winmidi: rework initialization

Author: jcelerier

include/libremidi/backends/coremidi/midi_out.hpp

@@ -111,8 +111,8 @@ class midi_out_core final
     const MIDITimeStamp timestamp = LIBREMIDI_AUDIO_GET_CURRENT_HOST_TIME();
 
     const ByteCount bufsize = nBytes > 65535 ? 65535 : nBytes;
-    Byte buffer[bufsize + 16]; // pad for other struct members
-    ByteCount listSize = sizeof(buffer);
+    Byte* buffer = (Byte*)alloca(bufsize + 16); // pad for other struct members
+    ByteCount listSize = bufsize + 16;
     MIDIPacketList* packetList = (MIDIPacketList*)buffer;
 
     ByteCount remainingBytes = nBytes;

include/libremidi/backends/winmidi.hpp

@@ -19,6 +19,8 @@ struct backend
   static const constexpr std::string_view name = "winmidi";
   static const constexpr std::string_view display_name = "Windows MIDI Services";
 
-  static constexpr inline bool available() noexcept { return true; }
+  static inline bool available() noexcept {
+    return libremidi::instance<winmidi_shared_data_instance>()->ready;
+  }
 };
 } // NAMESPACE_LIBREMIDI

include/libremidi/backends/winmidi/helpers.hpp

@@ -24,14 +24,14 @@
         LIBREMIDI_STATIC constexpr const type name = {l,w1,w2,{b1,b2,b3,b4,b5,b6,b7,b8}}
 
 NAMESPACE_LIBREMIDI {
-  LIBREMIDI_DEFINE_GUID_CONSTEXPR(IID, IID_IMidiEndpointConnectionMessagesReceivedCallback, 0x8087b303,0x0519,0x31d1,0x31,0xd1,0x00,0x00,0x00,0x00,0x00,0x10);
-  LIBREMIDI_DEFINE_GUID_CONSTEXPR(IID, IID_IMidiEndpointConnectionRaw, 0x8087b303,0x0519,0x31d1,0x31,0xd1,0x00,0x00,0x00,0x00,0x00,0x20);
-  LIBREMIDI_DEFINE_GUID_CONSTEXPR(IID, IID_IMidiClientInitializer, 0x8087b303, 0xd551, 0xbce2, 0x1e, 0xad, 0xa2, 0x50, 0x0d, 0x50, 0xc5, 0x80);
-  LIBREMIDI_DEFINE_GUID_CONSTEXPR(IID, IID_MidiClientInitializerUuid, 0xc3263827, 0xc3b0, 0xbdbd, 0x25, 0x00, 0xce, 0x63, 0xa3, 0xf3, 0xf2, 0xc3);
+  LIBREMIDI_DEFINE_GUID_CONSTEXPR(IID, IID_IMidiEndpointConnectionMessagesReceivedCallback, 0x8087b303, 0x0519, 0x31d1, 0x31, 0xd1, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10);
+  LIBREMIDI_DEFINE_GUID_CONSTEXPR(IID, IID_IMidiEndpointConnectionRaw,                      0x8087b303, 0x0519, 0x31d1, 0x31, 0xd1, 0x00, 0x00, 0x00, 0x00, 0x00, 0x20);
+  LIBREMIDI_DEFINE_GUID_CONSTEXPR(IID, IID_IMidiClientInitializer,                          0x8087b303, 0xd551, 0xbce2, 0x1e, 0xad, 0xa2, 0x50, 0x0d, 0x50, 0xc5, 0x80);
+  LIBREMIDI_DEFINE_GUID_CONSTEXPR(IID, IID_MidiClientInitializerUuid,                       0xc3263827, 0xc3b0, 0xbdbd, 0x25, 0x00, 0xce, 0x63, 0xa3, 0xf3, 0xf2, 0xc3);
+  LIBREMIDI_DEFINE_GUID_CONSTEXPR(IID, IID_MidiSrvTransportUuid,                            0x2ba15e4e, 0x5417, 0x4a66, 0x85, 0xb8, 0x2b, 0x22, 0x60, 0xef, 0xbc, 0x84);
 }
 #endif
 
