kc3-lang/harfbuzz/src/hb-aat-layout-bsln-table.hh

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• Author : Ebrahim Byagowi
  Date : 2020-07-18 22:14:52
  Hash : d0e2addd
  Message : minor

• src/hb-aat-layout-bsln-table.hh

• /*
   * Copyright © 2018  Ebrahim Byagowi
   *
   *  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.
   */
  
  #ifndef HB_AAT_LAYOUT_BSLN_TABLE_HH
  #define HB_AAT_LAYOUT_BSLN_TABLE_HH
  
  #include "hb-aat-layout-common.hh"
  
  /*
   * bsln -- Baseline
   * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6bsln.html
   */
  #define HB_AAT_TAG_bsln HB_TAG('b','s','l','n')
  
  
  namespace AAT {
  
  
  struct BaselineTableFormat0Part
  {
    bool sanitize (hb_sanitize_context_t *c) const
    {
      TRACE_SANITIZE (this);
      return_trace (likely (c->check_struct (this)));
    }
  
    protected:
    // Roman, Ideographic centered, Ideographic low, Hanging and Math
    // are the default defined ones, but any other maybe accessed also.
    HBINT16	deltas[32];	/* These are the FUnit distance deltas from
  				 * the font's natural baseline to the other
  				 * baselines used in the font. */
    public:
    DEFINE_SIZE_STATIC (64);
  };
  
  struct BaselineTableFormat1Part
  {
    bool sanitize (hb_sanitize_context_t *c) const
    {
      TRACE_SANITIZE (this);
      return_trace (likely (c->check_struct (this) &&
  			  lookupTable.sanitize (c)));
    }
  
    protected:
    HBINT16	deltas[32];	/* ditto */
    Lookup<HBUINT16>
  		lookupTable;	/* Lookup table that maps glyphs to their
  				 * baseline values. */
    public:
    DEFINE_SIZE_MIN (66);
  };
  
  struct BaselineTableFormat2Part
  {
    bool sanitize (hb_sanitize_context_t *c) const
    {
      TRACE_SANITIZE (this);
      return_trace (likely (c->check_struct (this)));
    }
  
    protected:
    HBGlyphID	stdGlyph;	/* The specific glyph index number in this
  				 * font that is used to set the baseline values.
  				 * This is the standard glyph.
  				 * This glyph must contain a set of control points
  				 * (whose numbers are contained in the ctlPoints field)
  				 * that are used to determine baseline distances. */
    HBUINT16	ctlPoints[32];	/* Set of control point numbers,
  				 * associated with the standard glyph.
  				 * A value of 0xFFFF means there is no corresponding
  				 * control point in the standard glyph. */
    public:
    DEFINE_SIZE_STATIC (66);
  };
  
  struct BaselineTableFormat3Part
  {
    bool sanitize (hb_sanitize_context_t *c) const
    {
      TRACE_SANITIZE (this);
      return_trace (likely (c->check_struct (this) && lookupTable.sanitize (c)));
    }
  
    protected:
    HBGlyphID	stdGlyph;	/* ditto */
    HBUINT16	ctlPoints[32];	/* ditto */
    Lookup<HBUINT16>
  		lookupTable;	/* Lookup table that maps glyphs to their
  				 * baseline values. */
    public:
    DEFINE_SIZE_MIN (68);
  };
  
  struct bsln
  {
    static constexpr hb_tag_t tableTag = HB_AAT_TAG_bsln;
  
    bool sanitize (hb_sanitize_context_t *c) const
    {
      TRACE_SANITIZE (this);
      if (unlikely (!(c->check_struct (this) && defaultBaseline < 32)))
        return_trace (false);
  
      switch (format)
      {
      case 0: return_trace (parts.format0.sanitize (c));
      case 1: return_trace (parts.format1.sanitize (c));
      case 2: return_trace (parts.format2.sanitize (c));
      case 3: return_trace (parts.format3.sanitize (c));
      default:return_trace (true);
      }
    }
  
    protected:
    FixedVersion<>version;	/* Version number of the Baseline table. */
    HBUINT16	format;		/* Format of the baseline table. Only one baseline
  				 * format may be selected for the font. */
    HBUINT16	defaultBaseline;/* Default baseline value for all glyphs.
  				 * This value can be from 0 through 31. */
    union {
    // Distance-Based Formats
    BaselineTableFormat0Part	format0;
    BaselineTableFormat1Part	format1;
    // Control Point-based Formats
    BaselineTableFormat2Part	format2;
    BaselineTableFormat3Part	format3;
    } parts;
    public:
    DEFINE_SIZE_MIN (8);
  };
  
  } /* namespace AAT */
  
  
  #endif /* HB_AAT_LAYOUT_BSLN_TABLE_HH */