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feature.cpp
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feature.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 "qgsgeometry.h"
#include "pal.h"
#include "layer.h"
#include "feature.h"
#include "geomfunction.h"
#include "labelposition.h"
#include "pointset.h"
#include "util.h"
#include "qgis.h"
#include "qgsgeos.h"
#include "qgsmessagelog.h"
#include "costcalculator.h"
#include "qgsgeometryutils.h"
#include "qgslabeling.h"
#include "qgspolygon.h"
#include <QLinkedList>
#include <cmath>
#include <cfloat>
using namespace pal;
FeaturePart::FeaturePart( QgsLabelFeature *feat, const GEOSGeometry *geom )
: mLF( feat )
{
// we'll remove const, but we won't modify that geometry
mGeos = const_cast<GEOSGeometry *>( geom );
mOwnsGeom = false; // geometry is owned by Feature class
extractCoords( geom );
holeOf = nullptr;
for ( int i = 0; i < mHoles.count(); i++ )
{
mHoles.at( i )->holeOf = this;
}
}
FeaturePart::FeaturePart( const FeaturePart &other )
: PointSet( other )
, mLF( other.mLF )
{
for ( const FeaturePart *hole : qgis::as_const( other.mHoles ) )
{
mHoles << new FeaturePart( *hole );
mHoles.last()->holeOf = this;
}
}
FeaturePart::~FeaturePart()
{
// X and Y are deleted in PointSet
qDeleteAll( mHoles );
mHoles.clear();
}
void FeaturePart::extractCoords( const GEOSGeometry *geom )
{
const GEOSCoordSequence *coordSeq = nullptr;
GEOSContextHandle_t geosctxt = QgsGeos::getGEOSHandler();
type = GEOSGeomTypeId_r( geosctxt, geom );
if ( type == GEOS_POLYGON )
{
if ( GEOSGetNumInteriorRings_r( geosctxt, geom ) > 0 )
{
int numHoles = GEOSGetNumInteriorRings_r( geosctxt, geom );
for ( int i = 0; i < numHoles; ++i )
{
const GEOSGeometry *interior = GEOSGetInteriorRingN_r( geosctxt, geom, i );
FeaturePart *hole = new FeaturePart( mLF, interior );
hole->holeOf = nullptr;
// possibly not needed. it's not done for the exterior ring, so I'm not sure
// why it's just done here...
GeomFunction::reorderPolygon( hole->nbPoints, hole->x, hole->y );
mHoles << hole;
}
}
// use exterior ring for the extraction of coordinates that follows
geom = GEOSGetExteriorRing_r( geosctxt, geom );
}
else
{
qDeleteAll( mHoles );
mHoles.clear();
}
// find out number of points
nbPoints = GEOSGetNumCoordinates_r( geosctxt, geom );
coordSeq = GEOSGeom_getCoordSeq_r( geosctxt, geom );
// initialize bounding box
xmin = ymin = std::numeric_limits<double>::max();
xmax = ymax = std::numeric_limits<double>::lowest();
// initialize coordinate arrays
deleteCoords();
x.resize( nbPoints );
y.resize( nbPoints );
for ( int i = 0; i < nbPoints; ++i )
{
#if GEOS_VERSION_MAJOR>3 || GEOS_VERSION_MINOR>=8
GEOSCoordSeq_getXY_r( geosctxt, coordSeq, i, &x[i], &y[i] );
#else
GEOSCoordSeq_getX_r( geosctxt, coordSeq, i, &x[i] );
GEOSCoordSeq_getY_r( geosctxt, coordSeq, i, &y[i] );
#endif
xmax = x[i] > xmax ? x[i] : xmax;
xmin = x[i] < xmin ? x[i] : xmin;
ymax = y[i] > ymax ? y[i] : ymax;
ymin = y[i] < ymin ? y[i] : ymin;
}
}
Layer *FeaturePart::layer()
{
return mLF->layer();
}
QgsFeatureId FeaturePart::featureId() const
{
return mLF->id();
}
std::size_t FeaturePart::maximumPointCandidates() const
{
return mLF->layer()->maximumPointLabelCandidates();
}
std::size_t FeaturePart::maximumLineCandidates() const
{
if ( mCachedMaxLineCandidates > 0 )
return mCachedMaxLineCandidates;
const double l = length();
if ( l > 0 )
{
const std::size_t candidatesForLineLength = static_cast< std::size_t >( std::ceil( mLF->layer()->mPal->maximumLineCandidatesPerMapUnit() * l ) );
const std::size_t maxForLayer = mLF->layer()->maximumLineLabelCandidates();
if ( maxForLayer == 0 )
mCachedMaxLineCandidates = candidatesForLineLength;
else
mCachedMaxLineCandidates = std::min( candidatesForLineLength, maxForLayer );
}
else
{
mCachedMaxLineCandidates = 1;
}
