sdl_syscdrom.c

SDL库 在进行视频显示程序spcaview安装时必须的库文件

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2004 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
    [e-mail]
*/
#include "SDL_config.h"

#ifdef SDL_CDROM_MINT

/*
	Atari MetaDOS CD-ROM functions

	Patrice Mandin
*/

#include <errno.h>

#include <cdromio.h>
#include <metados.h>

#include "SDL_cdrom.h"
#include "../SDL_syscdrom.h"

/* Some ioctl() errno values which occur when the tray is empty */
#ifndef ENOMEDIUM
#define ENOMEDIUM ENOENT
#endif
#define ERRNO_TRAYEMPTY(errno)	\
	((errno == EIO)    || (errno == ENOENT) || \
	 (errno == EINVAL) || (errno == ENOMEDIUM))

/* The maximum number of CD-ROM drives we'll detect */
#define MAX_DRIVES	32	

typedef struct {
	unsigned char device[3];	/* Physical device letter + ':' + '\0' */
	metaopen_t	metaopen;		/* Infos on opened drive */
} metados_drive_t;

static metados_drive_t metados_drives[MAX_DRIVES];

/* The system-dependent CD control functions */
static const char *SDL_SYS_CDName(int drive);
static int SDL_SYS_CDOpen(int drive);
static void SDL_SYS_CDClose(SDL_CD *cdrom);
static int SDL_SYS_CDioctl(int id, int command, void *arg);
static int SDL_SYS_CDGetTOC(SDL_CD *cdrom);
static CDstatus SDL_SYS_CDStatus(SDL_CD *cdrom, int *position);
static int SDL_SYS_CDPlay(SDL_CD *cdrom, int start, int length);
static int SDL_SYS_CDPause(SDL_CD *cdrom);
static int SDL_SYS_CDResume(SDL_CD *cdrom);
static int SDL_SYS_CDStop(SDL_CD *cdrom);
static int SDL_SYS_CDEject(SDL_CD *cdrom);

int SDL_SYS_CDInit(void)
{
	metainit_t	metainit={0,0,0,0};
	metaopen_t	metaopen;
	int i, handle;
	struct cdrom_subchnl info;

	Metainit(&metainit);
	if (metainit.version == NULL) {
#ifdef DEBUG_CDROM
		fprintf(stderr, "MetaDOS not installed\n");
#endif
		return -1;
	}

	if (metainit.drives_map == 0) {
#ifdef DEBUG_CDROM
		fprintf(stderr, "No MetaDOS devices present\n");
#endif
		return -1;
	}

	SDL_numcds = 0;
	
	for (i='A'; i<='Z'; i++) {
		metados_drives[SDL_numcds].device[0] = 0;
		metados_drives[SDL_numcds].device[1] = ':';
		metados_drives[SDL_numcds].device[2] = 0;

		if (metainit.drives_map & (1<<(i-'A'))) {
			handle = Metaopen(i, &metaopen);
			if (handle == 0) {

				info.cdsc_format = CDROM_MSF;
				if ( (Metaioctl(i, METADOS_IOCTL_MAGIC, CDROMSUBCHNL, &info) == 0) || ERRNO_TRAYEMPTY(errno) ) {
					metados_drives[SDL_numcds].device[0] = i;
					++SDL_numcds;
				}

				Metaclose(i);
			}
		}
	}

	/* Fill in our driver capabilities */
	SDL_CDcaps.Name = SDL_SYS_CDName;
	SDL_CDcaps.Open = SDL_SYS_CDOpen;
	SDL_CDcaps.Close = SDL_SYS_CDClose;

	SDL_CDcaps.GetTOC = SDL_SYS_CDGetTOC;
	SDL_CDcaps.Status = SDL_SYS_CDStatus;
	SDL_CDcaps.Play = SDL_SYS_CDPlay;
	SDL_CDcaps.Pause = SDL_SYS_CDPause;
	SDL_CDcaps.Resume = SDL_SYS_CDResume;
	SDL_CDcaps.Stop = SDL_SYS_CDStop;
	SDL_CDcaps.Eject = SDL_SYS_CDEject;

	return 0;
}

void SDL_SYS_CDQuit(void)
{
	SDL_numcds = 0;
}

static const char *SDL_SYS_CDName(int drive)
{
	return(metados_drives[drive].device);
}

static int SDL_SYS_CDOpen(int drive)
{
	int handle;

	handle = Metaopen(metados_drives[drive].device[0], &(metados_drives[drive].metaopen));
	if (handle == 0) {
		return drive;
	}

	return -1;
}

static void SDL_SYS_CDClose(SDL_CD *cdrom)
{
	Metaclose(metados_drives[cdrom->id].device[0]);
}

static int SDL_SYS_CDioctl(int id, int command, void *arg)
{
	int retval;

	retval = Metaioctl(metados_drives[id].device[0], METADOS_IOCTL_MAGIC, command, arg);
	if ( retval < 0 ) {
		SDL_SetError("ioctl() error: %s", strerror(errno));
	}
	return(retval);
}

static int SDL_SYS_CDGetTOC(SDL_CD *cdrom)
{
	int i,okay;
	struct cdrom_tochdr toc;
	struct cdrom_tocentry entry;

