diff options
Diffstat (limited to 'distrib/sdl-1.2.15/src/audio/dc/SDL_dcaudio.c')
| -rw-r--r-- | distrib/sdl-1.2.15/src/audio/dc/SDL_dcaudio.c | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/distrib/sdl-1.2.15/src/audio/dc/SDL_dcaudio.c b/distrib/sdl-1.2.15/src/audio/dc/SDL_dcaudio.c new file mode 100644 index 0000000..88daa87 --- /dev/null +++ b/distrib/sdl-1.2.15/src/audio/dc/SDL_dcaudio.c @@ -0,0 +1,246 @@ +/* + 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 Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with this library; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + + Sam Lantinga + slouken@libsdl.org + +*/ +#include "SDL_config.h" + +/* Output dreamcast aica */ + +#include "SDL_timer.h" +#include "SDL_audio.h" +#include "../SDL_audiomem.h" +#include "../SDL_audio_c.h" +#include "../SDL_audiodev_c.h" +#include "SDL_dcaudio.h" + +#include "aica.h" +#include <dc/spu.h> + +/* Audio driver functions */ +static int DCAUD_OpenAudio(_THIS, SDL_AudioSpec *spec); +static void DCAUD_WaitAudio(_THIS); +static void DCAUD_PlayAudio(_THIS); +static Uint8 *DCAUD_GetAudioBuf(_THIS); +static void DCAUD_CloseAudio(_THIS); + +/* Audio driver bootstrap functions */ +static int DCAUD_Available(void) +{ + return 1; +} + +static void DCAUD_DeleteDevice(SDL_AudioDevice *device) +{ + SDL_free(device->hidden); + SDL_free(device); +} + +static SDL_AudioDevice *DCAUD_CreateDevice(int devindex) +{ + SDL_AudioDevice *this; + + /* Initialize all variables that we clean on shutdown */ + this = (SDL_AudioDevice *)SDL_malloc(sizeof(SDL_AudioDevice)); + if ( this ) { + SDL_memset(this, 0, (sizeof *this)); + this->hidden = (struct SDL_PrivateAudioData *) + SDL_malloc((sizeof *this->hidden)); + } + if ( (this == NULL) || (this->hidden == NULL) ) { + SDL_OutOfMemory(); + if ( this ) { + SDL_free(this); + } + return(0); + } + SDL_memset(this->hidden, 0, (sizeof *this->hidden)); + + /* Set the function pointers */ + this->OpenAudio = DCAUD_OpenAudio; + this->WaitAudio = DCAUD_WaitAudio; + this->PlayAudio = DCAUD_PlayAudio; + this->GetAudioBuf = DCAUD_GetAudioBuf; + this->CloseAudio = DCAUD_CloseAudio; + + this->free = DCAUD_DeleteDevice; + + spu_init(); + + return this; +} + +AudioBootStrap DCAUD_bootstrap = { + "dcaudio", "Dreamcast AICA audio", + DCAUD_Available, DCAUD_CreateDevice +}; + +/* This function waits until it is possible to write a full sound buffer */ +static void DCAUD_WaitAudio(_THIS) +{ + if (this->hidden->playing) { + /* wait */ + while(aica_get_pos(0)/this->spec.samples == this->hidden->nextbuf) { + thd_pass(); + } + } +} + +#define SPU_RAM_BASE 0xa0800000 + +static void spu_memload_stereo8(int leftpos,int rightpos,void *src0,size_t size) +{ + uint8 *src = src0; + uint32 *left = (uint32*)(leftpos +SPU_RAM_BASE); + uint32 *right = (uint32*)(rightpos+SPU_RAM_BASE); + size = (size+7)/8; + while(size--) { + unsigned lval,rval; + lval = *src++; + rval = *src++; + lval|= (*src++)<<8; + rval|= (*src++)<<8; + lval|= (*src++)<<16; + rval|= (*src++)<<16; + lval|= (*src++)<<24; + rval|= (*src++)<<24; + g2_write_32(left++,lval); + g2_write_32(right++,rval); + g2_fifo_wait(); + } +} + +static void spu_memload_stereo16(int