/*

SDL - Simple DirectMedia Layer

Copyright (C) 1997-2006 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)

{

switch(spec->format&0xff) {

case 8: spec->format = AUDIO_S8; break;

case 16: spec->format = AUDIO_S16LSB; break;

default:

SDL_SetError("Unsupported audio format");

return(-1);

}

/* 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);

}