| /* |
| SDL - Simple DirectMedia Layer |
| Copyright (C) 1997-2012 Sam Lantinga |
| |
| This library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Library General Public |
| License as published by the Free Software Foundation; either |
| version 2 of the License, or (at your option) any later version. |
| |
| This library 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. See the GNU |
| Library General Public License for more details. |
| |
| You should have received a copy of the GNU Library General Public |
| License along with this library; if not, write to the Free |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| |
| Sam Lantinga |
| slouken@libsdl.org |
| */ |
| #include "SDL_config.h" |
| |
| /* |
| Audio interrupt variables and callback function |
| |
| Patrice Mandin |
| */ |
| |
| #include <unistd.h> |
| |
| #include <mint/osbind.h> |
| #include <mint/falcon.h> |
| #include <mint/mintbind.h> |
| #include <mint/cookie.h> |
| |
| #include "SDL_audio.h" |
| #include "SDL_mintaudio.h" |
| #include "SDL_mintaudio_stfa.h" |
| |
| /* The audio device */ |
| |
| SDL_AudioDevice *SDL_MintAudio_device; |
| Uint8 *SDL_MintAudio_audiobuf[2]; /* Pointers to buffers */ |
| unsigned long SDL_MintAudio_audiosize; /* Length of audio buffer=spec->size */ |
| volatile unsigned short SDL_MintAudio_numbuf; /* Buffer to play */ |
| volatile unsigned short SDL_MintAudio_mutex; |
| volatile unsigned long SDL_MintAudio_clocktics; |
| cookie_stfa_t *SDL_MintAudio_stfa; |
| unsigned short SDL_MintAudio_hasfpu; |
| |
| /* MiNT thread variables */ |
| SDL_bool SDL_MintAudio_mint_present; |
| SDL_bool SDL_MintAudio_quit_thread; |
| SDL_bool SDL_MintAudio_thread_finished; |
| long SDL_MintAudio_thread_pid; |
| |
| /* The callback function, called by each driver whenever needed */ |
| |
| void SDL_MintAudio_Callback(void) |
| { |
| Uint8 *buffer; |
| SDL_AudioDevice *audio = SDL_MintAudio_device; |
| |
| buffer = SDL_MintAudio_audiobuf[SDL_MintAudio_numbuf]; |
| SDL_memset(buffer, audio->spec.silence, audio->spec.size); |
| |
| if (audio->paused) |
| return; |
| |
| if (audio->convert.needed) { |
| int silence; |
| |
| if ( audio->convert.src_format == AUDIO_U8 ) { |
| silence = 0x80; |
| } else { |
| silence = 0; |
| } |
| SDL_memset(audio->convert.buf, silence, audio->convert.len); |
| audio->spec.callback(audio->spec.userdata, |
| (Uint8 *)audio->convert.buf,audio->convert.len); |
| SDL_ConvertAudio(&audio->convert); |
| SDL_memcpy(buffer, audio->convert.buf, audio->convert.len_cvt); |
| } else { |
| audio->spec.callback(audio->spec.userdata, buffer, audio->spec.size); |
| } |
| } |
| |
| /* Add a new frequency/clock/predivisor to the current list */ |
| void SDL_MintAudio_AddFrequency(_THIS, Uint32 frequency, Uint32 clock, |
| Uint32 prediv, int gpio_bits) |
| { |
| int i, p; |
| |
| if (MINTAUDIO_freqcount==MINTAUDIO_maxfreqs) { |
| return; |
| } |
| |
| /* Search where to insert the frequency (highest first) */ |
| for (p=0; p<MINTAUDIO_freqcount; p++) { |
