Version 3.0

STK/TablLook.cpp

@@ -0,0 +1,96 @@
+/********************************************/
+/*  Table Lookup Class,                     */
+/*  by Gary P. Scavone, 1999                */ 
+/*                                          */
+/*  This class loads a table of floating    */
+/*  point doubles, which are assumed to be  */
+/*  in big-endian format.  Linear           */
+/*  interpolation is performed for          */
+/*  fractional lookup indexes.              */
+/********************************************/
+
+#include "TablLook.h"
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#ifdef __LITTLE_ENDIAN__
+  #include "swapstuf.h"
+#endif
+
+TablLook :: TablLook(char *fileName)
+{
+  extern double SwapDouble(double);
+
+  // Use the system call "stat" to determine the file length
+  struct stat filestat;
+  if (stat(fileName, &filestat) == -1)
+    { /* Opening file failed */
+      fprintf(stderr,"TablLook - Cannot access or find table lookup file: %s !!!\n",fileName);
+      exit(0);
+    }
+  length = (long) filestat.st_size / 8;  // length in 8-byte samples
+
+  // Open the file and read samples into data[]
+  FILE *fd;
+  fd = fopen(fileName,"rb");
+  if (!fd)   {
+    printf("TablLook - Couldn't open or find table lookup file %s !!!\n",fileName);
+    exit(0);
+  }
+
+  data = (MY_FLOAT *) new MY_FLOAT[length];
+
+  // Read samples into data[]
+  long i = 0;
+  double temp;
+  while (fread(&temp,8,1,fd)) {
+#ifdef __LITTLE_ENDIAN__
+    temp = SwapDouble(temp);
+#endif
+    data[i++] = (MY_FLOAT) temp;
+  }
+  fclose(fd);
+
+  lastOutput = 0.0;
+}
+
+TablLook :: ~TablLook()
+{
+  delete [ ] data;
+}
+
+long TablLook :: getLength()
+{
+  return length;
+}
+
+MY_FLOAT TablLook :: tick(MY_FLOAT index)
+{
+  static MY_FLOAT alpha;
+  static long temp;
+
+  if (index > length-1) {
+    fprintf(stderr,"TablLook: Index (%f) exceeds table length ... sticking at end!\n", index);
+    index = length-1;
+  }
+  if (index < 0.0) {
+    fprintf(stderr,"TablLook: Index (%f) is less than zero ... setting to zero\n", index);
+    index = 0.0;
+  }
+
+  // Index OK (in range 0 to length-1)
+  temp = (long) index;                  // Integer part of index
+  alpha = index - (MY_FLOAT) temp;      // Fractional part of index
+  if (alpha > 0.0) {                    // Do linear interpolation
+    lastOutput = data[temp];
+    lastOutput += (alpha*(data[temp+1] - lastOutput));
+  }
+  else lastOutput = data[temp];
+
+  return lastOutput;
+}
+
+MY_FLOAT TablLook :: lastOut()
+{
+  return lastOutput;
+}