1 files changed, 434 insertions, 0 deletions

diff --git a/SDL-3.2.8/src/core/windows/SDL_immdevice.c b/SDL-3.2.8/src/core/windows/SDL_immdevice.c
new file mode 100644
index 0000000..802a412
--- /dev/null
+++ b/SDL-3.2.8/src/core/windows/SDL_immdevice.c
@@ -0,0 +1,434 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "SDL_internal.h"
+
+#if defined(SDL_PLATFORM_WINDOWS) && defined(HAVE_MMDEVICEAPI_H)
+
+#include "SDL_windows.h"
+#include "SDL_immdevice.h"
+#include "../../audio/SDL_sysaudio.h"
+#include <objbase.h> // For CLSIDFromString
+
+typedef struct SDL_IMMDevice_HandleData
+{
+    LPWSTR immdevice_id;
+    GUID directsound_guid;
+} SDL_IMMDevice_HandleData;
+
+static const ERole SDL_IMMDevice_role = eConsole; // !!! FIXME: should this be eMultimedia? Should be a hint?
+
+// This is global to the WASAPI target, to handle hotplug and default device lookup.
+static IMMDeviceEnumerator *enumerator = NULL;
+static SDL_IMMDevice_callbacks immcallbacks;
+
+// PropVariantInit() is an inline function/macro in PropIdl.h that calls the C runtime's memset() directly. Use ours instead, to avoid dependency.
+#ifdef PropVariantInit
+#undef PropVariantInit
+#endif
+#define PropVariantInit(p) SDL_zerop(p)
+
+// Some GUIDs we need to know without linking to libraries that aren't available before Vista.
+/* *INDENT-OFF* */ // clang-format off
+static const CLSID SDL_CLSID_MMDeviceEnumerator = { 0xbcde0395, 0xe52f, 0x467c,{ 0x8e, 0x3d, 0xc4, 0x57, 0x92, 0x91, 0x69, 0x2e } };
+static const IID SDL_IID_IMMDeviceEnumerator = { 0xa95664d2, 0x9614, 0x4f35,{ 0xa7, 0x46, 0xde, 0x8d, 0xb6, 0x36, 0x17, 0xe6 } };
+static const IID SDL_IID_IMMNotificationClient = { 0x7991eec9, 0x7e89, 0x4d85,{ 0x83, 0x90, 0x6c, 0x70, 0x3c, 0xec, 0x60, 0xc0 } };
+static const IID SDL_IID_IMMEndpoint = { 0x1be09788, 0x6894, 0x4089,{ 0x85, 0x86, 0x9a, 0x2a, 0x6c, 0x26, 0x5a, 0xc5 } };
+static const PROPERTYKEY SDL_PKEY_Device_FriendlyName = { { 0xa45c254e, 0xdf1c, 0x4efd,{ 0x80, 0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0, } }, 14 };
+static const PROPERTYKEY SDL_PKEY_AudioEngine_DeviceFormat = { { 0xf19f064d, 0x82c, 0x4e27,{ 0xbc, 0x73, 0x68, 0x82, 0xa1, 0xbb, 0x8e, 0x4c, } }, 0 };
+static const PROPERTYKEY SDL_PKEY_AudioEndpoint_GUID = { { 0x1da5d803, 0xd492, 0x4edd,{ 0x8c, 0x23, 0xe0, 0xc0, 0xff, 0xee, 0x7f, 0x0e, } }, 4 };
+/* *INDENT-ON* */ // clang-format on
+
+static bool FindByDevIDCallback(SDL_AudioDevice *device, void *userdata)
+{
+    LPCWSTR devid = (LPCWSTR)userdata;
+    if (devid && device && device->handle) {
+        const SDL_IMMDevice_HandleData *handle = (const SDL_IMMDevice_HandleData *)device->handle;
+        if (handle->immdevice_id && SDL_wcscmp(handle->immdevice_id, devid) == 0) {
+            return true;
+        }
+    }
+    return false;
+}
+
+static SDL_AudioDevice *SDL_IMMDevice_FindByDevID(LPCWSTR devid)
+{
+    return SDL_FindPhysicalAudioDeviceByCallback(FindByDevIDCallback, (void *) devid);
+}
+
+LPGUID SDL_IMMDevice_GetDirectSoundGUID(SDL_AudioDevice *device)
+{
+    return (device && device->handle) ? &(((SDL_IMMDevice_HandleData *) device->handle)->directsound_guid) : NULL;
+}
+
+LPCWSTR SDL_IMMDevice_GetDevID(SDL_AudioDevice *device)
+{
