Home | History | Annotate | Download | only in cdrom
      1 /*
      2     SDL - Simple DirectMedia Layer
      3     Copyright (C) 1997-2012 Sam Lantinga
      4 
      5     This library is free software; you can redistribute it and/or
      6     modify it under the terms of the GNU Lesser General Public
      7     License as published by the Free Software Foundation; either
      8     version 2.1 of the License, or (at your option) any later version.
      9 
     10     This library is distributed in the hope that it will be useful,
     11     but WITHOUT ANY WARRANTY; without even the implied warranty of
     12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     13     Lesser General Public License for more details.
     14 
     15     You should have received a copy of the GNU Lesser General Public
     16     License along with this library; if not, write to the Free Software
     17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
     18 
     19     Sam Lantinga
     20     slouken (at) libsdl.org
     21 */
     22 #include "SDL_config.h"
     23 
     24 /* This is the CD-audio control API for Simple DirectMedia Layer */
     25 
     26 #include "SDL_cdrom.h"
     27 #include "SDL_syscdrom.h"
     28 
     29 #if !defined(__MACOS__)
     30 #define CLIP_FRAMES	10	/* Some CD-ROMs won't go all the way */
     31 #endif
     32 
     33 static int SDL_cdinitted = 0;
     34 static SDL_CD *default_cdrom;
     35 
     36 /* The system level CD-ROM control functions */
     37 struct CDcaps SDL_CDcaps = {
     38 	NULL,					/* Name */
     39 	NULL,					/* Open */
     40 	NULL,					/* GetTOC */
     41 	NULL,					/* Status */
     42 	NULL,					/* Play */
     43 	NULL,					/* Pause */
     44 	NULL,					/* Resume */
     45 	NULL,					/* Stop */
     46 	NULL,					/* Eject */
     47 	NULL,					/* Close */
     48 };
     49 int SDL_numcds;
     50 
     51 int SDL_CDROMInit(void)
     52 {
     53 	int retval;
     54 
     55 	SDL_numcds = 0;
     56 	retval = SDL_SYS_CDInit();
     57 	if ( retval == 0 ) {
     58 		SDL_cdinitted = 1;
     59 	}
     60 	default_cdrom = NULL;
     61 	return(retval);
     62 }
     63 
     64 /* Check to see if the CD-ROM subsystem has been initialized */
     65 static int CheckInit(int check_cdrom, SDL_CD **cdrom)
     66 {
     67 	int okay;
     68 
     69 	okay = SDL_cdinitted;
     70 	if ( check_cdrom && (*cdrom == NULL) ) {
     71 		*cdrom = default_cdrom;
     72 		if ( *cdrom == NULL ) {
     73 			SDL_SetError("CD-ROM not opened");
     74 			okay = 0;
     75 		}
     76 	}
     77 	if ( ! SDL_cdinitted ) {
     78 		SDL_SetError("CD-ROM subsystem not initialized");
     79 	}
     80 	return(okay);
     81 }
     82 
     83 int SDL_CDNumDrives(void)
     84 {
     85 	if ( ! CheckInit(0, NULL) ) {
     86 		return(-1);
     87 	}
     88 	return(SDL_numcds);
     89 }
     90 
     91 const char *SDL_CDName(int drive)
     92 {
     93 	if ( ! CheckInit(0, NULL) ) {
     94 		return(NULL);
     95 	}
     96 	if ( drive >= SDL_numcds ) {
     97 		SDL_SetError("Invalid CD-ROM drive index");
     98 		return(NULL);
     99 	}
    100 	if ( SDL_CDcaps.Name ) {
    101 		return(SDL_CDcaps.Name(drive));
    102 	} else {
    103 		return("");
    104 	}
    105 }
    106 
    107 SDL_CD *SDL_CDOpen(int drive)
    108 {
    109 	struct SDL_CD *cdrom;
    110 
