path: root/engines/sci/scicore/resource.cpp

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * This program 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 General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $URL$
 * $Id$
 *
 */

/* Resource library */

#include "common/util.h"

#include "sci/include/sci_memory.h"
#include "sci/include/sciresource.h"
#include "sci/include/vocabulary.h" /* For SCI version auto-detection */

#undef SCI_REQUIRE_RESOURCE_FILES
/* #define SCI_VERBOSE_RESMGR 1 */

// FIXME: Get rid of G_DIR_SEPARATOR  / G_DIR_SEPARATOR_S
#if _MSC_VER
#  define G_DIR_SEPARATOR_S "\\"
#  define G_DIR_SEPARATOR '\\'
#else
#  define G_DIR_SEPARATOR_S "/"
#  define G_DIR_SEPARATOR '/'
#endif

const char* sci_version_types[] = {
	"SCI version undetermined (Autodetect failed / not run)",
	"SCI version 0.xxx",
	"SCI version 0.xxx w/ 1.000 compression",
	"SCI version 1.000 w/ 0.xxx resource.map",
	"SCI version 1.000 w/ special resource.map",
	"SCI version 1.000 (early)",
	"SCI version 1.000 (late)",
	"SCI version 1.001",
	"SCI WIN/32"
};

const int sci_max_resource_nr[] = {65536, 1000, 2048, 2048, 2048, 8192, 8192, 65536};

const char* sci_error_types[] = {
	"No error",
	"I/O error",
	"Resource is empty (size 0)",
	"resource.map entry is invalid",
	"resource.map file not found",
	"No resource files found",
	"Unknown compression method",
	"Decompression failed: Decompression buffer overflow",
	"Decompression failed: Sanity check failed",
	"Decompression failed: Resource too big",
	"SCI version is unsupported"
};

const char* sci_resource_types[] = {"view", "pic", "script", "text", "sound",
                                    "memory", "vocab", "font", "cursor",
                                    "patch", "bitmap", "palette", "cdaudio",
                                    "audio", "sync", "message", "map", "heap"
                                   };
/* These are the 18 resource types supported by SCI1 */

const char *sci_resource_type_suffixes[] = {"v56", "p56", "scr", "tex", "snd",
        "   ", "voc", "fon", "cur", "pat",
        "bit", "pal", "cda", "aud", "syn",
        "msg", "map", "hep"
                                           };


int resourcecmp(const void *first, const void *second);


typedef int decomp_funct(resource_t *result, int resh, int sci_version);
typedef void patch_sprintf_funct(char *string, resource_t *res);

static decomp_funct *decompressors[] = {
	NULL,
	&decompress0,
	&decompress01,
	&decompress01,
	&decompress01,
	&decompress1,
	&decompress1,
	&decompress11,
	NULL
};

static patch_sprintf_funct *patch_sprintfers[] = {
	NULL,
	&sci0_sprintf_patch_file_name,
	&sci0_sprintf_patch_file_name,
	&sci1_sprintf_patch_file_name,
	&sci1_sprintf_patch_file_name,
	&sci1_sprintf_patch_file_name,
	&sci1_sprintf_patch_file_name,
	&sci1_sprintf_patch_file_name,
	&sci1_sprintf_patch_file_name
};


int resourcecmp(const void *first, const void *second) {
	if (((resource_t *)first)->type ==
	        ((resource_t *)second)->type)
		return (((resource_t *)first)->number <
		        ((resource_t *)second)->number) ? -1 :
		       !(((resource_t *)first)->number ==
		         ((resource_t *)second)->number);
	else
		return (((resource_t *)first)->type <
		        ((resource_t *)second)->type) ? -1 : 1;
}





/*-----------------------------*/
/*-- Resmgr helper functions --*/
/*-----------------------------*/

void
_scir_add_altsource(resource_t *res, resource_source_t *source, unsigned int file_offset) {
	resource_altsource_t *rsrc = (resource_altsource_t*)sci_malloc(sizeof(resource_altsource_t));

	rsrc->next = res->alt_sources;
	rsrc->source = source;
	rsrc->file_offset = file_offset;
	res->alt_sources = rsrc;
}

resource_t *
_scir_find_resource_unsorted(resource_t *res, int res_nr, int type, int number) {
	int i;
	for (i = 0; i < res_nr; i++)
		if (res[i].number == number && res[i].type == type)
			return res + i;
	return NULL;
}

