projects / ceph.git / blame
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| 7c673cae FG |
1 | <html> |
| 2 | ||
| 3 | <head> | |
| 4 | <meta http-equiv="Content-Type" content="text/html; charset=windows-1252"> | |
| 5 | <title>Custom Polygon Set</title> | |
| 6 | </head> | |
| 7 | ||
| 8 | <body> | |
| 9 | ||
| 10 | <p><font face="Courier New">/*<br> | |
| 11 | Copyright 2008 Intel Corporation<br> | |
| 12 | <br> | |
| 13 | Use, modification and distribution are subject to the Boost Software License,<br> | |
| 14 | Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at<br> | |
| 15 | http://www.boost.org/LICENSE_1_0.txt).<br> | |
| 16 | */<br> | |
| 17 | #include <boost/polygon/polygon.hpp><br> | |
| 18 | #include <list><br> | |
| 19 | #include <time.h><br> | |
| 20 | #include <cassert><br> | |
| 21 | #include <deque><br> | |
| 22 | #include <iostream><br> | |
| 23 | namespace gtl = boost::polygon;<br> | |
| 24 | using namespace boost::polygon::operators;<br><br> | |
| 25 | //once again we make our usage of the library generic<br> | |
| 26 | //and parameterize it on the polygon set type<br> | |
| 27 | template <typename PolygonSet><br> | |
| 28 | void test_polygon_set() {<br> | |
| 29 | using namespace gtl; <br> | |
| 30 | PolygonSet ps;<br> | |
| 31 | ps += rectangle_data<int>(0, 0, 10, 10);<br> | |
| 32 | PolygonSet ps2;<br> | |
| 33 | ps2 += rectangle_data<int>(5, 5, 15, 15);<br> | |
| 34 | PolygonSet ps3;<br> | |
| 35 | assign(ps3, ps * ps2); <br> | |
| 36 | PolygonSet ps4;<br> | |
| 37 | ps4 += ps + ps2;<br> | |
| 38 | assert(area(ps4) == area(ps) + area(ps2) - area(ps3));<br> | |
| 39 | assert(equivalence((ps + ps2) - (ps * ps2), ps ^ ps2));<br> | |
| 40 | rectangle_data<int> rect;<br> | |
| 41 | assert(extents(rect, ps ^ ps2));<br> | |
| 42 | assert(area(rect) == 225);<br> | |
| 43 | assert(area(rect ^ (ps ^ ps2)) == area(rect) - area(ps ^ ps2)); <br> | |
| 44 | }<br> | |
| 45 | <br> | |
| 46 | //first thing is first, lets include all the code from previous examples<br> | |
| 47 | <br> | |
| 48 | //the CPoint example<br> | |
| 49 | struct CPoint {<br> | |
| 50 | int x;<br> | |
| 51 | int y;<br> | |
| 52 | };<br> | |
| 53 | <br> | |
| 54 | namespace boost { namespace polygon {<br> | |
| 55 | template <><br> | |
| 56 | struct geometry_concept<CPoint> { typedef point_concept type; };<br> | |
| 57 | template <><br> | |
| 58 | struct point_traits<CPoint> {<br> | |
| 59 | typedef int coordinate_type;<br> | |
| 60 | <br> | |
| 61 | static inline coordinate_type get(const CPoint& point, <br> | |
| 62 | | |
| 63 | orientation_2d orient) {<br> | |
| 64 | if(orient == HORIZONTAL)<br> | |
| 65 | return point.x;<br> | |
| 66 | return point.y;<br> | |
| 67 | }<br> | |
| 68 | };<br> | |
| 69 | <br> | |
| 70 | template <><br> | |
| 71 | struct point_mutable_traits<CPoint> {<br> | |
| 72 | typedef int coordinate_type;<br> | |
| 73 | <br> | |
| 74 | static inline void set(CPoint& point, orientation_2d orient, | |
| 75 | int value) {<br> | |
| 76 | if(orient == HORIZONTAL)<br> | |
| 77 | point.x = value;<br> | |
| 78 | else<br> | |
| 79 | point.y = value;<br> | |
| 80 | }<br> | |
| 81 | static inline CPoint construct(int x_value, int y_value) {<br> | |
