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Fixed point displacement renderer (and made it faster)
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@wonder-sk
wonder-sk committed Jan 13, 2014
1 parent 78841d9 commit 47d09fe
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Showing 2 changed files with 78 additions and 169 deletions.
226 changes: 65 additions & 161 deletions src/core/symbology-ng/qgspointdisplacementrenderer.cpp
View file
Expand Up @@ -53,7 +53,6 @@ QgsFeatureRendererV2* QgsPointDisplacementRenderer::clone()
{
QgsPointDisplacementRenderer* r = new QgsPointDisplacementRenderer( mLabelAttributeName );
r->setEmbeddedRenderer( mRenderer->clone() );
r->setDisplacementGroups( mDisplacementGroups );
r->setCircleWidth( mCircleWidth );
r->setCircleColor( mCircleColor );
r->setLabelFont( mLabelFont );
Expand All @@ -77,6 +76,13 @@ void QgsPointDisplacementRenderer::toSld( QDomDocument& doc, QDomElement &elemen
bool QgsPointDisplacementRenderer::renderFeature( QgsFeature& feature, QgsRenderContext& context, int layer, bool selected, bool drawVertexMarker )
{
Q_UNUSED( drawVertexMarker );
Q_UNUSED( context );
Q_UNUSED( layer );

//check, if there is already a point at that position
if ( !feature.geometry() )
return false;

//point position in screen coords
QgsGeometry* geom = feature.geometry();
QGis::WkbType geomType = geom->wkbType();
Expand All @@ -85,58 +91,55 @@ bool QgsPointDisplacementRenderer::renderFeature( QgsFeature& feature, QgsRender
//can only render point type
return false;
}
QPointF pt;
_getPoint( pt, context, geom->asWkb() );

if ( selected )
mSelectedFeatures.insert( feature.id() );

QList<QgsFeatureId> intersectList = mSpatialIndex->intersects( searchRect( feature.geometry()->asPoint() ) );
if ( intersectList.empty() )
{
mSpatialIndex->insertFeature( feature );
// create new group
DisplacementGroup newGroup;
newGroup.insert( feature.id(), feature );
mDisplacementGroups.push_back( newGroup );
// add to group index
mGroupIndex.insert( feature.id(), mDisplacementGroups.count() - 1 );
return true;
}

//go through all the displacement group maps and search an entry where the id equals the result of the spatial search
QgsFeatureId existingEntry = intersectList.at( 0 );

int groupIdx = mGroupIndex[ existingEntry ];
DisplacementGroup& group = mDisplacementGroups[groupIdx];

// add to a group
group.insert( feature.id(), feature );
// add to group index
mGroupIndex.insert( feature.id(), groupIdx );
return true;
}

void QgsPointDisplacementRenderer::drawGroup( const DisplacementGroup& group, QgsRenderContext& context )
{
const QgsFeature& feature = group.begin().value();
bool selected = mSelectedFeatures.contains( feature.id() ); // maybe we should highlight individual features instead of the whole group?

QPointF pt;
_getPoint( pt, context, feature.geometry()->asWkb() );

//get list of labels and symbols
QStringList labelAttributeList;
QList<QgsMarkerSymbolV2*> symbolList;

if ( mDisplacementIds.contains( feature.id() ) )
for ( DisplacementGroup::const_iterator attIt = group.constBegin(); attIt != group.constEnd(); ++attIt )
{
//create the symbol for the whole display group if the id is the first entry in a display group
QList<QMap<QgsFeatureId, QgsFeature> >::iterator it = mDisplacementGroups.begin();
for ( ; it != mDisplacementGroups.end(); ++it )
{
//create the symbol for the whole display group if the id is the first entry in a display group
if ( feature.id() == it->begin().key() )
{
QMap<QgsFeatureId, QgsFeature>::iterator attIt = it->begin();
for ( ; attIt != it->end(); ++attIt )
{
if ( mDrawLabels )
{
labelAttributeList << getLabel( attIt.value() );
}
else
{
labelAttributeList << QString();
}
symbolList << dynamic_cast<QgsMarkerSymbolV2*>( firstSymbolForFeature( mRenderer, attIt.value() ) );
}
}
}
}
else //only one feature
{
symbolList << dynamic_cast<QgsMarkerSymbolV2*>( firstSymbolForFeature( mRenderer, feature ) );
if ( mDrawLabels )
{
labelAttributeList << getLabel( feature );
}
else
{
labelAttributeList << QString();
}
}