+    return (device && device->handle) ? ((const SDL_IMMDevice_HandleData *) device->handle)->immdevice_id : NULL;
+}
+
+static void GetMMDeviceInfo(IMMDevice *device, char **utf8dev, WAVEFORMATEXTENSIBLE *fmt, GUID *guid)
+{
+    /* PKEY_Device_FriendlyName gives you "Speakers (SoundBlaster Pro)" which drives me nuts. I'd rather it be
+       "SoundBlaster Pro (Speakers)" but I guess that's developers vs users. Windows uses the FriendlyName in
+       its own UIs, like Volume Control, etc. */
+    IPropertyStore *props = NULL;
+    *utf8dev = NULL;
+    SDL_zerop(fmt);
+    if (SUCCEEDED(IMMDevice_OpenPropertyStore(device, STGM_READ, &props))) {
+        PROPVARIANT var;
+        PropVariantInit(&var);
+        if (SUCCEEDED(IPropertyStore_GetValue(props, &SDL_PKEY_Device_FriendlyName, &var))) {
+            *utf8dev = WIN_StringToUTF8W(var.pwszVal);
+        }
+        PropVariantClear(&var);
+        if (SUCCEEDED(IPropertyStore_GetValue(props, &SDL_PKEY_AudioEngine_DeviceFormat, &var))) {
+            SDL_memcpy(fmt, var.blob.pBlobData, SDL_min(var.blob.cbSize, sizeof(WAVEFORMATEXTENSIBLE)));
+        }
+        PropVariantClear(&var);
+        if (SUCCEEDED(IPropertyStore_GetValue(props, &SDL_PKEY_AudioEndpoint_GUID, &var))) {
+            (void)CLSIDFromString(var.pwszVal, guid);
+        }
+        PropVariantClear(&var);
+        IPropertyStore_Release(props);
+    }
+}
+
+void SDL_IMMDevice_FreeDeviceHandle(SDL_AudioDevice *device)
+{
+    if (device && device->handle) {
+        SDL_IMMDevice_HandleData *handle = (SDL_IMMDevice_HandleData *) device->handle;
+        SDL_free(handle->immdevice_id);
+        SDL_free(handle);
+        device->handle = NULL;
+    }
+}
+
+static SDL_AudioDevice *SDL_IMMDevice_Add(const bool recording, const char *devname, WAVEFORMATEXTENSIBLE *fmt, LPCWSTR devid, GUID *dsoundguid)
+{
+    /* You can have multiple endpoints on a device that are mutually exclusive ("Speakers" vs "Line Out" or whatever).
+       In a perfect world, things that are unplugged won't be in this collection. The only gotcha is probably for
+       phones and tablets, where you might have an internal speaker and a headphone jack and expect both to be
+       available and switch automatically. (!!! FIXME...?) */
+
+    if (!devname) {
+        return NULL;
+    }
+
+    // see if we already have this one first.
+    SDL_AudioDevice *device = SDL_IMMDevice_FindByDevID(devid);
+    if (device) {
+        if (SDL_GetAtomicInt(&device->zombie)) {
+            // whoa, it came back! This can happen if you unplug and replug USB headphones while we're still keeping the SDL object alive.
+            // Kill this device's IMMDevice id; the device will go away when the app closes it, or maybe a new default device is chosen
+            // (possibly this reconnected device), so we just want to make sure IMMDevice doesn't try to find the old device by the existing ID string.
+            SDL_IMMDevice_HandleData *handle = (SDL_IMMDevice_HandleData *) device->handle;
+            SDL_free(handle->immdevice_id);
+            handle->immdevice_id = NULL;
+            device = NULL;  // add a new device, below.
+        }
+    }
+
+    if (!device) {
+        // handle is freed by SDL_IMMDevice_FreeDeviceHandle!
