/src/harfbuzz/src/hb-ot-head-table.hh

Source (jump to first uncovered line)
/*
 * 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 */

Coverage Report

Created: 2025-07-11 06:34

Line	Count	Source (jump to first uncovered line)
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.hh"
33
34		/*
35		* head -- Font Header
36		* https://docs.microsoft.com/en-us/typography/opentype/spec/head
37		*/
38	0	#define HB_OT_TAG_head HB_TAG('h','e','a','d')
39
40
41		namespace OT {
42
43
44		struct head
45		{
46		friend struct OpenTypeOffsetTable;
47
48		static constexpr hb_tag_t tableTag = HB_OT_TAG_head;
49
50		unsigned int get_upem () const
51	0	{
52	0	unsigned int upem = unitsPerEm;
53		/* If no valid head table found, assume 1000, which matches typical Type1 usage. */
54	0	return 16 <= upem && upem <= 16384 ? upem : 1000;
55	0	}
56
57		bool serialize (hb_serialize_context_t *c) const
58	0	{
59	0	TRACE_SERIALIZE (this);
60	0	return_trace ((bool) c->embed (this));
61	0	}
62
63		bool subset (hb_subset_context_t *c) const
64	0	{
65	0	TRACE_SUBSET (this);
66	0	head *out = c->serializer->embed (this);
67	0	if (unlikely (!out)) return_trace (false);
68	0
69	0	if (c->plan->normalized_coords)
70	0	{
71	0	if (unlikely (!c->serializer->check_assign (out->xMin, c->plan->head_maxp_info.xMin,
72	0	HB_SERIALIZE_ERROR_INT_OVERFLOW)))
73	0	return_trace (false);
74	0	if (unlikely (!c->serializer->check_assign (out->xMax, c->plan->head_maxp_info.xMax,
75	0	HB_SERIALIZE_ERROR_INT_OVERFLOW)))
76	0	return_trace (false);
77	0	if (unlikely (!c->serializer->check_assign (out->yMin, c->plan->head_maxp_info.yMin,
78	0	HB_SERIALIZE_ERROR_INT_OVERFLOW)))
79	0	return_trace (false);
80	0	if (unlikely (!c->serializer->check_assign (out->yMax, c->plan->head_maxp_info.yMax,
81	0	HB_SERIALIZE_ERROR_INT_OVERFLOW)))
82	0	return_trace (false);
83	0	}
84	0	return_trace (true);
85	0	}
86
87		enum mac_style_flag_t {
88		BOLD = 1u<<0,
89		ITALIC = 1u<<1,
90		UNDERLINE = 1u<<2,
91		OUTLINE = 1u<<3,
92		SHADOW = 1u<<4,
93		CONDENSED = 1u<<5,
94		EXPANDED = 1u<<6,
95		};
96
97	0	bool is_bold () const { return macStyle & BOLD; }
98	0	bool is_italic () const { return macStyle & ITALIC; }
99	0	bool is_condensed () const { return macStyle & CONDENSED; }
100	0	bool is_expanded () const { return macStyle & EXPANDED; }
101
102		bool sanitize (hb_sanitize_context_t *c) const
103	0	{
104	0	TRACE_SANITIZE (this);
105	0	return_trace (c->check_struct (this) &&
106	0	hb_barrier () &&
107	0	version.major == 1 &&
108	0	magicNumber == 0x5F0F3CF5u);
109	0	}
110
111		protected:
112		FixedVersion<>version; /* Version of the head table--currently
113		* 0x00010000u for version 1.0. */
114		FixedVersion<>fontRevision; /* Set by font manufacturer. */
115		HBUINT32 checkSumAdjustment; /* To compute: set it to 0, sum the
116		* entire font as HBUINT32, then store
117		* 0xB1B0AFBAu - sum. */
118		HBUINT32 magicNumber; /* Set to 0x5F0F3CF5u. */
119		public:
120		HBUINT16 flags; /* Bit 0: Baseline for font at y=0;
121		* Bit 1: Left sidebearing point at x=0;
122		* Bit 2: Instructions may depend on point size;
123		* Bit 3: Force ppem to integer values for all
124		* internal scaler math; may use fractional
125		* ppem sizes if this bit is clear;
126		* Bit 4: Instructions may alter advance width
127		* (the advance widths might not scale linearly);
