Playing ideas

Test Cases:
1. Pure Tone: Clear all. Draw only the 1st bar (Fundamental). Result: Sine Wave.
2. Square: Select "Square-like" (or draw odd bars descending). Result: Blocky wave.
3. Phase Shift: With a complex shape (e.g., Saw), click "Phase Randomize".
    Observe: The Waveform shape changes drastically, but the Harmonic bars stay exactly the same.