From 8ee47d557356bbd358c2197a1a6a535b32c89820 Mon Sep 17 00:00:00 2001
From: Chris Robinson <chris.kcat@gmail.com>
Date: Tue, 10 Mar 2009 02:46:42 -0700
Subject: [PATCH] Dynamically load dsound when possible

---
 Alc/dsound.c   | 38 ++++++++++++++++++++++++++++++++++++--
 CMakeLists.txt | 21 +++++++++++----------
 2 files changed, 47 insertions(+), 12 deletions(-)

diff --git a/Alc/dsound.c b/Alc/dsound.c
index 899a0936..6ce4c66e 100644
--- a/Alc/dsound.c
+++ b/Alc/dsound.c
@@ -39,6 +39,10 @@
 
 DEFINE_GUID(KSDATAFORMAT_SUBTYPE_PCM, 0x00000001, 0x0000, 0x0010, 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71);
 
+static void *ds_handle;
+static HRESULT (WINAPI *pDirectSoundCreate)(LPCGUID pcGuidDevice, LPDIRECTSOUND *ppDS, LPUNKNOWN pUnkOuter);
+static HRESULT (WINAPI *pDirectSoundEnumerateA)(LPDSENUMCALLBACKA pDSEnumCallback, LPVOID pContext);
+
 // Since DSound doesn't report the fragment size, emulate it
 static int num_frags;
 
@@ -136,6 +140,9 @@ static ALCboolean DSoundOpenPlayback(ALCdevice *device, const ALCchar *deviceNam
     DWORD speakers;
     HRESULT hr;
 
+    if(ds_handle == NULL)
+        return ALC_FALSE;
+
     if(deviceName)
     {
         int i;
@@ -167,7 +174,7 @@ static ALCboolean DSoundOpenPlayback(ALCdevice *device, const ALCchar *deviceNam
     }
 
     //DirectSound Init code
-    hr = DirectSoundCreate(guid, &pData->lpDS, NULL);
+    hr = pDirectSoundCreate(guid, &pData->lpDS, NULL);
     if(SUCCEEDED(hr))
         hr = IDirectSound_SetCooperativeLevel(pData->lpDS, GetForegroundWindow(), DSSCL_PRIORITY);
 
@@ -411,10 +418,37 @@ void alcDSoundInit(BackendFuncs *FuncList)
 
     *FuncList = DSoundFuncs;
 
+#ifdef _WIN32
+    ds_handle = LoadLibraryA("dsound.dll");
+    if(ds_handle == NULL)
+    {
+        AL_PRINT("Failed to load dsound.dll\n");
+        return;
+    }
+
+#define LOAD_FUNC(f) do { \
+    p##f = (void*)GetProcAddress((HMODULE)ds_handle, #f); \
+    if(p##f == NULL) \
+    { \
+        FreeLibrary(ds_handle); \
+        ds_handle = NULL; \
+        AL_PRINT("Could not load %s from dsound.dll\n", #f); \
+        return; \
+    } \
+} while(0)
+#else
+    ds_handle = (void*)0xDEADBEEF;
+#define LOAD_FUNC(f) p##f = f
+#endif
+
+LOAD_FUNC(DirectSoundCreate);
+LOAD_FUNC(DirectSoundEnumerateA);
+#undef LOAD_FUNC
+
     num_frags = GetConfigValueInt("dsound", "periods", 4);
     if(num_frags < 2) num_frags = 2;
 
-    hr = DirectSoundEnumerate(DSoundEnumDevices, &iter);
+    hr = pDirectSoundEnumerateA(DSoundEnumDevices, &iter);
     if(FAILED(hr))
         AL_PRINT("Error enumerating DirectSound devices (%#x)!\n", (unsigned int)hr);
 }
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 784713d2..f74dcd20 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -289,16 +289,17 @@ ENDIF()
 IF(DSOUND)
     CHECK_INCLUDE_FILE(dsound.h HAVE_DSOUND_H)
     IF(HAVE_DSOUND_H)
-        SET(HAVE_DSOUND 1)
-        SET(ALC_OBJS  ${ALC_OBJS} Alc/dsound.c)
-        SET(BACKENDS  "${BACKENDS} DirectSound,")
-
-        SET(CMAKE_REQUIRED_LIBRARIES dsound)
-        CHECK_C_SOURCE_COMPILES("int main() {return 0;}" HAVE_LIBDSOUND)
-        SET(CMAKE_REQUIRED_LIBRARIES "")
-#        CHECK_LIBRARY_EXISTS(dsound DirectSoundCreate "" HAVE_LIBDSOUND)
-        IF(HAVE_LIBDSOUND)
-            SET(EXTRA_LIBS dsound ${EXTRA_LIBS})
+        CHECK_LIBRARY_EXISTS(dsound DirectSoundCreate "" HAVE_LIBDSOUND)
+        IF(HAVE_LIBDSOUND OR WIN32)
+            SET(HAVE_DSOUND 1)
+            SET(ALC_OBJS  ${ALC_OBJS} Alc/dsound.c)
+
+            IF(WIN32)
+                SET(BACKENDS  "${BACKENDS} DirectSound,")
+            ELSE()
+                SET(BACKENDS  "${BACKENDS} DirectSound \(linked\),")
+                SET(EXTRA_LIBS dsound ${EXTRA_LIBS})
+            ENDIF()
         ENDIF()
     ENDIF()
 ENDIF()
-- 
2.11.4.GIT