jaildoctors_dilemma/source/jail_audio.cpp

#include "jail_audio.h"
#include <SDL2/SDL_rwops.h> // for SDL_RWFromMem
#include <SDL2/SDL_timer.h> // for SDL_GetTicks
#include <stdint.h>         // for uint8_t, uint32_t
#include <stdio.h>          // for NULL, fseek, fclose, fopen, fread, ftell
#include <stdlib.h>         // for free, malloc
#include "stb_vorbis.c"     // for stb_vorbis_decode_memory

constexpr int JA_MAX_SIMULTANEOUS_CHANNELS = 20;

struct JA_Sound_t
{
    Uint32 length{0};
    Uint8 *buffer{NULL};
};

struct JA_Channel_t
{
    JA_Sound_t *sound;
    int pos{0};
    int times{0};
    JA_Channel_state state{JA_CHANNEL_FREE};
};

struct JA_Music_t
{
    int samples{0};
    Uint32 length{0};
    int pos{0};
    int times{0};
    short *output{NULL};
    JA_Music_state state{JA_MUSIC_INVALID};
};

JA_Music_t *current_music{NULL};
JA_Channel_t channels[JA_MAX_SIMULTANEOUS_CHANNELS];

int JA_freq{48000};
SDL_AudioFormat JA_format{AUDIO_S16};
Uint8 JA_channels{2};
int JA_musicVolume = 128;
int JA_soundVolume = 64;
bool JA_musicEnabled = true;
bool JA_soundEnabled = true;
SDL_AudioDeviceID sdlAudioDevice = 0;

bool fading = false;
int fade_start_time;
int fade_duration;
int fade_initial_volume;

void audioCallback(void *userdata, uint8_t *stream, int len)
{
    SDL_memset(stream, 0, len);
    if (current_music != NULL && current_music->state == JA_MUSIC_PLAYING)
    {
        int volume = JA_musicVolume;
        if (fading)
        {
            int time = SDL_GetTicks();
            if (time > (fade_start_time + fade_duration))
            {
                fading = false;
                current_music->pos = 0;
                current_music->state = JA_MUSIC_STOPPED;
                volume = 0;
            }
            else
            {
                const int time_passed = time - fade_start_time;
                const float percent = (float)time_passed / (float)fade_duration;
                volume = JA_musicVolume * (1.0 - percent);
            }
        }
        const int size = SDL_min(len, current_music->length - current_music->pos);
        SDL_MixAudioFormat(stream, (Uint8 *)(current_music->output) + current_music->pos, AUDIO_S16, size, volume);
        current_music->pos += size;
        if (size < len)
        {
            if (current_music->times != 0)
            {
                SDL_MixAudioFormat(stream + size, (Uint8 *)current_music->output, AUDIO_S16, len - size, volume);
                current_music->pos = len - size;
                if (current_music->times > 0)
                    current_music->times--;
            }
            else
            {
                current_music->pos = 0;
                current_music->state = JA_MUSIC_STOPPED;
            }
        }
    }
    // Mixar els channels mi amol
    for (int i = 0; i < JA_MAX_SIMULTANEOUS_CHANNELS; i++)
    {
        if (channels[i].state == JA_CHANNEL_PLAYING)
        {
            const int size = SDL_min(len, channels[i].sound->length - channels[i].pos);
            SDL_MixAudioFormat(stream, channels[i].sound->buffer + channels[i].pos, AUDIO_S16, size, JA_soundVolume);
            channels[i].pos += size;
            if (size < len)
            {
                if (channels[i].times != 0)
                {
                    SDL_MixAudioFormat(stream + size, channels[i].sound->buffer, AUDIO_S16, len - size, JA_soundVolume);
                    channels[i].pos = len - size;
                    if (channels[i].times > 0)
                        channels[i].times--;
                }
                else
                {
                    JA_StopChannel(i);
                }
            }
        }
    }
}

void JA_Init(const int freq, const SDL_AudioFormat format, const int channels)
{
    JA_freq = freq;
    JA_format = format;
    JA_channels = channels;
    SDL_AudioSpec audioSpec{JA_freq, JA_format, JA_channels, 0, 1024, 0, 0, audioCallback, NULL};
    if (sdlAudioDevice != 0)
        SDL_CloseAudioDevice(sdlAudioDevice);
    sdlAudioDevice = SDL_OpenAudioDevice(NULL, 0, &audioSpec, NULL, 0);
    SDL_PauseAudioDevice(sdlAudioDevice, 0);
}

void JA_Quit()
{
    SDL_PauseAudioDevice(sdlAudioDevice, 1);
    if (sdlAudioDevice != 0)
        SDL_CloseAudioDevice(sdlAudioDevice);
    sdlAudioDevice = 0;
}

JA_Music_t *JA_LoadMusic(Uint8 *buffer, Uint32 length)
{
    int chan, samplerate;
    JA_Music_t *music = new JA_Music_t();

    music->samples = stb_vorbis_decode_memory(buffer, length, &chan, &samplerate, &music->output);

