Implement midi player using Windows API

src/midiPlayer.cpp

@@ -0,0 +1,85 @@
+#include "midiPlayer.h"
+
+#include <cmath>
+#include <thread>
+
+//--------------------------------------------------------------
+/* Default constructor */
+MidiPlayer::MidiPlayer()
+{
+  init();
+}
+//--------------------------------------------------------------
+/* Constructor */
+MidiPlayer::MidiPlayer(const std::span<const pitches::Note> notes)
+{
+  init();
+  playBuffer(notes);
+}
+//--------------------------------------------------------------
+/* Set MIDI instrument */
+void MidiPlayer::setInstrument(uint8_t instrument) const
+{
+  if (instrument > 127)
+    instrument = 0;     // Default to Acoustic Grand Piano if out of range
+
+  const DWORD message = 0xC0 | (instrument << 8);     // Program Change
+  midiOutShortMsg(m_midiOut, message);
+}
+//--------------------------------------------------------------
+/* Default destructor */
+MidiPlayer::~MidiPlayer()
+{
+  release();
+}
+//--------------------------------------------------------------
+/* Play a MIDI buffer */
+void MidiPlayer::playBuffer(const std::span<const pitches::Note> notes) const
+{
+  for (const auto note : notes)
+  {
+    const auto noteNumber = frequencyToMidiNote(note.frequency);
+
+    // Send Note On message (0x90) with the note number and velocity
+    DWORD message = 0x90 | (noteNumber << 8) | (m_velocity << 16);     // Note On
+    midiOutShortMsg(m_midiOut, message);
+
+    // Wait for the duration of the note
+    std::this_thread::sleep_for(note.duration);
+
+    // Send Note Off message (0x80) with the note number
+    message = 0x80 | (noteNumber << 8);     // Note Off
+    midiOutShortMsg(m_midiOut, message);
+  }
+}
+//--------------------------------------------------------------
+/* Initialize MIDI output */
+void MidiPlayer::init()
+{
+  midiOutOpen(&m_midiOut,         // phmo
+              0,                  // uDeviceID
+              0,                  // dwCallback
+              0,                  // dwInstance
+              CALLBACK_NULL);     // fdwOpen
+}
+//--------------------------------------------------------------
+/* Release MIDI output */
+void MidiPlayer::release()
+{
+  midiOutClose(m_midiOut);
+  m_midiOut = nullptr;
+}
+//--------------------------------------------------------------
+/* Convert frequency to MIDI note number */
+int MidiPlayer::frequencyToMidiNote(const uint16_t frequency) const
+{
+  constexpr double A4_FREQUENCY         = 440.0;
+  constexpr double A4_MIDI_NOTE         = 69.0;
+  constexpr double SEMITONES_PER_OCTAVE = 12.0;
+
+  if (frequency == 0)
+    return 0;     // Silent
+
+  return static_cast<int>(std::round(A4_MIDI_NOTE + SEMITONES_PER_OCTAVE * log2(static_cast<double>(frequency) / A4_FREQUENCY)));
+}
+//--------------------------------------------------------------

src/midiPlayer.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include "pitches/pitches.h"
+
+#include <cstdint>
+#include <span>
+#include <windows.h>
+
+// Include the Windows Multimedia API header for MIDI functions
+#include <mmsystem.h>
+
+//--------------------------------------------------------------
+class MidiPlayer
+{
+  public:
+  MidiPlayer();                                                  // Default constructor
+  virtual ~MidiPlayer();                                         // Default destructor
+  MidiPlayer(const MidiPlayer &obj)                = delete;     // Copy constructor
+  MidiPlayer(MidiPlayer &&obj) noexcept            = delete;     // Move constructor
+  MidiPlayer &operator=(const MidiPlayer &obj)     = delete;     // Copy assignment operator
+  MidiPlayer &operator=(MidiPlayer &&obj) noexcept = delete;     // Move assignment operator
+
+  explicit MidiPlayer(std::span<const pitches::Note> notes);     // Constructor
+
+  void setInstrument(uint8_t instrument) const;                    // Set MIDI instrument
+  void playBuffer(std::span<const pitches::Note> notes) const;     // Play a MIDI buffer
+
+  protected:
+  HMIDIOUT m_midiOut  = nullptr;
+  uint16_t m_velocity = 127;     // MIDI velocity (0-127)
+
+  private:
+  void init();        // Initialize MIDI output
+  void release();     // Release MIDI output
+
+  [[nodiscard]] int frequencyToMidiNote(uint16_t frequency) const;     // Convert frequency to MIDI note number
+};
+//--------------------------------------------------------------