    111 	if ( ! CheckInit(0, NULL) ) {
    112 		return(NULL);
    113 	}
    114 	if ( drive >= SDL_numcds ) {
    115 		SDL_SetError("Invalid CD-ROM drive index");
    116 		return(NULL);
    117 	}
    118 	cdrom = (SDL_CD *)SDL_malloc(sizeof(*cdrom));
    119 	if ( cdrom == NULL ) {
    120 		SDL_OutOfMemory();
    121 		return(NULL);
    122 	}
    123 	SDL_memset(cdrom, 0, sizeof(*cdrom));
    124 	cdrom->id = SDL_CDcaps.Open(drive);
    125 	if ( cdrom->id < 0 ) {
    126 		SDL_free(cdrom);
    127 		return(NULL);
    128 	}
    129 	default_cdrom = cdrom;
    130 	return(cdrom);
    131 }
    132 
    133 CDstatus SDL_CDStatus(SDL_CD *cdrom)
    134 {
    135 	CDstatus status;
    136 	int i;
    137 	Uint32 position;
    138 
    139 	/* Check if the CD-ROM subsystem has been initialized */
    140 	if ( ! CheckInit(1, &cdrom) ) {
    141 		return(CD_ERROR);
    142 	}
    143 
    144 	/* Get the current status of the drive */
    145 	cdrom->numtracks = 0;
    146 	cdrom->cur_track = 0;
    147 	cdrom->cur_frame = 0;
    148 	status = SDL_CDcaps.Status(cdrom, &i);
    149 	position = (Uint32)i;
    150 	cdrom->status = status;
    151 
    152 	/* Get the table of contents, if there's a CD available */
    153 	if ( CD_INDRIVE(status) ) {
    154 		if ( SDL_CDcaps.GetTOC(cdrom) < 0 ) {
    155 			status = CD_ERROR;
    156 		}
    157 		/* If the drive is playing, get current play position */
    158 		if ( (status == CD_PLAYING) || (status == CD_PAUSED) ) {
    159 			for ( i=1; cdrom->track[i].offset <= position; ++i ) {
    160 				/* Keep looking */;
    161 			}
    162 #ifdef DEBUG_CDROM
    163   fprintf(stderr, "Current position: %d, track = %d (offset is %d)\n",
    164 				position, i-1, cdrom->track[i-1].offset);
    165 #endif
    166 			cdrom->cur_track = i-1;
    167 			position -= cdrom->track[cdrom->cur_track].offset;
    168 			cdrom->cur_frame = position;
    169 		}
    170 	}
    171 	return(status);
    172 }
    173 
    174 int SDL_CDPlayTracks(SDL_CD *cdrom,
    175 			int strack, int sframe, int ntracks, int nframes)
    176 {
    177 	int etrack, eframe;
    178 	int start, length;
    179 
    180 	/* Check if the CD-ROM subsystem has been initialized */
    181 	if ( ! CheckInit(1, &cdrom) ) {
    182 		return(CD_ERROR);
    183 	}
    184 
    185 	/* Determine the starting and ending tracks */
    186 	if ( (strack < 0) || (strack >= cdrom->numtracks) ) {
    187 		SDL_SetError("Invalid starting track");
    188 		return(CD_ERROR);
    189 	}
    190 	if ( ! ntracks && ! nframes ) {
    191 		etrack = cdrom->numtracks;
    192 		eframe = 0;
    193 	} else {
    194 		etrack = strack+ntracks;
    195 		if ( etrack == strack ) {
    196 			eframe = sframe + nframes;
    197 		} else {
    198 			eframe = nframes;
    199 		}
    200 	}
    201 	if ( etrack > cdrom->numtracks ) {
    202 		SDL_SetError("Invalid play length");
    203 		return(CD_ERROR);
    204 	}
    205 
    206 	/* Skip data tracks and verify frame offsets */
    207 	while ( (strack <= etrack) &&
    208 			(cdrom->track[strack].type == SDL_DATA_TRACK) ) {
    209 		++strack;
    210 	}
    211 	if ( sframe >= (int)cdrom->track[strack].length ) {
    212 		SDL_SetError("Invalid starting frame for track %d", strack);
    213 		return(CD_ERROR);
    214 	}
    215 	while ( (etrack > strack) &&
    216 			(cdrom->track[etrack-1].type == SDL_DATA_TRACK) ) {
