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1 /****************************************************************************
2  *
3  * wofftypes.h
4  *
5  *   Basic WOFF/WOFF2 type definitions and interface (specification
6  *   only).
7  *
8  * Copyright (C) 1996-2020 by
9  * David Turner, Robert Wilhelm, and Werner Lemberg.
10  *
11  * This file is part of the FreeType project, and may only be used,
12  * modified, and distributed under the terms of the FreeType project
13  * license, LICENSE.TXT.  By continuing to use, modify, or distribute
14  * this file you indicate that you have read the license and
15  * understand and accept it fully.
16  *
17  */
18 
19 
20 #ifndef WOFFTYPES_H_
21 #define WOFFTYPES_H_
22 
23 
24 #include <freetype/tttables.h>
25 #include <freetype/internal/ftobjs.h>
26 
27 
28 FT_BEGIN_HEADER
29 
30 
31   /**************************************************************************
32    *
33    * @struct:
34    *   WOFF_HeaderRec
35    *
36    * @description:
37    *   WOFF file format header.
38    *
39    * @fields:
40    *   See
41    *
42    *     https://www.w3.org/TR/WOFF/#WOFFHeader
43    */
44   typedef struct  WOFF_HeaderRec_
45   {
46     FT_ULong   signature;
47     FT_ULong   flavor;
48     FT_ULong   length;
49     FT_UShort  num_tables;
50     FT_UShort  reserved;
51     FT_ULong   totalSfntSize;
52     FT_UShort  majorVersion;
53     FT_UShort  minorVersion;
54     FT_ULong   metaOffset;
55     FT_ULong   metaLength;
56     FT_ULong   metaOrigLength;
57     FT_ULong   privOffset;
58     FT_ULong   privLength;
59 
60   } WOFF_HeaderRec, *WOFF_Header;
61 
62 
63   /**************************************************************************
64    *
65    * @struct:
66    *   WOFF_TableRec
67    *
68    * @description:
69    *   This structure describes a given table of a WOFF font.
70    *
71    * @fields:
72    *   Tag ::
73    *     A four-bytes tag describing the table.
74    *
75    *   Offset ::
76    *     The offset of the table from the start of the WOFF font in its
77    *     resource.
78    *
79    *   CompLength ::
80    *     Compressed table length (in bytes).
81    *
82    *   OrigLength ::
83    *     Uncompressed table length (in bytes).
84    *
85    *   CheckSum ::
86    *     The table checksum.  This value can be ignored.
87    *
88    *   OrigOffset ::
89    *     The uncompressed table file offset.  This value gets computed while
90    *     constructing the (uncompressed) SFNT header.  It is not contained in
91    *     the WOFF file.
92    */
93   typedef struct  WOFF_TableRec_
94   {
95     FT_ULong  Tag;           /* table ID                  */
96     FT_ULong  Offset;        /* table file offset         */
97     FT_ULong  CompLength;    /* compressed table length   */
98     FT_ULong  OrigLength;    /* uncompressed table length */
99     FT_ULong  CheckSum;      /* uncompressed checksum     */
100 
101     FT_ULong  OrigOffset;    /* uncompressed table file offset */
102                              /* (not in the WOFF file)         */
103   } WOFF_TableRec, *WOFF_Table;
104 
105 
106   /**************************************************************************
107    *
108    * @struct:
109    *   WOFF2_TtcFontRec
110    *
111    * @description:
112    *   Metadata for a TTC font entry in WOFF2.
113    *
114    * @fields:
115    *   flavor ::
116    *     TTC font flavor.
117    *
118    *   num_tables ::
119    *     Number of tables in TTC, indicating number of elements in
120    *     `table_indices`.
121    *
122    *   table_indices ::
123    *     Array of table indices for each TTC font.
124    */
125   typedef struct  WOFF2_TtcFontRec_
126   {
127     FT_ULong    flavor;
128     FT_UShort   num_tables;
129     FT_UShort*  table_indices;
130 
131   } WOFF2_TtcFontRec, *WOFF2_TtcFont;
132 
133 
134   /**************************************************************************
135    *
136    * @struct:
137    *   WOFF2_HeaderRec
138    *
139    * @description:
140    *   WOFF2 file format header.
141    *
142    * @fields:
143    *   See
144    *
145    *     https://www.w3.org/TR/WOFF2/#woff20Header
146    *
147    * @note:
148    *   We don't care about the fields `reserved`, `majorVersion` and
149    *   `minorVersion`, so they are not included.  The `totalSfntSize` field
150    *   does not necessarily represent the actual size of the uncompressed
151    *   SFNT font stream, so that is used as a reference value instead.
