SDL audio subsystem created.

svn-id: r49369

1 files changed, 116 insertions, 0 deletions

diff --git a/backends/platform/sdl/audio.h b/backends/platform/sdl/audio.h
new file mode 100644
index 0000000000..4ef560999e
--- /dev/null
+++ b/backends/platform/sdl/audio.h
@@ -0,0 +1,116 @@
+/* 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.
+ *
+ * $URL$
+ * $Id$
+ *
+ */
+
+#ifndef BACKENDS_SDL_SUBSYS_AUDIO_H
+#define BACKENDS_SDL_SUBSYS_AUDIO_H
+
+#include "backends/base-subsys-audio.h"
+
+#if defined(__SYMBIAN32__)
+#include <esdl\SDL.h>
+#else
+#include <SDL.h>
+#endif
+
+#if defined(MACOSX)
+// On Mac OS X, we need to double buffer the audio buffer, else anything
+// which produces sampled data with high latency (like the MT-32 emulator)
+// will sound terribly.
+// This could be enabled for more / most ports in the future, but needs some
+// testing.
+#define MIXER_DOUBLE_BUFFERING 1
+#endif
+
+namespace Audio {
+	class MixerImpl;
+}
+
+class SdlSubSys_Audio : public BaseSubSys_Audio {
+public:
+	SdlSubSys_Audio();
+	~SdlSubSys_Audio();
+
+	virtual void audioInit();
+	virtual void audioDone();
+
+	bool hasFeature(Feature f);
+	void setFeatureState(Feature f, bool enable);
+	bool getFeatureState(Feature f);
+
+	// Set function that generates samples
+	virtual void setupMixer();
+	static void mixCallback(void *s, byte *samples, int len);
+
+	virtual void closeMixer();
+
+	virtual Audio::Mixer *getMixer();
+
+	virtual bool openCD(int drive);
+
+	// Poll CD status
+	// Returns true if cd audio is playing
+	bool pollCD();
+
+	// Play CD audio track
+	void playCD(int track, int num_loops, int start_frame, int duration);
+
+	// Stop CD audio track
+	void stopCD();
+
+	// Update CD audio status
+	void updateCD();
+
+protected:
+	bool _inited;
+
+	SDL_AudioSpec _obtainedRate;
+
+	// CD Audio
+	SDL_CD *_cdrom;
+	int _cdTrack, _cdNumLoops, _cdStartFrame, _cdDuration;
+	uint32 _cdEndTime, _cdStopTime;
+
+#ifdef MIXER_DOUBLE_BUFFERING
+	SDL_mutex *_soundMutex;
+	SDL_cond *_soundCond;
+	SDL_Thread *_soundThread;
+	bool _soundThreadIsRunning;
+	bool _soundThreadShouldQuit;
+
+	byte _activeSoundBuf;
+	uint _soundBufSize;
+	byte *_soundBuffers[2];
+
+	void mixerProducerThread();
+	static int SDLCALL mixerProducerThreadEntry(void *arg);
+	void initThreadedMixer(Audio::MixerImpl *mixer, uint bufSize);
+	void deinitThreadedMixer();
+#endif
+
+	Audio::MixerImpl *_mixer;
+};
+
+
+#endif