audio_stream_playlist.h

/**************************************************************************/
/*  audio_stream_playlist.h                                               */
/**************************************************************************/
/*                         This file is part of:                          */
/*                             GODOT ENGINE                               */
/*                        https://godotengine.org                         */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
/*                                                                        */
/* Permission is hereby granted, free of charge, to any person obtaining  */
/* a copy of this software and associated documentation files (the        */
/* "Software"), to deal in the Software without restriction, including    */
/* without limitation the rights to use, copy, modify, merge, publish,    */
/* distribute, sublicense, and/or sell copies of the Software, and to     */
/* permit persons to whom the Software is furnished to do so, subject to  */
/* the following conditions:                                              */
/*                                                                        */
/* The above copyright notice and this permission notice shall be         */
/* included in all copies or substantial portions of the Software.        */
/*                                                                        */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
/**************************************************************************/

#pragma once

#include "servers/audio/audio_stream.h"

class AudioStreamPlaybackPlaylist;

class AudioStreamPlaylist : public AudioStream {
	GDCLASS(AudioStreamPlaylist, AudioStream)
	OBJ_SAVE_TYPE(AudioStream)

private:
	friend class AudioStreamPlaybackPlaylist;

	enum {
		MAX_STREAMS = 64
	};

	bool shuffle = false;
	bool loop = true;
	double fade_time = 0.3;

	int stream_count = 0;
	Ref<AudioStream> audio_streams[MAX_STREAMS];
	HashSet<AudioStreamPlaybackPlaylist *> playbacks;

public:
	virtual double get_bpm() const override;
	void set_stream_count(int p_count);
	int get_stream_count() const;
	void set_fade_time(float p_time);
	float get_fade_time() const;
	void set_shuffle(bool p_shuffle);
	bool get_shuffle() const;
	void set_loop(bool p_loop);
	virtual bool has_loop() const override;
	void set_list_stream(int p_stream_index, Ref<AudioStream> p_stream);
	Ref<AudioStream> get_list_stream(int p_stream_index) const;

	virtual Ref<AudioStreamPlayback> instantiate_playback() override;
	virtual String get_stream_name() const override;
	virtual double get_length() const override;
	virtual bool is_meta_stream() const override { return true; }

protected:
	static void _bind_methods();
	void _validate_property(PropertyInfo &r_property) const;
};

///////////////////////////////////////

class AudioStreamPlaybackPlaylist : public AudioStreamPlayback {
	GDCLASS(AudioStreamPlaybackPlaylist, AudioStreamPlayback)
	friend class AudioStreamPlaylist;

private:
	enum {
		MIX_BUFFER_SIZE = 128
	};
	AudioFrame mix_buffer[MIX_BUFFER_SIZE];
	AudioFrame fade_buffer[MIX_BUFFER_SIZE];

	Ref<AudioStreamPlaylist> playlist;
	Ref<AudioStreamPlayback> playback[AudioStreamPlaylist::MAX_STREAMS];

	int play_order[AudioStreamPlaylist::MAX_STREAMS] = {};

	double stream_todo = 0.0;
	int fade_index = -1;
	double fade_volume = 1.0;
	int play_index = 0;
	double offset = 0.0;

	int loop_count = 0;

	bool active = false;

	void _update_order();

	void _update_playback_instances();

public:
	virtual void start(double p_from_pos = 0.0) override;
	virtual void stop() override;
	virtual bool is_playing() const override;
	virtual int get_loop_count() const override; // times it looped
	virtual double get_playback_position() const override;
	virtual void seek(double p_time) override;
	virtual int mix(AudioFrame *p_buffer, float p_rate_scale, int p_frames) override;

	virtual void tag_used_streams() override;

	~AudioStreamPlaybackPlaylist();
};