128		* Bits 5-10: These should be set according to
129		* Apple's specification. However, they are not
130		* implemented in OpenType.
131		* Bit 5: This bit should be set in fonts that are
132		* intended to e laid out vertically, and in
133		* which the glyphs have been drawn such that an
134		* x-coordinate of 0 corresponds to the desired
135		* vertical baseline.
136		* Bit 6: This bit must be set to zero.
137		* Bit 7: This bit should be set if the font
138		* requires layout for correct linguistic
139		* rendering (e.g. Arabic fonts).
140		* Bit 8: This bit should be set for a GX font
141		* which has one or more metamorphosis effects
142		* designated as happening by default.
143		* Bit 9: This bit should be set if the font
144		* contains any strong right-to-left glyphs.
145		* Bit 10: This bit should be set if the font
146		* contains Indic-style rearrangement effects.
147		* Bit 11: Font data is 'lossless,' as a result
148		* of having been compressed and decompressed
149		* with the Agfa MicroType Express engine.
150		* Bit 12: Font converted (produce compatible metrics)
151		* Bit 13: Font optimized for ClearType™.
152		* Note, fonts that rely on embedded bitmaps (EBDT)
153		* for rendering should not be considered optimized
154		* for ClearType, and therefore should keep this bit
155		* cleared.
156		* Bit 14: Last Resort font. If set, indicates that
157		* the glyphs encoded in the cmap subtables are simply
158		* generic symbolic representations of code point
159		* ranges and don’t truly represent support for those
160		* code points. If unset, indicates that the glyphs
161		* encoded in the cmap subtables represent proper
162		* support for those code points.
163		* Bit 15: Reserved, set to 0. */
164		protected:
165		HBUINT16 unitsPerEm; /* Valid range is from 16 to 16384. This value
166		* should be a power of 2 for fonts that have
167		* TrueType outlines. */
168		LONGDATETIME created; /* Number of seconds since 12:00 midnight,
169		January 1, 1904. 64-bit integer */
170		LONGDATETIME modified; /* Number of seconds since 12:00 midnight,
171		January 1, 1904. 64-bit integer */
172		public:
173		HBINT16 xMin; /* For all glyph bounding boxes. */
174		HBINT16 yMin; /* For all glyph bounding boxes. */
175		HBINT16 xMax; /* For all glyph bounding boxes. */
176		HBINT16 yMax; /* For all glyph bounding boxes. */
177		protected:
178		HBUINT16 macStyle; /* Bit 0: Bold (if set to 1);
179		* Bit 1: Italic (if set to 1)
180		* Bit 2: Underline (if set to 1)
181		* Bit 3: Outline (if set to 1)
182		* Bit 4: Shadow (if set to 1)
183		* Bit 5: Condensed (if set to 1)
184		* Bit 6: Extended (if set to 1)
185		* Bits 7-15: Reserved (set to 0). */
186		HBUINT16 lowestRecPPEM; /* Smallest readable size in pixels. */
187		HBINT16 fontDirectionHint; /* Deprecated (Set to 2).
188		* 0: Fully mixed directional glyphs;
189		* 1: Only strongly left to right;
190		* 2: Like 1 but also contains neutrals;
191		* -1: Only strongly right to left;
192		* -2: Like -1 but also contains neutrals. */
193		public:
194		HBUINT16 indexToLocFormat; /* 0 for short offsets, 1 for long. */
195		HBUINT16 glyphDataFormat; /* 0 for current format. */
196
197		DEFINE_SIZE_STATIC (54);
198		};
199
200
201		} /* namespace OT */
202
203
204		#endif /* HB_OT_HEAD_TABLE_HH */