152    */
153   typedef struct  WOFF2_HeaderRec_
154   {
155     FT_ULong   signature;
156     FT_ULong   flavor;
157     FT_ULong   length;
158     FT_UShort  num_tables;
159     FT_ULong   totalSfntSize;
160     FT_ULong   totalCompressedSize;
161     FT_ULong   metaOffset;
162     FT_ULong   metaLength;
163     FT_ULong   metaOrigLength;
164     FT_ULong   privOffset;
165     FT_ULong   privLength;
166 
167     FT_ULong   uncompressed_size;    /* uncompressed brotli stream size */
168     FT_ULong   compressed_offset;    /* compressed stream offset        */
169     FT_ULong   header_version;       /* version of original TTC Header  */
170     FT_UShort  num_fonts;            /* number of fonts in TTC          */
171     FT_ULong   actual_sfnt_size;     /* actual size of sfnt stream      */
172 
173     WOFF2_TtcFont  ttc_fonts;        /* metadata for fonts in a TTC     */
174 
175   } WOFF2_HeaderRec, *WOFF2_Header;
176 
177 
178   /**************************************************************************
179    *
180    * @struct:
181    *   WOFF2_TableRec
182    *
183    * @description:
184    *   This structure describes a given table of a WOFF2 font.
185    *
186    * @fields:
187    *   See
188    *
189    *     https://www.w3.org/TR/WOFF2/#table_dir_format
190    */
191   typedef struct  WOFF2_TableRec_
192   {
193     FT_Byte   FlagByte;           /* table type and flags      */
194     FT_ULong  Tag;                /* table file offset         */
195     FT_ULong  dst_length;         /* uncompressed table length */
196     FT_ULong  TransformLength;    /* transformed length        */
197 
198     FT_ULong  flags;              /* calculated flags          */
199     FT_ULong  src_offset;         /* compressed table offset   */
200     FT_ULong  src_length;         /* compressed table length   */
201     FT_ULong  dst_offset;         /* uncompressed table offset */
202 
203   } WOFF2_TableRec, *WOFF2_Table;
204 
205 
206   /**************************************************************************
207    *
208    * @struct:
209    *   WOFF2_InfoRec
210    *
211    * @description:
212    *   Metadata for WOFF2 font that may be required for reconstruction of
213    *   sfnt tables.
214    *
215    * @fields:
216    *   header_checksum ::
217    *     Checksum of SFNT offset table.
218    *
219    *   num_glyphs ::
220    *     Number of glyphs in the font.
221    *
222    *   num_hmetrics ::
223    *     `numberOfHMetrics` field in the 'hhea' table.
224    *
225    *   x_mins ::
226    *     `xMin` values of glyph bounding box.
227    *
228    *   glyf_table ::
229    *     A pointer to the `glyf' table record.
230    *
231    *   loca_table ::
232    *     A pointer to the `loca' table record.
233    *
234    *   head_table ::
235    *     A pointer to the `head' table record.
236    */
237   typedef struct  WOFF2_InfoRec_
238   {
239     FT_ULong   header_checksum;
240     FT_UShort  num_glyphs;
241     FT_UShort  num_hmetrics;
242     FT_Short*  x_mins;
243 
244     WOFF2_Table  glyf_table;
245     WOFF2_Table  loca_table;
246     WOFF2_Table  head_table;
247 
248   } WOFF2_InfoRec, *WOFF2_Info;
249 
250 
251   /**************************************************************************
252    *
253    * @struct:
254    *   WOFF2_SubstreamRec
255    *
256    * @description:
257    *   This structure stores information about a substream in the transformed
258    *   'glyf' table in a WOFF2 stream.
259    *
260    * @fields:
261    *   start ::
262    *     Beginning of the substream relative to uncompressed table stream.
263    *
264    *   offset ::
265    *     Offset of the substream relative to uncompressed table stream.
266    *
267    *   size ::
268    *     Size of the substream.
269    */
270   typedef struct  WOFF2_SubstreamRec_
271   {
272     FT_ULong  start;
273     FT_ULong  offset;
274     FT_ULong  size;
275 
276   } WOFF2_SubstreamRec, *WOFF2_Substream;
277 
278 
279   /**************************************************************************
280    *
281    * @struct:
282    *   WOFF2_PointRec
283    *
284    * @description:
285    *   This structure stores information about a point in the transformed
286    *   'glyf' table in a WOFF2 stream.
287    *
288    * @fields:
289    *   x ::
290    *     x-coordinate of point.
291    *
292    *   y ::
293    *     y-coordinate of point.
294    *
295    *   on_curve ::
296    *     Set if point is on-curve.
297    */
298   typedef struct  WOFF2_PointRec_
299   {
300     FT_Int   x;
301     FT_Int   y;
302     FT_Bool  on_curve;
303 
304   } WOFF2_PointRec, *WOFF2_Point;
305 
306 
307 FT_END_HEADER
308 
309 #endif /* WOFFTYPES_H_ */
310 
311 
312 /* END */
313