src/sound/sdl_s.cpp

   1 /* $Id: sdl_s.cpp 22406 2011-05-01 19:51:52Z rubidium $ */
   2
   3 /*
   4  * This file is part of OpenTTD.
   5  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
   6  * OpenTTD 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.
   7  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   8  */
   9
  10 /** @file sdl_s.cpp Playing sound via SDL. */
  11
  12 #ifdef WITH_SDL
  13
  14 #include "../stdafx.h"
  15
  16 #include "../mixer.h"
  17 #include "../sdl.h"
  18 #include "sdl_s.h"
  19 #include <SDL.h>
  20
  21 #include "../safeguards.h"
  22
  23 /** Factory for the SDL sound driver. */
  24 static FSoundDriver_SDL iFSoundDriver_SDL;
  25
  26 /**
  27  * Callback that fills the sound buffer.
  28  * @param userdata Ignored.
  29  * @param stream   The stream to put data into.
  30  * @param len      The length of the stream in bytes.
  31  */
  32 static void CDECL fill_sound_buffer(void *userdata, Uint8 *stream, int len)
  33 {
  34         MxMixSamples(stream, len / 4);
  35 }
  36
  37 const char *SoundDriver_SDL::Start(const char * const *parm)
  38 {
  39         SDL_AudioSpec spec;
  40
  41         const char *s = SdlOpen(SDL_INIT_AUDIO);
  42         if (s != nullptr) return s;
  43
  44         spec.freq = GetDriverParamInt(parm, "hz", 44100);
  45         spec.format = AUDIO_S16SYS;
  46         spec.channels = 2;
  47         spec.samples = GetDriverParamInt(parm, "samples", 1024);
  48         spec.callback = fill_sound_buffer;
  49         MxInitialize(spec.freq);
  50         SDL_CALL SDL_OpenAudio(&spec, &spec);
  51         SDL_CALL SDL_PauseAudio(0);
  52         return nullptr;
  53 }
  54
  55 void SoundDriver_SDL::Stop()
  56 {
  57         SDL_CALL SDL_CloseAudio();
  58         SdlClose(SDL_INIT_AUDIO);
  59 }
  60
  61 #endif /* WITH_SDL */