QGIS API Documentation  2.99.0-Master (585a4d3)
feature.h
Go to the documentation of this file.
1 /*
2  * libpal - Automated Placement of Labels Library
3  *
4  * Copyright (C) 2008 Maxence Laurent, MIS-TIC, HEIG-VD
5  * University of Applied Sciences, Western Switzerland
6  * http://www.hes-so.ch
7  *
8  * Contact:
9  * maxence.laurent <at> heig-vd <dot> ch
10  * or
11  * eric.taillard <at> heig-vd <dot> ch
12  *
13  * This file is part of libpal.
14  *
15  * libpal is free software: you can redistribute it and/or modify
16  * it under the terms of the GNU General Public License as published by
17  * the Free Software Foundation, either version 3 of the License, or
18  * (at your option) any later version.
19  *
20  * libpal is distributed in the hope that it will be useful,
21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23  * GNU General Public License for more details.
24  *
25  * You should have received a copy of the GNU General Public License
26  * along with libpal. If not, see <http://www.gnu.org/licenses/>.
27  *
28  */
29 
30 #ifndef FEATURE_H
31 #define FEATURE_H
32 
33 #define SIP_NO_FILE
34 
35 
36 #include "qgis_core.h"
37 #include "pointset.h"
38 #include "labelposition.h" // for LabelPosition enum
39 #include "qgslabelfeature.h"
40 #include "rtree.hpp"
41 #include <iostream>
42 #include <fstream>
43 #include <cmath>
44 #include <QString>
45 
52 namespace pal
53 {
55  class CORE_EXPORT LabelInfo
56  {
57  public:
58  typedef struct
59  {
60  double width;
61  } CharacterInfo;
62 
63  LabelInfo( int num, double height, double maxinangle = 20.0, double maxoutangle = -20.0 )
64  {
65  max_char_angle_inside = maxinangle;
66  // outside angle should be negative
67  max_char_angle_outside = maxoutangle > 0 ? -maxoutangle : maxoutangle;
68  label_height = height;
69  char_num = num;
70  char_info = new CharacterInfo[num];
71  }
72  ~LabelInfo() { delete [] char_info; }
73 
75  LabelInfo( const LabelInfo &rh ) = delete;
77  LabelInfo &operator=( const LabelInfo &rh ) = delete;
78 
81  double label_height;
82  int char_num;
83  CharacterInfo *char_info = nullptr;
84 
85  };
86 
87  class LabelPosition;
88  class FeaturePart;
89 
96  class CORE_EXPORT FeaturePart : public PointSet
97  {
98 
99  public:
100 
106  FeaturePart( QgsLabelFeature *lf, const GEOSGeometry *geom );
107 
108  FeaturePart( const FeaturePart &other );
109 
113  ~FeaturePart() override;
114 
118  QgsLabelFeature *feature() { return mLF; }
119 
123  Layer *layer();
124 
128  QgsFeatureId featureId() const;
129 
138  int createCandidates( QList<LabelPosition *> &lPos, const GEOSPreparedGeometry *mapBoundary, PointSet *mapShape, RTree<LabelPosition *, double, 2, double> *candidates );
139 
148  int createCandidatesAroundPoint( double x, double y, QList<LabelPosition *> &lPos, double angle );
149 
158  int createCandidatesOverPoint( double x, double y, QList<LabelPosition *> &lPos, double angle );
159 
168  int createCandidatesAtOrderedPositionsOverPoint( double x, double y, QList<LabelPosition *> &lPos, double angle );
169 
176  int createCandidatesAlongLine( QList<LabelPosition *> &lPos, PointSet *mapShape );
177 
185  int createCandidatesAlongLineNearStraightSegments( QList<LabelPosition *> &lPos, PointSet *mapShape );
186 
196  int createCandidatesAlongLineNearMidpoint( QList<LabelPosition *> &lPos, PointSet *mapShape, double initialCost = 0.0 );
197 
209  LabelPosition *curvedPlacementAtOffset( PointSet *path_positions, double *path_distances,
210  int &orientation, int index, double distance, bool &reversed, bool &flip );
211 
218  int createCurvedCandidatesAlongLine( QList<LabelPosition *> &lPos, PointSet *mapShape );
219 
226  int createCandidatesForPolygon( QList<LabelPosition *> &lPos, PointSet *mapShape );
227 
234  bool hasSameLabelFeatureAs( FeaturePart *part ) const;
235 
236 #if 0
237 
242  void print();
243 #endif
244 
245  double getLabelWidth() const { return mLF->size().width(); }
246  double getLabelHeight() const { return mLF->size().height(); }
