api: use std::variant instead of std::any for API configurations

Necessary as std::any just does not work across dylibs on macOS
celtera · Jan 8, 2025 · d131e30 · d131e30
1 parent d818732
commit d131e30
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Showing 17 changed files with 283 additions and 175 deletions.
diff --git a/include/libremidi/api.hpp b/include/libremidi/api.hpp
@@ -2,7 +2,6 @@
 #include <libremidi/api-c.h>
 #include <libremidi/config.hpp>
 
-#include <any>
 #include <string_view>
 #include <vector>
 
@@ -31,9 +30,6 @@ LIBREMIDI_EXPORT std::vector<libremidi::API> available_apis() noexcept;
 */
 LIBREMIDI_EXPORT std::vector<libremidi::API> available_ump_apis() noexcept;
 
-LIBREMIDI_EXPORT
-libremidi::API midi_api(const std::any& conf);
-
 //! A static function to determine the current version.
 LIBREMIDI_EXPORT std::string_view get_version() noexcept;
 

diff --git a/include/libremidi/backends.hpp b/include/libremidi/backends.hpp
@@ -1,7 +1,6 @@
 #pragma once
 #include <libremidi/config.hpp>
 
-#include <any>
 #include <tuple>
 
 #if !__has_include(<weak_libjack.h>) && !__has_include(<jack/jack.h>)
@@ -202,10 +201,10 @@ auto for_backend(libremidi::API api, F&& f)
   midi2::for_backend(api, f);
 }
 
-void for_input_configuration(auto f, std::any& api_conf)
+void for_input_configuration(auto f, libremidi::input_api_configuration& api_conf)
 {
   auto from_api = [&]<typename T>(T& /*backend*/) mutable {
-    if (auto conf = std::any_cast<typename T::midi_in_configuration>(&api_conf))
+    if (auto conf = std::get_if<typename T::midi_in_configuration>(&api_conf))
     {
       f(*conf);
       return true;
@@ -217,10 +216,10 @@ void for_input_configuration(auto f, std::any& api_conf)
   std::apply([&](auto&&... b) { return (from_api(b) || ...); }, midi2::available_backends);
 }
 
-void for_output_configuration(auto f, std::any& api_conf)
+void for_output_configuration(auto f, libremidi::output_api_configuration& api_conf)
 {
   auto from_api = [&]<typename T>(T& /*backend*/) mutable {
-    if (auto conf = std::any_cast<typename T::midi_out_configuration>(&api_conf))
+    if (auto conf = std::get_if<typename T::midi_out_configuration>(&api_conf))
     {
       f(*conf);
       return true;
@@ -232,10 +231,10 @@ void for_output_configuration(auto f, std::any& api_conf)
   std::apply([&](auto&&... b) { return (from_api(b) || ...); }, midi2::available_backends);
 }
 
-void for_observer_configuration(auto f, std::any& api_conf)
+void for_observer_configuration(auto f, libremidi::observer_api_configuration& api_conf)
 {
   auto from_api = [&]<typename T>(T& /*backend*/) mutable {
-    if (auto conf = std::any_cast<typename T::midi_observer_configuration>(&api_conf))
+    if (auto conf = std::get_if<typename T::midi_observer_configuration>(&api_conf))
     {
       f(*conf);
       return true;

diff --git a/include/libremidi/backends/alsa_raw_ump.hpp b/include/libremidi/backends/alsa_raw_ump.hpp
@@ -16,9 +16,8 @@ struct backend
   using midi_observer = observer_impl;
   using midi_in_configuration = alsa_raw_ump::input_configuration;
   using midi_out_configuration = alsa_raw_ump::output_configuration;
-  struct midi_observer_configuration : alsa_raw_observer_configuration
-  {
-  };
+  using midi_observer_configuration = alsa_raw_ump::observer_configuration;
+
   static const constexpr auto API = libremidi::API::ALSA_RAW_UMP;
   static const constexpr std::string_view name = "alsa_raw_ump";
   static const constexpr std::string_view display_name = "ALSA (raw UMP)";

diff --git a/include/libremidi/backends/alsa_raw_ump/config.hpp b/include/libremidi/backends/alsa_raw_ump/config.hpp
@@ -18,8 +18,7 @@ struct output_configuration
   std::optional<chunking_parameters> chunking;
 };
 
