MIDI: add sndio midi backend

New sndio MIDI backend for OpenBSD written by Alexandre Ratchov.
Tested with an external MT-32 and fluidsynth.

backends/midi/sndio.cpp

@@ -0,0 +1,152 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+// Disable symbol overrides so that we can use system headers.
+#define FORBIDDEN_SYMBOL_ALLOW_ALL
+
+#include "common/scummsys.h"
+
+#if defined(USE_SNDIO)
+
+#include "common/error.h"
+#include "common/textconsole.h"
+#include "common/util.h"
+#include "audio/musicplugin.h"
+#include "audio/mpu401.h"
+
+#include <sndio.h>
+
+////////////////////////////////////////
+//
+// sndio MIDI driver
+//
+////////////////////////////////////////
+
+class MidiDriver_Sndio : public MidiDriver_MPU401 {
+public:
+	MidiDriver_Sndio();
+	int open();
+	bool isOpen() const { return hdl != NULL; }
+	void close();
+	void send(uint32 b);
+	void sysEx(const byte *msg, uint16 length);
+
+private:
+	struct mio_hdl *hdl;
+};
+
+MidiDriver_Sndio::MidiDriver_Sndio() {
+	hdl = NULL;
+}
+
+int MidiDriver_Sndio::open() {
+	if (hdl != NULL)
+		return MERR_ALREADY_OPEN;
+
+	hdl = ::mio_open(NULL, MIO_OUT, 0);
+	if (hdl == NULL)
+		warning("Could open MIDI port (no music)");
+	return 0;
+}
+
+void MidiDriver_Sndio::close() {
+	MidiDriver_MPU401::close();
+	if (!hdl)
+		return;
+	mio_close(hdl);
+	hdl = NULL;
+}
+
+void MidiDriver_Sndio::send(uint32 b) {
+	unsigned char buf[4];
+	unsigned int len;
+
+	if (!hdl)
+		return;
+	buf[0] = b & 0xff;	
+	buf[1] = (b >> 8) & 0xff;
+	buf[2] = (b >> 16) & 0xff;
+	buf[3] = (b >> 24) & 0xff;
+	switch (buf[0] & 0xf0) {
+	case 0xf0:
+		return;
+	case 0xc0:
+	case 0xd0:
+		len = 2;
+		break;
+	default:
+		len = 3;
+	}
+	mio_write(hdl, buf, len);
+}
+
+void MidiDriver_Sndio::sysEx(const byte *msg, uint16 length) {
+	if (!hdl)
+		return;
+	
+	unsigned char buf[266];
+
+	assert(length + 2 <= ARRAYSIZE(buf));
+
+	// Add SysEx frame
+	buf[0] = 0xF0;
+	memcpy(buf + 1, msg, length);
+	buf[length + 1] = 0xF7;
+
+	mio_write(hdl, buf, length + 2);
+}
+
+
+// Plugin interface
+
+class SndioMusicPlugin : public MusicPluginObject {
+public:
+	const char *getName() const {
+		return "Sndio";
+	}
+
+	const char *getId() const {
+		return "sndio";
+	}
+
+	MusicDevices getDevices() const;
+	Common::Error createInstance(MidiDriver **mididriver, MidiDriver::DeviceHandle = 0) const;
+};
+
+MusicDevices SndioMusicPlugin::getDevices() const {
+	MusicDevices devices;
+	devices.push_back(MusicDevice(this, "", MT_GM));
+	return devices;
+}
+
+Common::Error SndioMusicPlugin::createInstance(MidiDriver **mididriver, MidiDriver::DeviceHandle) const {
+	*mididriver = new MidiDriver_Sndio();
+
+	return Common::kNoError;
+}
+
+//#if PLUGIN_ENABLED_DYNAMIC(Sndio)
+	//REGISTER_PLUGIN_DYNAMIC(SNDIO, PLUGIN_TYPE_MUSIC, SndioMusicPlugin);
+//#else
+	REGISTER_PLUGIN_STATIC(SNDIO, PLUGIN_TYPE_MUSIC, SndioMusicPlugin);
+//#endif
+
+#endif