| 82 | CPoint retval;<br> | |
| 83 | retval.x = x_value;<br> | |
| 84 | retval.y = y_value; <br> | |
| 85 | return retval;<br> | |
| 86 | }<br> | |
| 87 | };<br> | |
| 88 | } }<br> | |
| 89 | <br> | |
| 90 | //the CPolygon example<br> | |
| 91 | typedef std::list<CPoint> CPolygon;<br> | |
| 92 | <br> | |
| 93 | //we need to specialize our polygon concept mapping in boost polygon<br> | |
| 94 | namespace boost { namespace polygon {<br> | |
| 95 | //first register CPolygon as a polygon_concept type<br> | |
| 96 | template <><br> | |
| 97 | struct geometry_concept<CPolygon>{ typedef polygon_concept type; };<br> | |
| 98 | <br> | |
| 99 | template <><br> | |
| 100 | struct polygon_traits<CPolygon> {<br> | |
| 101 | typedef int coordinate_type;<br> | |
| 102 | typedef CPolygon::const_iterator iterator_type;<br> | |
| 103 | typedef CPoint point_type;<br> | |
| 104 | <br> | |
| 105 | // Get the begin iterator<br> | |
| 106 | static inline iterator_type begin_points(const CPolygon& t) {<br> | |
| 107 | return t.begin();<br> | |
| 108 | }<br> | |
| 109 | <br> | |
| 110 | // Get the end iterator<br> | |
| 111 | static inline iterator_type end_points(const CPolygon& t) {<br> | |
| 112 | return t.end();<br> | |
| 113 | }<br> | |
| 114 | <br> | |
| 115 | // Get the number of sides of the polygon<br> | |
| 116 | static inline std::size_t size(const CPolygon& t) {<br> | |
| 117 | return t.size();<br> | |
| 118 | }<br> | |
| 119 | <br> | |
| 120 | // Get the winding direction of the polygon<br> | |
| 121 | static inline winding_direction winding(const CPolygon& t) {<br> | |
| 122 | return unknown_winding;<br> | |
| 123 | }<br> | |
| 124 | };<br> | |
| 125 | <br> | |
| 126 | template <><br> | |
| 127 | struct polygon_mutable_traits<CPolygon> {<br> | |
| 128 | //expects stl style iterators<br> | |
| 129 | template <typename iT><br> | |
| 130 | static inline CPolygon& set_points(CPolygon& t, <br> | |
| 131 | | |
| 132 | iT input_begin, iT input_end) {<br> | |
| 133 | t.clear();<br> | |
| 134 | while(input_begin != input_end) {<br> | |
| 135 | t.push_back(CPoint());<br> | |
| 136 | gtl::assign(t.back(), *input_begin);<br> | |
| 137 | ++input_begin;<br> | |
| 138 | }<br> | |
| 139 | return t;<br> | |
| 140 | }<br> | |
| 141 | <br> | |
| 142 | };<br> | |
| 143 | } }<br> | |
| 144 | <br> | |
| 145 | //OK, finally we get to declare our own polygon set type<br> | |
| 146 | typedef std::deque<CPolygon> CPolygonSet;<br> | |
| 147 | <br> | |
| 148 | //deque isn't automatically a polygon set in the library<br> | |
| 149 | //because it is a standard container there is a shortcut<br> | |
| 150 | //for mapping it to polygon set concept, but I'll do it<br> | |
| 151 | //the long way that you would use in the general case.<br> | |
| 152 | namespace boost { namespace polygon {<br> | |
| 153 | //first we register CPolygonSet as a polygon set<br> | |
| 154 | template <><br> | |
| 155 | struct geometry_concept<CPolygonSet> { typedef polygon_set_concept type; | |
| 156 | };<br> | |
| 157 | <br> | |
| 158 | //next we map to the concept through traits<br> | |
| 159 | template <><br> | |
| 160 | struct polygon_set_traits<CPolygonSet> {<br> | |
| 161 | typedef int coordinate_type;<br> | |