/*-----------------------------------*/
/** Resource source list management **/
/*-----------------------------------*/

resource_source_t *
scir_add_external_map(resource_mgr_t *mgr, char *file_name) {
	resource_source_t *newsrc = (resource_source_t *)
	                            malloc(sizeof(resource_source_t));

	/* Add the new source to the SLL of sources */
	newsrc->next = mgr->sources;
	mgr->sources = newsrc;

	newsrc->source_type = RESSOURCE_TYPE_EXTERNAL_MAP;
	newsrc->location.file.name = strdup(file_name);
	newsrc->scanned = 0;
	newsrc->associated_map = NULL;

	return newsrc;
}

resource_source_t *
scir_add_volume(resource_mgr_t *mgr, resource_source_t *map, char *filename,
                int number, int extended_addressing) {
	resource_source_t *newsrc = (resource_source_t *)
	                            malloc(sizeof(resource_source_t));

	/* Add the new source to the SLL of sources */
	newsrc->next = mgr->sources;
	mgr->sources = newsrc;

	newsrc->source_type = RESSOURCE_TYPE_VOLUME;
	newsrc->scanned = 0;
	newsrc->location.file.name = strdup(filename);
	newsrc->location.file.volume_number = number;
	newsrc->associated_map = map;
	return 0;
}

resource_source_t *
scir_add_patch_dir(resource_mgr_t *mgr, int type, char *dirname) {
	resource_source_t *newsrc = (resource_source_t *)
	                            malloc(sizeof(resource_source_t));

	/* Add the new source to the SLL of sources */
	newsrc->next = mgr->sources;
	mgr->sources = newsrc;

	newsrc->source_type = RESSOURCE_TYPE_DIRECTORY;
	newsrc->scanned = 0;
	newsrc->location.dir.name = strdup(dirname);
	return 0;
}

resource_source_t *
scir_get_volume(resource_mgr_t *mgr, resource_source_t *map, int volume_nr) {
	resource_source_t *seeker = mgr->sources;

	while (seeker) {
		if (seeker->source_type == RESSOURCE_TYPE_VOLUME &&
		        seeker->associated_map == map &&
		        seeker->location.file.volume_number == volume_nr)
			return seeker;
		seeker = seeker->next;
	}

	return NULL;
}

/*------------------------------------------------*/
/** Resource manager constructors and operations **/
/*------------------------------------------------*/

static void
_scir_init_trivial(resource_mgr_t *mgr) {
	mgr->resources_nr = 0;
	mgr->resources = (resource_t*)sci_malloc(1);
}


static void
_scir_load_from_patch_file(int fh, resource_t *res, char *filename) {
	unsigned int really_read;

	res->data = (unsigned char*)sci_malloc(res->size);
	really_read = read(fh, res->data, res->size);

	if (really_read < res->size) {
		sciprintf("Error: Read %d bytes from %s but expected %d!\n",
		          really_read, filename, res->size);
		exit(1);
	}

	res->status = SCI_STATUS_ALLOCATED;
}

static void
_scir_load_resource(resource_mgr_t *mgr, resource_t *res, int protect) {
	char filename[MAXPATHLEN];
	int fh;
	resource_t backup;
	char *save_cwd = sci_getcwd();

	memcpy(&backup, res, sizeof(resource_t));

	/* First try lower-case name */
	if (res->source->source_type == RESSOURCE_TYPE_DIRECTORY) {

		if (!patch_sprintfers[mgr->sci_version]) {
			sciprintf("Resource manager's SCI version (%d) has no patch file name printers -> internal error!\n",
			          mgr->sci_version);
			exit(1);
		}

