[idd] audio: add virtual playback and capture driver

Add a WaveRT adapter with render and capture endpoints backed by a
local ring buffer and shared presentation clock.

Advertise PCM formats through 192 kHz, eight channels, and packed
24-bit samples. Register LGAudio in the IDD solution and package it as
Looking Glass Audio.

idd/LGAudio/Driver.cpp

@@ -0,0 +1,99 @@
+/**
+ * Looking Glass
+ * Copyright © 2017-2026 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "Common.h"
+#include "Adapter.h"
+
+extern "C" DRIVER_INITIALIZE DriverEntry;
+
+namespace
+{
+NTSTATUS AddAudioDevice(
+  _In_ PDRIVER_OBJECT driverObject,
+  _In_ PDEVICE_OBJECT physicalDeviceObject)
+{
+  constexpr ULONG kSubdeviceCount = 4;
+  return PcAddAdapterDevice(driverObject, physicalDeviceObject,
+    StartAudioDevice, kSubdeviceCount, 0);
+}
+}
+
+extern "C" NTSTATUS DriverEntry(
+  _In_ PDRIVER_OBJECT driverObject,
+  _In_ PUNICODE_STRING registryPath)
+{
+  return PcInitializeAdapterDriver(driverObject, registryPath,
+    AddAudioDevice);
+}
+
+#pragma warning(push)
+#pragma warning(disable: 4996)
+void * __cdecl operator new(
+  size_t size,
+  POOL_TYPE poolType,
+  ULONG tag)
+{
+  void *memory = ExAllocatePoolWithTag(poolType, size, tag);
+  if (memory)
+    RtlZeroMemory(memory, size);
+  return memory;
+}
+
+void * __cdecl operator new(
+  size_t size,
+  POOL_FLAGS poolFlags,
+  ULONG tag)
+{
+  const POOL_TYPE poolType = (poolFlags & POOL_FLAG_PAGED) ?
+    PagedPool : NonPagedPoolNx;
+  return operator new(size, poolType, tag);
+}
+#pragma warning(pop)
+
+void __cdecl operator delete(void *memory) noexcept
+{
+  if (memory)
+    ExFreePool(memory);
+}
+
+void __cdecl operator delete(void *memory, size_t size) noexcept
+{
+  UNREFERENCED_PARAMETER(size);
+  operator delete(memory);
+}
+
+void __cdecl operator delete(
+  void *memory,
+  POOL_TYPE poolType,
+  ULONG tag) noexcept
+{
+  UNREFERENCED_PARAMETER(poolType);
+  UNREFERENCED_PARAMETER(tag);
+  operator delete(memory);
+}
+void __cdecl operator delete(
+  void *memory,
+  POOL_FLAGS poolFlags,
+  ULONG tag) noexcept
+{
+  UNREFERENCED_PARAMETER(poolFlags);
+  UNREFERENCED_PARAMETER(tag);
+  operator delete(memory);
+}