204 lines
7.5 KiB
C++
204 lines
7.5 KiB
C++
/*
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* Copyright © 2010 Red Hat, Inc.
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* Copyright © 2012 Google, Inc.
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*
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* This is part of HarfBuzz, a text shaping library.
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*
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* Permission is hereby granted, without written agreement and without
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* license or royalty fees, to use, copy, modify, and distribute this
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* software and its documentation for any purpose, provided that the
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* above copyright notice and the following two paragraphs appear in
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* all copies of this software.
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*
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* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
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* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
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* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
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* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
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* DAMAGE.
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*
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* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
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* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
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* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
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* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
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*
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* Red Hat Author(s): Behdad Esfahbod
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* Google Author(s): Behdad Esfahbod
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*/
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#ifndef HB_OT_HEAD_TABLE_HH
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#define HB_OT_HEAD_TABLE_HH
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#include "hb-open-type.hh"
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/*
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* head -- Font Header
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* https://docs.microsoft.com/en-us/typography/opentype/spec/head
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*/
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#define HB_OT_TAG_head HB_TAG('h','e','a','d')
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namespace OT {
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struct head
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{
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friend struct OpenTypeOffsetTable;
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static constexpr hb_tag_t tableTag = HB_OT_TAG_head;
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unsigned int get_upem () const
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{
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unsigned int upem = unitsPerEm;
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/* If no valid head table found, assume 1000, which matches typical Type1 usage. */
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return 16 <= upem && upem <= 16384 ? upem : 1000;
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}
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bool serialize (hb_serialize_context_t *c) const
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{
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TRACE_SERIALIZE (this);
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return_trace ((bool) c->embed (this));
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}
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bool subset (hb_subset_context_t *c) const
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{
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TRACE_SUBSET (this);
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head *out = c->serializer->embed (this);
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if (unlikely (!out)) return_trace (false);
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if (c->plan->normalized_coords)
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{
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if (unlikely (!c->serializer->check_assign (out->xMin, c->plan->head_maxp_info.xMin,
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HB_SERIALIZE_ERROR_INT_OVERFLOW)))
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return_trace (false);
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if (unlikely (!c->serializer->check_assign (out->xMax, c->plan->head_maxp_info.xMax,
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HB_SERIALIZE_ERROR_INT_OVERFLOW)))
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return_trace (false);
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if (unlikely (!c->serializer->check_assign (out->yMin, c->plan->head_maxp_info.yMin,
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HB_SERIALIZE_ERROR_INT_OVERFLOW)))
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return_trace (false);
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if (unlikely (!c->serializer->check_assign (out->yMax, c->plan->head_maxp_info.yMax,
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HB_SERIALIZE_ERROR_INT_OVERFLOW)))
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return_trace (false);
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}
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return_trace (true);
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}
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enum mac_style_flag_t {
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BOLD = 1u<<0,
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ITALIC = 1u<<1,
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UNDERLINE = 1u<<2,
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OUTLINE = 1u<<3,
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SHADOW = 1u<<4,
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CONDENSED = 1u<<5,
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EXPANDED = 1u<<6,
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};
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bool is_bold () const { return macStyle & BOLD; }
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bool is_italic () const { return macStyle & ITALIC; }
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bool is_condensed () const { return macStyle & CONDENSED; }
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bool is_expanded () const { return macStyle & EXPANDED; }
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bool sanitize (hb_sanitize_context_t *c) const
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{
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TRACE_SANITIZE (this);
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return_trace (c->check_struct (this) &&
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version.major == 1 &&
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magicNumber == 0x5F0F3CF5u);
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}
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protected:
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FixedVersion<>version; /* Version of the head table--currently
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* 0x00010000u for version 1.0. */
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FixedVersion<>fontRevision; /* Set by font manufacturer. */
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HBUINT32 checkSumAdjustment; /* To compute: set it to 0, sum the
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* entire font as HBUINT32, then store
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* 0xB1B0AFBAu - sum. */
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HBUINT32 magicNumber; /* Set to 0x5F0F3CF5u. */
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public:
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HBUINT16 flags; /* Bit 0: Baseline for font at y=0;
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* Bit 1: Left sidebearing point at x=0;
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* Bit 2: Instructions may depend on point size;
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* Bit 3: Force ppem to integer values for all
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* internal scaler math; may use fractional
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* ppem sizes if this bit is clear;
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* Bit 4: Instructions may alter advance width
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* (the advance widths might not scale linearly);
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* Bits 5-10: These should be set according to
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* Apple's specification. However, they are not
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* implemented in OpenType.
