1 : /*
2 : * Copyright © 2010 Red Hat, Inc.
3 : *
4 : * This is part of HarfBuzz, a text shaping library.
5 : *
6 : * Permission is hereby granted, without written agreement and without
7 : * license or royalty fees, to use, copy, modify, and distribute this
8 : * software and its documentation for any purpose, provided that the
9 : * above copyright notice and the following two paragraphs appear in
10 : * all copies of this software.
11 : *
12 : * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 : * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 : * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 : * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16 : * DAMAGE.
17 : *
18 : * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 : * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 : * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 : * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 : * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23 : *
24 : * Red Hat Author(s): Behdad Esfahbod
25 : */
26 :
27 : #ifndef HB_OT_HEAD_TABLE_HH
28 : #define HB_OT_HEAD_TABLE_HH
29 :
30 : #include "hb-open-type-private.hh"
31 :
32 :
33 :
34 : /*
35 : * head -- Font Header
36 : */
37 :
38 : #define HB_OT_TAG_head HB_TAG('h','e','a','d')
39 :
40 : struct head
41 : {
42 : static const hb_tag_t Tag = HB_OT_TAG_head;
43 :
44 0 : inline unsigned int get_upem (void) const {
45 0 : unsigned int upem = unitsPerEm;
46 : /* If no valid head table found, assume 1000, which matches typicaly Type1 usage. */
47 0 : return 16 <= upem && upem <= 16384 ? upem : 1000;
48 : }
49 :
50 0 : inline bool sanitize (hb_sanitize_context_t *c) {
51 0 : TRACE_SANITIZE ();
52 0 : return c->check_struct (this) && likely (version.major == 1);
53 : }
54 :
55 : private:
56 : FixedVersion version; /* Version of the head table--currently
57 : * 0x00010000 for version 1.0. */
58 : FixedVersion fontRevision; /* Set by font manufacturer. */
59 : ULONG checkSumAdjustment; /* To compute: set it to 0, sum the
60 : * entire font as ULONG, then store
61 : * 0xB1B0AFBA - sum. */
62 : ULONG magicNumber; /* Set to 0x5F0F3CF5. */
63 : USHORT flags; /* Bit 0: Baseline for font at y=0;
64 : * Bit 1: Left sidebearing point at x=0;
65 : * Bit 2: Instructions may depend on point size;
66 : * Bit 3: Force ppem to integer values for all
67 : * internal scaler math; may use fractional
68 : * ppem sizes if this bit is clear;
69 : * Bit 4: Instructions may alter advance width
70 : * (the advance widths might not scale linearly);
71 :
72 : * Bits 5-10: These should be set according to
73 : * Apple's specification. However, they are not
74 : * implemented in OpenType.
75 : * Bit 5: This bit should be set in fonts that are
76 : * intended to e laid out vertically, and in
77 : * which the glyphs have been drawn such that an
78 : * x-coordinate of 0 corresponds to the desired
79 : * vertical baseline.
80 : * Bit 6: This bit must be set to zero.
81 : * Bit 7: This bit should be set if the font
82 : * requires layout for correct linguistic
83 : * rendering (e.g. Arabic fonts).
84 : * Bit 8: This bit should be set for a GX font
85 : * which has one or more metamorphosis effects
86 : * designated as happening by default.
87 : * Bit 9: This bit should be set if the font
88 : * contains any strong right-to-left glyphs.
89 : * Bit 10: This bit should be set if the font
90 : * contains Indic-style rearrangement effects.
91 :
92 : * Bit 11: Font data is 'lossless,' as a result
93 : * of having been compressed and decompressed
94 : * with the Agfa MicroType Express engine.
95 : * Bit 12: Font converted (produce compatible metrics)
96 : * Bit 13: Font optimized for ClearType™.
97 : * Note, fonts that rely on embedded bitmaps (EBDT)
98 : * for rendering should not be considered optimized
99 : * for ClearType, and therefore should keep this bit
100 : * cleared.
101 : * Bit 14: Last Resort font. If set, indicates that
102 : * the glyphs encoded in the cmap subtables are simply
103 : * generic symbolic representations of code point
104 : * ranges and don’t truly represent support for those
105 : * code points. If unset, indicates that the glyphs
106 : * encoded in the cmap subtables represent proper
107 : * support for those code points.
108 : * Bit 15: Reserved, set to 0. */
109 : USHORT unitsPerEm; /* Valid range is from 16 to 16384. This value
110 : * should be a power of 2 for fonts that have
111 : * TrueType outlines. */
112 : LONGDATETIME created; /* Number of seconds since 12:00 midnight,
113 : January 1, 1904. 64-bit integer */
114 : LONGDATETIME modified; /* Number of seconds since 12:00 midnight,
115 : January 1, 1904. 64-bit integer */
116 : SHORT xMin; /* For all glyph bounding boxes. */
117 : SHORT yMin; /* For all glyph bounding boxes. */
118 : SHORT xMax; /* For all glyph bounding boxes. */
119 : SHORT yMax; /* For all glyph bounding boxes. */
120 : USHORT macStyle; /* Bit 0: Bold (if set to 1);
121 : * Bit 1: Italic (if set to 1)
122 : * Bit 2: Underline (if set to 1)
123 : * Bit 3: Outline (if set to 1)
124 : * Bit 4: Shadow (if set to 1)
125 : * Bit 5: Condensed (if set to 1)
126 : * Bit 6: Extended (if set to 1)
127 : * Bits 7-15: Reserved (set to 0). */
128 : USHORT lowestRecPPEM; /* Smallest readable size in pixels. */
129 : SHORT fontDirectionHint; /* Deprecated (Set to 2).
130 : * 0: Fully mixed directional glyphs;
131 : * 1: Only strongly left to right;
132 : * 2: Like 1 but also contains neutrals;
133 : * -1: Only strongly right to left;
134 : * -2: Like -1 but also contains neutrals. */
135 : SHORT indexToLocFormat; /* 0 for short offsets, 1 for long. */
136 : SHORT glyphDataFormat; /* 0 for current format. */
137 : public:
138 : DEFINE_SIZE_STATIC (54);
139 : };
140 :
141 :
142 :
143 : #endif /* HB_OT_HEAD_TABLE_HH */
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