/usr/include/boost/geometry/algorithms/detail/overlay/follow.hpp is in libboost1.55-dev 1.55.0+dfsg-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 | // Boost.Geometry (aka GGL, Generic Geometry Library)
// Copyright (c) 2007-2012 Barend Gehrels, Amsterdam, the Netherlands.
// Use, modification and distribution is subject to the Boost Software License,
// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
#ifndef BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_FOLLOW_HPP
#define BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_FOLLOW_HPP
#include <cstddef>
#include <boost/range.hpp>
#include <boost/mpl/assert.hpp>
#include <boost/geometry/algorithms/detail/point_on_border.hpp>
#include <boost/geometry/algorithms/detail/overlay/append_no_duplicates.hpp>
#include <boost/geometry/algorithms/detail/overlay/copy_segments.hpp>
#include <boost/geometry/algorithms/detail/overlay/turn_info.hpp>
#include <boost/geometry/algorithms/covered_by.hpp>
namespace boost { namespace geometry
{
#ifndef DOXYGEN_NO_DETAIL
namespace detail { namespace overlay
{
namespace following
{
template <typename Turn, typename Operation>
static inline bool is_entering(Turn const& /* TODO remove this parameter */, Operation const& op)
{
// (Blocked means: blocked for polygon/polygon intersection, because
// they are reversed. But for polygon/line it is similar to continue)
return op.operation == operation_intersection
|| op.operation == operation_continue
|| op.operation == operation_blocked
;
}
template
<
typename Turn,
typename Operation,
typename LineString,
typename Polygon
>
static inline bool last_covered_by(Turn const& turn, Operation const& op,
LineString const& linestring, Polygon const& polygon)
{
// Check any point between the this one and the first IP
typedef typename geometry::point_type<LineString>::type point_type;
point_type point_in_between;
detail::point_on_border::midpoint_helper
<
point_type,
0, dimension<point_type>::value
>::apply(point_in_between, linestring[op.seg_id.segment_index], turn.point);
return geometry::covered_by(point_in_between, polygon);
}
template
<
typename Turn,
typename Operation,
typename LineString,
typename Polygon
>
static inline bool is_leaving(Turn const& turn, Operation const& op,
bool entered, bool first,
LineString const& linestring, Polygon const& polygon)
{
if (op.operation == operation_union)
{
return entered
|| turn.method == method_crosses
|| (first && last_covered_by(turn, op, linestring, polygon))
;
}
return false;
}
template
<
typename Turn,
typename Operation,
typename LineString,
typename Polygon
>
static inline bool is_staying_inside(Turn const& turn, Operation const& op,
bool entered, bool first,
LineString const& linestring, Polygon const& polygon)
{
if (turn.method == method_crosses)
{
// The normal case, this is completely covered with entering/leaving
// so stay out of this time consuming "covered_by"
return false;
}
if (is_entering(turn, op))
{
return entered || (first && last_covered_by(turn, op, linestring, polygon));
}
return false;
}
template
<
typename Turn,
typename Operation,
typename Linestring,
typename Polygon
>
static inline bool was_entered(Turn const& turn, Operation const& op, bool first,
Linestring const& linestring, Polygon const& polygon)
{
if (first && (turn.method == method_collinear || turn.method == method_equal))
{
return last_covered_by(turn, op, linestring, polygon);
}
return false;
}
// Template specialization structure to call the right actions for the right type
template<overlay_type OverlayType>
struct action_selector
{
// If you get here the overlay type is not intersection or difference
// BOOST_MPL_ASSERT(false);
};
// Specialization for intersection, containing the implementation
template<>
struct action_selector<overlay_intersection>
{
template
<
typename OutputIterator,
typename LineStringOut,
typename LineString,
typename Point,
typename Operation
>
static inline void enter(LineStringOut& current_piece,
LineString const& ,
segment_identifier& segment_id,
int , Point const& point,
Operation const& operation, OutputIterator& )
{
// On enter, append the intersection point and remember starting point
detail::overlay::append_no_duplicates(current_piece, point);
segment_id = operation.seg_id;
}
template
<
typename OutputIterator,
typename LineStringOut,
typename LineString,
typename Point,
typename Operation
>
static inline void leave(LineStringOut& current_piece,
LineString const& linestring,
segment_identifier& segment_id,
int index, Point const& point,
Operation const& , OutputIterator& out)
{
// On leave, copy all segments from starting point, append the intersection point
// and add the output piece
geometry::copy_segments<false>(linestring, segment_id, index, current_piece);
detail::overlay::append_no_duplicates(current_piece, point);
if (current_piece.size() > 1)
{
*out++ = current_piece;
}
current_piece.clear();
}
static inline bool is_entered(bool entered)
{
return entered;
}
template <typename Point, typename Geometry>
static inline bool included(Point const& point, Geometry const& geometry)
{
return geometry::covered_by(point, geometry);
}
};
// Specialization for difference, which reverses these actions
template<>
struct action_selector<overlay_difference>
{
typedef action_selector<overlay_intersection> normal_action;
template
<
typename OutputIterator,
typename LineStringOut,
typename LineString,
typename Point,
typename Operation
>
static inline void enter(LineStringOut& current_piece,
LineString const& linestring,
segment_identifier& segment_id,
int index, Point const& point,
Operation const& operation, OutputIterator& out)
{
normal_action::leave(current_piece, linestring, segment_id, index,
point, operation, out);
}
template
<
typename OutputIterator,
typename LineStringOut,
typename LineString,
typename Point,
typename Operation
>
static inline void leave(LineStringOut& current_piece,
LineString const& linestring,
segment_identifier& segment_id,
int index, Point const& point,
Operation const& operation, OutputIterator& out)
{
normal_action::enter(current_piece, linestring, segment_id, index,
point, operation, out);
}
static inline bool is_entered(bool entered)
{
return ! normal_action::is_entered(entered);
}
template <typename Point, typename Geometry>
static inline bool included(Point const& point, Geometry const& geometry)
{
return ! normal_action::included(point, geometry);
}
};
}
/*!