return mCachedMaxLineCandidates;
}
std::size_t FeaturePart::maximumPolygonCandidates() const
{
if ( mCachedMaxPolygonCandidates > 0 )
return mCachedMaxPolygonCandidates;
const double a = area();
if ( a > 0 )
{
const std::size_t candidatesForArea = static_cast< std::size_t >( std::ceil( mLF->layer()->mPal->maximumPolygonCandidatesPerMapUnitSquared() * a ) );
const std::size_t maxForLayer = mLF->layer()->maximumPolygonLabelCandidates();
if ( maxForLayer == 0 )
mCachedMaxPolygonCandidates = candidatesForArea;
else
mCachedMaxPolygonCandidates = std::min( candidatesForArea, maxForLayer );
}
else
{
mCachedMaxPolygonCandidates = 1;
}
return mCachedMaxPolygonCandidates;
}
bool FeaturePart::hasSameLabelFeatureAs( FeaturePart *part ) const
{
if ( !part )
return false;
if ( mLF->layer()->name() != part->layer()->name() )
return false;
if ( mLF->id() == part->featureId() )
return true;
// any part of joined features are also treated as having the same label feature
int connectedFeatureId = mLF->layer()->connectedFeatureId( mLF->id() );
return connectedFeatureId >= 0 && connectedFeatureId == mLF->layer()->connectedFeatureId( part->featureId() );
}
LabelPosition::Quadrant FeaturePart::quadrantFromOffset() const
{
QPointF quadOffset = mLF->quadOffset();
qreal quadOffsetX = quadOffset.x(), quadOffsetY = quadOffset.y();
if ( quadOffsetX < 0 )
{
if ( quadOffsetY < 0 )
{
return LabelPosition::QuadrantAboveLeft;
}
else if ( quadOffsetY > 0 )
{
return LabelPosition::QuadrantBelowLeft;
}
else
{
return LabelPosition::QuadrantLeft;
}
}
else if ( quadOffsetX > 0 )
{
if ( quadOffsetY < 0 )
{
return LabelPosition::QuadrantAboveRight;
}
else if ( quadOffsetY > 0 )
{
return LabelPosition::QuadrantBelowRight;
}
else
{
return LabelPosition::QuadrantRight;
}
}
else
{
if ( quadOffsetY < 0 )
{
return LabelPosition::QuadrantAbove;
}
else if ( quadOffsetY > 0 )
{
return LabelPosition::QuadrantBelow;
}
else
{
return LabelPosition::QuadrantOver;
}
}
}
int FeaturePart::totalRepeats() const
{
return mTotalRepeats;
}
void FeaturePart::setTotalRepeats( int totalRepeats )
{
mTotalRepeats = totalRepeats;
}
std::size_t FeaturePart::createCandidateCenteredOverPoint( double x, double y, std::vector< std::unique_ptr< LabelPosition > > &lPos, double angle )
{
// get from feature
double labelW = getLabelWidth( angle );
double labelH = getLabelHeight( angle );
double cost = 0.00005;
int id = lPos.size();
double xdiff = -labelW / 2.0;
double ydiff = -labelH / 2.0;
feature()->setAnchorPosition( QgsPointXY( x, y ) );
double lx = x + xdiff;
double ly = y + ydiff;
if ( mLF->permissibleZonePrepared() )
{
if ( !GeomFunction::containsCandidate( mLF->permissibleZonePrepared(), lx, ly, labelW, labelH, angle ) )
{
return 0;
}
}
lPos.emplace_back( qgis::make_unique< LabelPosition >( id, lx, ly, labelW, labelH, angle, cost, this, false, LabelPosition::QuadrantOver ) );
return 1;
}
std::size_t FeaturePart::createCandidatesOverPoint( double x, double y, std::vector< std::unique_ptr< LabelPosition > > &lPos, double angle )
{
// get from feature
double labelW = getLabelWidth( angle );
double labelH = getLabelHeight( angle );
double cost = 0.0001;
int id = lPos.size();
double xdiff = -labelW / 2.0;
double ydiff = -labelH / 2.0;
feature()->setAnchorPosition( QgsPointXY( x, y ) );
if ( !qgsDoubleNear( mLF->quadOffset().x(), 0.0 ) )
{
xdiff += labelW / 2.0 * mLF->quadOffset().x();
}
if ( !qgsDoubleNear( mLF->quadOffset().y(), 0.0 ) )
{
ydiff += labelH / 2.0 * mLF->quadOffset().y();
}
if ( ! mLF->hasFixedPosition() )
{
if ( !qgsDoubleNear( angle, 0.0 ) )
{
double xd = xdiff * std::cos( angle ) - ydiff * std::sin( angle );
double yd = xdiff * std::sin( angle ) + ydiff * std::cos( angle );
xdiff = xd;
ydiff = yd;
}
}
if ( mLF->layer()->arrangement() == QgsPalLayerSettings::AroundPoint )
{
