Added an SDL2 OpenBSD sndio(7) audio target.

--HG--
extra : rebase_source : 5ad387265cff73c1635ca4f2c3635848ba722614

configure.in

@@ -910,6 +910,52 @@ AC_HELP_STRING([--enable-nas-shared], [dynamically load NAS audio support [[defa
     fi
 }
 
+dnl See if the sndio audio interface is supported
+CheckSNDIO()
+{
+    AC_ARG_ENABLE(sndio,
+AC_HELP_STRING([--enable-sndio], [support the sndio audio API [[default=yes]]]),
+                  , enable_sndio=yes)
+    if test x$enable_audio = xyes -a x$enable_sndio = xyes; then
+        AC_CHECK_HEADER(sndio.h, have_sndio_hdr=yes)
+        AC_CHECK_LIB(sndio, sio_open, have_sndio_lib=yes)
+
+        AC_MSG_CHECKING(for sndio audio support)
+        have_sndio=no
+
+        if test x$have_sndio_hdr = xyes -a x$have_sndio_lib = xyes; then
+            have_sndio=yes
+            SNDIO_LIBS="-lsndio"
+        fi
+
+        AC_MSG_RESULT($have_sndio)
+
+        if test x$have_sndio = xyes; then
+            AC_ARG_ENABLE(sndio-shared,
+AC_HELP_STRING([--enable-sndio-shared], [dynamically load sndio audio support [[default=yes]]]),
+                          , enable_sndio_shared=yes)
+            sndio_lib=[`find_lib "libsndio.so.*" "$SNDIO_LIBS" | sed 's/.*\/\(.*\)/\1/; q'`]
+
+            if test x$have_loadso != xyes && \
+               test x$enable_sndio_shared = xyes; then
+                AC_MSG_WARN([You must have SDL_LoadObject() support for dynamic sndio loading])
+            fi
+            if test x$have_loadso = xyes && \
+               test x$enable_sndio_shared = xyes && test x$sndio_lib != x; then
+                echo "-- dynamic libsndio -> $sndio_lib"
+                AC_DEFINE_UNQUOTED(SDL_AUDIO_DRIVER_SNDIO_DYNAMIC, "$sndio_lib", [ ])
+            else
+                EXTRA_LDFLAGS="$EXTRA_LDFLAGS $SNDIO_LIBS"
+            fi
+
+            AC_DEFINE(SDL_AUDIO_DRIVER_SNDIO, 1, [ ])
+            SOURCES="$SOURCES $srcdir/src/audio/sndio/*.c"
+            EXTRA_CFLAGS="$EXTRA_CFLAGS $SNDIO_CFLAGS"
+            have_audio=yes
+        fi
+    fi
+}
+
 dnl rcg07142001 See if the user wants the disk writer audio driver...
 CheckDiskAudio()
 {
@@ -2262,6 +2308,7 @@ case "$host" in
         CheckARTSC
         CheckESD
         CheckNAS
+        CheckSNDIO
         CheckX11
         CheckDirectFB
         CheckFusionSound