    217 		--etrack;
    218 	}
    219 	if ( eframe > (int)cdrom->track[etrack].length ) {
    220 		SDL_SetError("Invalid ending frame for track %d", etrack);
    221 		return(CD_ERROR);
    222 	}
    223 
    224 	/* Determine start frame and play length */
    225 	start = (cdrom->track[strack].offset+sframe);
    226 	length = (cdrom->track[etrack].offset+eframe)-start;
    227 #ifdef CLIP_FRAMES
    228 	/* I've never seen this necessary, but xmcd does it.. */
    229 	length -= CLIP_FRAMES;	/* CLIP_FRAMES == 10 */
    230 #endif
    231 	if ( length < 0 ) {
    232 		return(0);
    233 	}
    234 
    235 	/* Play! */
    236 #ifdef DEBUG_CDROM
    237   fprintf(stderr, "Playing %d frames at offset %d\n", length, start);
    238 #endif
    239 	return(SDL_CDcaps.Play(cdrom, start, length));
    240 }
    241 
    242 int SDL_CDPlay(SDL_CD *cdrom, int sframe, int length)
    243 {
    244 	/* Check if the CD-ROM subsystem has been initialized */
    245 	if ( ! CheckInit(1, &cdrom) ) {
    246 		return(CD_ERROR);
    247 	}
    248 
    249 	return(SDL_CDcaps.Play(cdrom, sframe, length));
    250 }
    251 
    252 int SDL_CDPause(SDL_CD *cdrom)
    253 {
    254 	CDstatus status;
    255 	int retval;
    256 
    257 	/* Check if the CD-ROM subsystem has been initialized */
    258 	if ( ! CheckInit(1, &cdrom) ) {
    259 		return(CD_ERROR);
    260 	}
    261 
    262 	status = SDL_CDcaps.Status(cdrom, NULL);
    263 	switch (status) {
    264 		case CD_PLAYING:
    265 			retval = SDL_CDcaps.Pause(cdrom);
    266 			break;
    267 		default:
    268 			retval = 0;
    269 			break;
    270 	}
    271 	return(retval);
    272 }
    273 
    274 int SDL_CDResume(SDL_CD *cdrom)
    275 {
    276 	CDstatus status;
    277 	int retval;
    278 
    279 	/* Check if the CD-ROM subsystem has been initialized */
    280 	if ( ! CheckInit(1, &cdrom) ) {
    281 		return(CD_ERROR);
    282 	}
    283 
    284 	status = SDL_CDcaps.Status(cdrom, NULL);
    285 	switch (status) {
    286 		case CD_PAUSED:
    287 			retval = SDL_CDcaps.Resume(cdrom);
    288 		default:
    289 			retval = 0;
    290 			break;
    291 	}
    292 	return(retval);
    293 }
    294 
    295 int SDL_CDStop(SDL_CD *cdrom)
    296 {
    297 	CDstatus status;
    298 	int retval;
    299 
    300 	/* Check if the CD-ROM subsystem has been initialized */
    301 	if ( ! CheckInit(1, &cdrom) ) {
    302 		return(CD_ERROR);
    303 	}
    304 
    305 	status = SDL_CDcaps.Status(cdrom, NULL);
    306 	switch (status) {
    307 		case CD_PLAYING:
    308 		case CD_PAUSED:
    309 			retval = SDL_CDcaps.Stop(cdrom);
    310 		default:
    311 			retval = 0;
    312 			break;
    313 	}
    314 	return(retval);
    315 }
    316 
    317 int SDL_CDEject(SDL_CD *cdrom)
    318 {
    319 	/* Check if the CD-ROM subsystem has been initialized */
    320 	if ( ! CheckInit(1, &cdrom) ) {
    321 		return(CD_ERROR);
    322 	}
    323 	return(SDL_CDcaps.Eject(cdrom));
    324 }
    325 
    326 void SDL_CDClose(SDL_CD *cdrom)
    327 {
    328 	/* Check if the CD-ROM subsystem has been initialized */
    329 	if ( ! CheckInit(1, &cdrom) ) {
    330 		return;
    331 	}
    332 	SDL_CDcaps.Close(cdrom);
    333 	SDL_free(cdrom);
    334 	default_cdrom = NULL;
    335 }
    336 
    337 void SDL_CDROMQuit(void)
    338 {
    339 	SDL_SYS_CDQuit();
    340 	SDL_cdinitted = 0;
    341 }
    342