Mmc-august-2012/Lab1

Lab 1 - Oscillators

In this lab, we will experiment with a variety of oscillators, both by themselves and in combination as FM operators.

Audio Bootup

Make sure you are up-to-date with your Xcode install, and that you are able to load code onto your iOS device. Create a new project ("single-view application"), and add MoAudio as described in the audioStuff download (found here: audioStuff.zip). To test everything out, write an audio callback that generates a sine wave at a fixed frequency, making sure that it runs in both the simulator and your device.

Basic Oscillators

Implement sine wave, triangle wave, sawtooth, and square wave oscillators using the phase-increment method shown in class. For each of these, structure the oscillator as a function that accepts a phase between [0,1] and returns the value at that phase, like this:

float exampleOsc(float p)
{
    return ???; // <-- fancy math goes here to figure out value for phase
}

Call this function from your callback, incrementing the phase after each frame. Software engineers may recognize this basic design pattern as modularity: the structuring of code into reusable blocks. As we will see later, we can and will reuse these oscillators for more than simple waveform generation.