QGIS API Documentation  3.0.2-Girona (307d082)
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 
48  class CORE_EXPORT GeomFunction
49  {
50  public:
51 
52  /*
53  * o(x2,y2)
54  * /
55  * cp > 0 /
56  * / cp < 0
57  * /
58  * /
59  * o (x1, y1)
60  */
61  static inline double cross_product( double x1, double y1, double x2, double y2, double x3, double y3 )
62  {
63  return ( x2 - x1 ) * ( y3 - y1 ) - ( x3 - x1 ) * ( y2 - y1 );
64  }
65 
66  static inline double dist_euc2d( double x1, double y1, double x2, double y2 )
67  {
68  return std::sqrt( ( x2 - x1 ) * ( x2 - x1 ) + ( y2 - y1 ) * ( y2 - y1 ) );
69  }
70 
71  static inline double dist_euc2d_sq( double x1, double y1, double x2, double y2 )
72  {
73  return ( x2 - x1 ) * ( x2 - x1 ) + ( y2 - y1 ) * ( y2 - y1 );
74  }
75 
76  static void findLineCircleIntersection( double cx, double cy, double radius,
77  double x1, double y1, double x2, double y2,
78  double &xRes, double &yRes );
79 
89  static int convexHullId( int *id, const double *const x, const double *const y, int n, int *&cHull );
90 
94  static bool isSegIntersects( double x1, double y1, double x2, double y2, // 1st segment
95  double x3, double y3, double x4, double y4 ); // 2nd segment
96 
101  static bool computeLineIntersection( double x1, double y1, double x2, double y2, // 1st line (segment)
102  double x3, double y3, double x4, double y4, // 2nd line segment
103  double *x, double *y );
104 
106  static int reorderPolygon( int nbPoints, double *x, double *y );
107 
118  static bool containsCandidate( const GEOSPreparedGeometry *geom, double x, double y, double width, double height, double alpha );
119 
120  };
121 } //namespace
122 
123 #endif
static double cross_product(double x1, double y1, double x2, double y2, double x3, double y3)
Definition: geomfunction.h:61
static double dist_euc2d(double x1, double y1, double x2, double y2)
Definition: geomfunction.h:66
static double dist_euc2d_sq(double x1, double y1, double x2, double y2)
Definition: geomfunction.h:71