    SDL_AudioCVT cvt;
    SDL_BuildAudioCVT(&cvt, AUDIO_S16, chan, samplerate, JA_format, JA_channels, JA_freq);
    if (cvt.needed)
    {
        cvt.len = music->samples * chan * 2;
        music->length = cvt.len;
        cvt.buf = (Uint8 *)SDL_malloc(cvt.len * cvt.len_mult);
        SDL_memcpy(cvt.buf, music->output, cvt.len);
        SDL_ConvertAudio(&cvt);
        free(music->output);
        music->output = (short *)cvt.buf;
    }
    music->length = music->samples * chan * 2;
    music->pos = 0;
    music->state = JA_MUSIC_STOPPED;

    return music;
}

JA_Music_t *JA_LoadMusic(const char *filename)
{
    // [RZC 28/08/22] Carreguem primer el arxiu en memòria i després el descomprimim. Es algo més rapid.
    FILE *f = fopen(filename, "rb");
    fseek(f, 0, SEEK_END);
    long fsize = ftell(f);
    fseek(f, 0, SEEK_SET);
    Uint8 *buffer = (Uint8 *)malloc(fsize + 1);
    if (fread(buffer, fsize, 1, f) != 1)
        return NULL;
    fclose(f);

    JA_Music_t *music = JA_LoadMusic(buffer, fsize);

    free(buffer);

    return music;
}

void JA_PlayMusic(JA_Music_t *music, const int loop)
{
    if (!JA_musicEnabled)
        return;

    if (current_music != NULL)
    {
        current_music->pos = 0;
        current_music->state = JA_MUSIC_STOPPED;
    }
    current_music = music;
    current_music->pos = 0;
    current_music->state = JA_MUSIC_PLAYING;
    current_music->times = loop;
}

void JA_PauseMusic()
{
    if (!JA_musicEnabled)
        return;

    if (current_music == NULL || current_music->state == JA_MUSIC_INVALID)
        return;
    current_music->state = JA_MUSIC_PAUSED;
}

void JA_ResumeMusic()
{
    if (!JA_musicEnabled)
        return;

    if (current_music == NULL || current_music->state == JA_MUSIC_INVALID)
        return;
    current_music->state = JA_MUSIC_PLAYING;
}

void JA_StopMusic()
{
    if (!JA_musicEnabled)
        return;

    if (current_music == NULL || current_music->state == JA_MUSIC_INVALID)
        return;
    current_music->pos = 0;
    current_music->state = JA_MUSIC_STOPPED;
}

void JA_FadeOutMusic(const int milliseconds)
{
    if (!JA_musicEnabled)
        return;
    if (current_music == NULL || current_music->state == JA_MUSIC_INVALID)
        return;

    fading = true;
    fade_start_time = SDL_GetTicks();
    fade_duration = milliseconds;
    fade_initial_volume = JA_musicVolume;
}

JA_Music_state JA_GetMusicState()
{
    if (!JA_musicEnabled)
        return JA_MUSIC_DISABLED;

    if (current_music == NULL)
        return JA_MUSIC_INVALID;
    return current_music->state;
}

void JA_DeleteMusic(JA_Music_t *music)
{
    if (current_music == music)
        current_music = NULL;
    free(music->output);
    delete music;
}

int JA_SetMusicVolume(int volume)
{
    JA_musicVolume = volume > 128 ? 128 : volume < 0 ? 0
                                                     : volume;
    return JA_musicVolume;
}

void JA_SetMusicPosition(float value)
{
    if (!current_music)
        return;
    current_music->pos = value * JA_freq;
}

float JA_GetMusicPosition()
{
    if (!current_music)
        return 0;
    return float(current_music->pos) / float(JA_freq);
}

void JA_EnableMusic(const bool value)
{
    if (!value && current_music != NULL && current_music->state == JA_MUSIC_PLAYING)
        JA_StopMusic();

    JA_musicEnabled = value;
}

JA_Sound_t *JA_NewSound(Uint8 *buffer, Uint32 length)
{
    JA_Sound_t *sound = new JA_Sound_t();
    sound->buffer = buffer;
    sound->length = length;
    return sound;
}

JA_Sound_t *JA_LoadSound(uint8_t *buffer, uint32_t size)
{
    JA_Sound_t *sound = new JA_Sound_t();
    SDL_AudioSpec wavSpec;
    SDL_LoadWAV_RW(SDL_RWFromMem(buffer, size), 1, &wavSpec, &sound->buffer, &sound->length);

    SDL_AudioCVT cvt;
    SDL_BuildAudioCVT(&cvt, wavSpec.format, wavSpec.channels, wavSpec.freq, JA_format, JA_channels, JA_freq);
    cvt.len = sound->length;
    cvt.buf = (Uint8 *)SDL_malloc(cvt.len * cvt.len_mult);
    SDL_memcpy(cvt.buf, sound->buffer, sound->length);
    SDL_ConvertAudio(&cvt);
    SDL_FreeWAV(sound->buffer);
    sound->buffer = cvt.buf;
    sound->length = cvt.len_cvt;

    return sound;
}

JA_Sound_t *JA_LoadSound(const char *filename)
{
    JA_Sound_t *sound = new JA_Sound_t();
    SDL_AudioSpec wavSpec;
    SDL_LoadWAV(filename, &wavSpec, &sound->buffer, &sound->length);