leftpos,int rightpos,void *src0,size_t size) +{ + uint16 *src = src0; + uint32 *left = (uint32*)(leftpos +SPU_RAM_BASE); + uint32 *right = (uint32*)(rightpos+SPU_RAM_BASE); + size = (size+7)/8; + while(size--) { + unsigned lval,rval; + lval = *src++; + rval = *src++; + lval|= (*src++)<<16; + rval|= (*src++)<<16; + g2_write_32(left++,lval); + g2_write_32(right++,rval); + g2_fifo_wait(); + } +} + +static void DCAUD_PlayAudio(_THIS) +{ + SDL_AudioSpec *spec = &this->spec; + unsigned int offset; + + if (this->hidden->playing) { + /* wait */ + while(aica_get_pos(0)/spec->samples == this->hidden->nextbuf) { + thd_pass(); + } + } + + offset = this->hidden->nextbuf*spec->size; + this->hidden->nextbuf^=1; + /* Write the audio data, checking for EAGAIN on broken audio drivers */ + if (spec->channels==1) { + spu_memload(this->hidden->leftpos+offset,this->hidden->mixbuf,this->hidden->mixlen); + } else { + offset/=2; + if ((this->spec.format&255)==8) { + spu_memload_stereo8(this->hidden->leftpos+offset,this->hidden->rightpos+offset,this->hidden->mixbuf,this->hidden->mixlen); + } else { + spu_memload_stereo16(this->hidden->leftpos+offset,this->hidden->rightpos+offset,this->hidden->mixbuf,this->hidden->mixlen); + } + } + + if (!this->hidden->playing) { + int mode; + this->hidden->playing = 1; + mode = (spec->format==AUDIO_S8)?SM_8BIT:SM_16BIT; + if (spec->channels==1) { + aica_play(0,mode,this->hidden->leftpos,0,spec->samples*2,spec->freq,255,128,1); + } else { + aica_play(0,mode,this->hidden->leftpos ,0,spec->samples*2,spec->freq,255,0,1); + aica_play(1,mode,this->hidden->rightpos,0,spec->samples*2,spec->freq,255,255,1); + } + } +} + +static Uint8 *DCAUD_GetAudioBuf(_THIS) +{ + return(this->hidden->mixbuf); +} + +static void DCAUD_CloseAudio(_THIS) +{ + aica_stop(0); + if (this->spec.channels==2) aica_stop(1); + if ( this->hidden->mixbuf != NULL ) { + SDL_FreeAudioMem(this->hidden->mixbuf); + this->hidden->mixbuf = NULL; + } +} + +static int DCAUD_OpenAudio(_THIS, SDL_AudioSpec *spec) +{ + Uint16 test_format = SDL_FirstAudioFormat(spec->format); + int valid_datatype = 0; + while ((!valid_datatype) && (test_format)) { + spec->format = test_format; + switch (test_format) { + /* only formats Dreamcast accepts... */ + case AUDIO_S8: + case AUDIO_S16LSB: + valid_datatype = 1; + break; + + default: + test_format = SDL_NextAudioFormat(); + break; + } + } + + if (!valid_datatype) { /* shouldn't happen, but just in case... */ + SDL_SetError("Unsupported audio format"); + return (-1); + } + + if (spec->channels > 2) + spec->channels = 2; /* no more than stereo on the Dreamcast. */ + + /* Update the fragment size as size in bytes */ + SDL_CalculateAudioSpec(spec); + + /* Allocate mixing buffer */ + this->hidden->mixlen = spec->size; + this->hidden->mixbuf = (Uint8 *) SDL_AllocAudioMem(this->hidden->mixlen); + if ( this->hidden->mixbuf == NULL ) { + return(-1); + } + SDL_memset(this->hidden->mixbuf, spec->silence, spec->size); + this->hidden->leftpos = 0x11000; + this->hidden->rightpos = 0x11000+spec->size; + this->hidden->playing = 0; + this->hidden->nextbuf = 0; + + /* We're ready to rock and roll. :-) */ + return(0); +} |