Clip.hpp

//
// Created by jibbo on 2/22/21.
//
 
 
#ifndef MONOREPO_JSTRACESKI_CLIP_H
#define MONOREPO_JSTRACESKI_CLIP_H
 
#include <vector>
#include <SDL2/SDL.h>
#include <Base.hpp>
 
namespace Engine {
  struct Clip {
  public:
    Uint32 clipLen;         
    Uint32 trackPos = 0;    
    Uint8 *data;            
    SDL_AudioSpec spec;     
    bool loop = false;      
    bool active = false;    
    static std::vector<Ref<Clip>> sounds; 
    static void InitAudio() {
      SDL_AudioSpec fmt;
 
      fmt.freq = 44100;
      fmt.format = AUDIO_S16;
      fmt.channels = 2;
      fmt.samples = 4096;
      fmt.callback = Clip::callback;
      fmt.userdata = nullptr;
 
      /* Open the audio device */
      if ( SDL_OpenAudio(&fmt, nullptr) < 0 ){
        fprintf(stderr, "Couldn't open audio: %s\n", SDL_GetError());
      }
 
      /* Start playing */
      SDL_PauseAudio(0);
    }
 
    static Ref<Clip> LoadClip(const std::string& path);
 
    //TODO: add static and master list
    static void callback(void *userdata, Uint8 *stream, int len) {
      memset(stream, 0, len);
 
      for (const auto& s : sounds) {
        if (s->active) {
          if (s->trackPos + len >= s->clipLen) {
            Uint32 last = s->clipLen - s->trackPos;
            SDL_MixAudio(stream, &s->data[s->trackPos], last, SDL_MIX_MAXVOLUME);
 
            if (s->loop) {
              Uint32 extra = len - last;
              SDL_MixAudio(&stream[last], &s->data[0], extra, SDL_MIX_MAXVOLUME);
              s->trackPos = extra;
            } else {
              s->active = false;
            }
 
          } else {
            SDL_MixAudio(stream, &s->data[s->trackPos], len, SDL_MIX_MAXVOLUME);
            s->trackPos += len;
          }
        }
      }
    }
 
    void playClip();
 
    void loopClip();
 
    void endClip();
 
    ~Clip() {
      delete data;
    }
  };
 
}
 
 
#endif //MONOREPO_JSTRACESKI_CLIP_H