//if in "around point" placement mode, then we use the label distance to determine
//the label's offset
if ( qgsDoubleNear( mLF->quadOffset().x(), 0.0 ) )
{
ydiff += mLF->quadOffset().y() * mLF->distLabel();
}
else if ( qgsDoubleNear( mLF->quadOffset().y(), 0.0 ) )
{
xdiff += mLF->quadOffset().x() * mLF->distLabel();
}
else
{
xdiff += mLF->quadOffset().x() * M_SQRT1_2 * mLF->distLabel();
ydiff += mLF->quadOffset().y() * M_SQRT1_2 * mLF->distLabel();
}
}
else
{
if ( !qgsDoubleNear( mLF->positionOffset().x(), 0.0 ) )
{
xdiff += mLF->positionOffset().x();
}
if ( !qgsDoubleNear( mLF->positionOffset().y(), 0.0 ) )
{
ydiff += mLF->positionOffset().y();
}
}
double lx = x + xdiff;
double ly = y + ydiff;
if ( mLF->permissibleZonePrepared() )
{
if ( !GeomFunction::containsCandidate( mLF->permissibleZonePrepared(), lx, ly, labelW, labelH, angle ) )
{
return 0;
}
}
lPos.emplace_back( qgis::make_unique< LabelPosition >( id, lx, ly, labelW, labelH, angle, cost, this, false, quadrantFromOffset() ) );
return 1;
}
std::unique_ptr<LabelPosition> FeaturePart::createCandidatePointOnSurface( PointSet *mapShape )
{
double px, py;
try
{
GEOSContextHandle_t geosctxt = QgsGeos::getGEOSHandler();
geos::unique_ptr pointGeom( GEOSPointOnSurface_r( geosctxt, mapShape->geos() ) );
if ( pointGeom )
{
const GEOSCoordSequence *coordSeq = GEOSGeom_getCoordSeq_r( geosctxt, pointGeom.get() );
#if GEOS_VERSION_MAJOR>3 || GEOS_VERSION_MINOR>=8
unsigned int nPoints = 0;
GEOSCoordSeq_getSize_r( geosctxt, coordSeq, &nPoints );
if ( nPoints == 0 )
return nullptr;
GEOSCoordSeq_getXY_r( geosctxt, coordSeq, 0, &px, &py );
#else
GEOSCoordSeq_getX_r( geosctxt, coordSeq, 0, &px );
GEOSCoordSeq_getY_r( geosctxt, coordSeq, 0, &py );
#endif
}
}
catch ( GEOSException &e )
{
QgsMessageLog::logMessage( QObject::tr( "Exception: %1" ).arg( e.what() ), QObject::tr( "GEOS" ) );
return nullptr;
}
return qgis::make_unique< LabelPosition >( 0, px, py, getLabelWidth(), getLabelHeight(), 0.0, 0.0, this, false, LabelPosition::QuadrantOver );
}
void createCandidateAtOrderedPositionOverPoint( double &labelX, double &labelY, LabelPosition::Quadrant &quadrant, double x, double y, double labelWidth, double labelHeight, QgsPalLayerSettings::PredefinedPointPosition position, double distanceToLabel, const QgsMargins &visualMargin, double symbolWidthOffset, double symbolHeightOffset )
{
double alpha = 0.0;
double deltaX = 0;
double deltaY = 0;
switch ( position )
{
case QgsPalLayerSettings::TopLeft:
quadrant = LabelPosition::QuadrantAboveLeft;
alpha = 3 * M_PI_4;
deltaX = -labelWidth + visualMargin.right() - symbolWidthOffset;
deltaY = -visualMargin.bottom() + symbolHeightOffset;
break;
case QgsPalLayerSettings::TopSlightlyLeft:
quadrant = LabelPosition::QuadrantAboveRight; //right quadrant, so labels are left-aligned
alpha = M_PI_2;
deltaX = -labelWidth / 4.0 - visualMargin.left();
deltaY = -visualMargin.bottom() + symbolHeightOffset;
break;
case QgsPalLayerSettings::TopMiddle:
quadrant = LabelPosition::QuadrantAbove;
alpha = M_PI_2;
deltaX = -labelWidth / 2.0;
deltaY = -visualMargin.bottom() + symbolHeightOffset;
break;
case QgsPalLayerSettings::TopSlightlyRight:
quadrant = LabelPosition::QuadrantAboveLeft; //left quadrant, so labels are right-aligned
alpha = M_PI_2;
deltaX = -labelWidth * 3.0 / 4.0 + visualMargin.right();
deltaY = -visualMargin.bottom() + symbolHeightOffset;
break;
case QgsPalLayerSettings::TopRight:
quadrant = LabelPosition::QuadrantAboveRight;
alpha = M_PI_4;
deltaX = - visualMargin.left() + symbolWidthOffset;
deltaY = -visualMargin.bottom() + symbolHeightOffset;
break;
case QgsPalLayerSettings::MiddleLeft:
quadrant = LabelPosition::QuadrantLeft;
alpha = M_PI;
deltaX = -labelWidth + visualMargin.right() - symbolWidthOffset;
deltaY = -labelHeight / 2.0;// TODO - should this be adjusted by visual margin??