		/* Get patch file name */
		patch_sprintfers[mgr->sci_version](filename, res);
		chdir(res->source->location.dir.name);
	} else
		strcpy(filename, res->source->location.file.name);

	fh = open(filename, O_RDONLY | O_BINARY);


	if (!IS_VALID_FD(fh)) {
		char *raiser = filename;
		while (*raiser) {
			*raiser = toupper(*raiser); /* Uppercasify */
			++raiser;
		}
		fh = sci_open(filename, O_RDONLY | O_BINARY);
	}    /* Try case-insensitively name */

	if (!IS_VALID_FD(fh)) {
		sciprintf("Failed to open %s!\n", filename);
		res->data = NULL;
		res->status = SCI_STATUS_NOMALLOC;
		res->size = 0;
		chdir(save_cwd);
		free(save_cwd);
		return;
	}


	lseek(fh, res->file_offset, SEEK_SET);

	if (res->source->source_type == RESSOURCE_TYPE_DIRECTORY ||
	        res->source->source_type == RESSOURCE_TYPE_AUDIO_DIRECTORY)
		_scir_load_from_patch_file(fh, res, filename);
	else if (!decompressors[mgr->sci_version]) {
		/* Check whether we support this at all */
		sciprintf("Resource manager's SCI version (%d) is invalid!\n",
		          mgr->sci_version);
		exit(1);
	} else {
		int error = /* Decompress from regular resource file */
		    decompressors[mgr->sci_version](res, fh, mgr->sci_version);

		if (error) {
			sciprintf("Error %d occured while reading %s.%03d"
			          " from resource file: %s\n",
			          error, sci_resource_types[res->type], res->number,
			          sci_error_types[error]);

			if (protect)
				memcpy(res, &backup, sizeof(resource_t));

			res->data = NULL;
			res->status = SCI_STATUS_NOMALLOC;
			res->size = 0;
			chdir(save_cwd);
			free(save_cwd);
			return;
		}
	}

	close(fh);
}

resource_t *
scir_test_resource(resource_mgr_t *mgr, int type, int number) {
	resource_t binseeker;
	binseeker.type = type;
	binseeker.number = number;
	return (resource_t *)
	       bsearch(&binseeker, mgr->resources, mgr->resources_nr,
	               sizeof(resource_t), resourcecmp);
}

int sci0_get_compression_method(int resh);

int
sci_test_view_type(resource_mgr_t *mgr) {
	int fh;
	char filename[MAXPATHLEN];
	int compression;
	resource_t *res;
	int i;

	mgr->sci_version = SCI_VERSION_AUTODETECT;

	for (i = 0;i < 1000;i++) {
		res = scir_test_resource(mgr, sci_view, i);

		if (!res) continue;

		if (res->source->source_type == RESSOURCE_TYPE_DIRECTORY ||
		        res->source->source_type == RESSOURCE_TYPE_AUDIO_DIRECTORY)
			continue;

		strcpy(filename, res->source->location.file.name);
		fh = open(filename, O_RDONLY | O_BINARY);

		if (!IS_VALID_FD(fh)) {
			char *raiser = filename;
			while (*raiser) {
				*raiser = toupper(*raiser); /* Uppercasify */
				++raiser;
			}
			fh = sci_open(filename, O_RDONLY | O_BINARY);
		}    /* Try case-insensitively name */

		if (!IS_VALID_FD(fh)) continue;
		lseek(fh, res->file_offset, SEEK_SET);

		compression = sci0_get_compression_method(fh);
		close(fh);

		if (compression == 3)
			return (mgr->sci_version = SCI_VERSION_01_VGA);
	}

	/* Try the same thing with pics */
	for (i = 0;i < 1000;i++) {
		res = scir_test_resource(mgr, sci_pic, i);

		if (!res) continue;

		if (res->source->source_type == RESSOURCE_TYPE_DIRECTORY ||
		        res->source->source_type == RESSOURCE_TYPE_AUDIO_DIRECTORY)
			continue;

		strcpy(filename, res->source->location.file.name);
		fh = open(filename, O_RDONLY | O_BINARY);


		if (!IS_VALID_FD(fh)) {
			char *raiser = filename;
			while (*raiser) {
				*raiser = toupper(*raiser); /* Uppercasify */
				++raiser;
			}
			fh = sci_open(filename, O_RDONLY | O_BINARY);
		}    /* Try case-insensitively name */

		if (!IS_VALID_FD(fh)) continue;
		lseek(fh, res->file_offset, SEEK_SET);

		compression = sci0_get_compression_method(fh);
		close(fh);