-#include <init/Microsoft.Windows.Devices.Midi2.Initialization.hpp>
 // clang-format on
 
 namespace midi2 = winrt::Microsoft::Windows::Devices::Midi2;
@@ -44,7 +44,6 @@ using namespace winrt::Windows::Foundation;
 using namespace winrt::Windows::Devices::Enumeration;
 using namespace winrt::Windows::Storage::Streams;
 using namespace winrt::Microsoft::Windows::Devices::Midi2;
-using namespace ::Microsoft::Windows::Devices::Midi2::Initialization;
 
 inline bool ichar_equals(char a, char b)
 {
@@ -82,16 +81,138 @@ get_port(const std::string& device_name, int group_terminal_block)
   }
   return {nullptr, nullptr};
 }
+
+// From Microsoft.Windows.Devices.Midi2.Initialization.hpp
+typedef enum
+{
+  Platform_x64 = 1,
+  //    Platform_Arm64 = 2,
+  //    Platform_Arm64EC = 3,
+  Platform_Arm64X = 4,
+} MidiAppSDKPlatform;
+
+struct IMidiClientInitializer : ::IUnknown
+{
+  // returns the SDK version info. Supply nullptr for arguments you don't care about
+  STDMETHOD(GetInstalledWindowsMidiServicesSdkVersion)(
+      MidiAppSDKPlatform* buildPlatform,
+      USHORT* versionMajor,
+      USHORT* versionMinor,
+      USHORT* versionPatch,
+
+      LPWSTR* buildSource,
+      LPWSTR* versionName,
+      LPWSTR* versionFullString
+      ) = 0;
+
+  // demand-starts the service if present
+  STDMETHOD(EnsureServiceAvailable)() = 0;
+};
+struct winmidi_shared_data_instance
+{
+  IMidiClientInitializer* initializer{nullptr};
+  bool ready{false};
+  winmidi_shared_data_instance()
+  {
+    // 1. Check if MIDI Services are available
+    {
+      ::IUnknown* servicePointer{ nullptr };
+      auto hr = CoCreateInstance(
+          libremidi::IID_MidiSrvTransportUuid,
+          NULL,
+          CLSCTX_INPROC_SERVER,
+          IID_PPV_ARGS(&servicePointer)
+          );
+
+      if (SUCCEEDED(hr))
+      {
+        if (servicePointer == nullptr)
+        {
+          ready = false;
+          return;
+        }
+
+        // Here is the good case:
+        servicePointer->Release();
+        servicePointer = nullptr;
+        ready = true;
+      }
+      else if (hr == REGDB_E_CLASSNOTREG)
+      {
+        servicePointer = nullptr;
+        ready = false;
+        return;
+      }
+      else
+      {
+        servicePointer = nullptr;
+        ready = false;
+        return;
+      }
+    }
+
+    // 2. Check if MIDI services can be created
+    {
+      if (SUCCEEDED(CoCreateInstance(
+              libremidi::IID_MidiClientInitializerUuid,
+              NULL,
+              CLSCTX::CLSCTX_INPROC_SERVER | CLSCTX::CLSCTX_FROM_DEFAULT_CONTEXT,
+              libremidi::IID_IMidiClientInitializer,
+              reinterpret_cast<void**>(&initializer)
+              )))
+      {
+        if (initializer != nullptr)
+        {
+          ready = true;
+        }
+        else
+        {
+          ready = false;
+          return;
+        }
+      }
+      else
+      {
+        ready = false;
+        return;
+      }
+    }
+
+    // 3. Check if MIDI services can be used
+    if (SUCCEEDED(initializer->EnsureServiceAvailable()))
+    {
+      ready = true;
+    }
+    else
+    {
+      ready = false;
+      initializer->Release();
+      initializer = nullptr;
+      return;
+    }
+  }
+
+  ~winmidi_shared_data_instance()
+  {
+    if (initializer != nullptr)
+    {
+      initializer->Release();
+      initializer = nullptr;
+    }
+  }
+};
+
 struct winmidi_shared_data
 {
-  std::shared_ptr<MidiDesktopAppSdkInitializer> initializer;
-  bool m_ready{false};
+  std::shared_ptr<winmidi_shared_data_instance> self = libremidi::instance<winmidi_shared_data_instance>();
+
   winmidi_shared_data()
-      : initializer{libremidi::instance<MidiDesktopAppSdkInitializer>()}
-      , m_ready{
-            initializer && initializer->InitializeSdkRuntime()
-            && initializer->EnsureServiceAvailable()}
+  {
+  }
+
+  ~winmidi_shared_data()
   {
   }
 };
+
 }