hb-open-file-private.h

   1 #ifndef HB_OPEN_FILE_PRIVATE_H
   2 #define HB_OPEN_FILE_PRIVATE_H
   3
   4 // Organization of an OpenType Font
   5 // note: structs are supposely properly aligned to avoid the use of packing
   6
   7
   8 #define IDX_NOT_FOUND 0xffff
   9
  10 struct tbl_rec
  11 {
  12   uint32_t tag;    //4-byte identifier
  13   uint32_t chk_sum;//Check sum for this table
  14   uint32_t of;     //Offset from beginning of TrueType font file
  15   uint32_t len;    //Length of this table
  16 };
  17 #define ot_tbl tbl_rec
  18
  19 struct ot_fnt_face
  20 {
  21   uint32_t sfnt_ver;      //'\0\001\0\00' if TrueType / 'OTTO' if CFF
  22   uint16_t tbls_n;        //Number of tables
  23   uint16_t search_range;  //(Maximum power of 2 <= tbls_n) * 16
  24   uint16_t entry_selector;//Log2(maximum power of 2 <= tbls_n)
  25   uint16_t range_shift;   //tbls_n * 16 - search_range
  26   struct tbl_rec tbls[1]; //tbl_rec entries. tbls_n items.
  27 };
  28 #define of_tbl ot_fnt_face
  29
  30 struct fixed_ver
  31 {
  32   uint16_t major;
  33   uint16_t minor;
  34 };
  35
  36 struct ttc_hdr_ver1
  37 {
  38   uint32_t ttc_tag;       //TrueType Collection ID string: 'ttcf'
  39   struct fixed_ver ver;   //Version of the TTC Header (1.0), 0x00010000
  40   uint32_t of_tbls_ofs[1];//Array of offsets to the OffsetTable for each
  41                           //font from the beginning of the file
  42 };
  43
  44 struct ttc_hdr
  45 {
  46   union {
  47     struct {
  48       uint32_t ttc_tag;    //TrueType Collection ID string: 'ttcf'
  49       struct fixed_ver ver;//Version of the TTC Header (1.0 or 2.0),
  50                            //* 0x00010000 or 0x00020000 */
  51     } hdr;
  52     struct ttc_hdr_ver1 ver1;
  53   } u;
  54 };
  55
  56 //OpenType with Postscript outlines
  57 #define CFF_TAG HB_TAG('O','T','T','O')
  58 //OpenType with TrueType outlines
  59 #define TRUETYPE_TAG HB_TAG( 0 , 1 , 0 , 0 )
  60 //TrueType Collection
  61 #define TTC_TAG HB_TAG('t','t','c','f')
  62 //Obsolete Apple TrueType
  63 #define TRUE_TAG HB_TAG('t','r','u','e')
  64 //Obsolete Apple Type1 font in SFNT container
  65 #define TYP1_TAG HB_TAG('t','y','p','1')
  66
  67 struct ot_fnt_file
  68 {
  69   union {
  70     uint32_t tag;
  71     struct ot_fnt_face fnt_face;
  72     struct ttc_hdr ttc_hdr;
  73   } u;
  74 };
  75
  76 struct ot_fnt_face *
  77 ot_fnt_file_get_face(struct ot_fnt_file *ot_fnt_file, unsigned i);
  78
  79 struct tbl_rec *
  80 ot_fnt_face_get_tbl_by_tag(struct ot_fnt_face *ot_fnt_face, hb_tag_t tag);
  81 #endif