-struct observer_configuration
+struct observer_configuration : public alsa_raw_observer_configuration
 {
-  std::chrono::milliseconds poll_period{100};
 };
 }
diff --git a/include/libremidi/backends/keyboard/config.hpp b/include/libremidi/backends/keyboard/config.hpp
@@ -6,87 +6,149 @@
 
 namespace libremidi
 {
+enum kbd_event
+{
+  NOTE_0 = 0x0,         // C
+  VEL_0 = NOTE_0 + 128, // Set velocity to 0
+  OCT_0 = VEL_0 + 128,  // Set octave to 0
+  OCTAVE_PLUS = OCT_0 + 128,
+  OCTAVE_MINUS,
+  VELOCITY_PLUS,
+  VELOCITY_MINUS,
+};
+
+// Default map
+//
+// ,---,---,---,---,---,---,---,---,---,---,---,---,---,-------,
+// | V0| V1| V2| V3| V4| V5| V6| V7| V8| V9|V10|V11|V12| <-    |
+// |---'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-----|
+// | ->| |   | C#| D#|   | F#| G#| A#|   | C#| D#|   | F#|     |
+// |-----',--',--',--',--',--',--',--',--',--',--',--',--'|    |
+// | Caps | C | D | E | F | G | A | B | C | D | E | F | G |    |
+// |----,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'---'----|
+// | -^ |   | O-| O+| V-| V+|   |   |   |   |   |   |   ----^  |
+// |----'-,-',--'--,'---'---'---'---'---'---'-,-'---',--,------|
+// | ctrl |  | alt |                          |altgr |  | ctrl |
+// '------'  '-----'--------------------------'------'  '------'
+
+// clang-format off
+
+// actually based on macOS virtual codes as it seems
+// impossible to get raw scan codes.
+// https://eastmanreference.com/complete-list-of-applescript-key-codes
+static inline const std::map<int, int>& scancode_map_macos(){
+  static const std::map<int, int> ret{
+  {  0, NOTE_0}, // C0
+  { 13, NOTE_0 + 1},
+  {  1, NOTE_0 + 2},
+  { 14, NOTE_0 + 3},
+  {  2, NOTE_0 + 4},
+  {  3, NOTE_0 + 5},
+  { 17, NOTE_0 + 6},
+  {  5, NOTE_0 + 7},
+  { 16, NOTE_0 + 8},
+  {  4, NOTE_0 + 9},
+  { 32, NOTE_0 + 10},
+  { 38, NOTE_0 + 11},
+  { 40, NOTE_0 + 12}, // C1
+  { 31, NOTE_0 + 13},
+  { 37, NOTE_0 + 14},
+  { 35, NOTE_0 + 15},
+  { 41, NOTE_0 + 16},
+  { 39, NOTE_0 + 17},
+  { 30, NOTE_0 + 18},
+  { 42, NOTE_0 + 19},
+
+  { 50, VEL_0 + int(0)},
+  { 18, VEL_0 + int(1 * 127 / 12)},
+  { 19, VEL_0 + int(2 * 127 / 12)},
+  { 20, VEL_0 + int(3 * 127 / 12)},
+  { 21, VEL_0 + int(4 * 127 / 12)},
+  { 23, VEL_0 + int(5 * 127 / 12)},
+  { 22, VEL_0 + int(6 * 127 / 12)},
+  { 26, VEL_0 + int(7 * 127 / 12)},
+  { 28, VEL_0 + int(8 * 127 / 12)},
+  { 25, VEL_0 + int(9 * 127 / 12)},
+  { 29, VEL_0 + int(10 * 127 / 12)},
+  { 27, VEL_0 + int(11 * 127 / 12)},
+  { 24, VEL_0 + int(127)},
+
+  { 6, OCTAVE_MINUS },
+  { 7, OCTAVE_PLUS },
+  { 8, VELOCITY_MINUS },
+  { 9, VELOCITY_PLUS},
+  };
+  return ret;
+}
+
+// Use: https://kbdlayout.info/KBDUSX/scancodes
+// Also valid for windows
+static inline const std::map<int, int>& scancode_map_linux() {
+  static const std::map<int, int> ret{
+  { 0x1E, NOTE_0}, // C0
+  { 0x11, NOTE_0 + 1},
+  { 0x1F, NOTE_0 + 2},
+  { 0x12, NOTE_0 + 3},
+  { 0x20, NOTE_0 + 4},
+  { 0x21, NOTE_0 + 5},
+  { 0x14, NOTE_0 + 6},
+  { 0x22, NOTE_0 + 7},
+  { 0x15, NOTE_0 + 8},
+  { 0x23, NOTE_0 + 9},
+  { 0x16, NOTE_0 + 10},
+  { 0x24, NOTE_0 + 11},
+  { 0x25, NOTE_0 + 12}, // C1
+  { 0x18, NOTE_0 + 13},
+  { 0x26, NOTE_0 + 14},
+  { 0x19, NOTE_0 + 15},
+  { 0x27, NOTE_0 + 16},
+  { 0x28, NOTE_0 + 17},
+  { 0x1B, NOTE_0 + 18},
+  { 0x2B, NOTE_0 + 19},
+
+  { 0x29, VEL_0 + int(0)},
+  { 0x02, VEL_0 + int(1 * 127 / 12)},
+  { 0x03, VEL_0 + int(2 * 127 / 12)},
+  { 0x04, VEL_0 + int(3 * 127 / 12)},
+  { 0x05, VEL_0 + int(4 * 127 / 12)},
+  { 0x06, VEL_0 + int(5 * 127 / 12)},
+  { 0x07, VEL_0 + int(6 * 127 / 12)},
+  { 0x08, VEL_0 + int(7 * 127 / 12)},
+  { 0x09, VEL_0 + int(8 * 127 / 12)},
+  { 0x0A, VEL_0 + int(9 * 127 / 12)},
+  { 0x0B, VEL_0 + int(10 * 127 / 12)},
+  { 0x0C, VEL_0 + int(11 * 127 / 12)},
+  { 0x0D, VEL_0 + int(127)},
+
+  { 0x2C, OCTAVE_MINUS },
+  { 0x2D, OCTAVE_PLUS },
+  { 0x2E, VELOCITY_MINUS },
+  { 0x2F, VELOCITY_PLUS},
+  };
+  return ret;
+}
+// clang-format on
 /**
  * Used to set up keyboard input.
  * Your app should pass a function that will give you a callback
  * that you should call whenever you are getting a key input (press or release).
  */
 struct kbd_input_configuration
 {
+  // Note that on Linux with X11 scancodes should be offset by 8 (an X11 legacy quirk)
+  // ex.: pass QKeyEvent::nativeScanCode() - 8 to this API
   using scancode_callback = std::function<void(int)>;
+
   // First argument is on key press, second on key release
   std::function<void(scancode_callback, scancode_callback)> set_input_scancode_callbacks
-      = [](scancode_callback, scancode_callback) {};
-
-  enum kbd_event
-  {
-    NOTE_0 = 0x0,         // C
-    VEL_0 = NOTE_0 + 128, // Set velocity to 0
-    OCT_0 = VEL_0 + 128,  // Set octave to 0
-    OCTAVE_PLUS = OCT_0 + 128,
-    OCTAVE_MINUS,
-    VELOCITY_PLUS,
-    VELOCITY_MINUS,
-  };
+      = [](scancode_callback, scancode_callback) { };
 
