Mercurial > vba-clojure

     1 // VisualBoyAdvance - Nintendo Gameboy/GameboyAdvance (TM) emulator.

     2 // Copyright (C) 2008 VBA-M development team

     3 

     4 // This program is free software; you can redistribute it and/or modify

     5 // it under the terms of the GNU General Public License as published by

     6 // the Free Software Foundation; either version 2, or(at your option)

     7 // any later version.

     8 //

     9 // This program is distributed in the hope that it will be useful,

    10 // but WITHOUT ANY WARRANTY; without even the implied warranty of

    11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    12 // GNU General Public License for more details.

    13 //

    14 // You should have received a copy of the GNU General Public License

    15 // along with this program; if not, write to the Free Software Foundation,

    16 // Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

    17 

    18 #include "SoundSDL.h"

    19 #include <stdio.h>

    20 

    21 

    22 extern int emulating;

    23 extern bool speedup;

    24 

    25 // Hold up to 100 ms of data in the ring buffer

    26 const float SoundSDL::_delay = 0.1f;

    27 

    28 SoundSDL::SoundSDL():

    29 	_rbuf(0),

    30 	_initialized(false)

    31 {

    32 

    33 }

    34 

    35 void SoundSDL::soundCallback(void *data, u8 *stream, int len)

    36 {

    37 	reinterpret_cast<SoundSDL*>(data)->read(reinterpret_cast<u16 *>(stream), len);

    38 }

    39 

    40 void SoundSDL::read(u16 * stream, int length)

    41 {

    42   if (!_initialized || length <= 0 || !emulating)

    43     return;

    44 

    45   SDL_mutexP(_mutex);

    46   _rbuf.read(stream, std::min(static_cast<std::size_t>(length) / 2, _rbuf.used()));

    47 

    48   SDL_CondSignal(_cond);

    49   SDL_mutexV(_mutex);

    50 }

    51 

    52 void SoundSDL::write(u16 * finalWave, int length)

    53 {

    54   if (!_initialized)

    55     return;

    56 

    57   if (SDL_GetAudioStatus() != SDL_AUDIO_PLAYING){

    58     SDL_PauseAudio(0);

    59     printf("SDLPauseAudio\n");

    60   }

    61 

    62   SDL_mutexP(_mutex);

    63 

    64   //printf("RLM: length = %d\n", length);

    65 

    66   unsigned int samples = length / 4;

    67 

    68   // printf("RLM: length / 4 = %d\n", samples);

    69 

    70   std::size_t avail;

    71   while ((avail = _rbuf.avail() / 2) < samples)

    72     {

    73       _rbuf.write(finalWave, avail * 2);

    74 

    75       finalWave += avail * 2;

    76       samples -= avail;

    77 

    78       // If emulating and not in speed up mode, synchronize to audio

    79       // by waiting till there is enough room in the buffer

    80       if (emulating && !speedup)

    81 	{

    82 	  //printf("SDL_CondWait\n");

    83 	  SDL_CondWait(_cond,_mutex);

    84 	}

    85       else

    86 	{

    87 	  // Drop the remainder of the audio data

    88 	  printf("RLM: Drop samples!\n");

    89 	  SDL_mutexV(_mutex);

    90 	  return;

    91 	}

    92     }

    93 

    94   _rbuf.write(finalWave, samples * 2);

    95   //printf("RLM: writing %d samples\n", samples);

    96   SDL_mutexV(_mutex);

    97 }

    98 

    99 

   100 bool SoundSDL::init()

   101 {

   102 	SDL_AudioSpec audio;

   103 	audio.freq = SDL_SAMPLE_RATE;

   104 	audio.format = AUDIO_S16SYS;

   105 	audio.channels = 2;

   106 	audio.samples = 1024;

   107 	audio.callback = soundCallback;

   108 	audio.userdata = this;

   109 

   110 	if(SDL_OpenAudio(&audio, NULL))

   111 	{

   112 		fprintf(stderr,"Failed to open audio: %s\n", SDL_GetError());

   113 		return false;

   114 	}

   115 

   116 	_rbuf.reset(_delay * SDL_SAMPLE_RATE * 2);

   117 

   118 	_cond  = SDL_CreateCond();

   119 	_mutex = SDL_CreateMutex();

   120 	_initialized = true;

   121 

   122 	return true;

   123 }

   124 

   125 SoundSDL::~SoundSDL()

   126 {

   127 	if (!_initialized)

   128 		return;

   129 

   130 	SDL_mutexP(_mutex);

   131 	int iSave = emulating;

   132 	emulating = 0;

   133 	SDL_CondSignal(_cond);

   134 	SDL_mutexV(_mutex);

   135 

   136 	SDL_DestroyCond(_cond);

   137 	_cond = NULL;

   138 

   139 	SDL_DestroyMutex(_mutex);

   140 	_mutex = NULL;

   141 

   142 	SDL_CloseAudio();

   143 

   144 	emulating = iSave;

   145 }

   146 

   147 void SoundSDL::pause()

   148 {

   149 	if (!_initialized)

   150 		return;

   151 

   152 	SDL_PauseAudio(1);

   153 }

   154 

   155 void SoundSDL::resume()

   156 {

   157 	if (!_initialized)

   158 		return;

   159 

   160 	SDL_PauseAudio(0);

   161 }

   162 

   163 void SoundSDL::reset()

   164 {

   165 }

   166 

   167 bool SoundSDL::setThrottle(unsigned short throttle){

   168 	switch(throttle){

   169 		case 25:

   170 		case 50:

   171 		case 100:

   172 		case 200:

   173 		case 400:

   174 			break;

   175 		default:

   176 			return false;

   177 	}

   178 	SDL_CloseAudio();

   179 	SDL_AudioSpec audio;

   180 	audio.freq = SDL_SAMPLE_RATE*throttle/100;

   181 	audio.format = AUDIO_S16SYS;

   182 	audio.channels = 2;

   183 	audio.samples = 1024;

   184 	audio.callback = soundCallback;

   185 	audio.userdata = this;

   186 	_rbuf.reset((_delay * SDL_SAMPLE_RATE * throttle * 2)/100);

   187 	return !SDL_OpenAudio(&audio,NULL);

   188 }
author	Robert McIntyre <rlm@mit.edu>
date	Sun, 24 Jun 2012 13:12:51 -0500
parents	f9f4f1b99eed
children