\brief Follows a linestring from intersection point to intersection point, outputting which
is inside, or outside, a ring or polygon
\ingroup overlay
*/
template
<
typename LineStringOut,
typename LineString,
typename Polygon,
overlay_type OverlayType
>
class follow
{
template<typename Turn>
struct sort_on_segment
{
// In case of turn point at the same location, we want to have continue/blocked LAST
// because that should be followed (intersection) or skipped (difference).
inline int operation_order(Turn const& turn) const
{
operation_type const& operation = turn.operations[0].operation;
switch(operation)
{
case operation_opposite : return 0;
case operation_none : return 0;
case operation_union : return 1;
case operation_intersection : return 2;
case operation_blocked : return 3;
case operation_continue : return 4;
}
return -1;
};
inline bool use_operation(Turn const& left, Turn const& right) const
{
// If they are the same, OK.
return operation_order(left) < operation_order(right);
}
inline bool use_distance(Turn const& left, Turn const& right) const
{
return geometry::math::equals(left.operations[0].enriched.distance, right.operations[0].enriched.distance)
? use_operation(left, right)
: left.operations[0].enriched.distance < right.operations[0].enriched.distance
;
}
inline bool operator()(Turn const& left, Turn const& right) const
{
segment_identifier const& sl = left.operations[0].seg_id;
segment_identifier const& sr = right.operations[0].seg_id;
return sl == sr
? use_distance(left, right)
: sl < sr
;
}
};
public :
template <typename Point, typename Geometry>
static inline bool included(Point const& point, Geometry const& geometry)
{
return following::action_selector<OverlayType>::included(point, geometry);
}
template<typename Turns, typename OutputIterator>
static inline OutputIterator apply(LineString const& linestring, Polygon const& polygon,
detail::overlay::operation_type , // TODO: this parameter might be redundant
Turns& turns, OutputIterator out)
{
typedef typename boost::range_iterator<Turns>::type turn_iterator;
typedef typename boost::range_value<Turns>::type turn_type;
typedef typename boost::range_iterator
<
typename turn_type::container_type
>::type turn_operation_iterator_type;
typedef following::action_selector<OverlayType> action;
// Sort intersection points on segments-along-linestring, and distance
// (like in enrich is done for poly/poly)
std::sort(boost::begin(turns), boost::end(turns), sort_on_segment<turn_type>());
LineStringOut current_piece;
geometry::segment_identifier current_segment_id(0, -1, -1, -1);
// Iterate through all intersection points (they are ordered along the line)
bool entered = false;
bool first = true;
for (turn_iterator it = boost::begin(turns); it != boost::end(turns); ++it)
{
turn_operation_iterator_type iit = boost::begin(it->operations);
if (following::was_entered(*it, *iit, first, linestring, polygon))
{
debug_traverse(*it, *iit, "-> Was entered");
entered = true;
}
if (following::is_staying_inside(*it, *iit, entered, first, linestring, polygon))
{
debug_traverse(*it, *iit, "-> Staying inside");
entered = true;
}
else if (following::is_entering(*it, *iit))
{
debug_traverse(*it, *iit, "-> Entering");
entered = true;
action::enter(current_piece, linestring, current_segment_id, iit->seg_id.segment_index, it->point, *iit, out);
}
else if (following::is_leaving(*it, *iit, entered, first, linestring, polygon))
{
debug_traverse(*it, *iit, "-> Leaving");
entered = false;
action::leave(current_piece, linestring, current_segment_id, iit->seg_id.segment_index, it->point, *iit, out);
}
first = false;
}
if (action::is_entered(entered))
{
geometry::copy_segments<false>(linestring, current_segment_id,
boost::size(linestring) - 1,
current_piece);
}
// Output the last one, if applicable
if (current_piece.size() > 1)
{
*out++ = current_piece;
}
return out;
}
};
}} // namespace detail::overlay
#endif // DOXYGEN_NO_DETAIL
}} // namespace boost::geometry
#endif // BOOST_GEOMETRY_ALGORITHMS_DETAIL_OVERLAY_FOLLOW_HPP
|