-  // Default map
-  //
-  // ,---,---,---,---,---,---,---,---,---,---,---,---,---,-------,
-  // | V0| V1| V2| V3| V4| V5| V6| V7| V8| V9|V10|V11|V12| <-    |
-  // |---'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-----|
-  // | ->| |   | C#| D#|   | F#| G#| A#|   | C#| D#|   | F#|     |
-  // |-----',--',--',--',--',--',--',--',--',--',--',--',--'|    |
-  // | Caps | C | D | E | F | G | A | B | C | D | E | F | G |    |
-  // |----,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'-,-'---'----|
-  // | -^ |   | O-| O+| V-| V+|   |   |   |   |   |   |   ----^  |
-  // |----'-,-',--'--,'---'---'---'---'---'---'-,-'---',--,------|
-  // | ctrl |  | alt |                          |altgr |  | ctrl |
-  // '------'  '-----'--------------------------'------'  '------'
-
-  // clang-format off
-  // Use: https://kbdlayout.info/KBDUSX/scancodes
-  std::map<int, int> scancode_map{
-      { 0x1E, NOTE_0}, // C0
-      { 0x11, NOTE_0 + 1},
-      { 0x1F, NOTE_0 + 2},
-      { 0x12, NOTE_0 + 3},
-      { 0x20, NOTE_0 + 4},
-      { 0x21, NOTE_0 + 5},
-      { 0x14, NOTE_0 + 6},
-      { 0x22, NOTE_0 + 7},
-      { 0x15, NOTE_0 + 8},
-      { 0x23, NOTE_0 + 9},
-      { 0x16, NOTE_0 + 10},
-      { 0x24, NOTE_0 + 11},
-      { 0x25, NOTE_0 + 12}, // C1
-      { 0x18, NOTE_0 + 13}, 
-      { 0x26, NOTE_0 + 14}, 
-      { 0x19, NOTE_0 + 15},
-      { 0x27, NOTE_0 + 16},
-      { 0x28, NOTE_0 + 17},
-      { 0x1B, NOTE_0 + 18},
-      { 0x2B, NOTE_0 + 19},
-
-      { 0x29, VEL_0 + int(0)},
-      { 0x02, VEL_0 + int(1 * 127 / 12)},
-      { 0x03, VEL_0 + int(2 * 127 / 12)},
-      { 0x04, VEL_0 + int(3 * 127 / 12)},
-      { 0x05, VEL_0 + int(4 * 127 / 12)},
-      { 0x06, VEL_0 + int(5 * 127 / 12)},
-      { 0x07, VEL_0 + int(6 * 127 / 12)},
-      { 0x08, VEL_0 + int(7 * 127 / 12)},
-      { 0x09, VEL_0 + int(8 * 127 / 12)},
-      { 0x0A, VEL_0 + int(9 * 127 / 12)},
-      { 0x0B, VEL_0 + int(10 * 127 / 12)},
-      { 0x0C, VEL_0 + int(11 * 127 / 12)},
-      { 0x0D, VEL_0 + int(127)},
-
-      { 0x2C, OCTAVE_MINUS },
-      { 0x2D, OCTAVE_PLUS },
-      { 0x2E, VELOCITY_MINUS },
-      { 0x2F, VELOCITY_PLUS}, 
-  };
-  // clang-format on
+  std::map<int, int> scancode_map
+#if defined(__APPLE__)
+      = scancode_map_macos()
+#else
+      = scancode_map_linux()
+#endif
+      ;
 };
-
 }
diff --git a/include/libremidi/backends/keyboard/midi_in.hpp b/include/libremidi/backends/keyboard/midi_in.hpp
@@ -45,7 +45,7 @@ class midi_in_kbd final
 
