kc3-lang/harfbuzz/src/hb-ot-var-avar-table.hh

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• Hash : 9507b05a
  Author :
  Date : 2018-09-10T23:18:07
  

  Simplify sanitize->check_array()
  
  Fix a bug in CBDT sanitize, and redundant check in avar.
  

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• src/hb-ot-var-avar-table.hh

• /*
   * Copyright © 2017  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.
   *
   * Google Author(s): Behdad Esfahbod
   */
  
  #ifndef HB_OT_VAR_AVAR_TABLE_HH
  #define HB_OT_VAR_AVAR_TABLE_HH
  
  #include "hb-open-type.hh"
  
  /*
   * avar -- Axis Variations
   * https://docs.microsoft.com/en-us/typography/opentype/spec/avar
   */
  
  #define HB_OT_TAG_avar HB_TAG('a','v','a','r')
  
  
  namespace OT {
  
  
  struct AxisValueMap
  {
    inline bool sanitize (hb_sanitize_context_t *c) const
    {
      TRACE_SANITIZE (this);
      return_trace (c->check_struct (this));
    }
  
    public:
    F2DOT14	fromCoord;	/* A normalized coordinate value obtained using
  				 * default normalization. */
    F2DOT14	toCoord;	/* The modified, normalized coordinate value. */
  
    public:
    DEFINE_SIZE_STATIC (4);
  };
  
  struct SegmentMaps : ArrayOf<AxisValueMap>
  {
    inline int map (int value) const
    {
      /* The following special-cases are not part of OpenType, which requires
       * that at least -1, 0, and +1 must be mapped. But we include these as
       * part of a better error recovery scheme. */
  
      if (len < 2)
      {
        if (!len)
  	return value;
        else /* len == 1*/
  	return value - arrayZ[0].fromCoord + arrayZ[0].toCoord;
      }
  
      if (value <= arrayZ[0].fromCoord)
        return value - arrayZ[0].fromCoord + arrayZ[0].toCoord;
  
      unsigned int i;
      unsigned int count = len;
      for (i = 1; i < count && value > arrayZ[i].fromCoord; i++)
        ;
  
      if (value >= arrayZ[i].fromCoord)
        return value - arrayZ[i].fromCoord + arrayZ[i].toCoord;
  
      if (unlikely (arrayZ[i-1].fromCoord == arrayZ[i].fromCoord))
        return arrayZ[i-1].toCoord;
  
      int denom = arrayZ[i].fromCoord - arrayZ[i-1].fromCoord;
      return arrayZ[i-1].toCoord +
  	   ((arrayZ[i].toCoord - arrayZ[i-1].toCoord) *
  	    (value - arrayZ[i-1].fromCoord) + denom/2) / denom;
    }
  
    public:
    DEFINE_SIZE_ARRAY (2, arrayZ);
  };
  
  struct avar
  {
    static const hb_tag_t tableTag	= HB_OT_TAG_avar;
  
    inline bool sanitize (hb_sanitize_context_t *c) const
    {
      TRACE_SANITIZE (this);
      if (unlikely (!(version.sanitize (c) &&
  		    version.major == 1 &&
  		    c->check_struct (this))))
        return_trace (false);
  
      const SegmentMaps *map = axisSegmentMapsZ.arrayZ;
      unsigned int count = axisCount;
      for (unsigned int i = 0; i < count; i++)
      {
        if (unlikely (!map->sanitize (c)))
          return_trace (false);
        map = &StructAfter<SegmentMaps> (*map);
      }
  
      return_trace (true);
    }
  
    inline void map_coords (int *coords, unsigned int coords_length) const
    {
      unsigned int count = MIN<unsigned int> (coords_length, axisCount);
  
      const SegmentMaps *map = axisSegmentMapsZ.arrayZ;
      for (unsigned int i = 0; i < count; i++)
      {
        coords[i] = map->map (coords[i]);
        map = &StructAfter<SegmentMaps> (*map);
      }
    }
  
    protected:
    FixedVersion<>version;	/* Version of the avar table
  				 * initially set to 0x00010000u */
    HBUINT16	reserved;	/* This field is permanently reserved. Set to 0. */
    HBUINT16	axisCount;	/* The number of variation axes in the font. This
  				 * must be the same number as axisCount in the
  				 * 'fvar' table. */
    UnsizedArrayOf<SegmentMaps>
  		axisSegmentMapsZ;
  
    public:
    DEFINE_SIZE_MIN (8);
  };
  
  } /* namespace OT */
  
  
  #endif /* HB_OT_VAR_AVAR_TABLE_HH */
  

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