include/loaders/GP_MetaData.h

   1 /*****************************************************************************
   2  * This file is part of gfxprim library.                                     *
   3  *                                                                           *
   4  * Gfxprim is free software; you can redistribute it and/or                  *
   5  * modify it under the terms of the GNU Lesser General Public                *
   6  * License as published by the Free Software Foundation; either              *
   7  * version 2.1 of the License, or (at your option) any later version.        *
   8  *                                                                           *
   9  * Gfxprim is distributed in the hope that it will be useful,                *
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of            *
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU         *
  12  * Lesser General Public License for more details.                           *
  13  *                                                                           *
  14  * You should have received a copy of the GNU Lesser General Public          *
  15  * License along with gfxprim; if not, write to the Free Software            *
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor,                        *
  17  * Boston, MA  02110-1301  USA                                               *
  18  *                                                                           *
  19  * Copyright (C) 2009-2012 Cyril Hrubis <metan@ucw.cz>                       *
  20  *                                                                           *
  21  *****************************************************************************/
  22
  23 #ifndef LOADERS_METADATA_H
  24 #define LOADERS_METADATA_H
  25
  26 #define GP_META_RECORD_ID_MAX 32
  27
  28 enum GP_MetaType {
  29         GP_META_INT,
  30         GP_META_STRING,
  31         GP_META_DOUBLE,
  32         GP_META_RATIONAL,
  33 };
  34
  35 struct GP_MetaRational {
  36         int num;
  37         int den;
  38 };
  39
  40 union GP_MetaValue {
  41         int i;
  42         double d;
  43         const char *str;
  44         struct GP_MetaRational r;
  45 };
  46
  47 typedef struct GP_MetaRecord {
  48         char id[GP_META_RECORD_ID_MAX];
  49         unsigned int hash;
  50         enum GP_MetaType type;
  51         struct GP_MetaRecord *next;
  52         union GP_MetaValue val;
  53 } GP_MetaRecord;
  54
  55 typedef struct GP_MetaData GP_MetaData;
  56
  57 /*
  58  * Creates a metadata storage for at least expected_records values.
  59  *
  60  * Returns NULL if allocation has failed.
  61  */
  62 GP_MetaData *GP_MetaDataCreate(unsigned int expected_records);
  63
  64 /*
  65  * Clears meta-data storage.
  66  */
  67 void GP_MetaDataClear(GP_MetaData *self);
  68
  69 /*
  70  * Destroys metadata (frees all alocated memory).
  71  */
  72 void GP_MetaDataDestroy(GP_MetaData *self);
  73
  74 /*
  75  * Prints metadata into the stdout.
  76  */
  77 void GP_MetaDataPrint(GP_MetaData *self);
  78
  79 /*
  80  * Looks for metadata record with id.
  81  */
  82 GP_MetaRecord *GP_MetaDataGetRecord(GP_MetaData *self, const char *id);
  83
  84 /*
  85  * Looks for integer metadata with id. Returns 0 on success and res is set to
  86  * found metadata value.
  87  */
  88 int GP_MetaDataGetInt(GP_MetaData *self, const char *id, int *res);
  89
  90 /*
  91  * Looks for string metadata by id. Returns pointe to found string, or NULL if
  92  * there was no such value.
  93  */
  94 const char *GP_MetaDataGetString(GP_MetaData *self, const char *id);
  95
  96 /*
  97  * Creates an record and returns pointer to it.
  98  *
  99  * May return NULL if allocation has failed.
 100  */
 101 GP_MetaRecord *GP_MetaDataCreateRecord(GP_MetaData *self, const char *id);
 102
 103 /*
 104  * Creates an integer record and returns pointer to it.
 105  */
 106 GP_MetaRecord *GP_MetaDataCreateInt(GP_MetaData *self, const char *id, int val);
 107
 108 GP_MetaRecord *GP_MetaDataCreateRat(GP_MetaData *self, const char *id,
 109                                     int num, int den);
 110
 111 /*
 112  * Creates an double record and returns pointer to it.
 113  */
 114 GP_MetaRecord *GP_MetaDataCreateDouble(GP_MetaData *self, const char *id,
 115                                        double val);
 116
 117 /*
 118  * Creates an string record and returns pointer to it.
 119  *
 120  * If len == 0, string is copied to the terminating '\0', otherwise len
 121  * characters is copied. This has no effect if dup == 0.
 122  *
 123  * If dup is set to 1, the string is duplicated inside of the MetaData
 124  * structure, otherwise only the pointer is saved.
 125  */
 126 GP_MetaRecord *GP_MetaDataCreateString(GP_MetaData *self, const char *id,
 127                                        const char *str, int len, int dup);
 128
 129 /*
 130  * Parses Exif data from passed buffer. The start of the buffer must point to
 131  * the ASCII 'Exif' string.
 132  */
 133 int GP_MetaDataFromExif(GP_MetaData *self, void *buf, size_t buf_len);
 134
 135 #endif /* LOADERS_GP_METADATA_H */