src/audio/amigaos/SDL_ahiaudio.c

/*
    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"

/* Allow access to a raw mixing buffer (for AmigaOS) */

#include "SDL_audio.h"
#include "../SDL_audio_c.h"
#include "SDL_ahiaudio.h"

/* Audio driver functions */
static int AHI_OpenAudio(_THIS, SDL_AudioSpec * spec);
static void AHI_WaitAudio(_THIS);
static void AHI_PlayAudio(_THIS);
static Uint8 *AHI_GetAudioBuf(_THIS);
static void AHI_CloseAudio(_THIS);

#ifndef __SASC
#define mymalloc(x) AllocVec(x,MEMF_PUBLIC)
#define myfree FreeVec
#else
#define mymalloc malloc
#define myfree free
#endif

/* Audio driver bootstrap functions */

static int
Audio_Available(void)
{
    int ok = 0;
    struct MsgPort *p;
    struct AHIRequest *req;

    if (p = CreateMsgPort()) {
        if (req =
            (struct AHIRequest *) CreateIORequest(p,
                                                  sizeof(struct
                                                         AHIRequest))) {
            req->ahir_Version = 4;

            if (!OpenDevice(AHINAME, 0, (struct IORequest *) req, NULL)) {
                D(bug("AHI available.\n"));
                ok = 1;
                CloseDevice((struct IORequest *) req);
            }
            DeleteIORequest((struct IORequest *) req);
        }
        DeleteMsgPort(p);
    }

    D(if (!ok) bug("AHI not available\n"));
    return ok;
}

static void
Audio_DeleteDevice(SDL_AudioDevice * device)
{
    SDL_free(device->hidden);
    SDL_free(device);
}

static SDL_AudioDevice *
Audio_CreateDevice(int devindex)
{
    SDL_AudioDevice *this;

#ifndef NO_AMIGADEBUG
    D(bug("AHI created...\n"));
#endif

    /* 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 = AHI_OpenAudio;
    this->WaitAudio = AHI_WaitAudio;
    this->PlayAudio = AHI_PlayAudio;
    this->GetAudioBuf = AHI_GetAudioBuf;
    this->CloseAudio = AHI_CloseAudio;

    this->free = Audio_DeleteDevice;

    return this;
}

AudioBootStrap AHI_bootstrap = {
    "AHI", Audio_Available, Audio_CreateDevice
};


void static
AHI_WaitAudio(_THIS)
{
    if (!CheckIO((struct IORequest *) audio_req[current_buffer])) {
        WaitIO((struct IORequest *) audio_req[current_buffer]);
//              AbortIO((struct IORequest *)audio_req[current_buffer]);
    }
}

static void
AHI_PlayAudio(_THIS)
{
    if (playing > 1)
        WaitIO((struct IORequest *) audio_req[current_buffer]);

    /* Write the audio data out */
    audio_req[current_buffer]->ahir_Std.io_Message.mn_Node.ln_Pri = 60;
    audio_req[current_buffer]->ahir_Std.io_Data = mixbuf[current_buffer];
    audio_req[current_buffer]->ahir_Std.io_Length = this->hidden->size;
    audio_req[current_buffer]->ahir_Std.io_Offset = 0;
    audio_req[current_buffer]->ahir_Std.io_Command = CMD_WRITE;
    audio_req[current_buffer]->ahir_Frequency = this->hidden->freq;
    audio_req[current_buffer]->ahir_Volume = 0x10000;
    audio_req[current_buffer]->ahir_Type = this->hidden->type;
    audio_req[current_buffer]->ahir_Position = 0x8000;
    audio_req[current_buffer]->ahir_Link =
        (playing > 0 ? audio_req[current_buffer ^ 1] : NULL);

    SendIO((struct IORequest *) audio_req[current_buffer]);
    current_buffer ^= 1;

    playing++;
}

static Uint8 *
AHI_GetAudioBuf(_THIS)
{
    return (mixbuf[current_buffer]);
}

static void
AHI_CloseAudio(_THIS)
{
    D(bug("Closing audio...\n"));

    playing = 0;

    if (audio_req[0]) {
        if (audio_req[1]) {
            D(bug("Break req[1]...\n"));

            AbortIO((struct IORequest *) audio_req[1]);
            WaitIO((struct IORequest *) audio_req[1]);
        }

        D(bug("Break req[0]...\n"));

        AbortIO((struct IORequest *) audio_req[0]);
        WaitIO((struct IORequest *) audio_req[0]);

        if (audio_req[1]) {
            D(bug("Break AGAIN req[1]...\n"));
            AbortIO((struct IORequest *) audio_req[1]);
            WaitIO((struct IORequest *) audio_req[1]);
        }
// Double abort to be sure to break the dbuffering process.

