#define MIXER_FLAG_NONE         0x0
#define MIXER_FLAG_SPATIALIZE   0x1

#define MIXER_DESC(...) ((M_TrackDesc) { \
    .flags      = 0, \
\
    .volume     = 1.0, \
    .speed      = 1.0, \
    .looping    = 0, \
\
    .pos        = VEC2(0, 0), \
\
    __VA_ARGS__ \
})

Struct(M_TrackDesc) {
    u32 flags;
    f32 volume;     /* 0 -> 1.0+ */
    f32 speed;      /* 0 -> 1.0+ */
    b32 looping;

    /* MIXER_FLAG_SPATIALIZE */
    Vec2 pos;
};

Struct(M_Handle) {
    u64 gen;
    void *data;
};

/* Stereo mix of 32 bit float samples */
Struct(M_PcmF32) {
    u64 count;
    f32 *samples;
};

Struct(M_StartupReceipt) { i32 _; };
M_StartupReceipt mixer_startup(void);

/* Interface */
M_Handle mixer_play(SND_Sound *sound);
M_Handle mixer_play_ex(SND_Sound *sound, M_TrackDesc desc);
M_TrackDesc mixer_track_get(M_Handle handle);
void mixer_track_set(M_Handle handle, M_TrackDesc desc);
void mixer_set_listener(Vec2 pos, Vec2 dir);

/* Mixing */
M_PcmF32 mixer_update(Arena *arena, u64 frame_request_count);