| if (frequency > MINTAUDIO_frequencies[p].frequency) { |
| break; |
| } |
| } |
| |
| /* Put all following ones farer */ |
| if (MINTAUDIO_freqcount>0) { |
| for (i=MINTAUDIO_freqcount; i>p; i--) { |
| SDL_memcpy(&MINTAUDIO_frequencies[i], &MINTAUDIO_frequencies[i-1], sizeof(mint_frequency_t)); |
| } |
| } |
| |
| /* And insert new one */ |
| MINTAUDIO_frequencies[p].frequency = frequency; |
| MINTAUDIO_frequencies[p].masterclock = clock; |
| MINTAUDIO_frequencies[p].predivisor = prediv; |
| MINTAUDIO_frequencies[p].gpio_bits = gpio_bits; |
| |
| MINTAUDIO_freqcount++; |
| } |
| |
| /* Search for the nearest frequency */ |
| int SDL_MintAudio_SearchFrequency(_THIS, int desired_freq) |
| { |
| int i; |
| |
| /* Only 1 freq ? */ |
| if (MINTAUDIO_freqcount==1) { |
| return 0; |
| } |
| |
| /* Check the array */ |
| for (i=0; i<MINTAUDIO_freqcount; i++) { |
| if (desired_freq >= ((MINTAUDIO_frequencies[i].frequency+ |
| MINTAUDIO_frequencies[i+1].frequency)>>1)) { |
| return i; |
| } |
| } |
| |
| /* Not in the array, give the latest */ |
| return MINTAUDIO_freqcount-1; |
| } |
| |
| /* Check if FPU is present */ |
| void SDL_MintAudio_CheckFpu(void) |
| { |
| long cookie_fpu; |
| |
| SDL_MintAudio_hasfpu = 0; |
| if (Getcookie(C__FPU, &cookie_fpu) != C_FOUND) { |
| return; |
| } |
| switch ((cookie_fpu>>16)&0xfffe) { |
| case 2: |
| case 4: |
| case 6: |
| case 8: |
| case 16: |
| SDL_MintAudio_hasfpu = 1; |
| break; |
| } |
| } |
| |
| /* The thread function, used under MiNT with xbios */ |
| int SDL_MintAudio_Thread(long param) |
| { |
| SndBufPtr pointers; |
| SDL_bool buffers_filled[2] = {SDL_FALSE, SDL_FALSE}; |
| |
| SDL_MintAudio_thread_finished = SDL_FALSE; |
| while (!SDL_MintAudio_quit_thread) { |
| if (Buffptr(&pointers)!=0) |
| continue; |
| |
| if (( (unsigned long)pointers.play>=(unsigned long)SDL_MintAudio_audiobuf[0]) |
| && ( (unsigned long)pointers.play<=(unsigned long)SDL_MintAudio_audiobuf[1])) |
| { |
| /* DMA is reading buffer #0, setup buffer #1 if not already done */ |
| if (!buffers_filled[1]) { |
| SDL_MintAudio_numbuf = 1; |
| SDL_MintAudio_Callback(); |
| Setbuffer(0, SDL_MintAudio_audiobuf[1], SDL_MintAudio_audiobuf[1] + SDL_MintAudio_audiosize); |
| buffers_filled[1]=SDL_TRUE; |
| buffers_filled[0]=SDL_FALSE; |
| } |
| } else { |
| /* DMA is reading buffer #1, setup buffer #0 if not already done */ |
| if (!buffers_filled[0]) { |
| SDL_MintAudio_numbuf = 0; |
| SDL_MintAudio_Callback(); |
| Setbuffer(0, SDL_MintAudio_audiobuf[0], SDL_MintAudio_audiobuf[0] + SDL_MintAudio_audiosize); |
| buffers_filled[0]=SDL_TRUE; |
| buffers_filled[1]=SDL_FALSE; |
| } |
| } |
| |
| usleep(100); |
| } |
| SDL_MintAudio_thread_finished = SDL_TRUE; |
| return 0; |
| } |
| |
| void SDL_MintAudio_WaitThread(void) |
| { |
| if (!SDL_MintAudio_mint_present) |
| return; |
| |
| if (SDL_MintAudio_thread_finished) |
| return; |
| |
| SDL_MintAudio_quit_thread = SDL_TRUE; |
| while (!SDL_MintAudio_thread_finished) { |
| Syield(); |
| } |
| } |