1 /* 2 SDL - Simple DirectMedia Layer 3 Copyright (C) 1997-2004 Sam Lantinga 4 5 This library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Library General Public 7 License as published by the Free Software Foundation; either 8 version 2 of the License, or (at your option) any later version. 9 10 This library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Library General Public License for more details. 14 15 You should have received a copy of the GNU Library General Public 16 License along with this library; if not, write to the Free 17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18 19 Sam Lantinga 20 slouken (at) libsdl.org 21 */ 22 #include "SDL_config.h" 23 24 /* 25 Audio interrupt variables and callback function 26 27 Patrice Mandin 28 */ 29 30 #include <unistd.h> 31 32 #include <mint/osbind.h> 33 #include <mint/falcon.h> 34 #include <mint/mintbind.h> 35 #include <mint/cookie.h> 36 37 #include "SDL_audio.h" 38 #include "SDL_mintaudio.h" 39 #include "SDL_mintaudio_stfa.h" 40 41 /* The audio device */ 42 43 SDL_AudioDevice *SDL_MintAudio_device; 44 Uint8 *SDL_MintAudio_audiobuf[2]; /* Pointers to buffers */ 45 unsigned long SDL_MintAudio_audiosize; /* Length of audio buffer=spec->size */ 46 volatile unsigned short SDL_MintAudio_numbuf; /* Buffer to play */ 47 volatile unsigned short SDL_MintAudio_mutex; 48 volatile unsigned long SDL_MintAudio_clocktics; 49 cookie_stfa_t *SDL_MintAudio_stfa; 50 unsigned short SDL_MintAudio_hasfpu; 51 52 /* MiNT thread variables */ 53 SDL_bool SDL_MintAudio_mint_present; 54 SDL_bool SDL_MintAudio_quit_thread; 55 SDL_bool SDL_MintAudio_thread_finished; 56 long SDL_MintAudio_thread_pid; 57 58 /* The callback function, called by each driver whenever needed */ 59 60 void SDL_MintAudio_Callback(void) 61 { 62 Uint8 *buffer; 63 SDL_AudioDevice *audio = SDL_MintAudio_device; 64 65 buffer = SDL_MintAudio_audiobuf[SDL_MintAudio_numbuf]; 66 SDL_memset(buffer, audio->spec.silence, audio->spec.size); 67 68 if (audio->paused) 69 return; 70 71 if (audio->convert.needed) { 72 int silence; 73 74 if ( audio->convert.src_format == AUDIO_U8 ) { 75 silence = 0x80; 76 } else { 77 silence = 0; 78 } 79 SDL_memset(audio->convert.buf, silence, audio->convert.len); 80 audio->spec.callback(audio->spec.userdata, 81 (Uint8 *)audio->convert.buf,audio->convert.len); 82 SDL_ConvertAudio(&audio->convert); 83 SDL_memcpy(buffer, audio->convert.buf, audio->convert.len_cvt); 84 } else { 85 audio->spec.callback(audio->spec.userdata, buffer, audio->spec.size); 86 } 87 } 88 89 /* Add a new frequency/clock/predivisor to the current list */ 90 void SDL_MintAudio_AddFrequency(_THIS, Uint32 frequency, Uint32 clock, 91 Uint32 prediv, int gpio_bits) 92 { 93 int i, p; 94 95 if (MINTAUDIO_freqcount==MINTAUDIO_maxfreqs) { 96 return; 97 } 98 99 /* Search where to insert the frequency (highest first) */ 100 for (p=0; p<MINTAUDIO_freqcount; p++) { 101 if (frequency > MINTAUDIO_frequencies[p].frequency) { 