text: /*
    Simple DirectMedia Layer
    Copyright (C) 1997-2017 Sam Lantinga <slouken@libsdl.org>
  
    This software is provided 'as-is', without any express or implied
    warranty.  In no event will the authors be held liable for any damages
    arising from the use of this software.
  
    Permission is granted to anyone to use this software for any purpose,
    including commercial applications, and to alter it and redistribute it
    freely, subject to the following restrictions:
  
    1. The origin of this software must not be misrepresented; you must not
       claim that you wrote the original software. If you use this software
       in a product, an acknowledgment in the product documentation would be
       appreciated but is not required.
    2. Altered source versions must be plainly marked as such, and must not be
       misrepresented as being the original software.
    3. This notice may not be removed or altered from any source distribution.
  */
  
  #include "../../SDL_internal.h"
  
  #if SDL_AUDIO_DRIVER_JACK
  
  #include "SDL_assert.h"
  #include "SDL_timer.h"
  #include "SDL_audio.h"
  #include "../SDL_audio_c.h"
  #include "SDL_jackaudio.h"
  #include "SDL_loadso.h"
  #include "../../thread/SDL_systhread.h"
  
  
  static jack_client_t * (*JACK_jack_client_open) (const char *, jack_options_t, jack_status_t *, ...);
  static int (*JACK_jack_client_close) (jack_client_t *);
  static void (*JACK_jack_on_shutdown) (jack_client_t *, JackShutdownCallback, void *);
  static int (*JACK_jack_activate) (jack_client_t *);
  static int (*JACK_jack_deactivate) (jack_client_t *);
  static void * (*JACK_jack_port_get_buffer) (jack_port_t *, jack_nframes_t);
  static int (*JACK_jack_port_unregister) (jack_client_t *, jack_port_t *);
  static void (*JACK_jack_free) (void *);
  static const char ** (*JACK_jack_get_ports) (jack_client_t *, const char *, const char *, unsigned long);
  static jack_nframes_t (*JACK_jack_get_sample_rate) (jack_client_t *);
  static jack_nframes_t (*JACK_jack_get_buffer_size) (jack_client_t *);
  static jack_port_t * (*JACK_jack_port_register) (jack_client_t *, const char *, const char *, unsigned long, unsigned long);
  static const char * (*JACK_jack_port_name) (const jack_port_t *);
  static int (*JACK_jack_connect) (jack_client_t *, const char *, const char *);
  static int (*JACK_jack_set_process_callback) (jack_client_t *, JackProcessCallback, void *);
  
  static int load_jack_syms(void);
  
  
  #ifdef SDL_AUDIO_DRIVER_JACK_DYNAMIC
  
  static const char *jack_library = SDL_AUDIO_DRIVER_JACK_DYNAMIC;
  static void *jack_handle = NULL;
  
  /* !!! FIXME: this is copy/pasted in several places now */
  static int
  load_jack_sym(const char *fn, void **addr)
  {
      *addr = SDL_LoadFunction(jack_handle, fn);
      if (*addr == NULL) {
          /* Don't call SDL_SetError(): SDL_LoadFunction already did. */
          return 0;
      }
  
      return 1;
  }
  
  /* cast funcs to char* first, to please GCC's strict aliasing rules. */
  #define SDL_JACK_SYM(x) \
      if (!load_jack_sym(#x, (void **) (char *) &JACK_##x)) return -1
  
  static void
  UnloadJackLibrary(void)
  {
      if (jack_handle != NULL) {
          SDL_UnloadObject(jack_handle);
          jack_handle = NULL;
      }
  }
  
  static int
  LoadJackLibrary(void)
  {
      int retval = 0;
      if (jack_handle == NULL) {
          jack_handle = SDL_LoadObject(jack_library);
          if (jack_handle == NULL) {
              retval = -1;
              /* Don't call SDL_SetError(): SDL_LoadObject already did. */
          } else {
              retval = load_jack_syms();
              if (retval < 0) {
                  UnloadJackLibrary();
              }
          }
      }
      return retval;
  }
  