247  double getLabelDistance() const { return mLF->distLabel(); }
248 
250  bool hasFixedRotation() const { return mLF->hasFixedAngle(); }
251 
253  double fixedAngle() const { return mLF->fixedAngle(); }
254 
256  bool hasFixedPosition() const { return mLF->hasFixedPosition(); }
257 
262  bool alwaysShow() const { return mLF->alwaysShow(); }
263 
265  bool isObstacle() const { return mLF->isObstacle(); }
266 
271  double obstacleFactor() const { return mLF->obstacleFactor(); }
272 
274  double repeatDistance() const { return mLF->repeatDistance(); }
275 
277  int getNumSelfObstacles() const { return mHoles.count(); }
279  FeaturePart *getSelfObstacle( int i ) { return mHoles.at( i ); }
280 
282  bool isConnected( FeaturePart *p2 );
283 
287  bool mergeWithFeaturePart( FeaturePart *other );
288 
289  void addSizePenalty( int nbp, QList<LabelPosition *> &lPos, double bbx[4], double bby[4] );
290 
297  double calculatePriority() const;
298 
300  bool showUprightLabels() const;
301 
303  bool nextCharPosition( double charWidth, double segment_length, PointSet *path_positions, int &index, double &distance,
304  double &start_x, double &start_y, double &end_x, double &end_y ) const;
305 
306  protected:
307 
308  QgsLabelFeature *mLF = nullptr;
309  QList<FeaturePart *> mHoles;
310 
312  void extractCoords( const GEOSGeometry *geom );
313 
314  private:
315 
316  LabelPosition::Quadrant quadrantFromOffset() const;
317  };
318 
319 } // end namespace pal
320 
321 #endif
double obstacleFactor() const
Returns the feature&#39;s obstacle factor, which represents the penalty incurred for a label to overlap t...
Definition: feature.h:271
double fixedAngle() const
Returns the fixed angle for the feature&#39;s label.
Definition: feature.h:253
double max_char_angle_outside
Definition: feature.h:80
QgsLabelFeature * feature()
Returns the parent feature.
Definition: feature.h:118
bool hasFixedRotation() const
Returns true if the feature&#39;s label has a fixed rotation.
Definition: feature.h:250
A set of features which influence the labeling process.
Definition: layer.h:63
bool alwaysShow() const
Returns true if the feature&#39;s label should always been shown, even when it collides with other labels...
Definition: feature.h:262
int getNumSelfObstacles() const
Get number of holes (inner rings) - they are considered as obstacles.
Definition: feature.h:277
LabelInfo(int num, double height, double maxinangle=20.0, double maxoutangle=-20.0)
Definition: feature.h:63
double getLabelDistance() const
Definition: feature.h:247
double ANALYSIS_EXPORT angle(QgsPoint *p1, QgsPoint *p2, QgsPoint *p3, QgsPoint *p4)
Calculates the angle between two segments (in 2 dimension, z-values are ignored)
Definition: MathUtils.cpp:786
double repeatDistance() const
Returns the distance between repeating labels for this feature.
Definition: feature.h:274
bool isObstacle() const
Returns true if the feature should act as an obstacle to labels.
Definition: feature.h:265
Optional additional info about label (for curved labels)
Definition: feature.h:55
double label_height
Definition: feature.h:81
double getLabelHeight() const
Definition: feature.h:246
Main class to handle feature.
Definition: feature.h:96
bool hasFixedPosition() const
Returns true if the feature&#39;s label has a fixed position.
Definition: feature.h:256
The QgsLabelFeature class describes a feature that should be used within the labeling engine...
QList< FeaturePart * > mHoles
Definition: feature.h:309
double max_char_angle_inside
Definition: feature.h:79
FeaturePart * getSelfObstacle(int i)
Get hole (inner ring) - considered as obstacle.
Definition: feature.h:279
double getLabelWidth() const
Definition: feature.h:245
LabelPosition is a candidate feature label position.
Definition: labelposition.h:55
qint64 QgsFeatureId
Definition: qgsfeature.h:37
Quadrant
Position of label candidate relative to feature.
Definition: labelposition.h:65
int char_num
Definition: feature.h:82