Line data Source code
1 : /*
2 : * Copyright © 2010 Red Hat, Inc.
3 : * Copyright © 2012 Google, Inc.
4 : *
5 : * This is part of HarfBuzz, a text shaping library.
6 : *
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.
12 : *
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
17 : * DAMAGE.
18 : *
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.
24 : *
25 : * Red Hat Author(s): Behdad Esfahbod
26 : * Google Author(s): Behdad Esfahbod
27 : */
28 :
29 : #ifndef HB_OT_HEAD_TABLE_HH
30 : #define HB_OT_HEAD_TABLE_HH
31 :
32 : #include "hb-open-type-private.hh"
33 :
34 :
35 : namespace OT {
36 :
37 :
38 : /*
39 : * head -- Font Header
40 : */
41 :
42 : #define HB_OT_TAG_head HB_TAG('h','e','a','d')
43 :
44 : struct head
45 : {
46 : static const hb_tag_t tableTag = HB_OT_TAG_head;
47 :
48 2 : inline unsigned int get_upem (void) const
49 : {
50 2 : unsigned int upem = unitsPerEm;
51 : /* If no valid head table found, assume 1000, which matches typical Type1 usage. */
52 2 : return 16 <= upem && upem <= 16384 ? upem : 1000;
53 : }
54 :
55 2 : inline bool sanitize (hb_sanitize_context_t *c) const
56 : {
57 2 : TRACE_SANITIZE (this);
58 2 : return_trace (c->check_struct (this) &&
59 : version.major == 1 &&
60 : magicNumber == 0x5F0F3CF5u);
61 : }
62 :
63 : protected:
64 : FixedVersion<>version; /* Version of the head table--currently
65 : * 0x00010000u for version 1.0. */
66 : FixedVersion<>fontRevision; /* Set by font manufacturer. */
67 : ULONG checkSumAdjustment; /* To compute: set it to 0, sum the
68 : * entire font as ULONG, then store
69 : * 0xB1B0AFBAu - sum. */
70 : ULONG magicNumber; /* Set to 0x5F0F3CF5u. */
71 : USHORT flags; /* Bit 0: Baseline for font at y=0;
72 : * Bit 1: Left sidebearing point at x=0;
73 : * Bit 2: Instructions may depend on point size;
74 : * Bit 3: Force ppem to integer values for all
75 : * internal scaler math; may use fractional
76 : * ppem sizes if this bit is clear;
77 : * Bit 4: Instructions may alter advance width
78 : * (the advance widths might not scale linearly);
79 :
80 : * Bits 5-10: These should be set according to
81 : * Apple's specification. However, they are not
82 : * implemented in OpenType.
83 : * Bit 5: This bit should be set in fonts that are
84 : * intended to e laid out vertically, and in
85 : * which the glyphs have been drawn such that an
86 : * x-coordinate of 0 corresponds to the desired
87 : * vertical baseline.
88 : * Bit 6: This bit must be set to zero.
89 : * Bit 7: This bit should be set if the font
90 : * requires layout for correct linguistic
91 : * rendering (e.g. Arabic fonts).
92 : * Bit 8: This bit should be set for a GX font
93 : * which has one or more metamorphosis effects
94 : * designated as happening by default.
95 : * Bit 9: This bit should be set if the font
96 : * contains any strong right-to-left glyphs.
97 : * Bit 10: This bit should be set if the font
98 : * contains Indic-style rearrangement effects.
99 :
100 : * Bit 11: Font data is 'lossless,' as a result
101 : * of having been compressed and decompressed
102 : * with the Agfa MicroType Express engine.
103 : * Bit 12: Font converted (produce compatible metrics)
104 : * Bit 13: Font optimized for ClearType™.
105 : * Note, fonts that rely on embedded bitmaps (EBDT)
106 : * for rendering should not be considered optimized
107 : * for ClearType, and therefore should keep this bit
108 : * cleared.
109 : * Bit 14: Last Resort font. If set, indicates that
110 : * the glyphs encoded in the cmap subtables are simply
111 : * generic symbolic representations of code point
112 : * ranges and don’t truly represent support for those
113 : * code points. If unset, indicates that the glyphs
114 : * encoded in the cmap subtables represent proper
115 : * support for those code points.
116 : * Bit 15: Reserved, set to 0. */
117 : USHORT unitsPerEm; /* Valid range is from 16 to 16384. This value
118 : * should be a power of 2 for fonts that have
119 : * TrueType outlines. */
120 : LONGDATETIME created; /* Number of seconds since 12:00 midnight,
121 : January 1, 1904. 64-bit integer */
122 : LONGDATETIME modified; /* Number of seconds since 12:00 midnight,
123 : January 1, 1904. 64-bit integer */
124 : SHORT xMin; /* For all glyph bounding boxes. */
125 : SHORT yMin; /* For all glyph bounding boxes. */
126 : SHORT xMax; /* For all glyph bounding boxes. */
127 : SHORT yMax; /* For all glyph bounding boxes. */
128 : USHORT macStyle; /* Bit 0: Bold (if set to 1);
129 : * Bit 1: Italic (if set to 1)
130 : * Bit 2: Underline (if set to 1)
131 : * Bit 3: Outline (if set to 1)
132 : * Bit 4: Shadow (if set to 1)
133 : * Bit 5: Condensed (if set to 1)
134 : * Bit 6: Extended (if set to 1)
135 : * Bits 7-15: Reserved (set to 0). */
136 : USHORT lowestRecPPEM; /* Smallest readable size in pixels. */
137 : SHORT fontDirectionHint; /* Deprecated (Set to 2).
138 : * 0: Fully mixed directional glyphs;
139 : * 1: Only strongly left to right;
140 : * 2: Like 1 but also contains neutrals;
141 : * -1: Only strongly right to left;
142 : * -2: Like -1 but also contains neutrals. */
143 : public:
144 : SHORT indexToLocFormat; /* 0 for short offsets, 1 for long. */
145 : SHORT glyphDataFormat; /* 0 for current format. */
146 :
147 : DEFINE_SIZE_STATIC (54);
148 : };
149 :
150 :
151 : } /* namespace OT */
152 :
153 :
154 : #endif /* HB_OT_HEAD_TABLE_HH */
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