  #else
  
  #define SDL_JACK_SYM(x) JACK_##x = x
  
  static void
  UnloadJackLibrary(void)
  {
  }
  
  static int
  LoadJackLibrary(void)
  {
      load_jack_syms();
      return 0;
  }
  
  #endif /* SDL_AUDIO_DRIVER_JACK_DYNAMIC */
  
  
  static int
  load_jack_syms(void)
  {
      SDL_JACK_SYM(jack_client_open);
      SDL_JACK_SYM(jack_client_close);
      SDL_JACK_SYM(jack_on_shutdown);
      SDL_JACK_SYM(jack_activate);
      SDL_JACK_SYM(jack_deactivate);
      SDL_JACK_SYM(jack_port_get_buffer);
      SDL_JACK_SYM(jack_port_unregister);
      SDL_JACK_SYM(jack_free);
      SDL_JACK_SYM(jack_get_ports);
      SDL_JACK_SYM(jack_get_sample_rate);
      SDL_JACK_SYM(jack_get_buffer_size);
      SDL_JACK_SYM(jack_port_register);
      SDL_JACK_SYM(jack_port_name);
      SDL_JACK_SYM(jack_connect);
      SDL_JACK_SYM(jack_set_process_callback);
      return 0;
  }
  
  
  static void
  jackShutdownCallback(void *arg)  /* JACK went away; device is lost. */
  {
      SDL_AudioDevice *this = (SDL_AudioDevice *) arg;
      SDL_OpenedAudioDeviceDisconnected(this);
      SDL_SemPost(this->hidden->iosem);  /* unblock the SDL thread. */
  }
  
  // !!! FIXME: implement and register these!
  //typedef int(* JackSampleRateCallback)(jack_nframes_t nframes, void *arg)
  //typedef int(* JackBufferSizeCallback)(jack_nframes_t nframes, void *arg)
  
  static int
  jackProcessPlaybackCallback(jack_nframes_t nframes, void *arg)
  {
      SDL_AudioDevice *this = (SDL_AudioDevice *) arg;
      jack_port_t **ports = this->hidden->sdlports;
      const int total_channels = this->spec.channels;
      const int total_frames = this->spec.samples;
      int channelsi;
  
      if (!SDL_AtomicGet(&this->enabled)) {
          /* silence the buffer to avoid repeats and corruption. */
          SDL_memset(this->hidden->iobuffer, '\0', this->spec.size);
      }
  
      for (channelsi = 0; channelsi < total_channels; channelsi++) {
          float *dst = (float *) JACK_jack_port_get_buffer(ports[channelsi], nframes);
          if (dst) {
              const float *src = ((float *) this->hidden->iobuffer) + channelsi;
              int framesi;
              for (framesi = 0; framesi < total_frames; framesi++) {
                  *(dst++) = *src;
                  src += total_channels;
              }
          }
      }
  
      SDL_SemPost(this->hidden->iosem);  /* tell SDL thread we're done; refill the buffer. */
      return 0;  /* success */
  }
  
  
  /* This function waits until it is possible to write a full sound buffer */
  static void
  JACK_WaitDevice(_THIS)
  {
      if (SDL_AtomicGet(&this->enabled)) {
          if (SDL_SemWait(this->hidden->iosem) == -1) {
              SDL_OpenedAudioDeviceDisconnected(this);
          }
      }
  }
  
  static Uint8 *
  JACK_GetDeviceBuf(_THIS)
  {
      return (Uint8 *) this->hidden->iobuffer;
  }
  
  
  static int
  jackProcessCaptureCallback(jack_nframes_t nframes, void *arg)
  {
      SDL_AudioDevice *this = (SDL_AudioDevice *) arg;
      if (SDL_AtomicGet(&this->enabled)) {
          jack_port_t **ports = this->hidden->sdlports;
          const int total_channels = this->spec.channels;
          const int total_frames = this->spec.samples;
          int channelsi;
      
          for (channelsi = 0; channelsi < total_channels; channelsi++) {
              const float *src = (const float *) JACK_jack_port_get_buffer(ports[channelsi], nframes);
              if (src) {
                  float *dst = ((float *) this->hidden->iobuffer) + channelsi;
                  int framesi;
                  for (framesi = 0; framesi < total_frames; framesi++) {
                      *dst = *(src++);
                      dst += total_channels;
                  }
              }
          }
      }
  