backends/module.mk

@@ -11,6 +11,7 @@ MODULE_OBJS := \
 	midi/alsa.o \
 	midi/dmedia.o \
 	midi/seq.o \
+	midi/sndio.o \
 	midi/stmidi.o \
 	midi/timidity.o \
 	saves/savefile.o \

base/plugins.cpp

@@ -101,6 +101,9 @@ public:
 		#if defined(USE_SEQ_MIDI)
 		LINK_PLUGIN(SEQ)
 		#endif
+		#if defined(USE_SNDIO)
+		LINK_PLUGIN(SNDIO)
+		#endif
 		#if defined(__MINT__)
 		LINK_PLUGIN(STMIDI)
 		#endif

base/version.cpp

@@ -94,6 +94,10 @@ const char *gScummVMFeatures = ""
 	"SEQ "
 #endif
 
+#ifdef USE_SNDIO
+	"sndio "
+#endif
+
 #ifdef USE_TIMIDITY
 	"TiMidity "
 #endif

configure

@@ -93,6 +93,7 @@ _flac=auto
 _mad=auto
 _alsa=auto
 _seq_midi=auto
+_sndio=auto
 _timidity=auto
 _zlib=auto
 _sparkle=auto
@@ -852,6 +853,9 @@ Optional Libraries:
   --with-libunity-prefix=DIR   Prefix where libunity is installed (optional)
   --disable-libunity           disable Unity launcher integration [autodetect]
 
+  --with-sndio-prefix=DIR  Prefix where sndio is installed (optional)
+  --disable-sndio          disable sndio MIDI driver [autodetect]
+
 Some influential environment variables:
   LDFLAGS        linker flags, e.g. -L<lib dir> if you have libraries in a
                  nonstandard directory <lib dir>
@@ -877,6 +881,8 @@ for ac_option in $@; do
 	--disable-alsa)           _alsa=no        ;;
 	--enable-seq-midi)        _seq_midi=yes   ;;
 	--disable-seq-midi)       _seq_midi=no    ;;
+	--enable-sndio)           _sndio=yes      ;;
+	--disable-sndio)          _sndio=no       ;;
 	--enable-timidity)        _timidity=yes   ;;
 	--disable-timidity)       _timidity=no    ;;
 	--enable-vorbis)          _vorbis=yes     ;;
@@ -937,6 +943,11 @@ for ac_option in $@; do
 		ALSA_CFLAGS="-I$arg/include"
 		ALSA_LIBS="-L$arg/lib"
 		;;
+	--with-sndio-prefix=*)
+		arg=`echo $ac_option | cut -d '=' -f 2`
+		SNDIO_CFLAGS="-I$arg/include"
+		SNDIO_LIBS="-L$arg/lib"
+		;;
 	--with-ogg-prefix=*)
 		arg=`echo $ac_option | cut -d '=' -f 2`
 		OGG_CFLAGS="-I$arg/include"
@@ -3257,6 +3268,25 @@ fi
 define_in_config_h_if_yes "$_seq_midi" 'USE_SEQ_MIDI'
 echo "$_seq_midi"
 
+#
+# Check for sndio
+#
+echocheck "sndio"
+if test "$_sndio" = auto ; then
+	_sndio=no
+	cat > $TMPC << EOF
+#include <sndio.h>
+int main(void) { struct sio_par par; sio_initpar(&par); return 0; }
+EOF
+	cc_check $SNDIO_CFLAGS $SNDIO_LIBS -lsndio && _sndio=yes
+fi
+if test "$_sndio" = yes ; then
+	LIBS="$LIBS $SNDIO_LIBS -lsndio"
+	INCLUDES="$INCLUDES $SNDIO_CFLAGS"
+fi
+define_in_config_h_if_yes "$_sndio" 'USE_SNDIO'
+echo "$_sndio"
+
 #
 # Check for TiMidity(++)
 #