VSTPlugin-Linux.cpp: Add Support for various other types of plugins

See Github Issue obsproject#11 about plugins where OBS doesn't show an interface. Fixed.

Also added some pathing code... but have no idea if it works. Sorry.

linux/VSTPlugin-linux.cpp

@@ -23,20 +23,49 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 AEffect* VSTPlugin::loadEffect() {
 	AEffect *plugin = nullptr;
 
-	wchar_t *wpath;
-	os_utf8_to_wcs_ptr(pluginPath.c_str(), 0, &wpath);
-	soHandle = LoadLibraryW(wpath);
+	// Why is this a (non-portable) wide char?
+	wchar_t *wpath = NULL;
+
+	// We need to convert the above wide char to a 'normal' char
+	// 4096 elements should be enough to contain it... I hope.
+	// We also initialize the array with NULLs to prevent issues
+	// down the road.
+	char charPath[4096] = {NULL};
+	uint32_t wcs_returnValue;
+	//os_utf8_to_wcs_ptr(pluginPath.c_str(), 0, &wpath);
+	wcs_returnValue = wcstombs(charPath, wpath, sizeof(charPath));
+
+	// Now check for errors in the conversion before trying to open
+	// the file/path.
+	if (wcs_returnValue < 4) {
+		wprintf(L"Path conversion error from '%s'", wpath);
+		printf(", to '%s'\n", charPath);
+		return nullptr;
+	}
+
+	soHandle = os_dlopen(charPath);
 	bfree(wpath);
+	bfree(charPath);
 	if(soHandle == nullptr) {
 		printf("Failed trying to load VST from '%s', error %d\n",
-			pluginPath, GetLastError());
+		       pluginPath.c_str(), errno);
 		return nullptr;
 	}
 
 	vstPluginMain mainEntryPoint =
-		(vstPluginMain)GetProcAddress(soHandle, "VSTPluginMain");
+			(vstPluginMain)(soHandle, "VSTPluginMain");
+
+	if (mainEntryPoint == nullptr) {
+		mainEntryPoint =
+				(vstPluginMain)os_dlsym(soHandle, "VstPluginMain()");
+	}
+
+	if (mainEntryPoint == nullptr) {
+		mainEntryPoint = (vstPluginMain)os_dlsym(soHandle, "main");
+	}
 
-	if (!mainEntryPoint) {
+	if (mainEntryPoint == nullptr) {
+		printf("Couldn't get a pointer to plugin's main()");
 		return nullptr;
 	}