    SDL_AudioCVT cvt;
    SDL_BuildAudioCVT(&cvt, wavSpec.format, wavSpec.channels, wavSpec.freq, JA_format, JA_channels, JA_freq);
    cvt.len = sound->length;
    cvt.buf = (Uint8 *)SDL_malloc(cvt.len * cvt.len_mult);
    SDL_memcpy(cvt.buf, sound->buffer, sound->length);
    SDL_ConvertAudio(&cvt);
    SDL_FreeWAV(sound->buffer);
    sound->buffer = cvt.buf;
    sound->length = cvt.len_cvt;

    return sound;
}

int JA_PlaySound(JA_Sound_t *sound, const int loop)
{
    if (!JA_soundEnabled)
        return -1;

    int channel = 0;
    while (channel < JA_MAX_SIMULTANEOUS_CHANNELS && channels[channel].state != JA_CHANNEL_FREE)
    {
        channel++;
    }
    if (channel == JA_MAX_SIMULTANEOUS_CHANNELS)
        channel = 0;

    channels[channel].sound = sound;
    channels[channel].times = loop;
    channels[channel].pos = 0;
    channels[channel].state = JA_CHANNEL_PLAYING;
    return channel;
}

int JA_PlaySoundOnChannel(JA_Sound_t *sound, const int channel, const int loop)
{
    if (!JA_soundEnabled)
        return -1;

    if (channel >= JA_MAX_SIMULTANEOUS_CHANNELS)
        return -1;

    channels[channel].sound = sound;
    channels[channel].times = loop;
    channels[channel].pos = 0;
    channels[channel].state = JA_CHANNEL_PLAYING;
    return channel;
}

void JA_DeleteSound(JA_Sound_t *sound)
{
    for (int i = 0; i < JA_MAX_SIMULTANEOUS_CHANNELS; i++)
    {
        if (channels[i].sound == sound)
            JA_StopChannel(i);
    }
    SDL_free(sound->buffer);
    delete sound;
}

void JA_PauseChannel(const int channel)
{
    if (!JA_soundEnabled)
        return;

    if (channel == -1)
    {
        for (int i = 0; i < JA_MAX_SIMULTANEOUS_CHANNELS; i++)
        {
            if (channels[i].state == JA_CHANNEL_PLAYING)
                channels[i].state = JA_CHANNEL_PAUSED;
        }
    }
    else if (channel >= 0 && channel < JA_MAX_SIMULTANEOUS_CHANNELS)
    {
        if (channels[channel].state == JA_CHANNEL_PLAYING)
            channels[channel].state = JA_CHANNEL_PAUSED;
    }
}

void JA_ResumeChannel(const int channel)
{
    if (!JA_soundEnabled)
        return;

    if (channel == -1)
    {
        for (int i = 0; i < JA_MAX_SIMULTANEOUS_CHANNELS; i++)
        {
            if (channels[i].state == JA_CHANNEL_PAUSED)
                channels[i].state = JA_CHANNEL_PLAYING;
        }
    }
    else if (channel >= 0 && channel < JA_MAX_SIMULTANEOUS_CHANNELS)
    {
        if (channels[channel].state == JA_CHANNEL_PAUSED)
            channels[channel].state = JA_CHANNEL_PLAYING;
    }
}

void JA_StopChannel(const int channel)
{
    if (!JA_soundEnabled)
        return;

    if (channel == -1)
    {
        for (int i = 0; i < JA_MAX_SIMULTANEOUS_CHANNELS; i++)
        {
            channels[i].state = JA_CHANNEL_FREE;
            channels[i].pos = 0;
            channels[i].sound = NULL;
        }
    }
    else if (channel >= 0 && channel < JA_MAX_SIMULTANEOUS_CHANNELS)
    {
        channels[channel].state = JA_CHANNEL_FREE;
        channels[channel].pos = 0;
        channels[channel].sound = NULL;
    }
}

JA_Channel_state JA_GetChannelState(const int channel)
{
    if (!JA_soundEnabled)
        return JA_SOUND_DISABLED;

    if (channel < 0 || channel >= JA_MAX_SIMULTANEOUS_CHANNELS)
        return JA_CHANNEL_INVALID;
    return channels[channel].state;
}

int JA_SetSoundVolume(int volume)
{
    JA_soundVolume = volume > 128 ? 128 : volume < 0 ? 0
                                                     : volume;
    return JA_soundVolume;
}

void JA_EnableSound(const bool value)
{
    for (int i = 0; i < JA_MAX_SIMULTANEOUS_CHANNELS; i++)
    {
        if (channels[i].state == JA_CHANNEL_PLAYING)
            JA_StopChannel(i);
    }
    JA_soundEnabled = value;
}

int JA_SetVolume(int volume)
{
    JA_musicVolume = volume > 128 ? 128 : volume < 0 ? 0
                                                     : volume;
    JA_soundVolume = JA_musicVolume / 2;
    return JA_musicVolume;
}