		if (compression == 3)
			return (mgr->sci_version = SCI_VERSION_01_VGA);
	}

	return mgr->sci_version;
}



int
scir_add_appropriate_sources(resource_mgr_t *mgr,
                             int allow_patches,
                             char *dir) {
	const char *trailing_slash = "";
	//char path_separator;
	sci_dir_t dirent;
	char *name;
	resource_source_t *map;
	int fd;
	char fullname[MAXPATHLEN];

	if (dir[strlen(dir)-1] != G_DIR_SEPARATOR) {
		trailing_slash = G_DIR_SEPARATOR_S;
	}

	name = (char *)malloc(strlen(dir) + 1 +
	                      strlen("RESOURCE.MAP") + 1);

	sprintf(fullname, "%s%s%s", dir, trailing_slash, "RESOURCE.MAP");
	fd = sci_open("RESOURCE.MAP", O_RDONLY | O_BINARY);
	if (!IS_VALID_FD(fd)) return 0;
	close(fd);
	map = scir_add_external_map(mgr, fullname);
	free(name);
	sci_init_dir(&dirent);
	name = sci_find_first(&dirent, "RESOURCE.0??");
	while (name != NULL) {
		char *dot = strrchr(name, '.');
		int number = atoi(dot + 1);

		sprintf(fullname, "%s%s%s", dir, G_DIR_SEPARATOR_S, name);
		scir_add_volume(mgr, map, fullname, number, 0);
		name = sci_find_next(&dirent);
	}
	sci_finish_find(&dirent);

	sci_finish_find(&dirent);
	sprintf(fullname, "%s%s", dir, G_DIR_SEPARATOR_S);
	scir_add_patch_dir(mgr, RESSOURCE_TYPE_DIRECTORY, fullname);

	return 1;
}

static int
_scir_scan_new_sources(resource_mgr_t *mgr, int *detected_version, resource_source_t *source) {
	int preset_version = mgr->sci_version;
	int resource_error = 0;
	int dummy = mgr->sci_version;
//	resource_t **concat_ptr = &(mgr->resources[mgr->resources_nr-1].next);

	if (detected_version == NULL)
		detected_version = &dummy;

	*detected_version = mgr->sci_version;
	if (source->next)
		_scir_scan_new_sources(mgr, detected_version, source->next);

	if (!source->scanned) {
		source->scanned = 1;
		switch (source->source_type) {
		case RESSOURCE_TYPE_DIRECTORY:
			if (mgr->sci_version <= SCI_VERSION_01)
				sci0_read_resource_patches(source,
				                           &mgr->resources,
				                           &mgr->resources_nr);
			else
				sci1_read_resource_patches(source,
				                           &mgr->resources,
				                           &mgr->resources_nr);
			break;
		case RESSOURCE_TYPE_EXTERNAL_MAP:
			if (preset_version <= SCI_VERSION_01_VGA_ODD
			        /* || preset_version == SCI_VERSION_AUTODETECT -- subsumed by the above line */) {
				resource_error =
				    sci0_read_resource_map(mgr,
				                           source,
				                           &mgr->resources,
				                           &mgr->resources_nr,
				                           detected_version);

#if 0
				if (resource_error >= SCI_ERROR_CRITICAL) {
					sciprintf("Resmgr: Error while loading resource map: %s\n",
					          sci_error_types[resource_error]);
					if (resource_error == SCI_ERROR_RESMAP_NOT_FOUND)
						sciprintf("Running SCI games without a resource map is not supported ATM\n");
					sci_free(mgr);
					chdir(caller_cwd);
					free(caller_cwd);
					return NULL;
				}
				if (resource_error == SCI_ERROR_RESMAP_NOT_FOUND) {
					/* fixme: Try reading w/o resource.map */
					resource_error = SCI_ERROR_NO_RESOURCE_FILES_FOUND;
				}

				if (resource_error == SCI_ERROR_NO_RESOURCE_FILES_FOUND) {
					/* Initialize empty resource manager */
					_scir_init_trivial(mgr);
					resource_error = 0;
				}
#endif
			}

