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/*
* 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) &&
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 */
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