text: /*
   * Copyright © 2018  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): Garret Rieger
   */
  
  #ifndef HB_OT_HDMX_TABLE_HH
  #define HB_OT_HDMX_TABLE_HH
  
  #include "hb-open-type.hh"
  
  /*
   * hdmx -- Horizontal Device Metrics
   * https://docs.microsoft.com/en-us/typography/opentype/spec/hdmx
   */
  #define HB_OT_TAG_hdmx HB_TAG('h','d','m','x')
  
  
  namespace OT {
  
  
  struct DeviceRecord
  {
    struct SubsetView
    {
      const DeviceRecord *source_device_record;
      unsigned int sizeDeviceRecord;
      hb_subset_plan_t *subset_plan;
  
      void init (const DeviceRecord *source_device_record,
                 unsigned int sizeDeviceRecord,
                 hb_subset_plan_t   *subset_plan)
      {
        this->source_device_record = source_device_record;
        this->sizeDeviceRecord = sizeDeviceRecord;
        this->subset_plan = subset_plan;
      }
  
      unsigned int len () const
      { return this->subset_plan->glyphs.length; }
  
      const HBUINT8* operator [] (unsigned int i) const
      {
        if (unlikely (i >= len ())) return nullptr;
        hb_codepoint_t gid = this->subset_plan->glyphs [i];
  
        if (gid >= sizeDeviceRecord - DeviceRecord::min_size)
          return nullptr;
        return &(this->source_device_record->widthsZ[gid]);
      }
    };
  
    static unsigned int get_size (unsigned int count)
    { return hb_ceil_to_4 (min_size + count * HBUINT8::static_size); }
  
    bool serialize (hb_serialize_context_t *c, const SubsetView &subset_view)
    {
      TRACE_SERIALIZE (this);
  
      unsigned int size = get_size (subset_view.len ());
      if (unlikely (!c->allocate_size<DeviceRecord> (size)))
      {
        DEBUG_MSG(SUBSET, nullptr, "Couldn't allocate enough space for DeviceRecord: %d.",
                   size);
        return_trace (false);
      }
  
      this->pixelSize.set (subset_view.source_device_record->pixelSize);
      this->maxWidth.set (subset_view.source_device_record->maxWidth);
  
      for (unsigned int i = 0; i < subset_view.len (); i++)
      {
        const HBUINT8 *width = subset_view[i];
        if (!width)
        {
          DEBUG_MSG(SUBSET, nullptr, "HDMX width for new gid %d is missing.", i);
          return_trace (false);
        }
        widthsZ[i].set (*width);
      }
  
      return_trace (true);
    }
  
    bool sanitize (hb_sanitize_context_t *c, unsigned int sizeDeviceRecord) const
    {
      TRACE_SANITIZE (this);
      return_trace (likely (c->check_struct (this) &&
                            c->check_range (this, sizeDeviceRecord)));
    }
  
    HBUINT8                       pixelSize;      /* Pixel size for following widths (as ppem). */
    HBUINT8                       maxWidth;       /* Maximum width. */
    UnsizedArrayOf<HBUINT8>       widthsZ;        /* Array of widths (numGlyphs is from the 'maxp' table). */
    public:
    DEFINE_SIZE_ARRAY (2, widthsZ);
  };
  
  
  struct hdmx
  {
    static constexpr hb_tag_t tableTag = HB_OT_TAG_hdmx;
  
    unsigned int get_size () const
    { return min_size + numRecords * sizeDeviceRecord; }
  
    const DeviceRecord& operator [] (unsigned int i) const
    {
      /* XXX Null(DeviceRecord) is NOT safe as it's num-glyphs lengthed.
       * https://github.com/harfbuzz/harfbuzz/issues/1300 */
      if (unlikely (i >= numRecords)) return Null (DeviceRecord);
      return StructAtOffset<DeviceRecord> (&this->firstDeviceRecord, i * sizeDeviceRecord);
    }
  
    bool serialize (hb_serialize_context_t *c, const hdmx *source_hdmx, hb_subset_plan_t *plan)
    {
      TRACE_SERIALIZE (this);
  
      if (unlikely (!c->extend_min ((*this))))  return_trace (false);
  
      this->version.set (source_hdmx->version);
      this->numRecords.set (source_hdmx->numRecords);
      this->sizeDeviceRecord.set (DeviceRecord::get_size (plan->glyphs.length));
  
      for (unsigned int i = 0; i < source_hdmx->numRecords; i++)
      {
        DeviceRecord::SubsetView subset_view;
        subset_view.init (&(*source_hdmx)[i], source_hdmx->sizeDeviceRecord, plan);
  
        if (!c->start_embed<DeviceRecord> ()->serialize (c, subset_view))
          return_trace (false);
      }
  
      return_trace (true);
    }
  
    static size_t get_subsetted_size (const hdmx *source_hdmx, hb_subset_plan_t *plan)
    {
      return min_size + source_hdmx->numRecords * DeviceRecord::get_size (plan->glyphs.length);
    }
  
    bool subset (hb_subset_plan_t *plan) const
    {
      size_t dest_size = get_subsetted_size (this, plan);
      hdmx *dest = (hdmx *) malloc (dest_size);
      if (unlikely (!dest))
      {
        DEBUG_MSG(SUBSET, nullptr, "Unable to alloc %lu for hdmx subset output.", (unsigned long) dest_size);
        return false;
      }
  
      hb_serialize_context_t c (dest, dest_size);
      hdmx *hdmx_prime = c.start_serialize<hdmx> ();
      if (!hdmx_prime || !hdmx_prime->serialize (&c, this, plan))
      {
        free (dest);
        DEBUG_MSG(SUBSET, nullptr, "Failed to serialize write new hdmx.");
        return false;
      }
      c.end_serialize ();
  
      hb_blob_t *hdmx_prime_blob = hb_blob_create ((const char *) dest,
                                                   dest_size,
                                                   HB_MEMORY_MODE_READONLY,
                                                   dest,
                                                   free);
      bool result = plan->add_table (HB_OT_TAG_hdmx, hdmx_prime_blob);
      hb_blob_destroy (hdmx_prime_blob);
  
      return result;
    }
  
    bool sanitize (hb_sanitize_context_t *c) const
    {
      TRACE_SANITIZE (this);
      return_trace (c->check_struct (this) &&
                    !hb_unsigned_mul_overflows (numRecords, sizeDeviceRecord) &&
                    sizeDeviceRecord >= DeviceRecord::min_size &&
                    c->check_range (this, get_size ()));
    }
  
    protected:
    HBUINT16              version;                /* Table version number (0) */
    HBUINT16              numRecords;             /* Number of device records. */
    HBUINT32              sizeDeviceRecord;       /* Size of a device record, 32-bit aligned. */
    DeviceRecord          firstDeviceRecord;      /* Array of device records. */
    public:
    DEFINE_SIZE_MIN (8);
  };
  
  } /* namespace OT */
  
  
  #endif /* HB_OT_HDMX_TABLE_HH */
  