			if ((preset_version == SCI_VERSION_1_EARLY) ||
			        (preset_version == SCI_VERSION_1_LATE) ||
			        (preset_version == SCI_VERSION_1_1) ||
			        ((*detected_version == SCI_VERSION_AUTODETECT) && (preset_version == SCI_VERSION_AUTODETECT))) {
				resource_error =
				    sci1_read_resource_map(mgr,
				                           source,
				                           scir_get_volume(mgr, source, 0),
				                           &mgr->resources,
				                           &mgr->resources_nr,
				                           detected_version);

				if (resource_error == SCI_ERROR_RESMAP_NOT_FOUND) {
					/* fixme: Try reading w/o resource.map */
					resource_error = SCI_ERROR_NO_RESOURCE_FILES_FOUND;
				}

				if (resource_error == SCI_ERROR_NO_RESOURCE_FILES_FOUND) {
					/* Initialize empty resource manager */
					_scir_init_trivial(mgr);
					resource_error = 0;
				}
			}

			mgr->sci_version = *detected_version;
			break;
		}
		qsort(mgr->resources, mgr->resources_nr, sizeof(resource_t),
		      resourcecmp); /* Sort resources */
	}
	return resource_error;
}

int
scir_scan_new_sources(resource_mgr_t *mgr, int *detected_version) {
	_scir_scan_new_sources(mgr, detected_version, mgr->sources);
	return 0;
}

static void
_scir_free_resource_sources(resource_source_t *rss) {
	if (rss) {
		_scir_free_resource_sources(rss->next);
		free(rss);
	}
}

resource_mgr_t *
scir_new_resource_manager(char *dir, int version,
                          char allow_patches, int max_memory) {
	int resource_error = 0;
	resource_mgr_t *mgr = (resource_mgr_t*)sci_malloc(sizeof(resource_mgr_t));
	char *caller_cwd = sci_getcwd();
	int resmap_version = version;

	if (chdir(dir)) {
		sciprintf("Resmgr: Directory '%s' is invalid!\n", dir);
		free(caller_cwd);
		return NULL;
	}

	mgr->max_memory = max_memory;

	mgr->memory_locked = 0;
	mgr->memory_lru = 0;

	mgr->resource_path = dir;

	mgr->resources = NULL;
	mgr->resources_nr = 0;
	mgr->sources = NULL;
	mgr->sci_version = version;

	scir_add_appropriate_sources(mgr, allow_patches, dir);
	scir_scan_new_sources(mgr, &resmap_version);

	if (!mgr->resources || !mgr->resources_nr) {
		if (mgr->resources) {
			free(mgr->resources);
			mgr->resources = NULL;
		}
		sciprintf("Resmgr: Could not retrieve a resource list!\n");
		_scir_free_resource_sources(mgr->sources);
		free(mgr);
		chdir(caller_cwd);
		free(caller_cwd);
		return NULL;
	}

	mgr->lru_first = NULL;
	mgr->lru_last = NULL;

	mgr->allow_patches = allow_patches;

	qsort(mgr->resources, mgr->resources_nr, sizeof(resource_t),
	      resourcecmp); /* Sort resources */

	if (version == SCI_VERSION_AUTODETECT)
		switch (resmap_version) {
		case SCI_VERSION_0:
			if (scir_test_resource(mgr, sci_vocab,
			                       VOCAB_RESOURCE_SCI0_MAIN_VOCAB)) {
				version = sci_test_view_type(mgr);
				if (version == SCI_VERSION_01_VGA) {
					sciprintf("Resmgr: Detected KQ5 or similar\n");
				} else {
					sciprintf("Resmgr: Detected SCI0\n");
					version = SCI_VERSION_0;
				}
			} else if (scir_test_resource(mgr, sci_vocab,
			                              VOCAB_RESOURCE_SCI1_MAIN_VOCAB)) {
				version = sci_test_view_type(mgr);
				if (version == SCI_VERSION_01_VGA) {
					sciprintf("Resmgr: Detected KQ5 or similar\n");
				} else {
					if (scir_test_resource(mgr, sci_vocab, 912)) {
						sciprintf("Resmgr: Running KQ1 or similar, using SCI0 resource encoding\n");
						version = SCI_VERSION_0;
					} else {
						version = SCI_VERSION_01;
						sciprintf("Resmgr: Detected SCI01\n");
					}
				}
			} else {
				version = sci_test_view_type(mgr);
				if (version == SCI_VERSION_01_VGA) {
					sciprintf("Resmgr: Detected KQ5 or similar\n");
				} else {
					sciprintf("Resmgr: Warning: Could not find vocabulary; assuming SCI0 w/o parser\n");
					version = SCI_VERSION_0;
				}
			}
			break;
		case SCI_VERSION_01_VGA_ODD:
			version = resmap_version;
			sciprintf("Resmgr: Detected Jones/CD or similar\n");
			break;
		case SCI_VERSION_1: {
			resource_t *res = scir_test_resource(mgr, sci_script, 0);