	/* Use standard ioctl() */	
	if (SDL_SYS_CDioctl(cdrom->id, CDROMREADTOCHDR, &toc)<0) {
		return -1;
	}

	cdrom->numtracks = toc.cdth_trk1-toc.cdth_trk0+1;
	if ( cdrom->numtracks > SDL_MAX_TRACKS ) {
		cdrom->numtracks = SDL_MAX_TRACKS;
	}

	/* Read all the track TOC entries */
	okay=1;
	for ( i=0; i<=cdrom->numtracks; ++i ) {
		if ( i == cdrom->numtracks ) {
			cdrom->track[i].id = CDROM_LEADOUT;
		} else {
			cdrom->track[i].id = toc.cdth_trk0+i;
		}
		entry.cdte_track = cdrom->track[i].id;
		entry.cdte_format = CDROM_MSF;
		if ( SDL_SYS_CDioctl(cdrom->id, CDROMREADTOCENTRY, &entry) < 0 ) {
			okay=0;
			break;
		} else {
			if ( entry.cdte_ctrl & CDROM_DATA_TRACK ) {
				cdrom->track[i].type = SDL_DATA_TRACK;
			} else {
				cdrom->track[i].type = SDL_AUDIO_TRACK;
			}
			cdrom->track[i].offset = MSF_TO_FRAMES(
				entry.cdte_addr.msf.minute,
				entry.cdte_addr.msf.second,
				entry.cdte_addr.msf.frame);
				cdrom->track[i].length = 0;
			if ( i > 0 ) {
				cdrom->track[i-1].length = cdrom->track[i].offset-cdrom->track[i-1].offset;
			}
		}
	}

	return(okay ? 0 : -1);
}

/* Get CD-ROM status */
static CDstatus SDL_SYS_CDStatus(SDL_CD *cdrom, int *position)
{
	CDstatus status;
	struct cdrom_tochdr toc;
	struct cdrom_subchnl info;

	info.cdsc_format = CDROM_MSF;
	if ( SDL_SYS_CDioctl(cdrom->id, CDROMSUBCHNL, &info) < 0 ) {
		if ( ERRNO_TRAYEMPTY(errno) ) {
			status = CD_TRAYEMPTY;
		} else {
			status = CD_ERROR;
		}
	} else {
		switch (info.cdsc_audiostatus) {
			case CDROM_AUDIO_INVALID:
			case CDROM_AUDIO_NO_STATUS:
				/* Try to determine if there's a CD available */
				if (SDL_SYS_CDioctl(cdrom->id, CDROMREADTOCHDR, &toc)==0) {
					status = CD_STOPPED;
				} else {
					status = CD_TRAYEMPTY;
				}
				break;
			case CDROM_AUDIO_COMPLETED:
				status = CD_STOPPED;
				break;
			case CDROM_AUDIO_PLAY:
				status = CD_PLAYING;
				break;
			case CDROM_AUDIO_PAUSED:
				/* Workaround buggy CD-ROM drive */
				if ( info.cdsc_trk == CDROM_LEADOUT ) {
					status = CD_STOPPED;
				} else {
					status = CD_PAUSED;
				}
				break;
			default:
				status = CD_ERROR;
				break;
		}
	}
	if ( position ) {
		if ( status == CD_PLAYING || (status == CD_PAUSED) ) {
			*position = MSF_TO_FRAMES(
					info.cdsc_absaddr.msf.minute,
					info.cdsc_absaddr.msf.second,
					info.cdsc_absaddr.msf.frame);
		} else {
			*position = 0;
		}
	}
	return(status);
}

/* Start play */
static int SDL_SYS_CDPlay(SDL_CD *cdrom, int start, int length)
{
	struct cdrom_msf playtime;

	FRAMES_TO_MSF(start,
	   &playtime.cdmsf_min0, &playtime.cdmsf_sec0, &playtime.cdmsf_frame0);
	FRAMES_TO_MSF(start+length,
	   &playtime.cdmsf_min1, &playtime.cdmsf_sec1, &playtime.cdmsf_frame1);
#ifdef DEBUG_CDROM
  fprintf(stderr, "Trying to play from %d:%d:%d to %d:%d:%d\n",
	playtime.cdmsf_min0, playtime.cdmsf_sec0, playtime.cdmsf_frame0,
	playtime.cdmsf_min1, playtime.cdmsf_sec1, playtime.cdmsf_frame1);
#endif

	return SDL_SYS_CDioctl(cdrom->id, CDROMPLAYMSF, &playtime);
}

/* Pause play */
static int SDL_SYS_CDPause(SDL_CD *cdrom)
{
	return SDL_SYS_CDioctl(cdrom->id, CDROMPAUSE, 0);
}

/* Resume play */
static int SDL_SYS_CDResume(SDL_CD *cdrom)
{
	return SDL_SYS_CDioctl(cdrom->id, CDROMRESUME, 0);
}

/* Stop play */
static int SDL_SYS_CDStop(SDL_CD *cdrom)
{
	return SDL_SYS_CDioctl(cdrom->id, CDROMSTOP, 0);
}

/* Eject the CD-ROM */
static int SDL_SYS_CDEject(SDL_CD *cdrom)
{
	return SDL_SYS_CDioctl(cdrom->id, CDROMEJECT, 0);
}

#endif /* SDL_CDROM_MINT */