if ( symbolList.isEmpty() && labelAttributeList.isEmpty() )
{
return true; //display all point symbols for one posi
labelAttributeList << ( mDrawLabels ? getLabel( attIt.value() ) : QString() );
QgsFeature& f = const_cast<QgsFeature&>( attIt.value() ); // other parts of API use non-const ref to QgsFeature :-/
symbolList << dynamic_cast<QgsMarkerSymbolV2*>( firstSymbolForFeature( mRenderer, f ) );
}


//draw symbol
double diagonal = 0;
double currentWidthFactor; //scale symbol size to map unit and output resolution
Expand Down Expand Up @@ -172,7 +175,7 @@ bool QgsPointDisplacementRenderer::renderFeature( QgsFeature& feature, QgsRender
{
if ( mCenterSymbol )
{
mCenterSymbol->renderPoint( pt, &feature, context, layer, selected );
mCenterSymbol->renderPoint( pt, &feature, context, -1, selected );
}
else
{
Expand All @@ -184,7 +187,6 @@ bool QgsPointDisplacementRenderer::renderFeature( QgsFeature& feature, QgsRender
drawSymbols( feature, context, symbolList, symbolPositions, selected );
//and also the labels
drawLabels( pt, symbolContext, labelPositions, labelAttributeList );
return true;
}

void QgsPointDisplacementRenderer::setEmbeddedRenderer( QgsFeatureRendererV2* r )
Expand All @@ -203,9 +205,10 @@ void QgsPointDisplacementRenderer::startRender( QgsRenderContext& context, const
{
mRenderer->startRender( context, fields );

//create groups with features that have the same position
createDisplacementGroups( 0, context.extent() );
printInfoDisplacementGroups(); //just for debugging
mDisplacementGroups.clear();
mGroupIndex.clear();
mSpatialIndex = new QgsSpatialIndex;
mSelectedFeatures.clear();

if ( mLabelAttributeName.isEmpty() )
{
Expand Down Expand Up @@ -234,6 +237,18 @@ void QgsPointDisplacementRenderer::startRender( QgsRenderContext& context, const
void QgsPointDisplacementRenderer::stopRender( QgsRenderContext& context )
{
QgsDebugMsg( "QgsPointDisplacementRenderer::stopRender" );

//printInfoDisplacementGroups(); //just for debugging

for ( QList<DisplacementGroup>::const_iterator it = mDisplacementGroups.begin(); it != mDisplacementGroups.end(); ++it )
drawGroup( *it, context );

mDisplacementGroups.clear();
mGroupIndex.clear();
delete mSpatialIndex;
mSpatialIndex = 0;
mSelectedFeatures.clear();

mRenderer->stopRender( context );
if ( mCenterSymbol )
{
Expand Down Expand Up @@ -339,95 +354,6 @@ QgsLegendSymbolList QgsPointDisplacementRenderer::legendSymbolItems( double scal
return QgsLegendSymbolList();
}

void QgsPointDisplacementRenderer::createDisplacementGroups( QgsVectorLayer* vlayer, const QgsRectangle& viewExtent )
{
Q_ASSERT( 0 && "Point Displacement Renderer is currently not working - it is now illegal to interact with QgsVectorLayer"
" in any way. The renderer should build groups in the renderFeature() calls and then do all rendering in stopRender()");

if ( !vlayer || ( vlayer->wkbType() != QGis::WKBPoint && vlayer->wkbType() != QGis::WKBPoint25D ) )
{
return;
}

mDisplacementGroups.clear();
mDisplacementIds.clear();

//use a spatial index to check if there is already a point at a position
QgsSpatialIndex spatialIndex;

//attributes
QgsAttributeList attList;
QList<QString> attributeStrings = usedAttributes();
QList<QString>::const_iterator attStringIt = attributeStrings.constBegin();
for ( ; attStringIt != attributeStrings.constEnd(); ++attStringIt )
{
attList.push_back( vlayer->fieldNameIndex( *attStringIt ) );
}