   void on_keypress(int scancode)
   {
-    using kevent = kbd_input_configuration::kbd_event;
+    using kevent = libremidi::kbd_event;
 
     auto it = configuration.scancode_map.find(scancode);
     if (it == configuration.scancode_map.end())
@@ -88,7 +88,7 @@ class midi_in_kbd final
 
   void on_keyrelease(int scancode)
   {
-    using kevent = kbd_input_configuration::kbd_event;
+    using kevent = libremidi::kbd_event;
 
     auto it = configuration.scancode_map.find(scancode);
     if (it == configuration.scancode_map.end())

diff --git a/include/libremidi/configurations.hpp b/include/libremidi/configurations.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <libremidi/api.hpp>
 #include <libremidi/backends/alsa_raw/config.hpp>
 #include <libremidi/backends/alsa_raw_ump/config.hpp>
 #include <libremidi/backends/alsa_seq/config.hpp>
@@ -14,11 +15,51 @@
 #include <libremidi/backends/winmidi/config.hpp>
 #include <libremidi/backends/winmm/config.hpp>
 #include <libremidi/backends/winuwp/config.hpp>
+#include <libremidi/config.hpp>
 
+#include <variant>
 namespace libremidi
 {
-
+struct unspecified_configuration
+{
+};
 struct dummy_configuration
 {
 };
+
+using input_api_configuration = std::variant<
+    unspecified_configuration, dummy_configuration, alsa_raw_input_configuration,
+    alsa_raw_ump::input_configuration, alsa_seq::input_configuration,
+    alsa_seq_ump::input_configuration, coremidi_input_configuration,
+    coremidi_ump::input_configuration, emscripten_input_configuration, jack_input_configuration,
+    kbd_input_configuration, libremidi::net::dgram_input_configuration,
+    libremidi::net_ump::dgram_input_configuration, pipewire_input_configuration,
+    winmidi::input_configuration, winmm_input_configuration, winuwp_input_configuration,
+    libremidi::API>;
+
+using output_api_configuration = std::variant<
+    unspecified_configuration, dummy_configuration, alsa_raw_output_configuration,
+    alsa_raw_ump::output_configuration, alsa_seq::output_configuration,
+    alsa_seq_ump::output_configuration, coremidi_output_configuration,
+    coremidi_ump::output_configuration, emscripten_output_configuration, jack_output_configuration,
+    libremidi::net::dgram_output_configuration, libremidi::net_ump::dgram_output_configuration,
+    pipewire_output_configuration, winmidi::output_configuration, winmm_output_configuration,
+    winuwp_output_configuration, libremidi::API>;
+
+using observer_api_configuration = std::variant<
+    unspecified_configuration, dummy_configuration, alsa_raw_observer_configuration,
+    alsa_raw_ump::observer_configuration, alsa_seq::observer_configuration,
+    alsa_seq_ump::observer_configuration, coremidi_observer_configuration,
+    coremidi_ump::observer_configuration, emscripten_observer_configuration,
+    jack_observer_configuration, libremidi::net::dgram_observer_configuration,
+    libremidi::net_ump::dgram_observer_configuration, pipewire_observer_configuration,
+    winmidi::observer_configuration, winmm_observer_configuration, winuwp_observer_configuration,
+    libremidi::API>;
+
+LIBREMIDI_EXPORT
+libremidi::API midi_api(const input_api_configuration& conf);
+LIBREMIDI_EXPORT
+libremidi::API midi_api(const output_api_configuration& conf);
+LIBREMIDI_EXPORT
+libremidi::API midi_api(const observer_api_configuration& conf);
 }