Cleanup sound manager class (#7158)

* Cleanup sound manager client

* Use some const refs
* Use auto on iterators
* Drop unused parameters
* Move sound_openal.* to client folder
* Move sound.cpp + OnDemandSoundFetcher to client/ folder + reorganize includes properly

src/client/sound.h

@@ -0,0 +1,111 @@
+/*
+Minetest
+Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser 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.
+*/
+
+#pragma once
+
+#include <set>
+#include <string>
+#include "irr_v3d.h"
+#include "../sound.h"
+
+class OnDemandSoundFetcher
+{
+public:
+	virtual void fetchSounds(const std::string &name,
+			std::set<std::string> &dst_paths,
+			std::set<std::string> &dst_datas) = 0;
+};
+
+class ISoundManager
+{
+public:
+	virtual ~ISoundManager() = default;
+
+	// Multiple sounds can be loaded per name; when played, the sound
+	// should be chosen randomly from alternatives
+	// Return value determines success/failure
+	virtual bool loadSoundFile(
+			const std::string &name, const std::string &filepath) = 0;
+	virtual bool loadSoundData(
+			const std::string &name, const std::string &filedata) = 0;
+
+	virtual void updateListener(
+			const v3f &pos, const v3f &vel, const v3f &at, const v3f &up) = 0;
+	virtual void setListenerGain(float gain) = 0;
+
+	// playSound functions return -1 on failure, otherwise a handle to the
+	// sound. If name=="", call should be ignored without error.
+	virtual int playSound(const std::string &name, bool loop, float volume,
+			float fade = 0.0f, float pitch = 1.0f) = 0;
+	virtual int playSoundAt(const std::string &name, bool loop, float volume, v3f pos,
+			float pitch = 1.0f) = 0;
+	virtual void stopSound(int sound) = 0;
+	virtual bool soundExists(int sound) = 0;
+	virtual void updateSoundPosition(int sound, v3f pos) = 0;
+	virtual bool updateSoundGain(int id, float gain) = 0;
+	virtual float getSoundGain(int id) = 0;
+	virtual void step(float dtime) = 0;
+	virtual void fadeSound(int sound, float step, float gain) = 0;
+
+	int playSound(const SimpleSoundSpec &spec, bool loop)
+	{
+		return playSound(spec.name, loop, spec.gain, spec.fade, spec.pitch);
+	}
+	int playSoundAt(const SimpleSoundSpec &spec, bool loop, const v3f &pos)
+	{
+		return playSoundAt(spec.name, loop, spec.gain, pos, spec.pitch);
+	}
+};
+
+class DummySoundManager : public ISoundManager
+{
+public:
+	virtual bool loadSoundFile(const std::string &name, const std::string &filepath)
+	{
+		return true;
+	}
+	virtual bool loadSoundData(const std::string &name, const std::string &filedata)
+	{
+		return true;
+	}
+	void updateListener(const v3f &pos, const v3f &vel, const v3f &at, const v3f &up)
+	{
+	}
+	void setListenerGain(float gain) {}
+	int playSound(const std::string &name, bool loop, float volume, float fade,
+			float pitch)
+	{
+		return 0;
+	}
+	int playSoundAt(const std::string &name, bool loop, float volume, v3f pos,
+			float pitch)
+	{
+		return 0;
+	}
+	void stopSound(int sound) {}
+	bool soundExists(int sound) { return false; }
+	void updateSoundPosition(int sound, v3f pos) {}
+	bool updateSoundGain(int id, float gain) { return false; }
+	float getSoundGain(int id) { return 0; }
+	void step(float dtime) {}
+	void fadeSound(int sound, float step, float gain) {}
+};
+
+// Global DummySoundManager singleton
+extern DummySoundManager dummySoundManager;