From f33993dcb5f1406ceaaa8527d0cb59bda297de5c Mon Sep 17 00:00:00 2001
From: Braden Obrzut <admin@maniacsvault.net>
Date: Tue, 9 Feb 2016 22:32:01 -0500
Subject: [PATCH] - Load OpenAL at runtime for all platforms because I can't
 think of a good reason not to handle them all the same right now.

---
 src/CMakeLists.txt     | 14 ++------------
 src/sound/oalload.h    |  6 +++++-
 src/sound/oalsound.cpp | 21 ++++++++++++++++-----
 3 files changed, 23 insertions(+), 18 deletions(-)

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 5d20ddf7c..a8e43bcf3 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -217,20 +217,10 @@ endif()
 if( NOT NO_OPENAL )
     find_package( OpenAL )
 	mark_as_advanced(CLEAR OPENAL_INCLUDE_DIR)
-	if( NOT WIN32 )
-		mark_as_advanced(CLEAR OPENAL_LIBRARY)
-	endif()
-    if( OPENAL_FOUND )
+    if( OPENAL_INCLUDE_DIR )
         include_directories( ${OPENAL_INCLUDE_DIR} )
-		if( NOT WIN32 )
-			set( ZDOOM_LIBS ${OPENAL_LIBRARY} ${ZDOOM_LIBS} )
-		endif()
     else()
-		if ( NOT WIN32 )
-			set( NO_OPENAL ON )
-		else()
-			include_directories( ${OPENAL_INCLUDE_DIR} )
-		endif()
+		set( NO_OPENAL ON )
     endif()
 endif()
 
diff --git a/src/sound/oalload.h b/src/sound/oalload.h
index 7d4e62287..986131b2c 100644
--- a/src/sound/oalload.h
+++ b/src/sound/oalload.h
@@ -1,7 +1,11 @@
 #ifndef OALDEF_H
 #define OALDEF_H
 
-#if defined _WIN32 && !defined NO_OPENAL
+#ifndef NO_OPENAL
+
+#ifndef _WIN32
+typedef void* FARPROC;
+#endif
 
 #define DEFINE_ENTRY(type, name) static type p_##name;
 #include "oaldef.h"
diff --git a/src/sound/oalsound.cpp b/src/sound/oalsound.cpp
index a5ec97f97..6030c9142 100644
--- a/src/sound/oalsound.cpp
+++ b/src/sound/oalsound.cpp
@@ -36,6 +36,8 @@
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
 #define USE_WINDOWS_DWORD
+#else
+#include <dlfcn.h>
 #endif
 
 #include "except.h"
@@ -61,14 +63,23 @@ CVAR (Bool, snd_efx, true, CVAR_ARCHIVE|CVAR_GLOBALCONFIG)
 
 #ifdef _WIN32
 static HMODULE hmodOpenAL;
+#define OPENALLIB "openal32.dll"
+#else
+static void* hmodOpenAL;
+#ifdef __APPLE__
+#define OPENALLIB "OpenAL.framework/OpenAL"
+#else
+#define OPENALLIB "libopenal.so"
+#endif
+#define LoadLibrary(x) dlopen((x), RTLD_LAZY)
+#define GetProcAddress(a,b) dlsym((a),(b))
+#define FreeLibrary(x) dlclose((x))
 #endif
 
 bool IsOpenALPresent()
 {
 #ifdef NO_OPENAL
 	return false;
-#elif !defined _WIN32
-	return true;
 #else
 	static bool cached_result = false;
 	static bool done = false;
@@ -78,10 +89,10 @@ bool IsOpenALPresent()
 		done = true;
 		if (hmodOpenAL == NULL)
 		{
-			hmodOpenAL = LoadLibrary(NicePath("$PROGDIR/openal32.dll"));
+			hmodOpenAL = LoadLibrary(NicePath("$PROGDIR/" OPENALLIB));
 			if (hmodOpenAL == NULL)
 			{
-				hmodOpenAL = LoadLibrary("openal32.dll");
+				hmodOpenAL = LoadLibrary(OPENALLIB);
 				if (hmodOpenAL == NULL)
 				{
 					return false;
@@ -90,7 +101,7 @@ bool IsOpenALPresent()
 			for(int i = 0; oalfuncs[i].name != NULL; i++)
 			{
 				*oalfuncs[i].funcaddr = GetProcAddress(hmodOpenAL, oalfuncs[i].name);
-				if (oalfuncs[i].funcaddr == NULL)
+				if (*oalfuncs[i].funcaddr == NULL)
 				{
 					FreeLibrary(hmodOpenAL);
 					hmodOpenAL = NULL;