/*

 * 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,

    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 */