util.cpp

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/*
 *   libpal - Automated Placement of Labels Library
 *
 *   Copyright (C) 2008 Maxence Laurent, MIS-TIC, HEIG-VD
 *                      University of Applied Sciences, Western Switzerland
 *                      http://www.hes-so.ch
 *
 *   Contact:
 *      maxence.laurent <at> heig-vd <dot> ch
 *    or
 *      eric.taillard <at> heig-vd <dot> ch
 *
 * This file is part of libpal.
 *
 * libpal is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * libpal is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with libpal.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#include "layer.h"
#include "internalexception.h"
#include "util.h"
#include "labelposition.h"
#include "feature.h"
#include "geomfunction.h"

#include "qgslogger.h"
#include <cfloat>

void pal::Util::sort( void **items, int N, bool ( *greater )( void *l, void *r ) )
{

  if ( N <= 0 )
    return;

  unsigned int n = static_cast< unsigned int >( N ), i = n / 2, parent, child;

  void *t = nullptr;

  for ( ;; )
  {
    if ( i > 0 )
    {
      i--;
      t = items[i];
    }
    else
    {
      n--;
      if ( n == 0 ) return;
      t = items[n];
      items[n] = items[0];
    }
    parent = i;
    child = i * 2 + 1;
    while ( child < n )
    {
      if ( child + 1 < n  &&  greater( items[child + 1], items[child] ) )
      {
        child++;
      }
      if ( greater( items[child], t ) )
      {
        items[parent] = items[child];
        parent = child;
        child = parent * 2 + 1;
      }
      else
      {
        break;
      }
    }
    items[parent] = t;
  }
}

QLinkedList<const GEOSGeometry *> *pal::Util::unmulti( const GEOSGeometry *the_geom )
{
  QLinkedList<const GEOSGeometry *> *queue = new QLinkedList<const GEOSGeometry *>;
  QLinkedList<const GEOSGeometry *> *final_queue = new QLinkedList<const GEOSGeometry *>;

  const GEOSGeometry *geom = nullptr;

  queue->append( the_geom );
  int nGeom;
  int i;

  GEOSContextHandle_t geosctxt = QgsGeos::getGEOSHandler();

  while ( !queue->isEmpty() )
  {
    geom = queue->takeFirst();
    int type = GEOSGeomTypeId_r( geosctxt, geom );
    switch ( type )
    {
      case GEOS_MULTIPOINT:
      case GEOS_MULTILINESTRING:
      case GEOS_MULTIPOLYGON:
      case GEOS_GEOMETRYCOLLECTION:
        nGeom = GEOSGetNumGeometries_r( geosctxt, geom );
        for ( i = 0; i < nGeom; i++ )
        {
          queue->append( GEOSGetGeometryN_r( geosctxt, geom, i ) );
        }
        break;
      case GEOS_POINT:
      case GEOS_LINESTRING:
      case GEOS_POLYGON:
        final_queue->append( geom );
        break;
      default:
        QgsDebugMsg( QStringLiteral( "unexpected geometry type:%1" ).arg( type ) );
        delete final_queue;
        delete queue;
        return nullptr;
    }
  }
  delete queue;

  return final_queue;
}