+        SDL_IMMDevice_HandleData *handle = (SDL_IMMDevice_HandleData *)SDL_malloc(sizeof(SDL_IMMDevice_HandleData));
+        if (!handle) {
+            return NULL;
+        }
+        handle->immdevice_id = SDL_wcsdup(devid);
+        if (!handle->immdevice_id) {
+            SDL_free(handle);
+            return NULL;
+        }
+        SDL_memcpy(&handle->directsound_guid, dsoundguid, sizeof(GUID));
+
+        SDL_AudioSpec spec;
+        SDL_zero(spec);
+        spec.channels = (Uint8)fmt->Format.nChannels;
+        spec.freq = fmt->Format.nSamplesPerSec;
+        spec.format = SDL_WaveFormatExToSDLFormat((WAVEFORMATEX *)fmt);
+
+        device = SDL_AddAudioDevice(recording, devname, &spec, handle);
+        if (!device) {
+            SDL_free(handle->immdevice_id);
+            SDL_free(handle);
+        }
+    }
+
+    return device;
+}
+
+/* We need a COM subclass of IMMNotificationClient for hotplug support, which is
+   easy in C++, but we have to tapdance more to make work in C.
+   Thanks to this page for coaching on how to make this work:
+     https://www.codeproject.com/Articles/13601/COM-in-plain-C */
+
+typedef struct SDLMMNotificationClient
+{
+    const IMMNotificationClientVtbl *lpVtbl;
+    SDL_AtomicInt refcount;
+} SDLMMNotificationClient;
+
+static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_QueryInterface(IMMNotificationClient *client, REFIID iid, void **ppv)
+{
+    if ((WIN_IsEqualIID(iid, &IID_IUnknown)) || (WIN_IsEqualIID(iid, &SDL_IID_IMMNotificationClient))) {
+        *ppv = client;
+        client->lpVtbl->AddRef(client);
+        return S_OK;
+    }
+
+    *ppv = NULL;
+    return E_NOINTERFACE;
+}
+
+static ULONG STDMETHODCALLTYPE SDLMMNotificationClient_AddRef(IMMNotificationClient *iclient)
+{
+    SDLMMNotificationClient *client = (SDLMMNotificationClient *)iclient;
+    return (ULONG)(SDL_AtomicIncRef(&client->refcount) + 1);
+}
+
+static ULONG STDMETHODCALLTYPE SDLMMNotificationClient_Release(IMMNotificationClient *iclient)
+{
+    // client is a static object; we don't ever free it.
+    SDLMMNotificationClient *client = (SDLMMNotificationClient *)iclient;
+    const ULONG rc = SDL_AtomicDecRef(&client->refcount);
+    if (rc == 0) {
+        SDL_SetAtomicInt(&client->refcount, 0); // uhh...
+        return 0;
+    }
+    return rc - 1;
+}
+
+// These are the entry points called when WASAPI device endpoints change.
+static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnDefaultDeviceChanged(IMMNotificationClient *iclient, EDataFlow flow, ERole role, LPCWSTR pwstrDeviceId)
+{
+    if (role == SDL_IMMDevice_role) {
+        immcallbacks.default_audio_device_changed(SDL_IMMDevice_FindByDevID(pwstrDeviceId));
+    }
+    return S_OK;
+}
+
+static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnDeviceAdded(IMMNotificationClient *iclient, LPCWSTR pwstrDeviceId)
+{
+    /* we ignore this; devices added here then progress to ACTIVE, if appropriate, in
+       OnDeviceStateChange, making that a better place to deal with device adds. More
+       importantly: the first time you plug in a USB audio device, this callback will
+       fire, but when you unplug it, it isn't removed (it's state changes to NOTPRESENT).
+       Plugging it back in won't fire this callback again. */
+    return S_OK;
+}
+
+static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnDeviceRemoved(IMMNotificationClient *iclient, LPCWSTR pwstrDeviceId)
+{
+    return S_OK;  // See notes in OnDeviceAdded handler about why we ignore this.