break;
case QgsPalLayerSettings::MiddleRight:
quadrant = LabelPosition::QuadrantRight;
alpha = 0.0;
deltaX = -visualMargin.left() + symbolWidthOffset;
deltaY = -labelHeight / 2.0;// TODO - should this be adjusted by visual margin??
break;
case QgsPalLayerSettings::BottomLeft:
quadrant = LabelPosition::QuadrantBelowLeft;
alpha = 5 * M_PI_4;
deltaX = -labelWidth + visualMargin.right() - symbolWidthOffset;
deltaY = -labelHeight + visualMargin.top() - symbolHeightOffset;
break;
case QgsPalLayerSettings::BottomSlightlyLeft:
quadrant = LabelPosition::QuadrantBelowRight; //right quadrant, so labels are left-aligned
alpha = 3 * M_PI_2;
deltaX = -labelWidth / 4.0 - visualMargin.left();
deltaY = -labelHeight + visualMargin.top() - symbolHeightOffset;
break;
case QgsPalLayerSettings::BottomMiddle:
quadrant = LabelPosition::QuadrantBelow;
alpha = 3 * M_PI_2;
deltaX = -labelWidth / 2.0;
deltaY = -labelHeight + visualMargin.top() - symbolHeightOffset;
break;
case QgsPalLayerSettings::BottomSlightlyRight:
quadrant = LabelPosition::QuadrantBelowLeft; //left quadrant, so labels are right-aligned
alpha = 3 * M_PI_2;
deltaX = -labelWidth * 3.0 / 4.0 + visualMargin.right();
deltaY = -labelHeight + visualMargin.top() - symbolHeightOffset;
break;
case QgsPalLayerSettings::BottomRight:
quadrant = LabelPosition::QuadrantBelowRight;
alpha = 7 * M_PI_4;
deltaX = -visualMargin.left() + symbolWidthOffset;
deltaY = -labelHeight + visualMargin.top() - symbolHeightOffset;
break;
}
//have bearing, distance - calculate reference point
double referenceX = std::cos( alpha ) * distanceToLabel + x;
double referenceY = std::sin( alpha ) * distanceToLabel + y;
labelX = referenceX + deltaX;
labelY = referenceY + deltaY;
}
std::size_t FeaturePart::createCandidatesAtOrderedPositionsOverPoint( double x, double y, std::vector< std::unique_ptr< LabelPosition > > &lPos, double angle )
{
const QVector< QgsPalLayerSettings::PredefinedPointPosition > positions = mLF->predefinedPositionOrder();
double labelWidth = getLabelWidth( angle );
double labelHeight = getLabelHeight( angle );
double distanceToLabel = getLabelDistance();
const QgsMargins &visualMargin = mLF->visualMargin();
double symbolWidthOffset = ( mLF->offsetType() == QgsPalLayerSettings::FromSymbolBounds ? mLF->symbolSize().width() / 2.0 : 0.0 );
double symbolHeightOffset = ( mLF->offsetType() == QgsPalLayerSettings::FromSymbolBounds ? mLF->symbolSize().height() / 2.0 : 0.0 );
double cost = 0.0001;
std::size_t i = lPos.size();
const std::size_t maxNumberCandidates = mLF->layer()->maximumPointLabelCandidates();
std::size_t created = 0;
for ( QgsPalLayerSettings::PredefinedPointPosition position : positions )
{
LabelPosition::Quadrant quadrant = LabelPosition::QuadrantAboveLeft;
double labelX = 0;
double labelY = 0;
createCandidateAtOrderedPositionOverPoint( labelX, labelY, quadrant, x, y, labelWidth, labelHeight, position, distanceToLabel, visualMargin, symbolWidthOffset, symbolHeightOffset );
if ( ! mLF->permissibleZonePrepared() || GeomFunction::containsCandidate( mLF->permissibleZonePrepared(), labelX, labelY, labelWidth, labelHeight, angle ) )
{
lPos.emplace_back( qgis::make_unique< LabelPosition >( i, labelX, labelY, labelWidth, labelHeight, angle, cost, this, false, quadrant ) );
created++;
//TODO - tweak
cost += 0.001;
if ( maxNumberCandidates > 0 && created >= maxNumberCandidates )
break;
}
++i;
}
return created;
}
std::size_t FeaturePart::createCandidatesAroundPoint( double x, double y, std::vector< std::unique_ptr< LabelPosition > > &lPos, double angle )
{
double labelWidth = getLabelWidth( angle );
double labelHeight = getLabelHeight( angle );
double distanceToLabel = getLabelDistance();
std::size_t maxNumberCandidates = mLF->layer()->maximumPointLabelCandidates();
if ( maxNumberCandidates == 0 )
maxNumberCandidates = 16;
int icost = 0;
int inc = 2;
int id = lPos.size();
double candidateAngleIncrement = 2 * M_PI / maxNumberCandidates; /* angle bw 2 pos */
/* various angles */
double a90 = M_PI_2;
double a180 = M_PI;
double a270 = a180 + a90;
double a360 = 2 * M_PI;
double gamma1, gamma2;
if ( distanceToLabel > 0 )
{
gamma1 = std::atan2( labelHeight / 2, distanceToLabel + labelWidth / 2 );
gamma2 = std::atan2( labelWidth / 2, distanceToLabel + labelHeight / 2 );
}
else
{
gamma1 = gamma2 = a90 / 3.0;
}
