/*

    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);

}

/* vi: set ts=4 sw=4 expandtab: */