| 162 | typedef CPolygonSet::const_iterator iterator_type;<br> | |
| 163 | typedef CPolygonSet operator_arg_type;<br> | |
| 164 | <br> | |
| 165 | static inline iterator_type begin(const CPolygonSet& | |
| 166 | polygon_set) {<br> | |
| 167 | return polygon_set.begin();<br> | |
| 168 | }<br> | |
| 169 | <br> | |
| 170 | static inline iterator_type end(const CPolygonSet& | |
| 171 | polygon_set) {<br> | |
| 172 | return polygon_set.end();<br> | |
| 173 | }<br> | |
| 174 | <br> | |
| 175 | //don't worry about these, just return false from them<br> | |
| 176 | static inline bool clean(const CPolygonSet& polygon_set) { | |
| 177 | return false; }<br> | |
| 178 | static inline bool sorted(const CPolygonSet& polygon_set) { | |
| 179 | return false; }<br> | |
| 180 | };<br> | |
| 181 | <br> | |
| 182 | template <><br> | |
| 183 | struct polygon_set_mutable_traits<CPolygonSet> {<br> | |
| 184 | template <typename input_iterator_type><br> | |
| 185 | static inline void set(CPolygonSet& polygon_set, | |
| 186 | input_iterator_type input_begin, input_iterator_type input_end) {<br> | |
| 187 | polygon_set.clear();<br> | |
| 188 | //this is kind of cheesy. I am copying the | |
| 189 | unknown input geometry<br> | |
| 190 | //into my own polygon set and then calling get to | |
| 191 | populate the<br> | |
| 192 | //deque<br> | |
| 193 | polygon_set_data<int> ps;<br> | |
| 194 | ps.insert(input_begin, input_end);<br> | |
| 195 | ps.get(polygon_set);<br> | |
| 196 | //if you had your own odd-ball polygon set you | |
| 197 | would probably have<br> | |
| 198 | //to iterate through each polygon at this point | |
| 199 | and do something<br> | |
| 200 | //extra<br> | |
| 201 | }<br> | |
| 202 | };<br> | |
| 203 | } }<br> | |
| 204 | <br> | |
| 205 | int main() {<br> | |
| 206 | long long c1 = clock();<br> | |
| 207 | for(int i = 0; i < 1000; ++i) <br> | |
| 208 | test_polygon_set<CPolygonSet>();<br> | |
| 209 | long long c2 = clock();<br> | |
| 210 | for(int i = 0; i < 1000; ++i) <br> | |
| 211 | test_polygon_set<gtl::polygon_set_data<int> >();<br> | |
| 212 | long long c3 = clock();<br> | |
| 213 | long long diff1 = c2 - c1;<br> | |
| 214 | long long diff2 = c3 - c2;<br> | |
| 215 | if(diff1 > 0 && diff2)<br> | |
| 216 | std::cout << "library polygon_set_data is " << | |
| 217 | float(diff1)/float(diff2) << "X faster than custom polygon set deque of CPolygon" | |
| 218 | << std::endl;<br> | |
| 219 | else<br> | |
| 220 | std::cout << "operation was too fast" << std::endl;<br> | |
| 221 | return 0;<br> | |
| 222 | }</font></p> | |
| 223 | <p><font face="Courier New">//Now you know how to map your own data type to | |
| 224 | polygon set concept<br> | |
| 225 | //Now you also know how to make your application code that operates on geometry<br> | |
| 226 | //data type agnostic from point through polygon set | |
| 227 | </font></p> | |
| 228 | ||
| 229 | ||
| 230 | <table class="docinfo" rules="none" frame="void" id="table1"> | |
| 231 | <colgroup> | |
| 232 | <col class="docinfo-name"><col class="docinfo-content"> | |
| 233 | </colgroup> | |
| 234 | <tbody vAlign="top"> | |
| 235 | <tr> | |
| 236 | <th class="docinfo-name">Copyright:</th> | |
| 237 |