if ( gamma1 > a90 / 3.0 )
gamma1 = a90 / 3.0;
if ( gamma2 > a90 / 3.0 )
gamma2 = a90 / 3.0;
std::size_t numberCandidatesGenerated = 0;
std::size_t i;
double angleToCandidate;
for ( i = 0, angleToCandidate = M_PI_4; i < maxNumberCandidates; i++, angleToCandidate += candidateAngleIncrement )
{
double labelX = x;
double labelY = y;
if ( angleToCandidate > a360 )
angleToCandidate -= a360;
LabelPosition::Quadrant quadrant = LabelPosition::QuadrantOver;
if ( angleToCandidate < gamma1 || angleToCandidate > a360 - gamma1 ) // on the right
{
labelX += distanceToLabel;
double iota = ( angleToCandidate + gamma1 );
if ( iota > a360 - gamma1 )
iota -= a360;
//ly += -yrm/2.0 + tan(alpha)*(distlabel + xrm/2);
labelY += -labelHeight + labelHeight * iota / ( 2 * gamma1 );
quadrant = LabelPosition::QuadrantRight;
}
else if ( angleToCandidate < a90 - gamma2 ) // top-right
{
labelX += distanceToLabel * std::cos( angleToCandidate );
labelY += distanceToLabel * std::sin( angleToCandidate );
quadrant = LabelPosition::QuadrantAboveRight;
}
else if ( angleToCandidate < a90 + gamma2 ) // top
{
//lx += -xrm/2.0 - tan(alpha+a90)*(distlabel + yrm/2);
labelX += -labelWidth * ( angleToCandidate - a90 + gamma2 ) / ( 2 * gamma2 );
labelY += distanceToLabel;
quadrant = LabelPosition::QuadrantAbove;
}
else if ( angleToCandidate < a180 - gamma1 ) // top left
{
labelX += distanceToLabel * std::cos( angleToCandidate ) - labelWidth;
labelY += distanceToLabel * std::sin( angleToCandidate );
quadrant = LabelPosition::QuadrantAboveLeft;
}
else if ( angleToCandidate < a180 + gamma1 ) // left
{
labelX += -distanceToLabel - labelWidth;
//ly += -yrm/2.0 - tan(alpha)*(distlabel + xrm/2);
labelY += - ( angleToCandidate - a180 + gamma1 ) * labelHeight / ( 2 * gamma1 );
quadrant = LabelPosition::QuadrantLeft;
}
else if ( angleToCandidate < a270 - gamma2 ) // down - left
{
labelX += distanceToLabel * std::cos( angleToCandidate ) - labelWidth;
labelY += distanceToLabel * std::sin( angleToCandidate ) - labelHeight;
quadrant = LabelPosition::QuadrantBelowLeft;
}
else if ( angleToCandidate < a270 + gamma2 ) // down
{
labelY += -distanceToLabel - labelHeight;
//lx += -xrm/2.0 + tan(alpha+a90)*(distlabel + yrm/2);
labelX += -labelWidth + ( angleToCandidate - a270 + gamma2 ) * labelWidth / ( 2 * gamma2 );
quadrant = LabelPosition::QuadrantBelow;
}
else if ( angleToCandidate < a360 ) // down - right
{
labelX += distanceToLabel * std::cos( angleToCandidate );
labelY += distanceToLabel * std::sin( angleToCandidate ) - labelHeight;
quadrant = LabelPosition::QuadrantBelowRight;
}
double cost;
if ( maxNumberCandidates == 1 )
cost = 0.0001;
else
cost = 0.0001 + 0.0020 * double( icost ) / double( maxNumberCandidates - 1 );
if ( mLF->permissibleZonePrepared() )
{
if ( !GeomFunction::containsCandidate( mLF->permissibleZonePrepared(), labelX, labelY, labelWidth, labelHeight, angle ) )
{
continue;
}
}
lPos.emplace_back( qgis::make_unique< LabelPosition >( id + i, labelX, labelY, labelWidth, labelHeight, angle, cost, this, false, quadrant ) );
numberCandidatesGenerated++;
icost += inc;
if ( icost == static_cast< int >( maxNumberCandidates ) )
{
icost = static_cast< int >( maxNumberCandidates ) - 1;
inc = -2;
}
else if ( icost > static_cast< int >( maxNumberCandidates ) )
{
icost = static_cast< int >( maxNumberCandidates ) - 2;
inc = -2;
}
}
return numberCandidatesGenerated;
}
std::size_t FeaturePart::createCandidatesAlongLine( std::vector< std::unique_ptr< LabelPosition > > &lPos, PointSet *mapShape, bool allowOverrun, Pal *pal )
{
if ( allowOverrun )
{
double shapeLength = mapShape->length();
if ( totalRepeats() > 1 && shapeLength < getLabelWidth() )
return 0;
else if ( shapeLength < getLabelWidth() - 2 * std::min( getLabelWidth(), mLF->overrunDistance() ) )
{
// label doesn't fit on this line, don't waste time trying to make candidates
return 0;
}
}
//prefer to label along straightish segments:
std::size_t candidates = createCandidatesAlongLineNearStraightSegments( lPos, mapShape, pal );
const std::size_t candidateTargetCount = maximumLineCandidates();
if ( candidates < candidateTargetCount )
{
// but not enough candidates yet, so fallback to labeling near whole line's midpoint
candidates = createCandidatesAlongLineNearMidpoint( lPos, mapShape, candidates > 0 ? 0.01 : 0.0, pal );
}
return candidates;
}
