playing_sound.h

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/*
Minetest
Copyright (C) 2022 DS
Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
OpenAL support based on work by:
Copyright (C) 2011 Sebastian 'Bahamada' Rühl
Copyright (C) 2011 Cyriaque 'Cisoun' Skrapits <cysoun@gmail.com>
Copyright (C) 2011 Giuseppe Bilotta <giuseppe.bilotta@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 "sound_data.h"
namespace sound { struct ALExtensions; }
 
namespace sound {
 
class PlayingSound final
{
        struct FadeState {
                f32 step;
                f32 target_gain;
        };
 
        ALuint m_source_id;
        std::shared_ptr<ISoundDataOpen> m_data;
        ALuint m_next_sample_pos = 0;
        bool m_looping;
        bool m_is_positional;
        bool m_stopped_means_dead = true;
        std::optional<FadeState> m_fade_state = std::nullopt;
 
public:
        PlayingSound(ALuint source_id, std::shared_ptr<ISoundDataOpen> data, bool loop,
                        f32 volume, f32 pitch, f32 start_time,
                        const std::optional<std::pair<v3f, v3f>> &pos_vel_opt,
                        const ALExtensions &exts [[maybe_unused]]);
 
        ~PlayingSound() noexcept
        {
                alDeleteSources(1, &m_source_id);
        }
 
        DISABLE_CLASS_COPY(PlayingSound)
 
        // return false means streaming finished
        bool stepStream(bool playback_speed_changed = false);
 
        // retruns true if it wasn't fading already
        bool fade(f32 step, f32 target_gain) noexcept;
 
        // returns true if more fade is needed later
        bool doFade(f32 dtime) noexcept;
 
        void updatePosVel(const v3f &pos, const v3f &vel) noexcept;
 
        void setGain(f32 gain) noexcept;
 
        f32 getGain() noexcept;
 
        void setPitch(f32 pitch);
 
        bool isStreaming() const noexcept { return m_data->isStreaming(); }
 
        void play() noexcept { alSourcePlay(m_source_id); }
 
        // returns one of AL_INITIAL, AL_PLAYING, AL_PAUSED, AL_STOPPED
        ALint getState() noexcept
        {
                ALint state;
                alGetSourcei(m_source_id, AL_SOURCE_STATE, &state);
                return state;
        }
 
        bool isDead() noexcept
        {
                // streaming sounds can (but should not) stop because the queue runs empty
                return m_stopped_means_dead && getState() == AL_STOPPED;
        }
 
        void pause() noexcept
        {
                // this is a NOP if state != AL_PLAYING
                alSourcePause(m_source_id);
        }
 
        void resume() noexcept
        {
                if (getState() == AL_PAUSED)
                        play();
        }
};
 
} // namespace sound