qgsflatterraingenerator.cpp

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/***************************************************************************
  qgsflatterraingenerator.cpp
  --------------------------------------
  Date                 : July 2017
  Copyright            : (C) 2017 by Martin Dobias
  Email                : wonder dot sk at gmail dot com
 ***************************************************************************
 *                                                                         *
 *   This program 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 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
#include "qgsflatterraingenerator.h"
 
#include <Qt3DRender/QGeometryRenderer>
#include <Qt3DCore/QTransform>
 
#include "qgs3dmapsettings.h"
#include "qgschunknode_p.h"
#include "qgsterrainentity_p.h"
#include "qgsterraintileentity_p.h"
 
 
//---------------
 
 
FlatTerrainChunkLoader::FlatTerrainChunkLoader( QgsTerrainEntity *terrain, QgsChunkNode *node )
  : QgsTerrainTileLoader( terrain, node )
{
  loadTexture();
}
 
 
Qt3DCore::QEntity *FlatTerrainChunkLoader::createEntity( Qt3DCore::QEntity *parent )
{
  QgsTerrainTileEntity *entity = new QgsTerrainTileEntity( mNode->tileId() );
 
  // make geometry renderer
 
  // simple quad geometry shared by all tiles
  // QPlaneGeometry by default is 1x1 with mesh resolution QSize(2,2), centered at 0
  // TODO: the geometry could be shared inside Terrain instance (within terrain-generator specific data?)
  mTileGeometry = new Qt3DExtras::QPlaneGeometry;
 
  Qt3DRender::QGeometryRenderer *mesh = new Qt3DRender::QGeometryRenderer;
  mesh->setGeometry( mTileGeometry ); // takes ownership if the component has no parent
  entity->addComponent( mesh ); // takes ownership if the component has no parent
 
  // create material
 
  const Qgs3DMapSettings &map = terrain()->map3D();
  createTextureComponent( entity, map.isTerrainShadingEnabled(), map.terrainShadingMaterial(), !map.layers().empty() );
 
  // create transform
 
  Qt3DCore::QTransform *transform = nullptr;
  transform = new Qt3DCore::QTransform();
  entity->addComponent( transform );
 
  // set up transform according to the extent covered by the quad geometry
  const QgsAABB bbox = mNode->bbox();
  const double side = bbox.xMax - bbox.xMin;
  const double half = side / 2;
 
  transform->setScale( side );
  transform->setTranslation( QVector3D( bbox.xMin + half, 0, bbox.zMin + half ) );
 
  entity->setParent( parent );
  return entity;
}
 
 
// ---------------
 
QgsChunkLoader *QgsFlatTerrainGenerator::createChunkLoader( QgsChunkNode *node ) const
{
  return new FlatTerrainChunkLoader( mTerrain, node );
}
 
QgsTerrainGenerator *QgsFlatTerrainGenerator::clone() const
{
  QgsFlatTerrainGenerator *cloned = new QgsFlatTerrainGenerator;
  cloned->mCrs = mCrs;
  cloned->mExtent = mExtent;
  cloned->updateTilingScheme();
  return cloned;
}
 
QgsTerrainGenerator::Type QgsFlatTerrainGenerator::type() const
{
  return QgsTerrainGenerator::Flat;
}
 
QgsRectangle QgsFlatTerrainGenerator::extent() const
{
  return mTerrainTilingScheme.tileToExtent( 0, 0, 0 );
}
 
void QgsFlatTerrainGenerator::rootChunkHeightRange( float &hMin, float &hMax ) const
{
  hMin = 0;
  hMax = 0;
}
 
void QgsFlatTerrainGenerator::writeXml( QDomElement &elem ) const
{
  const QgsRectangle r = mExtent;
  QDomElement elemExtent = elem.ownerDocument().createElement( QStringLiteral( "extent" ) );
  elemExtent.setAttribute( QStringLiteral( "xmin" ), QString::number( r.xMinimum() ) );
  elemExtent.setAttribute( QStringLiteral( "xmax" ), QString::number( r.xMaximum() ) );
  elemExtent.setAttribute( QStringLiteral( "ymin" ), QString::number( r.yMinimum() ) );
  elemExtent.setAttribute( QStringLiteral( "ymax" ), QString::number( r.yMaximum() ) );
  elem.appendChild( elemExtent );
 
  // crs is not read/written - it should be the same as destination crs of the map
}
 
void QgsFlatTerrainGenerator::readXml( const QDomElement &elem )
{
  const QDomElement elemExtent = elem.firstChildElement( QStringLiteral( "extent" ) );
  const double xmin = elemExtent.attribute( QStringLiteral( "xmin" ) ).toDouble();
  const double xmax = elemExtent.attribute( QStringLiteral( "xmax" ) ).toDouble();
  const double ymin = elemExtent.attribute( QStringLiteral( "ymin" ) ).toDouble();
  const double ymax = elemExtent.attribute( QStringLiteral( "ymax" ) ).toDouble();
 
  setExtent( QgsRectangle( xmin, ymin, xmax, ymax ) );
 
  // crs is not read/written - it should be the same as destination crs of the map
}
 
void QgsFlatTerrainGenerator::setCrs( const QgsCoordinateReferenceSystem &crs )
{
  mCrs = crs;
  updateTilingScheme();
}
 
void QgsFlatTerrainGenerator::setExtent( const QgsRectangle &extent )
{
  if ( mExtent == extent )
    return;
 
  mExtent = extent;
  updateTilingScheme();
 
  emit extentChanged();
}
 
void QgsFlatTerrainGenerator::updateTilingScheme()
{
  if ( mExtent.isNull() )
  {
    mTerrainTilingScheme = QgsTilingScheme();
  }
  else
  {
    // the real extent will be a square where the given extent fully fits
    mTerrainTilingScheme = QgsTilingScheme( mExtent, mCrs );
  }
}