std::size_t FeaturePart::createHorizontalCandidatesAlongLine( std::vector<std::unique_ptr<LabelPosition> > &lPos, PointSet *mapShape, Pal *pal )
{
const double labelWidth = getLabelWidth();
const double labelHeight = getLabelHeight();
PointSet *line = mapShape;
int nbPoints = line->nbPoints;
std::vector< double > &x = line->x;
std::vector< double > &y = line->y;
std::vector< double > segmentLengths( nbPoints - 1 ); // segments lengths distance bw pt[i] && pt[i+1]
std::vector< double >distanceToSegment( nbPoints ); // absolute distance bw pt[0] and pt[i] along the line
double totalLineLength = 0.0; // line length
for ( int i = 0; i < line->nbPoints - 1; i++ )
{
if ( i == 0 )
distanceToSegment[i] = 0;
else
distanceToSegment[i] = distanceToSegment[i - 1] + segmentLengths[i - 1];
segmentLengths[i] = GeomFunction::dist_euc2d( x[i], y[i], x[i + 1], y[i + 1] );
totalLineLength += segmentLengths[i];
}
distanceToSegment[line->nbPoints - 1] = totalLineLength;
const std::size_t candidateTargetCount = maximumLineCandidates();
const double lineStepDistance = totalLineLength / ( candidateTargetCount + 1 ); // distance to move along line with each candidate
double currentDistanceAlongLine = lineStepDistance;
double candidateCenterX, candidateCenterY;
int i = 0;
while ( currentDistanceAlongLine < totalLineLength )
{
if ( pal->isCanceled() )
{
return lPos.size();
}
line->getPointByDistance( segmentLengths.data(), distanceToSegment.data(), currentDistanceAlongLine, &candidateCenterX, &candidateCenterY );
// penalize positions which are further from the line's midpoint
double cost = std::fabs( totalLineLength / 2 - currentDistanceAlongLine ) / totalLineLength; // <0, 0.5>
cost /= 1000; // < 0, 0.0005 >
lPos.emplace_back( qgis::make_unique< LabelPosition >( i, candidateCenterX - labelWidth / 2, candidateCenterY - labelHeight / 2, labelWidth, labelHeight, 0, cost, this, false, LabelPosition::QuadrantOver ) );
currentDistanceAlongLine += lineStepDistance;
i++;
if ( lineStepDistance < 0 )
break;
}
return lPos.size();
}
std::size_t FeaturePart::createCandidatesAlongLineNearStraightSegments( std::vector< std::unique_ptr< LabelPosition > > &lPos, PointSet *mapShape, Pal *pal )
{
double labelWidth = getLabelWidth();
double labelHeight = getLabelHeight();
double distanceLineToLabel = getLabelDistance();
QgsLabeling::LinePlacementFlags flags = mLF->arrangementFlags();
if ( flags == 0 )
flags = QgsLabeling::LinePlacementFlag::OnLine; // default flag
// first scan through the whole line and look for segments where the angle at a node is greater than 45 degrees - these form a "hard break" which labels shouldn't cross over
QVector< int > extremeAngleNodes;
PointSet *line = mapShape;
int numberNodes = line->nbPoints;
std::vector< double > &x = line->x;
std::vector< double > &y = line->y;
// closed line? if so, we need to handle the final node angle
bool closedLine = qgsDoubleNear( x[0], x[ numberNodes - 1] ) && qgsDoubleNear( y[0], y[numberNodes - 1 ] );
for ( int i = 1; i <= numberNodes - ( closedLine ? 1 : 2 ); ++i )
{
double x1 = x[i - 1];
double x2 = x[i];
double x3 = x[ i == numberNodes - 1 ? 1 : i + 1]; // wraparound for closed linestrings
double y1 = y[i - 1];
double y2 = y[i];
double y3 = y[ i == numberNodes - 1 ? 1 : i + 1]; // wraparound for closed linestrings
if ( qgsDoubleNear( y2, y3 ) && qgsDoubleNear( x2, x3 ) )
continue;
if ( qgsDoubleNear( y1, y2 ) && qgsDoubleNear( x1, x2 ) )
continue;
double vertexAngle = M_PI - ( std::atan2( y3 - y2, x3 - x2 ) - std::atan2( y2 - y1, x2 - x1 ) );
vertexAngle = QgsGeometryUtils::normalizedAngle( vertexAngle );
// extreme angles form more than 45 degree angle at a node - these are the ones we don't want labels to cross
if ( vertexAngle < M_PI * 135.0 / 180.0 || vertexAngle > M_PI * 225.0 / 180.0 )
extremeAngleNodes << i;
}
extremeAngleNodes << numberNodes - 1;
if ( extremeAngleNodes.isEmpty() )
{
// no extreme angles - createCandidatesAlongLineNearMidpoint will be more appropriate
return 0;
}
// calculate lengths of segments, and work out longest straight-ish segment
std::vector< double > segmentLengths( numberNodes - 1 ); // segments lengths distance bw pt[i] && pt[i+1]
std::vector< double > distanceToSegment( numberNodes ); // absolute distance bw pt[0] and pt[i] along the line
double totalLineLength = 0.0;