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* Bit 5: This bit should be set in fonts that are
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* intended to e laid out vertically, and in
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* which the glyphs have been drawn such that an
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* x-coordinate of 0 corresponds to the desired
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* vertical baseline.
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* Bit 6: This bit must be set to zero.
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* Bit 7: This bit should be set if the font
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* requires layout for correct linguistic
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* rendering (e.g. Arabic fonts).
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* Bit 8: This bit should be set for a GX font
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* which has one or more metamorphosis effects
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* designated as happening by default.
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* Bit 9: This bit should be set if the font
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* contains any strong right-to-left glyphs.
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* Bit 10: This bit should be set if the font
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* contains Indic-style rearrangement effects.
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* Bit 11: Font data is 'lossless,' as a result
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* of having been compressed and decompressed
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* with the Agfa MicroType Express engine.
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* Bit 12: Font converted (produce compatible metrics)
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* Bit 13: Font optimized for ClearType™.
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* Note, fonts that rely on embedded bitmaps (EBDT)
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* for rendering should not be considered optimized
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* for ClearType, and therefore should keep this bit
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* cleared.
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* Bit 14: Last Resort font. If set, indicates that
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* the glyphs encoded in the cmap subtables are simply
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* generic symbolic representations of code point
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* ranges and don’t truly represent support for those
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* code points. If unset, indicates that the glyphs
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* encoded in the cmap subtables represent proper
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* support for those code points.
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* Bit 15: Reserved, set to 0. */
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protected:
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HBUINT16 unitsPerEm; /* Valid range is from 16 to 16384. This value
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* should be a power of 2 for fonts that have
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* TrueType outlines. */
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LONGDATETIME created; /* Number of seconds since 12:00 midnight,
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January 1, 1904. 64-bit integer */
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LONGDATETIME modified; /* Number of seconds since 12:00 midnight,
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January 1, 1904. 64-bit integer */
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public:
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HBINT16 xMin; /* For all glyph bounding boxes. */
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HBINT16 yMin; /* For all glyph bounding boxes. */
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HBINT16 xMax; /* For all glyph bounding boxes. */
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HBINT16 yMax; /* For all glyph bounding boxes. */
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protected:
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HBUINT16 macStyle; /* Bit 0: Bold (if set to 1);
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* Bit 1: Italic (if set to 1)
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* Bit 2: Underline (if set to 1)
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* Bit 3: Outline (if set to 1)
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* Bit 4: Shadow (if set to 1)
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* Bit 5: Condensed (if set to 1)
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* Bit 6: Extended (if set to 1)
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* Bits 7-15: Reserved (set to 0). */
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HBUINT16 lowestRecPPEM; /* Smallest readable size in pixels. */
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HBINT16 fontDirectionHint; /* Deprecated (Set to 2).
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* 0: Fully mixed directional glyphs;
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* 1: Only strongly left to right;
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* 2: Like 1 but also contains neutrals;
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* -1: Only strongly right to left;
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* -2: Like -1 but also contains neutrals. */
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public:
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HBUINT16 indexToLocFormat; /* 0 for short offsets, 1 for long. */
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HBUINT16 glyphDataFormat; /* 0 for current format. */
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DEFINE_SIZE_STATIC (54);
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};
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} /* namespace OT */
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#endif /* HB_OT_HEAD_TABLE_HH */
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