QGIS API Documentation  3.25.0-Master (10b47c2603)
qgsrulebasedchunkloader_p.cpp
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1 /***************************************************************************
2  qgsrulebasedchunkloader_p.cpp
3  --------------------------------------
4  Date : November 2019
5  Copyright : (C) 2019 by Martin Dobias
6  Email : wonder dot sk at gmail dot com
7  ***************************************************************************
8  * *
9  * This program is free software; you can redistribute it and/or modify *
10  * it under the terms of the GNU General Public License as published by *
11  * the Free Software Foundation; either version 2 of the License, or *
12  * (at your option) any later version. *
13  * *
14  ***************************************************************************/
15 
17 
18 #include "qgs3dutils.h"
19 #include "qgschunknode_p.h"
20 #include "qgspolygon3dsymbol_p.h"
21 #include "qgseventtracing.h"
22 
23 #include "qgsvectorlayer.h"
25 
26 #include "qgsrulebased3drenderer.h"
27 
28 #include <QtConcurrent>
29 #include <Qt3DCore/QTransform>
30 
32 
33 
34 QgsRuleBasedChunkLoader::QgsRuleBasedChunkLoader( const QgsRuleBasedChunkLoaderFactory *factory, QgsChunkNode *node )
35  : QgsChunkLoader( node )
36  , mFactory( factory )
37  , mContext( factory->mMap )
38  , mSource( new QgsVectorLayerFeatureSource( factory->mLayer ) )
39 {
40  if ( node->level() < mFactory->mLeafLevel )
41  {
42  QTimer::singleShot( 0, this, &QgsRuleBasedChunkLoader::finished );
43  return;
44  }
45 
46  QgsVectorLayer *layer = mFactory->mLayer;
47  const Qgs3DMapSettings &map = mFactory->mMap;
48 
50  exprContext.setFields( layer->fields() );
51  mContext.setExpressionContext( exprContext );
52 
53  // factory is shared among multiple loaders which may be run at the same time
54  // so we need a local copy of our rule tree that does not intefere with others
55  // (e.g. it happened that filter expressions with invalid syntax would cause
56  // nasty crashes when trying to simultaneously record evaluation error)
57  mRootRule.reset( mFactory->mRootRule->clone() );
58 
59  mRootRule->createHandlers( layer, mHandlers );
60 
61  QSet<QString> attributeNames;
62  mRootRule->prepare( mContext, attributeNames, mHandlers );
63 
64  // build the feature request
66  req.setDestinationCrs( map.crs(), map.transformContext() );
67  req.setSubsetOfAttributes( attributeNames, layer->fields() );
68 
69  // only a subset of data to be queried
70  const QgsRectangle rect = Qgs3DUtils::worldToMapExtent( node->bbox(), map.origin() );
71  req.setFilterRect( rect );
72 
73  //
74  // this will be run in a background thread
75  //
76  mFutureWatcher = new QFutureWatcher<void>( this );
77  connect( mFutureWatcher, &QFutureWatcher<void>::finished, this, &QgsChunkQueueJob::finished );
78 
79  const QFuture<void> future = QtConcurrent::run( [req, this]
80  {
81  const QgsEventTracing::ScopedEvent e( QStringLiteral( "3D" ), QStringLiteral( "RB chunk load" ) );
82 
83  QgsFeature f;
84  QgsFeatureIterator fi = mSource->getFeatures( req );
85  while ( fi.nextFeature( f ) )
86  {
87  if ( mCanceled )
88  break;
89  mContext.expressionContext().setFeature( f );
90  mRootRule->registerFeature( f, mContext, mHandlers );
91  }
92  } );
93 
94  // emit finished() as soon as the handler is populated with features
95  mFutureWatcher->setFuture( future );
96 }
97 
98 QgsRuleBasedChunkLoader::~QgsRuleBasedChunkLoader()
99 {
100  if ( mFutureWatcher && !mFutureWatcher->isFinished() )
101  {
102  disconnect( mFutureWatcher, &QFutureWatcher<void>::finished, this, &QgsChunkQueueJob::finished );
103  mFutureWatcher->waitForFinished();
104  }
105 
106  qDeleteAll( mHandlers );
107  mHandlers.clear();
108 }
109 
110 void QgsRuleBasedChunkLoader::cancel()
111 {
112  mCanceled = true;
113 }
114 
115 Qt3DCore::QEntity *QgsRuleBasedChunkLoader::createEntity( Qt3DCore::QEntity *parent )
116 {
117  if ( mNode->level() < mFactory->mLeafLevel )
118  {
119  return new Qt3DCore::QEntity( parent ); // dummy entity
120  }
121 
122  float zMin = std::numeric_limits<float>::max();
123  float zMax = std::numeric_limits<float>::min();
124 
125  Qt3DCore::QEntity *entity = new Qt3DCore::QEntity( parent );
126  for ( QgsFeature3DHandler *handler : mHandlers.values() )
127  {
128  handler->finalize( entity, mContext );
129  if ( handler->zMinimum() < zMin )
130  zMin = handler->zMinimum();
131  if ( handler->zMaximum() > zMax )
132  zMax = handler->zMaximum();
133  }
134 
135  // fix the vertical range of the node from the estimated vertical range to the true range
136  if ( zMin != std::numeric_limits<float>::max() && zMax != std::numeric_limits<float>::min() )
137  {
138  QgsAABB box = mNode->bbox();
139  box.yMin = zMin;
140  box.yMax = zMax;
141  mNode->setExactBbox( box );
142  mNode->updateParentBoundingBoxesRecursively();