			mgr->sci_version = version = SCI_VERSION_1_EARLY;
			_scir_load_resource(mgr, res, 1);

			if (res->status == SCI_STATUS_NOMALLOC)
				mgr->sci_version = version = SCI_VERSION_1_LATE;
			break;
		}
		case SCI_VERSION_1_1:
			/* No need to handle SCI 1.1 here - it was done in resource_map.c */
			version = SCI_VERSION_1_1;
			break;
		default:
			sciprintf("Resmgr: Warning: While autodetecting: Couldn't"
			          " determine SCI version!\n");
		}

	if (!resource_error) {
#if 0
		if (version <= SCI_VERSION_01)
			sci0_read_resource_patches(dir,
			                           &mgr->resources,
			                           &mgr->resources_nr);
		else
			sci1_read_resource_patches(dir,
			                           &mgr->resources,
			                           &mgr->resources_nr);
#endif

		qsort(mgr->resources, mgr->resources_nr, sizeof(resource_t),
		      resourcecmp); /* Sort resources */
	}

	mgr->sci_version = version;

	chdir(caller_cwd);
	free(caller_cwd);

	return mgr;
}

static void
_scir_free_altsources(resource_altsource_t *dynressrc) {
	if (dynressrc) {
		_scir_free_altsources(dynressrc->next);
		free(dynressrc);
	}
}

void
_scir_free_resources(resource_t *resources, int resources_nr) {
	int i;

	for (i = 0; i < resources_nr; i++) {
		resource_t *res = resources + i;

		// FIXME: alt_sources->next may point to an invalid memory location
		_scir_free_altsources(res->alt_sources);

		if (res->status != SCI_STATUS_NOMALLOC)
			free(res->data);
	}

	free(resources);
}

void
scir_free_resource_manager(resource_mgr_t *mgr) {
	_scir_free_resources(mgr->resources, mgr->resources_nr);
	_scir_free_resource_sources(mgr->sources);
	mgr->resources = NULL;

	free(mgr);
}


static void
_scir_unalloc(resource_t *res) {
	free(res->data);
	res->data = NULL;
	res->status = SCI_STATUS_NOMALLOC;
}


static void
_scir_remove_from_lru(resource_mgr_t *mgr, resource_t *res) {
	if (res->status != SCI_STATUS_ENQUEUED) {
		sciprintf("Resmgr: Oops: trying to remove resource that isn't"
		          " enqueued\n");
		return;
	}

	if (res->next)
		res->next->prev = res->prev;
	if (res->prev)
		res->prev->next = res->next;
	if (mgr->lru_first == res)
		mgr->lru_first = res->next;
	if (mgr->lru_last == res)
		mgr->lru_last = res->prev;

	mgr->memory_lru -= res->size;

	res->status = SCI_STATUS_ALLOCATED;
}

static void
_scir_add_to_lru(resource_mgr_t *mgr, resource_t *res) {
	if (res->status != SCI_STATUS_ALLOCATED) {
		sciprintf("Resmgr: Oops: trying to enqueue resource with state"
		          " %d\n", res->status);
		return;
	}

	res->prev = NULL;
	res->next = mgr->lru_first;
	mgr->lru_first = res;
	if (!mgr->lru_last)
		mgr->lru_last = res;
	if (res->next)
		res->next->prev = res;

	mgr->memory_lru += res->size;
#if (SCI_VERBOSE_RESMGR > 1)
	fprintf(stderr, "Adding %s.%03d (%d bytes) to lru control: %d bytes total\n",
	        sci_resource_types[res->type], res->number, res->size,
	        mgr->memory_lru);

