A non-band-limited triangle oscillator. Output ranges from -1 to +1.
| freq | 
 Frequency in Hertz. For efficiency reasons, only positive values result in correct behavior.  | 
| iphase | 
 Initial phase offset. For efficiency reasons this is a value ranging from 0 to 4.  | 
| mul | 
 Output will be multiplied by this value.  | 
| add | 
 This value will be added to the output.  |