From 6eeac735f2425ce4dffaee747b7e8823a793e464 Mon Sep 17 00:00:00 2001
From: Brecht Van Lommel <brechtvanlommel@gmail.com>
Date: Wed, 13 Mar 2019 13:00:03 +0100
Subject: [PATCH] Build environment: require Alsa/OSS/PulseAudio backends for
 OpenAL on Linux.

Otherwise we can silently build an OpenAL that can't actually playback audio.
---
 .../build_environment/cmake/openal.cmake      | 31 +++++++++++++------
 1 file changed, 22 insertions(+), 9 deletions(-)

diff --git a/build_files/build_environment/cmake/openal.cmake b/build_files/build_environment/cmake/openal.cmake
index 3cd3a0aac72..7a693b1fce2 100644
--- a/build_files/build_environment/cmake/openal.cmake
+++ b/build_files/build_environment/cmake/openal.cmake
@@ -18,18 +18,31 @@
 
 if(BUILD_MODE STREQUAL Release)
 	set(OPENAL_EXTRA_ARGS
-		-DALSOFT_UTILS=Off
-		-DALSOFT_NO_CONFIG_UTIL=On
-		-DALSOFT_EXAMPLES=Off
-		-DALSOFT_TESTS=Off
-		-DALSOFT_CONFIG=Off
-		-DALSOFT_HRTF_DEFS=Off
-		-DALSOFT_INSTALL=On
-		-DALSOFT_BACKEND_SNDIO=Off
+		-DALSOFT_UTILS=OFF
+		-DALSOFT_NO_CONFIG_UTIL=ON
+		-DALSOFT_EXAMPLES=OFF
+		-DALSOFT_TESTS=OFF
+		-DALSOFT_CONFIG=OFF
+		-DALSOFT_HRTF_DEFS=OFF
+		-DALSOFT_INSTALL=ON
+		-DALSOFT_BACKEND_SNDIO=OFF
 	)
 
 	if(UNIX)
-		set(OPENAL_EXTRA_ARGS ${OPENAL_EXTRA_ARGS} -DLIBTYPE=STATIC)
+		set(OPENAL_EXTRA_ARGS
+			${OPENAL_EXTRA_ARGS}
+			-DLIBTYPE=STATIC
+		)
+	endif()
+
+	if(UNIX AND NOT APPLE)
+		# Ensure we have backends for playback.
+		set(OPENAL_EXTRA_ARGS
+			${OPENAL_EXTRA_ARGS}
+			-DALSOFT_REQUIRE_ALSA=ON
+			-DALSOFT_REQUIRE_OSS=ON
+			-DALSOFT_REQUIRE_PULSEAUDIO=ON
+		)
 	endif()
 
 	ExternalProject_Add(external_openal