QgsFeature f;
QList<QgsFeatureId> intersectList;

//Because the new vector api does not allow querying features by id within a nextFeature loop, default constructed QgsFeature() is
//inserted first and the real features are created in a second loop

QgsFeatureIterator fit = vlayer->getFeatures( QgsFeatureRequest().setFilterRect( viewExtent ).setSubsetOfAttributes( attList ) );
while ( fit.nextFeature( f ) )
{
intersectList.clear();

//check, if there is already a point at that position
if ( f.geometry() )
{
intersectList = spatialIndex.intersects( searchRect( f.geometry()->asPoint() ) );
if ( intersectList.empty() )
{
spatialIndex.insertFeature( f );
}
else
{
//go through all the displacement group maps and search an entry where the id equals the result of the spatial search
QgsFeatureId existingEntry = intersectList.at( 0 );
bool found = false;
QList< QMap<QgsFeatureId, QgsFeature> >::iterator it = mDisplacementGroups.begin();
for ( ; it != mDisplacementGroups.end(); ++it )
{
if ( it->size() > 0 && it->contains( existingEntry ) )
{
found = true;
QgsFeature feature;
it->insert( f.id(), QgsFeature() );
mDisplacementIds.insert( f.id() );
break;
}
}

if ( !found )//insert the already existing feature and the new one into a map
{
QMap<QgsFeatureId, QgsFeature> newMap;
newMap.insert( existingEntry, QgsFeature() );
mDisplacementIds.insert( existingEntry );
newMap.insert( f.id(), QgsFeature() );
mDisplacementIds.insert( f.id() );
mDisplacementGroups.push_back( newMap );
}
}
}
}

//insert the real features into mDisplacementGroups
QList< QMap<QgsFeatureId, QgsFeature> >::iterator it = mDisplacementGroups.begin();
for ( ; it != mDisplacementGroups.end(); ++it )
{
QMap<QgsFeatureId, QgsFeature>::iterator mapIt = it->begin();
for ( ; mapIt != it->end(); ++mapIt )
{
QgsFeature fet;
vlayer->getFeatures( QgsFeatureRequest().setFilterFid( mapIt.key() ) ).nextFeature( fet );
mapIt.value() = fet;
}
}

}

QgsRectangle QgsPointDisplacementRenderer::searchRect( const QgsPoint& p ) const
{
Expand All @@ -447,28 +373,6 @@ void QgsPointDisplacementRenderer::printInfoDisplacementGroups()
QgsDebugMsg( FID_TO_STRING( it.key() ) );
}
}
QgsDebugMsg( "********all displacement ids*********" );
QSet<QgsFeatureId>::const_iterator iIt = mDisplacementIds.constBegin();
for ( ; iIt != mDisplacementIds.constEnd(); ++iIt )
{
QgsDebugMsg( FID_TO_STRING( *iIt ) );
}
}

void QgsPointDisplacementRenderer::setDisplacementGroups( const QList< QMap<QgsFeatureId, QgsFeature> >& list )
{
mDisplacementGroups = list;
mDisplacementIds.clear();

QList<QMap<QgsFeatureId, QgsFeature> >::const_iterator list_it = mDisplacementGroups.constBegin();
for ( ; list_it != mDisplacementGroups.constEnd(); ++list_it )
{
QMap<QgsFeatureId, QgsFeature>::const_iterator map_it = list_it->constBegin();
for ( ; map_it != list_it->constEnd(); ++map_it )
{
mDisplacementIds.insert( map_it.key() );
}
}
}

QString QgsPointDisplacementRenderer::getLabel( const QgsFeature& f )
Expand Down Expand Up @@ -537,7 +441,7 @@ void QgsPointDisplacementRenderer::drawCircle( double radiusPainterUnits, QgsSym
p->drawArc( QRectF( centerPoint.x() - radiusPainterUnits, centerPoint.y() - radiusPainterUnits, 2 * radiusPainterUnits, 2 * radiusPainterUnits ), 0, 5760 );
}