      SDL_SemPost(this->hidden->iosem);  /* tell SDL thread we're done; new buffer is ready! */
      return 0;  /* success */
  }
  
  static int
  JACK_CaptureFromDevice(_THIS, void *buffer, int buflen)
  {
      SDL_assert(buflen == this->spec.size);  /* we always fill a full buffer. */
  
      /* Wait for JACK to fill the iobuffer */
      if (SDL_SemWait(this->hidden->iosem) == -1) {
          return -1;
      }
  
      SDL_memcpy(buffer, this->hidden->iobuffer, buflen);
      return buflen;
  }
  
  static void
  JACK_FlushCapture(_THIS)
  {
      SDL_SemWait(this->hidden->iosem);
  }
  
  
  static void
  JACK_CloseDevice(_THIS)
  {
      if (this->hidden->client) {
          JACK_jack_deactivate(this->hidden->client);
  
          if (this->hidden->sdlports) {
              const int channels = this->spec.channels;
              int i;
              for (i = 0; i < channels; i++) {
                  JACK_jack_port_unregister(this->hidden->client, this->hidden->sdlports[i]);
              }
              SDL_free(this->hidden->sdlports);
          }
  
          JACK_jack_client_close(this->hidden->client);
      }
  
      if (this->hidden->iosem) {
          SDL_DestroySemaphore(this->hidden->iosem);
      }
  
      if (this->hidden->devports) {
          JACK_jack_free(this->hidden->devports);
      }
  
      SDL_free(this->hidden->iobuffer);
  }
  
  static int
  JACK_OpenDevice(_THIS, void *handle, const char *devname, int iscapture)
  {
      /* Note that JACK uses "output" for capture devices (they output audio
          data to us) and "input" for playback (we input audio data to them).
          Likewise, SDL's playback port will be "output" (we write data out)
          and capture will be "input" (we read data in). */
      const unsigned long sysportflags = iscapture ? JackPortIsOutput : JackPortIsInput;
      const unsigned long sdlportflags = iscapture ? JackPortIsInput : JackPortIsOutput;
      const JackProcessCallback callback = iscapture ? jackProcessCaptureCallback : jackProcessPlaybackCallback;
      const char *sdlportstr = iscapture ? "input" : "output";
      const char **devports = NULL;
      jack_client_t *client = NULL;
      jack_status_t status;
      int channels = 0;
      int i;
  
      /* Initialize all variables that we clean on shutdown */
      this->hidden = (struct SDL_PrivateAudioData *) SDL_calloc(1, sizeof (*this->hidden));
      if (this->hidden == NULL) {
          return SDL_OutOfMemory();
      }
  
      /* !!! FIXME: we _still_ need an API to specify an app name */
      client = JACK_jack_client_open("SDL", JackNoStartServer, &status, NULL);
      this->hidden->client = client;
      if (client == NULL) {
          return SDL_SetError("Can't open JACK client");
      }
  
      devports = JACK_jack_get_ports(client, NULL, NULL, JackPortIsPhysical | sysportflags);
      this->hidden->devports = devports;
      if (!devports || !devports[0]) {
          return SDL_SetError("No physical JACK ports available");
      }
  
      while (devports[++channels]) {
          /* spin to count devports */
      }
  
      /* !!! FIXME: docs say about buffer size: "This size may change, clients that depend on it must register a bufsize_callback so they will be notified if it does." */
  
