Defining Tones as Functions

Overview

If you have created a certain tone or sound, made of several separate oscillators (i.e, several separate calls to s.add<OscEnv>(t).set(...)), like so:

 s.add<OscEnv>(0).set(2,440,0.2,      0.02,0.09,0.4,-4,tbSin 0);
 s.add<OscEnv>(0).set(2,880,0.1, 0.02,0.09,0.4,-4, tbSin, 0);
 s.add<OscEnv>(0).set(2,660,0.05, 0.02,0.09,0.4,-4, tbSin, 0);
 s.add<OscEnv>(0).set(2,222,0.1,  0.02,0.09,0.4,-4,  tbSqr, 0);
 s.add<OscEnv>(0).set(2,220,0.35,  0.02,0.09,0.4,-4, tbSqr, 0);

it may be helpful to create a function to represent this, so that you can call this function once in your main() function instead of calling s.add over and over:

 ep1(0,2,440,1.0);

The Function

Step 1: Waveform array

First, within main(), after all the wavetables are defined and before Scheduler s is created, create an array of pointers to the various wavetables.

 ArrayPow2<float>* waves[] = {&tbSin,&tbSqr,&tbSaw...}

Note that this must be an array of pointers, not an array of the wavetables themselves (i.e. ArrayPow2<float> waves[] = {tbSin,tbSqr,tbSaw}) -- this is to avoid errors caused by ArrayPow2's copy constructor.

The point of this is that it allows a function to use multiple waveforms, not just one.

Step 2: Defining the Function

Outside of main(), define your function. Make sure to pass a reference to the scheduler (Scheduler& s) as an argument. In addition, pass as a parameter the above array of wavetables, ArrayPow2<float> waves[]. Example:

 void ep1(Scheduler& s, float t,float d,float f,float a, ArrayPow2<float>* wave[]){

In the function body, place the list of sounds you want to put together to make up the total sound. For each s.add call, refer to its desired waveform by its array index - for example, if the array you defined in your main() function looked like [&tbSaw, &tbSqr, &tbSin], then a sine wave would be waves[2]. Remember to dereference the pointer: *(waves[2]).

 //An electric-piano type sound.
 //Arguments: Scheduler, time, duration, fundamental frequency, overall amplitude, array of waveforms.
 void ep1(Scheduler& s, float t,float d,float f,float a, ArrayPow2<float>* wave[]){ 
   s.add<OscEnv>(t).set(d,f,0.2*a,      0.02,0.09,0.4,-4,*(wave[2]), 0);
   s.add<OscEnv>(t).set(d,f*2,0.1*a, 0.02,0.09,0.4,-4, *(wave[2]), 0);
   s.add<OscEnv>(t).set(d,f*1.5,0.05*a, 0.02,0.09,0.4,-4, *(wave[2]), 0);
   s.add<OscEnv>(t).set(d,(f*0.5)+2,0.1*a,  0.02,0.09,0.4,-4,  *(wave[1]), 0);
   s.add<OscEnv>(t).set(d,f*0.5,0.35*a,  0.02,0.09,0.4,-4, *(wave[1]), 0);
 };

Note how the array wave[] is passed to the function, and how the pointers are dereferenced in calls to s.add to give sine and square waves.

Step 3: Using the function

Back in main(), simply call the function.

 ep1(s,0.0,1.0,440,1.0,waves);

plays the electric-piano sound at time 0, for a duration of 1 second, with fundamental frequency 440 and amplitude 1.0.

The advantage of using this technique is that you only need to call the function ep1 once, each time you want to play one note with this sound.