QVector< double > straightSegmentLengths;
QVector< double > straightSegmentAngles;
straightSegmentLengths.reserve( extremeAngleNodes.size() + 1 );
straightSegmentAngles.reserve( extremeAngleNodes.size() + 1 );
double currentStraightSegmentLength = 0;
double longestSegmentLength = 0;
int segmentIndex = 0;
double segmentStartX = x[0];
double segmentStartY = y[0];
for ( int i = 0; i < numberNodes - 1; i++ )
{
if ( i == 0 )
distanceToSegment[i] = 0;
else
distanceToSegment[i] = distanceToSegment[i - 1] + segmentLengths[i - 1];
segmentLengths[i] = GeomFunction::dist_euc2d( x[i], y[i], x[i + 1], y[i + 1] );
totalLineLength += segmentLengths[i];
if ( extremeAngleNodes.contains( i ) )
{
// at an extreme angle node, so reset counters
straightSegmentLengths << currentStraightSegmentLength;
straightSegmentAngles << QgsGeometryUtils::normalizedAngle( std::atan2( y[i] - segmentStartY, x[i] - segmentStartX ) );
longestSegmentLength = std::max( longestSegmentLength, currentStraightSegmentLength );
segmentIndex++;
currentStraightSegmentLength = 0;
segmentStartX = x[i];
segmentStartY = y[i];
}
currentStraightSegmentLength += segmentLengths[i];
}
distanceToSegment[line->nbPoints - 1] = totalLineLength;
straightSegmentLengths << currentStraightSegmentLength;
straightSegmentAngles << QgsGeometryUtils::normalizedAngle( std::atan2( y[numberNodes - 1] - segmentStartY, x[numberNodes - 1] - segmentStartX ) );
longestSegmentLength = std::max( longestSegmentLength, currentStraightSegmentLength );
double middleOfLine = totalLineLength / 2.0;
if ( totalLineLength < labelWidth )
{
return 0; //createCandidatesAlongLineNearMidpoint will be more appropriate
}
const std::size_t candidateTargetCount = maximumLineCandidates();
double lineStepDistance = ( totalLineLength - labelWidth ); // distance to move along line with each candidate
lineStepDistance = std::min( std::min( labelHeight, labelWidth ), lineStepDistance / candidateTargetCount );
double distanceToEndOfSegment = 0.0;
int lastNodeInSegment = 0;
// finally, loop through all these straight segments. For each we create candidates along the straight segment.
for ( int i = 0; i < straightSegmentLengths.count(); ++i )
{
currentStraightSegmentLength = straightSegmentLengths.at( i );
double currentSegmentAngle = straightSegmentAngles.at( i );
lastNodeInSegment = extremeAngleNodes.at( i );
double distanceToStartOfSegment = distanceToEndOfSegment;
distanceToEndOfSegment = distanceToSegment[ lastNodeInSegment ];
double distanceToCenterOfSegment = 0.5 * ( distanceToEndOfSegment + distanceToStartOfSegment );
if ( currentStraightSegmentLength < labelWidth )
// can't fit a label on here
continue;
double currentDistanceAlongLine = distanceToStartOfSegment;
double candidateStartX, candidateStartY, candidateEndX, candidateEndY;
double candidateLength = 0.0;
double cost = 0.0;
double angle = 0.0;
double beta = 0.0;
//calculate some cost penalties
double segmentCost = 1.0 - ( distanceToEndOfSegment - distanceToStartOfSegment ) / longestSegmentLength; // 0 -> 1 (lower for longer segments)
double segmentAngleCost = 1 - std::fabs( std::fmod( currentSegmentAngle, M_PI ) - M_PI_2 ) / M_PI_2; // 0 -> 1, lower for more horizontal segments
while ( currentDistanceAlongLine + labelWidth < distanceToEndOfSegment )
{
if ( pal->isCanceled() )
{
return lPos.size();
}
// calculate positions along linestring corresponding to start and end of current label candidate
line->getPointByDistance( segmentLengths.data(), distanceToSegment.data(), currentDistanceAlongLine, &candidateStartX, &candidateStartY );
line->getPointByDistance( segmentLengths.data(), distanceToSegment.data(), currentDistanceAlongLine + labelWidth, &candidateEndX, &candidateEndY );
candidateLength = std::sqrt( ( candidateEndX - candidateStartX ) * ( candidateEndX - candidateStartX ) + ( candidateEndY - candidateStartY ) * ( candidateEndY - candidateStartY ) );
// LOTS OF DIFFERENT COSTS TO BALANCE HERE - feel free to tweak these, but please add a unit test
// which covers the situation you are adjusting for (e.g., "given equal length lines, choose the more horizontal line")
cost = candidateLength / labelWidth;
if ( cost > 0.98 )
cost = 0.0001;
else
{
// jaggy line has a greater cost
cost = ( 1 - cost ) / 100; // ranges from 0.0001 to 0.01 (however a cost 0.005 is already a lot!)
