Sending MIDI events

Once the synthesizer is up and running and a SoundFont is loaded, most people will want to do something useful with it. Make noise, for example. MIDI messages can be sent using the fluid_synth_noteon(), fluid_synth_noteoff(), fluid_synth_cc(), fluid_synth_pitch_bend(), fluid_synth_pitch_wheel_sens(), and fluid_synth_program_change() functions. For convenience, there's also a fluid_synth_bank_select() function (the bank select message is normally sent using a control change message).

The following example show a generic graphical button that plays a note when clicked:

class SoundButton : public SomeButton
{
public: 
 
    SoundButton() : SomeButton() {
        if (!_synth) {
            initSynth();
        }
    }
 
    static void initSynth() {
        _settings = new_fluid_settings();
        _synth = new_fluid_synth(_settings);
        _adriver = new_fluid_audio_driver(_settings, _synth);
    }
 
    /* ... */
 
    virtual int handleMouseDown(int x, int y) {
        /* Play a note on key 60 with velocity 100 on MIDI channel 0 */
        fluid_synth_noteon(_synth, 0, 60, 100);
    }
 
    virtual int handleMouseUp(int x, int y) {
        /* Release the note on key 60 */
        fluid_synth_noteoff(_synth, 0, 60);
    }
 
protected:
 
    static fluid_settings_t* _settings;
    static fluid_synth_t* _synth;
    static fluid_audio_driver_t* _adriver;
};