QGIS API Documentation  3.23.0-Master (eb871beae0)
geomfunction.h
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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 PAL_GEOM_FUNCTION
31 #define PAL_GEOM_FUNCTION
32 
33 #define SIP_NO_FILE
34 
35 
36 #include "qgis_core.h"
37 #include <cmath>
38 #include "qgsgeos.h"
39 
40 namespace pal
41 {
42 
49  class CORE_EXPORT GeomFunction
50  {
51  public:
52 
53  /*
54  * o(x2,y2)
55  * /
56  * cp > 0 /
57  * / cp < 0
58  * /
59  * /
60  * o (x1, y1)
61  */
62  static inline double cross_product( double x1, double y1, double x2, double y2, double x3, double y3 )
63  {
64  return ( x2 - x1 ) * ( y3 - y1 ) - ( x3 - x1 ) * ( y2 - y1 );
65  }
66 
67  static inline double dist_euc2d( double x1, double y1, double x2, double y2 )
68  {
69  return std::sqrt( ( x2 - x1 ) * ( x2 - x1 ) + ( y2 - y1 ) * ( y2 - y1 ) );
70  }
71 
72  static inline double dist_euc2d_sq( double x1, double y1, double x2, double y2 )
73  {
74  return ( x2 - x1 ) * ( x2 - x1 ) + ( y2 - y1 ) * ( y2 - y1 );
75  }
76 
77  static void findLineCircleIntersection( double cx, double cy, double radius,
78  double x1, double y1, double x2, double y2,
79  double &xRes, double &yRes );
80 
88  static std::vector< int > convexHullId( std::vector<int> &id, const std::vector< double > &x, const std::vector< double > &y );
89 
93  static bool isSegIntersects( double x1, double y1, double x2, double y2, // 1st segment
94  double x3, double y3, double x4, double y4 ); // 2nd segment
95 
100  static bool computeLineIntersection( double x1, double y1, double x2, double y2, // 1st line (segment)
101  double x3, double y3, double x4, double y4, // 2nd line segment
102  double *x, double *y );
103 
105  static bool reorderPolygon( std::vector< double > &x, std::vector< double> &y );
106 
117  static bool containsCandidate( const GEOSPreparedGeometry *geom, double x, double y, double width, double height, double alpha );
118 
119  };
120 } //namespace
121 
122 #endif
Pal labeling engine geometry functions.
Definition: geomfunction.h:50
static double dist_euc2d(double x1, double y1, double x2, double y2)
Definition: geomfunction.h:67
static double cross_product(double x1, double y1, double x2, double y2, double x3, double y3)
Definition: geomfunction.h:62
static double dist_euc2d_sq(double x1, double y1, double x2, double y2)
Definition: geomfunction.h:72