void QgsPointDisplacementRenderer::drawSymbols( QgsFeature& f, QgsRenderContext& context, const QList<QgsMarkerSymbolV2*>& symbolList, const QList<QPointF>& symbolPositions, bool selected )
void QgsPointDisplacementRenderer::drawSymbols( const QgsFeature& f, QgsRenderContext& context, const QList<QgsMarkerSymbolV2*>& symbolList, const QList<QPointF>& symbolPositions, bool selected )
{
QList<QPointF>::const_iterator symbolPosIt = symbolPositions.constBegin();
QList<QgsMarkerSymbolV2*>::const_iterator symbolIt = symbolList.constBegin();
Expand Down
21 changes: 13 additions & 8 deletions src/core/symbology-ng/qgspointdisplacementrenderer.h
View file
Expand Up @@ -25,7 +25,7 @@
#include <QFont>
#include <QSet>

class QgsVectorLayer;
class QgsSpatialIndex;

/**A renderer that automatically displaces points with the same position*/
class CORE_EXPORT QgsPointDisplacementRenderer: public QgsFeatureRendererV2
Expand Down Expand Up @@ -67,7 +67,8 @@ class CORE_EXPORT QgsPointDisplacementRenderer: public QgsFeatureRendererV2
QgsFeatureRendererV2* embeddedRenderer() { return mRenderer;}

//! not available in python bindings
void setDisplacementGroups( const QList<QMap<QgsFeatureId, QgsFeature> >& list );
//! @deprecated since 2.1
Q_DECL_DEPRECATED void setDisplacementGroups( const QList<QMap<QgsFeatureId, QgsFeature> >& list ) { Q_UNUSED( list ); }

void setLabelFont( const QFont& f ) { mLabelFont = f; }
QFont labelFont() const { return mLabelFont;}
Expand Down Expand Up @@ -125,13 +126,16 @@ class CORE_EXPORT QgsPointDisplacementRenderer: public QgsFeatureRendererV2
/**Maximum scale denominator for label display. Negative number means no scale limitation*/
double mMaxLabelScaleDenominator;

typedef QMap<QgsFeatureId, QgsFeature> DisplacementGroup;
/**Groups of features that have the same position*/
QList<QMap<QgsFeatureId, QgsFeature> > mDisplacementGroups;
/**Set that contains all the ids the display groups (for quicker lookup)*/
QSet<QgsFeatureId> mDisplacementIds;
QList<DisplacementGroup> mDisplacementGroups;
/**Mapping from feature ID to its group index*/
QMap<QgsFeatureId, int> mGroupIndex;
/**Spatial index for fast lookup of close points*/
QgsSpatialIndex* mSpatialIndex;
/** keeps trask which features are selected */
QSet<QgsFeatureId> mSelectedFeatures;

/**Create the displacement groups efficiently using a spatial index*/
void createDisplacementGroups( QgsVectorLayer *vlayer, const QgsRectangle& viewExtent );
/**Creates a search rectangle with mTolerance*/
QgsRectangle searchRect( const QgsPoint& p ) const;
/**This is a debugging function to check the entries in the displacement groups*/
Expand All @@ -146,8 +150,9 @@ class CORE_EXPORT QgsPointDisplacementRenderer: public QgsFeatureRendererV2

//helper functions
void calculateSymbolAndLabelPositions( const QPointF& centerPoint, int nPosition, double radius, double symbolDiagonal, QList<QPointF>& symbolPositions, QList<QPointF>& labelShifts ) const;
void drawGroup( const DisplacementGroup& group, QgsRenderContext& context );
void drawCircle( double radiusPainterUnits, QgsSymbolV2RenderContext& context, const QPointF& centerPoint, int nSymbols );
void drawSymbols( QgsFeature& f, QgsRenderContext& context, const QList<QgsMarkerSymbolV2*>& symbolList, const QList<QPointF>& symbolPositions, bool selected = false );
void drawSymbols( const QgsFeature& f, QgsRenderContext& context, const QList<QgsMarkerSymbolV2*>& symbolList, const QList<QPointF>& symbolPositions, bool selected = false );
void drawLabels( const QPointF& centerPoint, QgsSymbolV2RenderContext& context, const QList<QPointF>& labelShifts, const QStringList& labelList );
/**Returns first symbol for feature or 0 if none*/
QgsSymbolV2* firstSymbolForFeature( QgsFeatureRendererV2* r, QgsFeature& f );
Expand Down

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