        SDL_Delay(200);

        D(bug("Reqs breaked, closing device...\n"));
        CloseDevice((struct IORequest *) audio_req[0]);
        D(bug("Device closed, freeing memory...\n"));
        myfree(audio_req[1]);
        D(bug("Memory freed, deleting IOReq...\n"));
        DeleteIORequest((struct IORequest *) audio_req[0]);
        audio_req[0] = audio_req[1] = NULL;
    }

    D(bug("Freeing mixbuf[0]...\n"));
    if (mixbuf[0] != NULL) {
        myfree(mixbuf[0]);
//              SDL_FreeAudioMem(mixbuf[0]);
        mixbuf[0] = NULL;
    }

    D(bug("Freeing mixbuf[1]...\n"));
    if (mixbuf[1] != NULL) {
        myfree(mixbuf[1]);
//              SDL_FreeAudioMem(mixbuf[1]);
        mixbuf[1] = NULL;
    }

    D(bug("Freeing audio_port...\n"));

    if (audio_port != NULL) {
        DeleteMsgPort(audio_port);
        audio_port = NULL;
    }
    D(bug("...done!\n"));
}

static int
AHI_OpenAudio(_THIS, SDL_AudioSpec * spec)
{
//      int width;

    D(bug("AHI opening...\n"));

    /* Determine the audio parameters from the AudioSpec */
    switch (spec->format & 0xFF) {

    case 8:
        {                       /* Signed 8 bit audio data */
            D(bug("Samples a 8 bit...\n"));
            spec->format = AUDIO_S8;
            this->hidden->bytespersample = 1;
            if (spec->channels < 2)
                this->hidden->type = AHIST_M8S;
            else
                this->hidden->type = AHIST_S8S;
        }
        break;

    case 16:
        {                       /* Signed 16 bit audio data */
            D(bug("Samples a 16 bit...\n"));
            spec->format = AUDIO_S16MSB;
            this->hidden->bytespersample = 2;
            if (spec->channels < 2)
                this->hidden->type = AHIST_M16S;
            else
                this->hidden->type = AHIST_S16S;
        }
        break;

    default:
        {
            SDL_SetError("Unsupported audio format");
            return (-1);
        }
    }

    if (spec->channels != 1 && spec->channels != 2) {
        D(bug("Wrong channel number!\n"));
        SDL_SetError("Channel number non supported");
        return -1;
    }

    D(bug("Before CalculateAudioSpec\n"));
    /* Update the fragment size as size in bytes */
    SDL_CalculateAudioSpec(spec);

    D(bug("Before CreateMsgPort\n"));

    if (!(audio_port = CreateMsgPort())) {
        SDL_SetError("Unable to create a MsgPort");
        return -1;
    }

    D(bug("Before CreateIORequest\n"));

    if (!
        (audio_req[0] =
         (struct AHIRequest *) CreateIORequest(audio_port,
                                               sizeof(struct AHIRequest)))) {
        SDL_SetError("Unable to create an AHIRequest");
        DeleteMsgPort(audio_port);
        return -1;
    }

    audio_req[0]->ahir_Version = 4;

    if (OpenDevice(AHINAME, 0, (struct IORequest *) audio_req[0], NULL)) {
        SDL_SetError("Unable to open AHI device!\n");
        DeleteIORequest((struct IORequest *) audio_req[0]);
        DeleteMsgPort(audio_port);
        return -1;
    }

    D(bug("AFTER opendevice\n"));

    /* Set output frequency and size */
    this->hidden->freq = spec->freq;
    this->hidden->size = spec->size;

    D(bug("Before buffer allocation\n"));

    /* Allocate mixing buffer */
    mixbuf[0] = (Uint8 *) mymalloc(spec->size);
    mixbuf[1] = (Uint8 *) mymalloc(spec->size);

    D(bug("Before audio_req allocation\n"));

    if (!(audio_req[1] = mymalloc(sizeof(struct AHIRequest)))) {
        SDL_OutOfMemory();
        return (-1);
    }

    D(bug("Before audio_req memcpy\n"));

    SDL_memcpy(audio_req[1], audio_req[0], sizeof(struct AHIRequest));

    if (mixbuf[0] == NULL || mixbuf[1] == NULL) {
        SDL_OutOfMemory();
        return (-1);
    }

    D(bug("Before mixbuf memset\n"));

    SDL_memset(mixbuf[0], spec->silence, spec->size);
    SDL_memset(mixbuf[1], spec->silence, spec->size);

    current_buffer = 0;
    playing = 0;

    D(bug
      ("AHI opened: freq:%ld mixbuf:%lx/%lx buflen:%ld bits:%ld channels:%ld\n",
       spec->freq, mixbuf[0], mixbuf[1], spec->size,
       this->hidden->bytespersample * 8, spec->channels));

    /* We're ready to rock and roll. :-) */
    return (0);
}

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