143  }
144 
145  return entity;
146 }
147 
148 
150 
151 
152 QgsRuleBasedChunkLoaderFactory::QgsRuleBasedChunkLoaderFactory( const Qgs3DMapSettings &map, QgsVectorLayer *vl, QgsRuleBased3DRenderer::Rule *rootRule, int leafLevel, double zMin, double zMax )
153  : mMap( map )
154  , mLayer( vl )
155  , mRootRule( rootRule->clone() )
156  , mLeafLevel( leafLevel )
157 {
158  const QgsAABB rootBbox = Qgs3DUtils::layerToWorldExtent( vl->extent(), zMin, zMax, vl->crs(), map.origin(), map.crs(), map.transformContext() );
159  setupQuadtree( rootBbox, -1, leafLevel ); // negative root error means that the node does not contain anything
160 }
161 
162 QgsRuleBasedChunkLoaderFactory::~QgsRuleBasedChunkLoaderFactory() = default;
163 
164 QgsChunkLoader *QgsRuleBasedChunkLoaderFactory::createChunkLoader( QgsChunkNode *node ) const
165 {
166  return new QgsRuleBasedChunkLoader( this, node );
167 }
168 
169 
171 
172 QgsRuleBasedChunkedEntity::QgsRuleBasedChunkedEntity( QgsVectorLayer *vl, double zMin, double zMax, const QgsVectorLayer3DTilingSettings &tilingSettings, QgsRuleBased3DRenderer::Rule *rootRule, const Qgs3DMapSettings &map )
173  : QgsChunkedEntity( -1, // max. allowed screen error (negative tau means that we need to go until leaves are reached)
174  new QgsRuleBasedChunkLoaderFactory( map, vl, rootRule, tilingSettings.zoomLevelsCount() - 1, zMin, zMax ), true )
175 {
176  mTransform = new Qt3DCore::QTransform;
177  mTransform->setTranslation( QVector3D( 0.0f, map.terrainElevationOffset(), 0.0f ) );
178  this->addComponent( mTransform );
179  connect( &map, &Qgs3DMapSettings::terrainElevationOffsetChanged, this, &QgsRuleBasedChunkedEntity::onTerrainElevationOffsetChanged );
180 
181  setShowBoundingBoxes( tilingSettings.showBoundingBoxes() );
182 }
183 
184 QgsRuleBasedChunkedEntity::~QgsRuleBasedChunkedEntity()
185 {
186  // cancel / wait for jobs
187  cancelActiveJobs();
188 }
189 
190 void QgsRuleBasedChunkedEntity::onTerrainElevationOffsetChanged( float newOffset )
191 {
192  mTransform->setTranslation( QVector3D( 0.0f, newOffset, 0.0f ) );
193 }
194 
float terrainElevationOffset() const
Returns the elevation offset of the terrain (used to move the terrain up or down)
void terrainElevationOffsetChanged(float newElevation)
Emitted when the terrain elevation offset is changed.
QgsCoordinateReferenceSystem crs() const
Returns coordinate reference system used in the 3D scene.
QgsCoordinateTransformContext transformContext() const
Returns the coordinate transform context, which stores various information regarding which datum tran...
QgsVector3D origin() const
Returns coordinates in map CRS at which 3D scene has origin (0,0,0)
static QgsRectangle worldToMapExtent(const QgsAABB &bbox, const QgsVector3D &mapOrigin)
Converts axis aligned bounding box in 3D world coordinates to extent in map coordinates.
Definition: qgs3dutils.cpp:599
static QgsAABB layerToWorldExtent(const QgsRectangle &extent, double zMin, double zMax, const QgsCoordinateReferenceSystem &layerCrs, const QgsVector3D &mapOrigin, const QgsCoordinateReferenceSystem &mapCrs, const QgsCoordinateTransformContext &context)
Converts extent (in map layer's CRS) to axis aligned bounding box in 3D world coordinates.
Definition: qgs3dutils.cpp:576
static QgsExpressionContext globalProjectLayerExpressionContext(QgsVectorLayer *layer)
Returns expression context for use in preparation of 3D data of a layer.
Definition: qgs3dutils.cpp:662
3
Definition: qgsaabb.h:34
float yMax
Definition: qgsaabb.h:85
float yMin
Definition: qgsaabb.h:82
Expression contexts are used to encapsulate the parameters around which a QgsExpression should be eva...
Wrapper for iterator of features from vector data provider or vector layer.
bool nextFeature(QgsFeature &f)
This class wraps a request for features to a vector layer (or directly its vector data provider).
QgsFeatureRequest & setSubsetOfAttributes(const QgsAttributeList &attrs)
Set a subset of attributes that will be fetched.
QgsFeatureRequest & setDestinationCrs(const QgsCoordinateReferenceSystem &crs, const QgsCoordinateTransformContext &context)
Sets the destination crs for feature's geometries.
QgsFeatureRequest & setFilterRect(const QgsRectangle &rectangle)
Sets the rectangle from which features will be taken.
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
Definition: qgsfeature.h:56
QgsCoordinateReferenceSystem crs
Definition: qgsmaplayer.h:79
A rectangle specified with double values.
Definition: qgsrectangle.h:42
bool showBoundingBoxes() const
Returns whether to display bounding boxes of entity's tiles (for debugging)
Partial snapshot of vector layer's state (only the members necessary for access to features)
Represents a vector layer which manages a vector based data sets.
QgsFields fields() const FINAL
Returns the list of fields of this layer.
QgsRectangle extent() const FINAL
Returns the extent of the layer.