Function run

examples/SendNote/SendNoteExamplePlugin.cpp:116–168

Run/process function for plugins with MIDI input. This synthesizes the MIDI voices with a sum of sine waves. */

      This synthesizes the MIDI voices with a sum of sine waves.
    */
    void run(const float**, float** outputs, uint32_t frames,
             const MidiEvent* midiEvents, uint32_t midiEventCount) override
    {
        for (uint32_t i = 0; i < midiEventCount; ++i)
        {
            if (midiEvents[i].size <= 3)
            {
                uint8_t status = midiEvents[i].data[0];
                uint8_t note = midiEvents[i].data[1] & 127;
                uint8_t velocity = midiEvents[i].data[2] & 127;

                switch (status & 0xf0)
                {
                case 0x90:
                    if (velocity != 0)
                    {
                        fNotesPlayed[note] = velocity;
                        break;
                    }
                    /* fall through */
                case 0x80:
                    fNotesPlayed[note] = 0;
                    fOscillatorPhases[note] = 0;
                    break;
                }
            }
        }

        float* const output = outputs[0];
        std::memset(output, 0, frames * sizeof(float));

        for (uint32_t noteNumber = 0; noteNumber < 128; ++noteNumber)
        {
            if (fNotesPlayed[noteNumber] == 0)
                continue;

            float notePitch = 8.17579891564 * std::exp(0.0577622650 * noteNumber);

            float phase = fOscillatorPhases[noteNumber];
            float timeStep = notePitch / getSampleRate();
            float k2pi = 2.0 * M_PI;
            float gain = 0.1;

            for (uint32_t i = 0; i < frames; ++i)
            {
                output[i] += gain * std::sin(k2pi * phase);
                phase += timeStep;
                phase -= (int)phase;
            }

            fOscillatorPhases[noteNumber] = phase;
        }
    }

    // -------------------------------------------------------------------------------------------------------