| 1 | /* |
| 2 | SDL - Simple DirectMedia Layer |
| 3 | Copyright (C) 1997-2009 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@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 | } |