102 break; 103 } 104 } 105 106 /* Put all following ones farer */ 107 if (MINTAUDIO_freqcount>0) { 108 for (i=MINTAUDIO_freqcount; i>p; i--) { 109 SDL_memcpy(&MINTAUDIO_frequencies[i], &MINTAUDIO_frequencies[i-1], sizeof(mint_frequency_t)); 110 } 111 } 112 113 /* And insert new one */ 114 MINTAUDIO_frequencies[p].frequency = frequency; 115 MINTAUDIO_frequencies[p].masterclock = clock; 116 MINTAUDIO_frequencies[p].predivisor = prediv; 117 MINTAUDIO_frequencies[p].gpio_bits = gpio_bits; 118 119 MINTAUDIO_freqcount++; 120 } 121 122 /* Search for the nearest frequency */ 123 int SDL_MintAudio_SearchFrequency(_THIS, int desired_freq) 124 { 125 int i; 126 127 /* Only 1 freq ? */ 128 if (MINTAUDIO_freqcount==1) { 129 return 0; 130 } 131 132 /* Check the array */ 133 for (i=0; i<MINTAUDIO_freqcount; i++) { 134 if (desired_freq >= ((MINTAUDIO_frequencies[i].frequency+ 135 MINTAUDIO_frequencies[i+1].frequency)>>1)) { 136 return i; 137 } 138 } 139 140 /* Not in the array, give the latest */ 141 return MINTAUDIO_freqcount-1; 142 } 143 144 /* Check if FPU is present */ 145 void SDL_MintAudio_CheckFpu(void) 146 { 147 unsigned long cookie_fpu; 148 149 SDL_MintAudio_hasfpu = 0; 150 if (Getcookie(C__FPU, &cookie_fpu) != C_FOUND) { 151 return; 152 } 153 switch ((cookie_fpu>>16)&0xfffe) { 154 case 2: 155 case 4: 156 case 6: 157 case 8: 158 case 16: 159 SDL_MintAudio_hasfpu = 1; 160 break; 161 } 162 } 163 164 /* The thread function, used under MiNT with xbios */ 165 int SDL_MintAudio_Thread(long param) 166 { 167 SndBufPtr pointers; 168 SDL_bool buffers_filled[2] = {SDL_FALSE, SDL_FALSE}; 169 170 SDL_MintAudio_thread_finished = SDL_FALSE; 171 while (!SDL_MintAudio_quit_thread) { 172 if (Buffptr(&pointers)!=0) 173 continue; 174 175 if (( (unsigned long)pointers.play>=(unsigned long)SDL_MintAudio_audiobuf[0]) 176 && ( (unsigned long)pointers.play<=(unsigned long)SDL_MintAudio_audiobuf[1])) 177 { 178 /* DMA is reading buffer #0, setup buffer #1 if not already done */ 179 if (!buffers_filled[1]) { 180 SDL_MintAudio_numbuf = 1; 181 SDL_MintAudio_Callback(); 182 Setbuffer(0, SDL_MintAudio_audiobuf[1], SDL_MintAudio_audiobuf[1] + SDL_MintAudio_audiosize); 183 buffers_filled[1]=SDL_TRUE; 184 buffers_filled[0]=SDL_FALSE; 185 } 186 } else { 187 /* DMA is reading buffer #1, setup buffer #0 if not already done */ 188 if (!buffers_filled[0]) { 189 SDL_MintAudio_numbuf = 0; 190 SDL_MintAudio_Callback(); 191 Setbuffer(0, SDL_MintAudio_audiobuf[0], SDL_MintAudio_audiobuf[0] + SDL_MintAudio_audiosize); 192 buffers_filled[0]=SDL_TRUE; 193 buffers_filled[1]=SDL_FALSE; 194 } 195 } 196 197 usleep(100); 198 } 199 SDL_MintAudio_thread_finished = SDL_TRUE; 200 return 0; 201 } 202 203 void SDL_MintAudio_WaitThread(void) 204 { 205 if (!SDL_MintAudio_mint_present) 206 return; 207 208 if (SDL_MintAudio_thread_finished) 209 return; 210 211 SDL_MintAudio_quit_thread = SDL_TRUE; 212 while (!SDL_MintAudio_thread_finished) { 213 Syield(); 214 } 215 } 216
