ceph/src/boost/libs/geometry/doc/src/examples/quick_start.cpp

   1 // Boost.Geometry (aka GGL, Generic Geometry Library)
   2 // Quickbook Examples, for main page
   3
   4 // Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
   5 // Copyright (c) 2008-2012 Bruno Lalande, Paris, France.
   6 // Copyright (c) 2009-2012 Mateusz Loskot, London, UK.
   7
   8 // Parts of Boost.Geometry are redesigned from Geodan's Geographic Library
   9 // (geolib/GGL), copyright (c) 1995-2010 Geodan, Amsterdam, the Netherlands.
  10
  11 // Use, modification and distribution is subject to the Boost Software License,
  12 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  13 // http://www.boost.org/LICENSE_1_0.txt)
  14 //
  15
  16
  17 #if defined(_MSC_VER)
  18 // We deliberately mix float/double's here so turn off warning
  19 //#pragma warning( disable : 4244 )
  20 #endif // defined(_MSC_VER)
  21
  22 //[quickstart_include
  23
  24 #include <boost/geometry.hpp>
  25 #include <boost/geometry/geometries/point_xy.hpp>
  26 #include <boost/geometry/geometries/polygon.hpp>
  27
  28 using namespace boost::geometry;
  29 //]
  30
  31 #include <boost/geometry/geometries/register/point.hpp>
  32
  33
  34 //[quickstart_register_c_array
  35 #include <boost/geometry/geometries/adapted/c_array.hpp>
  36
  37 BOOST_GEOMETRY_REGISTER_C_ARRAY_CS(cs::cartesian)
  38 //]
  39
  40 //[quickstart_register_boost_tuple
  41 #include <boost/geometry/geometries/adapted/boost_tuple.hpp>
  42
  43 BOOST_GEOMETRY_REGISTER_BOOST_TUPLE_CS(cs::cartesian)
  44 //]
  45
  46 // Small QRect simulations following http://doc.trolltech.com/4.4/qrect.html
  47 // Todo: once work the traits out further, would be nice if there is a real example of this.
  48 // However for the example it makes no difference, it will work any way.
  49 struct QPoint
  50 {
  51     int x, y;
  52     // In Qt these are methods but for example below it makes no difference
  53 };
  54
  55 struct QRect
  56 {
  57     int x, y, width, height;
  58     QRect(int _x, int _y, int w, int h)
  59         : x(_x), y(_y), width(w), height(h)
  60     {}
  61     // In Qt these are methods but that will work as well, requires changing traits below
  62 };
  63
  64
  65 // Would be get/set with x(),y(),setX(),setY()
  66 BOOST_GEOMETRY_REGISTER_POINT_2D(QPoint, int, cs::cartesian, x, y)
  67
  68
  69 // Register the QT rectangle. The macro(s) does not offer (yet) enough flexibility to do this in one line,
  70 // but the traits classes do their job perfectly.
  71 namespace boost { namespace geometry { namespace traits
  72 {
  73
  74 template <> struct tag<QRect> { typedef box_tag type; };
  75 template <> struct point_type<QRect> { typedef QPoint type; };
  76
  77 template <size_t C, size_t D>
  78 struct indexed_access<QRect, C, D>
  79 {
  80     static inline int get(const QRect& qr)
  81     {
  82         // Would be: x(), y(), width(), height()
  83         return C == min_corner && D == 0 ? qr.x
  84                 : C == min_corner && D == 1 ? qr.y
  85                 : C == max_corner && D == 0 ? qr.x + qr.width
  86                 : C == max_corner && D == 1 ? qr.y + qr.height
  87                 : 0;
  88     }
  89
  90     static inline void set(QRect& qr, const int& value)
  91     {
  92         // Would be: setX, setY, setWidth, setHeight
  93         if (C == min_corner && D == 0) qr.x = value;
  94         else if (C == min_corner && D == 1) qr.y = value;
  95         else if (C == max_corner && D == 0) qr.width = value - qr.x;
  96         else if (C == max_corner && D == 1) qr.height = value - qr.y;
  97     }
  98 };
  99
 100
 101 }}}
 102
 103
 104 int main(void)
 105 {
 106     //[quickstart_distance
 107     model::d2::point_xy<int> p1(1, 1), p2(2, 2);
 108     std::cout << "Distance p1-p2 is: " << distance(p1, p2) << std::endl;
 109     //]
 110
 111     //[quickstart_distance_c_array
 112     int a[2] = {1,1};
 113     int b[2] = {2,3};
 114     double d = distance(a, b);
 115     std::cout << "Distance a-b is: " << d << std::endl;
 116     //]
 117
 118     //[quickstart_point_in_polygon
 119     double points[][2] = {{2.0, 1.3}, {4.1, 3.0}, {5.3, 2.6}, {2.9, 0.7}, {2.0, 1.3}};
 120     model::polygon<model::d2::point_xy<double> > poly;
 121     append(poly, points);
 122     boost::tuple<double, double> p = boost::make_tuple(3.7, 2.0);
 123     std::cout << "Point p is in polygon? " << std::boolalpha << within(p, poly) << std::endl;
 124     //]
 125
 126     //[quickstart_area
 127     std::cout << "Area: " << area(poly) << std::endl;
 128     //]
 129
 130     //[quickstart_distance_mixed
 131     double d2 = distance(a, p);
 132     std::cout << "Distance a-p is: " << d2 << std::endl;
 133     //]
 134
 135     //[quick_start_spherical
 136     typedef boost::geometry::model::point
 137         <
 138             double, 2, boost::geometry::cs::spherical_equatorial<boost::geometry::degree>
 139         > spherical_point;
 140
 141     spherical_point amsterdam(4.90, 52.37);
 142     spherical_point paris(2.35, 48.86);
 143
 144     double const earth_radius = 3959; // miles
 145     std::cout << "Distance in miles: " << distance(amsterdam, paris) * earth_radius << std::endl;
 146     //]
 147
 148     /***
 149     Now extension
 150     point_ll_deg  amsterdam, paris;
 151     parse(amsterdam, "52 22 23 N", "4 53 32 E");
 152     parse(paris, "48 52 0 N", "2 19 59 E");
 153     std::cout << "Distance A'dam-Paris: " << distance(amsterdam, paris) / 1000.0 << " kilometers " << std::endl;
 154     ***/
 155
 156     //[quickstart_qt
 157     QRect r1(100, 200, 15, 15);
 158     QRect r2(110, 210, 20, 20);
 159     if (overlaps(r1, r2))
 160     {
 161         assign_values(r2, 200, 300, 220, 320);
 162     }
 163     //]
 164
 165     return 0;
 166 }
 167