src/hb-ot-head-table.hh - third_party/harfbuzz - Git at Google

 /*
  * 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);
     return_trace (serialize (c->serializer));
   }

   enum mac_style_flag_t {
     BOLD	= 1u<<0,
     ITALIC	= 1u<<1,
     UNDERLINE	= 1u<<2,
     OUTLINE	= 1u<<3,
     SHADOW	= 1u<<4,
     CONDENSED	= 1u<<5
   };

   bool is_bold () const      { return macStyle & BOLD; }
   bool is_italic () const    { return macStyle & ITALIC; }
   bool is_condensed () const { return macStyle & CONDENSED; }

   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. */
   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. */
   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 */
   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. */
   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 */
	/*
	* 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);
	return_trace (serialize (c->serializer));
	}

	enum mac_style_flag_t {
	BOLD = 1u<<0,
	ITALIC = 1u<<1,
	UNDERLINE = 1u<<2,
	OUTLINE = 1u<<3,
	SHADOW = 1u<<4,
	CONDENSED = 1u<<5
	};

	bool is_bold () const { return macStyle & BOLD; }
	bool is_italic () const { return macStyle & ITALIC; }
	bool is_condensed () const { return macStyle & CONDENSED; }

	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. */
	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. */
	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 */
	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. */
	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 */