src/cdrom/SDL_cdrom.c
author Ryan C. Gordon
Wed, 29 Nov 2006 10:30:05 +0000
branchSDL-1.2
changeset 3900 ce3a2bd11305
parent 1402 d910939febfa
child 1662 782fd950bd46
child 1895 c121d94672cb
child 4159 a1b03ba2fcd0
permissions -rw-r--r--
Wrapped some macro params in parentheses for alloca wrappers.
Thansk, Suzuki Masahiro.
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2006 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@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 }