QGIS API Documentation 3.27.0-Master (1c05421486)
qgsvectorlayerchunkloader_p.cpp
Go to the documentation of this file.
1/***************************************************************************
2 qgsvectorlayerchunkloader_p.cpp
3 --------------------------------------
4 Date : July 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"
20#include "qgschunknode_p.h"
22#include "qgseventtracing.h"
23#include "qgslogger.h"
24#include "qgsvectorlayer.h"
26
27#include "qgsline3dsymbol.h"
28#include "qgspoint3dsymbol.h"
29#include "qgspolygon3dsymbol.h"
30
31#include "qgsapplication.h"
32#include "qgs3dsymbolregistry.h"
33
34#include <QtConcurrent>
35#include <Qt3DCore/QTransform>
36
38
39
40QgsVectorLayerChunkLoader::QgsVectorLayerChunkLoader( const QgsVectorLayerChunkLoaderFactory *factory, QgsChunkNode *node )
41 : QgsChunkLoader( node )
42 , mFactory( factory )
43 , mContext( factory->mMap )
44 , mSource( new QgsVectorLayerFeatureSource( factory->mLayer ) )
45{
46 if ( node->level() < mFactory->mLeafLevel )
47 {
48 QTimer::singleShot( 0, this, &QgsVectorLayerChunkLoader::finished );
49 return;
50 }
51
52 QgsVectorLayer *layer = mFactory->mLayer;
53 const Qgs3DMapSettings &map = mFactory->mMap;
54
55 QgsFeature3DHandler *handler = QgsApplication::symbol3DRegistry()->createHandlerForSymbol( layer, mFactory->mSymbol.get() );
56 if ( !handler )
57 {
58 QgsDebugMsg( QStringLiteral( "Unknown 3D symbol type for vector layer: " ) + mFactory->mSymbol->type() );
59 return;
60 }
61 mHandler.reset( handler );
62
64 exprContext.setFields( layer->fields() );
65 mContext.setExpressionContext( exprContext );
66
67 QSet<QString> attributeNames;
68 if ( !mHandler->prepare( mContext, attributeNames ) )
69 {
70 QgsDebugMsg( QStringLiteral( "Failed to prepare 3D feature handler!" ) );
71 return;
72 }
73
74 // build the feature request
76 req.setDestinationCrs( map.crs(), map.transformContext() );
77 req.setSubsetOfAttributes( attributeNames, layer->fields() );
78
79 // only a subset of data to be queried
80 const QgsRectangle rect = Qgs3DUtils::worldToMapExtent( node->bbox(), map.origin() );
81 req.setFilterRect( rect );
82
83 //
84 // this will be run in a background thread
85 //
86 mFutureWatcher = new QFutureWatcher<void>( this );
87 connect( mFutureWatcher, &QFutureWatcher<void>::finished, this, &QgsChunkQueueJob::finished );
88
89 const QFuture<void> future = QtConcurrent::run( [req, this]
90 {
91 const QgsEventTracing::ScopedEvent e( QStringLiteral( "3D" ), QStringLiteral( "VL chunk load" ) );
92
93 QgsFeature f;
94 QgsFeatureIterator fi = mSource->getFeatures( req );
95 while ( fi.nextFeature( f ) )
96 {
97 if ( mCanceled )
98 break;
99 mContext.expressionContext().setFeature( f );
100 mHandler->processFeature( f, mContext );
101 }
102 } );
103
104 // emit finished() as soon as the handler is populated with features
105 mFutureWatcher->setFuture( future );
106}
107
108QgsVectorLayerChunkLoader::~QgsVectorLayerChunkLoader()
109{
110 if ( mFutureWatcher && !mFutureWatcher->isFinished() )
111 {
112 disconnect( mFutureWatcher, &QFutureWatcher<void>::finished, this, &QgsChunkQueueJob::finished );
113 mFutureWatcher->waitForFinished();
114 }
115}
116
117void QgsVectorLayerChunkLoader::cancel()
118{
119 mCanceled = true;
120}
121
122Qt3DCore::QEntity *QgsVectorLayerChunkLoader::createEntity( Qt3DCore::QEntity *parent )
123{
124 if ( mNode->level() < mFactory->mLeafLevel )
125 {
126 return new Qt3DCore::QEntity( parent ); // dummy entity
127 }
128
129 if ( mHandler->featureCount() == 0 )
130 {
131 // an empty node, so we return no entity. This tags the node as having no data and effectively removes it.
