */
+    alpha = temp_time - (MY_FLOAT) temp;   /*  fractional part of time address */
+    lastOutput = data[temp];               /*  Do linear interpolation         */
+    lastOutput = lastOutput +              /*  same as alpha*data[temp+1]      */
+	(alpha * (data[temp+1] 
+		- lastOutput));            /*  + (1-alpha)data[temp]           */
+    
+    return lastOutput;                        
+}
+
+MY_FLOAT RawLoop :: lastOut()
+{
+    return lastOutput;
+}
+
+/************   Test Main Program   *****************/
+/*
+void main()
+{
+    RawLoop loopWave("rawwaves/sinewave.raw");
+    FILE *fd;
+    short data;
+    long i;
+    
+    loopWave.setFreq(5500);
+    fd = fopen("test.raw","wb");
+    for (i=0;i<4096;i++) {
+	data = loopWave.tick();
+	fwrite(&data,2,1,fd);
+    }
+    loopWave.setFreq(2750);
+    for (i=0;i<4096;i++) {
+	data = loopWave.tick();
+	fwrite(&data,2,1,fd);
+    }
+    fclose(fd);
+}
+*/