Flute acoustics: measurement, modelling and design - School of ...

APPENDIX B. PROGRAM LISTINGS 271
frequency = A4;
/* search for input ratio against A4 to the nearest cent
in range -49 to +50 cents around closest note */
if(input >= frequency) {
while(input >= r*frequency) {
frequency = r*frequency;
r_index++;
}
}
else {
while(input < frequency) {
frequency = frequency/r;
r_index--;
}
}
while(input >= cent*frequency) {
frequency = cent*frequency;
cent_index++;
}
if((cent*frequency - input) < (input - frequency))
cent_index++;
if(cent_index > 50) {
r_index++;
cent_index = 100 - cent_index;
if(cent_index != 0)
side = MINUS;
else
side = PLUS;
}
else
side = PLUS;
if(round) {
/* round cents to nearest 5 cents */
switch(cent_index%5) {
case 1:
cent_index = cent_index - 1;
break;
case 2:
cent_index = cent_index - 2;
break;
case 3:
cent_index = cent_index + 2;
break;
case 4:
cent_index = cent_index + 1;
break;
default:
break;
}
if(cent_index == 0)
side = PLUS;
}
/* fill string buffer with note information and return */
n->name = (char*)malloc(BUFSIZ*sizeof(char));
sprintf(n->name, "%s", notes[A4_INDEX + r_index]);