132 return nullptr;
133 }
134
135 Qt3DCore::QEntity *entity = new Qt3DCore::QEntity( parent );
136 mHandler->finalize( entity, mContext );
137
138 // fix the vertical range of the node from the estimated vertical range to the true range
139 if ( mHandler->zMinimum() != std::numeric_limits<float>::max() && mHandler->zMaximum() != std::numeric_limits<float>::lowest() )
140 {
141 QgsAABB box = mNode->bbox();
142 box.yMin = mHandler->zMinimum();
143 box.yMax = mHandler->zMaximum();
144 mNode->setExactBbox( box );
145 mNode->updateParentBoundingBoxesRecursively();
146 }
147
148 return entity;
149}
150
151
153
154
155QgsVectorLayerChunkLoaderFactory::QgsVectorLayerChunkLoaderFactory( const Qgs3DMapSettings &map, QgsVectorLayer *vl, QgsAbstract3DSymbol *symbol, int leafLevel, double zMin, double zMax )
156 : mMap( map )
157 , mLayer( vl )
158 , mSymbol( symbol->clone() )
159 , mLeafLevel( leafLevel )
160{
161 QgsAABB rootBbox = Qgs3DUtils::layerToWorldExtent( vl->extent(), zMin, zMax, vl->crs(), map.origin(), map.crs(), map.transformContext() );
162 // add small padding to avoid clipping of point features located at the edge of the bounding box
163 rootBbox.xMin -= 1.0;
164 rootBbox.xMax += 1.0;
165 rootBbox.yMin -= 1.0;
166 rootBbox.yMax += 1.0;
167 rootBbox.zMin -= 1.0;
168 rootBbox.zMax += 1.0;
169 setupQuadtree( rootBbox, -1, leafLevel ); // negative root error means that the node does not contain anything
170}
171
172QgsChunkLoader *QgsVectorLayerChunkLoaderFactory::createChunkLoader( QgsChunkNode *node ) const
173{
174 return new QgsVectorLayerChunkLoader( this, node );
175}
176
177
179
180
181QgsVectorLayerChunkedEntity::QgsVectorLayerChunkedEntity( QgsVectorLayer *vl, double zMin, double zMax, const QgsVectorLayer3DTilingSettings &tilingSettings, QgsAbstract3DSymbol *symbol, const Qgs3DMapSettings &map )
182 : QgsChunkedEntity( -1, // max. allowed screen error (negative tau means that we need to go until leaves are reached)
183 new QgsVectorLayerChunkLoaderFactory( map, vl, symbol, tilingSettings.zoomLevelsCount() - 1, zMin, zMax ), true )
184{
185 mTransform = new Qt3DCore::QTransform;
186 mTransform->setTranslation( QVector3D( 0.0f, map.terrainElevationOffset(), 0.0f ) );
187 this->addComponent( mTransform );
188
189 connect( &map, &Qgs3DMapSettings::terrainElevationOffsetChanged, this, &QgsVectorLayerChunkedEntity::onTerrainElevationOffsetChanged );
190
191 setShowBoundingBoxes( tilingSettings.showBoundingBoxes() );
192}
193
194QgsVectorLayerChunkedEntity::~QgsVectorLayerChunkedEntity()
195{
196 // cancel / wait for jobs
197 cancelActiveJobs();
198}
199
200void QgsVectorLayerChunkedEntity::onTerrainElevationOffsetChanged( float newOffset )
201{
202 QgsDebugMsgLevel( QStringLiteral( "QgsVectorLayerChunkedEntity::onTerrainElevationOffsetChanged" ), 2 );
203 mTransform->setTranslation( QVector3D( 0.0f, newOffset, 0.0f ) );
204}
205
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)
QgsFeature3DHandler * createHandlerForSymbol(QgsVectorLayer *layer, const QgsAbstract3DSymbol *symbol)
Creates a feature handler for a symbol, for the specified vector layer.
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 xMax
Definition: qgsaabb.h:84
float xMin
Definition: qgsaabb.h:81
float zMax
Definition: qgsaabb.h:86
float yMin
Definition: qgsaabb.h:82
float zMin
Definition: qgsaabb.h:83
static Qgs3DSymbolRegistry * symbol3DRegistry()
Returns registry of available 3D symbols.
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.
#define QgsDebugMsgLevel(str, level)
Definition: qgslogger.h:39
#define QgsDebugMsg(str)
Definition: qgslogger.h:38