1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
|
/*
* Copyright © 2010 Red Hat, Inc.
* Copyright © 2012 Google, Inc.
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Red Hat Author(s): Behdad Esfahbod
* Google Author(s): Behdad Esfahbod
*/
#ifndef HB_OT_HEAD_TABLE_HH
#define HB_OT_HEAD_TABLE_HH
#include "hb-open-type.hh"
/*
* head -- Font Header
* https://docs.microsoft.com/en-us/typography/opentype/spec/head
*/
#define HB_OT_TAG_head HB_TAG('h','e','a','d')
namespace OT {
struct head
{
friend struct OpenTypeOffsetTable;
static constexpr hb_tag_t tableTag = HB_OT_TAG_head;
unsigned int get_upem () const
{
unsigned int upem = unitsPerEm;
/* If no valid head table found, assume 1000, which matches typical Type1 usage. */
return 16 <= upem && upem <= 16384 ? upem : 1000;
}
bool serialize (hb_serialize_context_t *c) const
{
TRACE_SERIALIZE (this);
return_trace ((bool) c->embed (this));
}
bool subset (hb_subset_context_t *c) const
{
TRACE_SUBSET (this);
head *out = c->serializer->embed (this);
if (unlikely (!out)) return_trace (false);
if (c->plan->normalized_coords)
{
if (unlikely (!c->serializer->check_assign (out->xMin, c->plan->head_maxp_info.xMin,
HB_SERIALIZE_ERROR_INT_OVERFLOW)))
return_trace (false);
if (unlikely (!c->serializer->check_assign (out->xMax, c->plan->head_maxp_info.xMax,
HB_SERIALIZE_ERROR_INT_OVERFLOW)))
return_trace (false);
if (unlikely (!c->serializer->check_assign (out->yMin, c->plan->head_maxp_info.yMin,
HB_SERIALIZE_ERROR_INT_OVERFLOW)))
return_trace (false);
if (unlikely (!c->serializer->check_assign (out->yMax, c->plan->head_maxp_info.yMax,
HB_SERIALIZE_ERROR_INT_OVERFLOW)))
return_trace (false);
}
return_trace (true);
}
enum mac_style_flag_t {
BOLD = 1u<<0,
ITALIC = 1u<<1,
UNDERLINE = 1u<<2,
OUTLINE = 1u<<3,
SHADOW = 1u<<4,
CONDENSED = 1u<<5,
EXPANDED = 1u<<6,
};
bool is_bold () const { return macStyle & BOLD; }
bool is_italic () const { return macStyle & ITALIC; }
bool is_condensed () const { return macStyle & CONDENSED; }
bool is_expanded () const { return macStyle & EXPANDED; }
bool sanitize (hb_sanitize_context_t *c) const
{
TRACE_SANITIZE (this);
return_trace (c->check_struct (this) &&
hb_barrier () &&
version.major == 1 &&
magicNumber == 0x5F0F3CF5u);
}
protected:
FixedVersion<>version; /* Version of the head table--currently
* 0x00010000u for version 1.0. */
FixedVersion<>fontRevision; /* Set by font manufacturer. */
HBUINT32 checkSumAdjustment; /* To compute: set it to 0, sum the
* entire font as HBUINT32, then store
* 0xB1B0AFBAu - sum. */
HBUINT32 magicNumber; /* Set to 0x5F0F3CF5u. */
public:
HBUINT16 flags; /* Bit 0: Baseline for font at y=0;
* Bit 1: Left sidebearing point at x=0;
* Bit 2: Instructions may depend on point size;
* Bit 3: Force ppem to integer values for all
* internal scaler math; may use fractional
* ppem sizes if this bit is clear;
* Bit 4: Instructions may alter advance width
* (the advance widths might not scale linearly);
* Bits 5-10: These should be set according to
* Apple's specification. However, they are not
* implemented in OpenType.
* Bit 5: This bit should be set in fonts that are
* intended to e laid out vertically, and in
* which the glyphs have been drawn such that an
* x-coordinate of 0 corresponds to the desired
* vertical baseline.
* Bit 6: This bit must be set to zero.
* Bit 7: This bit should be set if the font
* requires layout for correct linguistic
* rendering (e.g. Arabic fonts).
* Bit 8: This bit should be set for a GX font
* which has one or more metamorphosis effects
* designated as happening by default.
* Bit 9: This bit should be set if the font
* contains any strong right-to-left glyphs.
* Bit 10: This bit should be set if the font
* contains Indic-style rearrangement effects.
* Bit 11: Font data is 'lossless,' as a result
* of having been compressed and decompressed
* with the Agfa MicroType Express engine.
* Bit 12: Font converted (produce compatible metrics)
* Bit 13: Font optimized for ClearType™.
* Note, fonts that rely on embedded bitmaps (EBDT)
* for rendering should not be considered optimized
* for ClearType, and therefore should keep this bit
* cleared.
* Bit 14: Last Resort font. If set, indicates that
* the glyphs encoded in the cmap subtables are simply
* generic symbolic representations of code point
* ranges and don’t truly represent support for those
* code points. If unset, indicates that the glyphs
* encoded in the cmap subtables represent proper
* support for those code points.
* Bit 15: Reserved, set to 0. */
protected:
HBUINT16 unitsPerEm; /* Valid range is from 16 to 16384. This value
* should be a power of 2 for fonts that have
* TrueType outlines. */
LONGDATETIME created; /* Number of seconds since 12:00 midnight,
January 1, 1904. 64-bit integer */
LONGDATETIME modified; /* Number of seconds since 12:00 midnight,
January 1, 1904. 64-bit integer */
public:
HBINT16 xMin; /* For all glyph bounding boxes. */
HBINT16 yMin; /* For all glyph bounding boxes. */
HBINT16 xMax; /* For all glyph bounding boxes. */
HBINT16 yMax; /* For all glyph bounding boxes. */
protected:
HBUINT16 macStyle; /* Bit 0: Bold (if set to 1);
* Bit 1: Italic (if set to 1)
* Bit 2: Underline (if set to 1)
* Bit 3: Outline (if set to 1)
* Bit 4: Shadow (if set to 1)
* Bit 5: Condensed (if set to 1)
* Bit 6: Extended (if set to 1)
* Bits 7-15: Reserved (set to 0). */
HBUINT16 lowestRecPPEM; /* Smallest readable size in pixels. */
HBINT16 fontDirectionHint; /* Deprecated (Set to 2).
* 0: Fully mixed directional glyphs;
* 1: Only strongly left to right;
* 2: Like 1 but also contains neutrals;
* -1: Only strongly right to left;
* -2: Like -1 but also contains neutrals. */
public:
HBUINT16 indexToLocFormat; /* 0 for short offsets, 1 for long. */
HBUINT16 glyphDataFormat; /* 0 for current format. */
DEFINE_SIZE_STATIC (54);
};
} /* namespace OT */
#endif /* HB_OT_HEAD_TABLE_HH */
|