#endif

	res->status = SCI_STATUS_ENQUEUED;
}

static void
_scir_print_lru_list(resource_mgr_t *mgr) {
	int mem = 0;
	int entries = 0;
	resource_t *res = mgr->lru_first;

	while (res) {
		fprintf(stderr, "\t%s.%03d: %d bytes\n",
		        sci_resource_types[res->type], res->number,
		        res->size);
		mem += res->size;
		++entries;
		res = res->next;
	}

	fprintf(stderr, "Total: %d entries, %d bytes (mgr says %d)\n",
	        entries, mem, mgr->memory_lru);
}

static void
_scir_free_old_resources(resource_mgr_t *mgr, int last_invulnerable) {
	while (mgr->max_memory < mgr->memory_lru
	        && (!last_invulnerable || mgr->lru_first != mgr->lru_last)) {
		resource_t *goner = mgr->lru_last;
		if (!goner) {
			fprintf(stderr, "Internal error: mgr->lru_last is NULL!\n");
			fprintf(stderr, "LRU-mem= %d\n", mgr->memory_lru);
			fprintf(stderr, "lru_first = %p\n", (void *)mgr->lru_first);
			_scir_print_lru_list(mgr);
		}

		_scir_remove_from_lru(mgr, goner);
		_scir_unalloc(goner);
#ifdef SCI_VERBOSE_RESMGR
		sciprintf("Resmgr-debug: LRU: Freeing %s.%03d (%d bytes)\n",
		          sci_resource_types[goner->type], goner->number,
		          goner->size);
#endif
	}
}

resource_t *
scir_find_resource(resource_mgr_t *mgr, int type, int number, int lock) {
	resource_t *retval;

	if (number >= sci_max_resource_nr[mgr->sci_version]) {
		int modded_number = number % sci_max_resource_nr[mgr->sci_version];
		sciprintf("[resmgr] Requested invalid resource %s.%d, mapped to %s.%d\n",
		          sci_resource_types[type], number,
		          sci_resource_types[type], modded_number);
		number = modded_number;
	}

	retval = scir_test_resource(mgr, type, number);

	if (!retval)
		return NULL;

	if (!retval->status)
		_scir_load_resource(mgr, retval, 0);

	else if (retval->status == SCI_STATUS_ENQUEUED)
		_scir_remove_from_lru(mgr, retval);
	/* Unless an error occured, the resource is now either
	** locked or allocated, but never queued or freed.  */

	if (lock) {
		if (retval->status == SCI_STATUS_ALLOCATED) {
			retval->status = SCI_STATUS_LOCKED;
			retval->lockers = 0;
			mgr->memory_locked += retval->size;
		}

		++retval->lockers;

	} else if (retval->status != SCI_STATUS_LOCKED) { /* Don't lock it */
		if (retval->status == SCI_STATUS_ALLOCATED)
			_scir_add_to_lru(mgr, retval);
	}

	_scir_free_old_resources(mgr, retval->status == SCI_STATUS_ALLOCATED);

	if (retval->data)
		return retval;
	else {
		sciprintf("Resmgr: Failed to read %s.%03d\n",
		          sci_resource_types[retval->type], retval->number);
		return NULL;
	}
}

void
scir_unlock_resource(resource_mgr_t *mgr, resource_t *res, int resnum, int restype) {
	if (!res) {
		if (restype >= ARRAYSIZE(sci_resource_types))
			sciprintf("Resmgr: Warning: Attempt to unlock non-existant resource %03d.%03d!\n", restype, resnum);
		else
			sciprintf("Resmgr: Warning: Attempt to unlock non-existant resource %s.%03d!\n", sci_resource_types[restype], resnum);
		return;
	}

	if (res->status != SCI_STATUS_LOCKED) {
		sciprintf("Resmgr: Warning: Attempt to unlock unlocked"
		          " resource %s.%03d\n",
		          sci_resource_types[res->type], res->number);
		return;
	}

	if (!--res->lockers) { /* No more lockers? */
		res->status = SCI_STATUS_ALLOCATED;
		mgr->memory_locked -= res->size;
		_scir_add_to_lru(mgr, res);
	}

	_scir_free_old_resources(mgr, 0);
}