2 * Copyright © 2010 Red Hat, Inc.
3 * Copyright © 2012 Google, Inc.
5 * This is part of HarfBuzz, a text shaping library.
7 * Permission is hereby granted, without written agreement and without
8 * license or royalty fees, to use, copy, modify, and distribute this
9 * software and its documentation for any purpose, provided that the
10 * above copyright notice and the following two paragraphs appear in
11 * all copies of this software.
13 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
14 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
15 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
16 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
19 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
20 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
22 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
23 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
25 * Red Hat Author(s): Behdad Esfahbod
26 * Google Author(s): Behdad Esfahbod
29 #ifndef HB_OT_HEAD_TABLE_HH
30 #define HB_OT_HEAD_TABLE_HH
32 #include "hb-open-type-private.hh"
40 #define HB_OT_TAG_head HB_TAG('h','e','a','d')
44 static const hb_tag_t Tag = HB_OT_TAG_head;
46 inline unsigned int get_upem (void) const {
47 unsigned int upem = unitsPerEm;
48 /* If no valid head table found, assume 1000, which matches typicaly Type1 usage. */
49 return 16 <= upem && upem <= 16384 ? upem : 1000;
52 inline bool sanitize (hb_sanitize_context_t *c) {
54 return TRACE_RETURN (c->check_struct (this) && likely (version.major == 1));
58 FixedVersion version; /* Version of the head table--currently
59 * 0x00010000 for version 1.0. */
60 FixedVersion fontRevision; /* Set by font manufacturer. */
61 ULONG checkSumAdjustment; /* To compute: set it to 0, sum the
62 * entire font as ULONG, then store
63 * 0xB1B0AFBA - sum. */
64 ULONG magicNumber; /* Set to 0x5F0F3CF5. */
65 USHORT flags; /* Bit 0: Baseline for font at y=0;
66 * Bit 1: Left sidebearing point at x=0;
67 * Bit 2: Instructions may depend on point size;
68 * Bit 3: Force ppem to integer values for all
69 * internal scaler math; may use fractional
70 * ppem sizes if this bit is clear;
71 * Bit 4: Instructions may alter advance width
72 * (the advance widths might not scale linearly);
74 * Bits 5-10: These should be set according to
75 * Apple's specification. However, they are not
76 * implemented in OpenType.
77 * Bit 5: This bit should be set in fonts that are
78 * intended to e laid out vertically, and in
79 * which the glyphs have been drawn such that an
80 * x-coordinate of 0 corresponds to the desired
82 * Bit 6: This bit must be set to zero.
83 * Bit 7: This bit should be set if the font
84 * requires layout for correct linguistic
85 * rendering (e.g. Arabic fonts).
86 * Bit 8: This bit should be set for a GX font
87 * which has one or more metamorphosis effects
88 * designated as happening by default.
89 * Bit 9: This bit should be set if the font
90 * contains any strong right-to-left glyphs.
91 * Bit 10: This bit should be set if the font
92 * contains Indic-style rearrangement effects.
94 * Bit 11: Font data is 'lossless,' as a result
95 * of having been compressed and decompressed
96 * with the Agfa MicroType Express engine.
97 * Bit 12: Font converted (produce compatible metrics)
98 * Bit 13: Font optimized for ClearType™.
99 * Note, fonts that rely on embedded bitmaps (EBDT)
100 * for rendering should not be considered optimized
101 * for ClearType, and therefore should keep this bit
103 * Bit 14: Last Resort font. If set, indicates that
104 * the glyphs encoded in the cmap subtables are simply
105 * generic symbolic representations of code point
106 * ranges and don’t truly represent support for those
107 * code points. If unset, indicates that the glyphs
108 * encoded in the cmap subtables represent proper
109 * support for those code points.
110 * Bit 15: Reserved, set to 0. */
111 USHORT unitsPerEm; /* Valid range is from 16 to 16384. This value
112 * should be a power of 2 for fonts that have
113 * TrueType outlines. */
114 LONGDATETIME created; /* Number of seconds since 12:00 midnight,
115 January 1, 1904. 64-bit integer */
116 LONGDATETIME modified; /* Number of seconds since 12:00 midnight,
117 January 1, 1904. 64-bit integer */
118 SHORT xMin; /* For all glyph bounding boxes. */
119 SHORT yMin; /* For all glyph bounding boxes. */
120 SHORT xMax; /* For all glyph bounding boxes. */
121 SHORT yMax; /* For all glyph bounding boxes. */
122 USHORT macStyle; /* Bit 0: Bold (if set to 1);
123 * Bit 1: Italic (if set to 1)
124 * Bit 2: Underline (if set to 1)
125 * Bit 3: Outline (if set to 1)
126 * Bit 4: Shadow (if set to 1)
127 * Bit 5: Condensed (if set to 1)
128 * Bit 6: Extended (if set to 1)
129 * Bits 7-15: Reserved (set to 0). */
130 USHORT lowestRecPPEM; /* Smallest readable size in pixels. */
131 SHORT fontDirectionHint; /* Deprecated (Set to 2).
132 * 0: Fully mixed directional glyphs;
133 * 1: Only strongly left to right;
134 * 2: Like 1 but also contains neutrals;
135 * -1: Only strongly right to left;
136 * -2: Like -1 but also contains neutrals. */
137 SHORT indexToLocFormat; /* 0 for short offsets, 1 for long. */
138 SHORT glyphDataFormat; /* 0 for current format. */
140 DEFINE_SIZE_STATIC (54);
145 #endif /* HB_OT_HEAD_TABLE_HH */