      /* Jack pretty much demands what it wants. */
      this->spec.format = AUDIO_F32SYS;
      this->spec.freq = JACK_jack_get_sample_rate(client);
      this->spec.channels = channels;
      this->spec.samples = JACK_jack_get_buffer_size(client);
  
      SDL_CalculateAudioSpec(&this->spec);
  
      this->hidden->iosem = SDL_CreateSemaphore(0);
      if (!this->hidden->iosem) {
          return -1;  /* error was set by SDL_CreateSemaphore */
      }
  
      this->hidden->iobuffer = (float *) SDL_calloc(1, this->spec.size);
      if (!this->hidden->iobuffer) {
          return SDL_OutOfMemory();
      }
  
      /* Build SDL's ports, which we will connect to the device ports. */
      this->hidden->sdlports = (jack_port_t **) SDL_calloc(channels, sizeof (jack_port_t *));
      if (this->hidden->sdlports == NULL) {
          return SDL_OutOfMemory();
      }
  
      for (i = 0; i < channels; i++) {
          char portname[32];
          SDL_snprintf(portname, sizeof (portname), "sdl_jack_%s_%d", sdlportstr, i);
          this->hidden->sdlports[i] = JACK_jack_port_register(client, portname, JACK_DEFAULT_AUDIO_TYPE, sdlportflags, 0);
          if (this->hidden->sdlports[i] == NULL) {
              return SDL_SetError("jack_port_register failed");
          }
      }
  
      if (JACK_jack_set_process_callback(client, callback, this) != 0) {
          return SDL_SetError("JACK: Couldn't set process callback");
      }
  
      JACK_jack_on_shutdown(client, jackShutdownCallback, this);
  
      if (JACK_jack_activate(client) != 0) {
          return SDL_SetError("Failed to activate JACK client");
      }
  
      /* once activated, we can connect all the ports. */
      for (i = 0; i < channels; i++) {
          const char *sdlport = JACK_jack_port_name(this->hidden->sdlports[i]);
          const char *srcport = iscapture ? devports[i] : sdlport;
          const char *dstport = iscapture ? sdlport : devports[i];
          if (JACK_jack_connect(client, srcport, dstport) != 0) {
              return SDL_SetError("Couldn't connect JACK ports: %s => %s", srcport, dstport);
          }
      }
  
      /* don't need these anymore. */
      this->hidden->devports = NULL;
      JACK_jack_free(devports);
  
      /* We're ready to rock and roll. :-) */
      return 0;
  }
  
  static void
  JACK_Deinitialize(void)
  {
      UnloadJackLibrary();
  }
  
  static int
  JACK_Init(SDL_AudioDriverImpl * impl)
  {
      if (LoadJackLibrary() < 0) {
          return 0;
      } else {
          /* Make sure a JACK server is running and available. */
          jack_status_t status;
          jack_client_t *client = JACK_jack_client_open("SDL", JackNoStartServer, &status, NULL);
          if (client == NULL) {
              UnloadJackLibrary();
              return 0;
          }
          JACK_jack_client_close(client);
      }
  
      /* Set the function pointers */
      impl->OpenDevice = JACK_OpenDevice;
      impl->WaitDevice = JACK_WaitDevice;
      impl->GetDeviceBuf = JACK_GetDeviceBuf;
      impl->CloseDevice = JACK_CloseDevice;
      impl->Deinitialize = JACK_Deinitialize;
      impl->CaptureFromDevice = JACK_CaptureFromDevice;
      impl->FlushCapture = JACK_FlushCapture;
      impl->OnlyHasDefaultOutputDevice = SDL_TRUE;
      impl->OnlyHasDefaultCaptureDevice = SDL_TRUE;
      impl->HasCaptureSupport = SDL_TRUE;
  
      return 1;   /* this audio target is available. */
  }
  
  AudioBootStrap JACK_bootstrap = {
      "jack", "JACK Audio Connection Kit", JACK_Init, 0
  };
  
  #endif /* SDL_AUDIO_DRIVER_JACK */
  
  /* vi: set ts=4 sw=4 expandtab: */
  