+}
+
+static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnDeviceStateChanged(IMMNotificationClient *iclient, LPCWSTR pwstrDeviceId, DWORD dwNewState)
+{
+    IMMDevice *device = NULL;
+
+    if (SUCCEEDED(IMMDeviceEnumerator_GetDevice(enumerator, pwstrDeviceId, &device))) {
+        IMMEndpoint *endpoint = NULL;
+        if (SUCCEEDED(IMMDevice_QueryInterface(device, &SDL_IID_IMMEndpoint, (void **)&endpoint))) {
+            EDataFlow flow;
+            if (SUCCEEDED(IMMEndpoint_GetDataFlow(endpoint, &flow))) {
+                const bool recording = (flow == eCapture);
+                if (dwNewState == DEVICE_STATE_ACTIVE) {
+                    char *utf8dev;
+                    WAVEFORMATEXTENSIBLE fmt;
+                    GUID dsoundguid;
+                    GetMMDeviceInfo(device, &utf8dev, &fmt, &dsoundguid);
+                    if (utf8dev) {
+                        SDL_IMMDevice_Add(recording, utf8dev, &fmt, pwstrDeviceId, &dsoundguid);
+                        SDL_free(utf8dev);
+                    }
+                } else {
+                    immcallbacks.audio_device_disconnected(SDL_IMMDevice_FindByDevID(pwstrDeviceId));
+                }
+            }
+            IMMEndpoint_Release(endpoint);
+        }
+        IMMDevice_Release(device);
+    }
+
+    return S_OK;
+}
+
+static HRESULT STDMETHODCALLTYPE SDLMMNotificationClient_OnPropertyValueChanged(IMMNotificationClient *client, LPCWSTR pwstrDeviceId, const PROPERTYKEY key)
+{
+    return S_OK; // we don't care about these.
+}
+
+static const IMMNotificationClientVtbl notification_client_vtbl = {
+    SDLMMNotificationClient_QueryInterface,
+    SDLMMNotificationClient_AddRef,
+    SDLMMNotificationClient_Release,
+    SDLMMNotificationClient_OnDeviceStateChanged,
+    SDLMMNotificationClient_OnDeviceAdded,
+    SDLMMNotificationClient_OnDeviceRemoved,
+    SDLMMNotificationClient_OnDefaultDeviceChanged,
+    SDLMMNotificationClient_OnPropertyValueChanged
+};
+
+static SDLMMNotificationClient notification_client = { &notification_client_vtbl, { 1 } };
+
+bool SDL_IMMDevice_Init(const SDL_IMMDevice_callbacks *callbacks)
+{
+    HRESULT ret;
+
+    // just skip the discussion with COM here.
+    if (!WIN_IsWindowsVistaOrGreater()) {
+        return SDL_SetError("IMMDevice support requires Windows Vista or later");
+    }
+
+    if (FAILED(WIN_CoInitialize())) {
+        return SDL_SetError("IMMDevice: CoInitialize() failed");
+    }
+
+    ret = CoCreateInstance(&SDL_CLSID_MMDeviceEnumerator, NULL, CLSCTX_INPROC_SERVER, &SDL_IID_IMMDeviceEnumerator, (LPVOID *)&enumerator);
+    if (FAILED(ret)) {
+        WIN_CoUninitialize();
+        return WIN_SetErrorFromHRESULT("IMMDevice CoCreateInstance(MMDeviceEnumerator)", ret);
+    }
+
+    if (callbacks) {
+        SDL_copyp(&immcallbacks, callbacks);
+    } else {
+        SDL_zero(immcallbacks);
+    }
+
+    if (!immcallbacks.audio_device_disconnected) {
+        immcallbacks.audio_device_disconnected = SDL_AudioDeviceDisconnected;
+    }
+    if (!immcallbacks.default_audio_device_changed) {
+        immcallbacks.default_audio_device_changed = SDL_DefaultAudioDeviceChanged;
+    }
+
+    return true;
+}
+
+void SDL_IMMDevice_Quit(void)
+{
+    if (enumerator) {
+        IMMDeviceEnumerator_UnregisterEndpointNotificationCallback(enumerator, (IMMNotificationClient *)&notification_client);
+        IMMDeviceEnumerator_Release(enumerator);
+        enumerator = NULL;
+    }
+
+    SDL_zero(immcallbacks);
+
+    WIN_CoUninitialize();
+}
+
+bool SDL_IMMDevice_Get(SDL_AudioDevice *device, IMMDevice **immdevice, bool recording)
+{
+    const Uint64 timeout = SDL_GetTicks() + 8000;  // intel's audio drivers can fail for up to EIGHT SECONDS after a device is connected or we wake from sleep.