}
// penalize positions which are further from the straight segments's midpoint
double labelCenter = currentDistanceAlongLine + labelWidth / 2.0;
double costCenter = 2 * std::fabs( labelCenter - distanceToCenterOfSegment ) / ( distanceToEndOfSegment - distanceToStartOfSegment ); // 0 -> 1
cost += costCenter * 0.0005; // < 0, 0.0005 >
if ( !closedLine )
{
// penalize positions which are further from absolute center of whole linestring
// this only applies to non closed linestrings, since the middle of a closed linestring is effectively arbitrary
// and irrelevant to labeling
double costLineCenter = 2 * std::fabs( labelCenter - middleOfLine ) / totalLineLength; // 0 -> 1
cost += costLineCenter * 0.0005; // < 0, 0.0005 >
}
cost += segmentCost * 0.0005; // prefer labels on longer straight segments
cost += segmentAngleCost * 0.0001; // prefer more horizontal segments, but this is less important than length considerations
if ( qgsDoubleNear( candidateEndY, candidateStartY ) && qgsDoubleNear( candidateEndX, candidateStartX ) )
{
angle = 0.0;
}
else
angle = std::atan2( candidateEndY - candidateStartY, candidateEndX - candidateStartX );
labelWidth = getLabelWidth( angle );
labelHeight = getLabelHeight( angle );
beta = angle + M_PI_2;
if ( mLF->layer()->arrangement() == QgsPalLayerSettings::Line )
{
// find out whether the line direction for this candidate is from right to left
bool isRightToLeft = ( angle > M_PI_2 || angle <= -M_PI_2 );
// meaning of above/below may be reversed if using map orientation and the line has right-to-left direction
bool reversed = ( ( flags & QgsLabeling::LinePlacementFlag::MapOrientation ) ? isRightToLeft : false );
bool aboveLine = ( !reversed && ( flags & QgsLabeling::LinePlacementFlag::AboveLine ) ) || ( reversed && ( flags & QgsLabeling::LinePlacementFlag::BelowLine ) );
bool belowLine = ( !reversed && ( flags & QgsLabeling::LinePlacementFlag::BelowLine ) ) || ( reversed && ( flags & QgsLabeling::LinePlacementFlag::AboveLine ) );
if ( belowLine )
{
if ( !mLF->permissibleZonePrepared() || GeomFunction::containsCandidate( mLF->permissibleZonePrepared(), candidateStartX - std::cos( beta ) * ( distanceLineToLabel + labelHeight ), candidateStartY - std::sin( beta ) * ( distanceLineToLabel + labelHeight ), labelWidth, labelHeight, angle ) )
{
const double candidateCost = cost + ( reversed ? 0 : 0.001 );
lPos.emplace_back( qgis::make_unique< LabelPosition >( i, candidateStartX - std::cos( beta ) * ( distanceLineToLabel + labelHeight ), candidateStartY - std::sin( beta ) * ( distanceLineToLabel + labelHeight ), labelWidth, labelHeight, angle, candidateCost, this, isRightToLeft, LabelPosition::QuadrantOver ) ); // Line
}
}
if ( aboveLine )
{
if ( !mLF->permissibleZonePrepared() || GeomFunction::containsCandidate( mLF->permissibleZonePrepared(), candidateStartX + std::cos( beta ) *distanceLineToLabel, candidateStartY + std::sin( beta ) *distanceLineToLabel, labelWidth, labelHeight, angle ) )
{
const double candidateCost = cost + ( !reversed ? 0 : 0.001 ); // no extra cost for above line placements
lPos.emplace_back( qgis::make_unique< LabelPosition >( i, candidateStartX + std::cos( beta ) *distanceLineToLabel, candidateStartY + std::sin( beta ) *distanceLineToLabel, labelWidth, labelHeight, angle, candidateCost, this, isRightToLeft, LabelPosition::QuadrantOver ) ); // Line
}
}