+
+    SDL_assert(device != NULL);
+    SDL_assert(immdevice != NULL);
+
+    LPCWSTR devid = SDL_IMMDevice_GetDevID(device);
+    SDL_assert(devid != NULL);
+
+    HRESULT ret;
+    while ((ret = IMMDeviceEnumerator_GetDevice(enumerator, devid, immdevice)) == E_NOTFOUND) {
+        const Uint64 now = SDL_GetTicks();
+        if (timeout > now) {
+            const Uint64 ticksleft = timeout - now;
+            SDL_Delay((Uint32)SDL_min(ticksleft, 300));   // wait awhile and try again.
+            continue;
+        }
+        break;
+    }
+
+    if (!SUCCEEDED(ret)) {
+        return WIN_SetErrorFromHRESULT("WASAPI can't find requested audio endpoint", ret);
+    }
+    return true;
+}
+
+static void EnumerateEndpointsForFlow(const bool recording, SDL_AudioDevice **default_device)
+{
+    /* Note that WASAPI separates "adapter devices" from "audio endpoint devices"
+       ...one adapter device ("SoundBlaster Pro") might have multiple endpoint devices ("Speakers", "Line-Out"). */
+
+    IMMDeviceCollection *collection = NULL;
+    if (FAILED(IMMDeviceEnumerator_EnumAudioEndpoints(enumerator, recording ? eCapture : eRender, DEVICE_STATE_ACTIVE, &collection))) {
+        return;
+    }
+
+    UINT total = 0;
+    if (FAILED(IMMDeviceCollection_GetCount(collection, &total))) {
+        IMMDeviceCollection_Release(collection);
+        return;
+    }
+
+    LPWSTR default_devid = NULL;
+    if (default_device) {
+        IMMDevice *default_immdevice = NULL;
+        const EDataFlow dataflow = recording ? eCapture : eRender;
+        if (SUCCEEDED(IMMDeviceEnumerator_GetDefaultAudioEndpoint(enumerator, dataflow, SDL_IMMDevice_role, &default_immdevice))) {
+            LPWSTR devid = NULL;
+            if (SUCCEEDED(IMMDevice_GetId(default_immdevice, &devid))) {
+                default_devid = SDL_wcsdup(devid);  // if this fails, oh well.
+                CoTaskMemFree(devid);
+            }
+            IMMDevice_Release(default_immdevice);
+        }
+    }
+
+    for (UINT i = 0; i < total; i++) {
+        IMMDevice *immdevice = NULL;
+        if (SUCCEEDED(IMMDeviceCollection_Item(collection, i, &immdevice))) {
+            LPWSTR devid = NULL;
+            if (SUCCEEDED(IMMDevice_GetId(immdevice, &devid))) {
+                char *devname = NULL;
+                WAVEFORMATEXTENSIBLE fmt;
+                GUID dsoundguid;
+                SDL_zero(fmt);
+                SDL_zero(dsoundguid);
+                GetMMDeviceInfo(immdevice, &devname, &fmt, &dsoundguid);
+                if (devname) {
+                    SDL_AudioDevice *sdldevice = SDL_IMMDevice_Add(recording, devname, &fmt, devid, &dsoundguid);
+                    if (default_device && default_devid && SDL_wcscmp(default_devid, devid) == 0) {
+                        *default_device = sdldevice;
+                    }
+                    SDL_free(devname);
+                }
+                CoTaskMemFree(devid);
+            }
+            IMMDevice_Release(immdevice);
+        }
+    }
+
+    SDL_free(default_devid);
+
+    IMMDeviceCollection_Release(collection);
+}
+
+void SDL_IMMDevice_EnumerateEndpoints(SDL_AudioDevice **default_playback, SDL_AudioDevice **default_recording)
+{
+    EnumerateEndpointsForFlow(false, default_playback);
+    EnumerateEndpointsForFlow(true, default_recording);
+
+    // if this fails, we just won't get hotplug events. Carry on anyhow.
+    IMMDeviceEnumerator_RegisterEndpointNotificationCallback(enumerator, (IMMNotificationClient *)&notification_client);
+}
+
+#endif // defined(SDL_PLATFORM_WINDOWS) && defined(HAVE_MMDEVICEAPI_H)