123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177 |
- // 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_GEOMETRY_POLICIES_RELATE_DE9IM_HPP
- #define BOOST_GEOMETRY_GEOMETRY_POLICIES_RELATE_DE9IM_HPP
- #include <boost/geometry/strategies/intersection_result.hpp>
- #include <boost/geometry/util/math.hpp>
- #include <boost/geometry/util/select_coordinate_type.hpp>
- namespace boost { namespace geometry
- {
- namespace policies { namespace relate
- {
- template <typename S1, typename S2>
- struct segments_de9im
- {
- typedef de9im_segment return_type;
- typedef S1 segment_type1;
- typedef S2 segment_type2;
- typedef typename select_coordinate_type<S1, S2>::type coordinate_type;
- static inline return_type rays_intersect(bool on_segment,
- double ra, double rb,
- coordinate_type const& dx1, coordinate_type const& dy1,
- coordinate_type const& dx2, coordinate_type const& dy2,
- coordinate_type const& wx, coordinate_type const& wy,
- S1 const& s1, S2 const& s2)
- {
- if(on_segment)
- {
- // 0 <= ra <= 1 and 0 <= rb <= 1
- // Now check if one of them is 0 or 1, these are "touch" cases
- bool a = math::equals(ra, 0.0) || math::equals(ra, 1.0);
- bool b = math::equals(rb, 0.0) || math::equals(rb, 1.0);
- if (a && b)
- {
- // Touch boundary/boundary: i-i == -1, i-b == -1, b-b == 0
- // Opposite: if both are equal they touch in opposite direction
- return de9im_segment(ra,rb,
- -1, -1, 1,
- -1, 0, 0,
- 1, 0, 2, false, math::equals(ra,rb));
- }
- else if (a || b)
- {
- // Touch boundary/interior: i-i == -1, i-b == -1 or 0, b-b == -1
- int A = a ? 0 : -1;
- int B = b ? 0 : -1;
- return de9im_segment(ra,rb,
- -1, B, 1,
- A, -1, 0,
- 1, 0, 2);
- }
- // Intersects: i-i == 0, i-b == -1, i-e == 1
- return de9im_segment(ra,rb,
- 0, -1, 1,
- -1, -1, 0,
- 1, 0, 2);
- }
- // Not on segment, disjoint
- return de9im_segment(ra,rb,
- -1, -1, 1,
- -1, -1, 0,
- 1, 0, 2);
- }
- static inline return_type collinear_touch(coordinate_type const& x,
- coordinate_type const& y, bool opposite, char)
- {
- return de9im_segment(0,0,
- -1, -1, 1,
- -1, 0, 0,
- 1, 0, 2,
- true, opposite);
- }
- template <typename S>
- static inline return_type collinear_interior_boundary_intersect(S const& s,
- bool a_within_b, bool opposite)
- {
- return a_within_b
- ? de9im_segment(0,0,
- 1, -1, -1,
- 0, 0, -1,
- 1, 0, 2,
- true, opposite)
- : de9im_segment(0,0,
- 1, 0, 1,
- -1, 0, 0,
- -1, -1, 2,
- true, opposite);
- }
- static inline return_type collinear_a_in_b(S1 const& s, bool opposite)
- {
- return de9im_segment(0,0,
- 1, -1, -1,
- 0, -1, -1,
- 1, 0, 2,
- true, opposite);
- }
- static inline return_type collinear_b_in_a(S2 const& s, bool opposite)
- {
- return de9im_segment(0,0,
- 1, 0, 1,
- -1, -1, 0,
- -1, -1, 2,
- true, opposite);
- }
- static inline return_type collinear_overlaps(
- coordinate_type const& x1, coordinate_type const& y1,
- coordinate_type const& x2, coordinate_type const& y2, bool opposite)
- {
- return de9im_segment(0,0,
- 1, 0, 1,
- 0, -1, 0,
- 1, 0, 2,
- true, opposite);
- }
- static inline return_type segment_equal(S1 const& s, bool opposite)
- {
- return de9im_segment(0,0,
- 1, -1, -1,
- -1, 0, -1,
- -1, -1, 2,
- true, opposite);
- }
- static inline return_type degenerate(S1 const& segment, bool a_degenerate)
- {
- return a_degenerate
- ? de9im_segment(0,0,
- 0, -1, -1,
- -1, -1, -1,
- 1, 0, 2,
- false, false, false, true)
- : de9im_segment(0,0,
- 0, -1, 1,
- -1, -1, 0,
- -1, -1, 2,
- false, false, false, true);
- }
- static inline return_type collinear_disjoint()
- {
- return de9im_segment(0,0,
- -1, -1, 1,
- -1, -1, 0,
- 1, 0, 2,
- true);
- }
- };
- }} // namespace policies::relate
- }} // namespace boost::geometry
- #endif // BOOST_GEOMETRY_GEOMETRY_POLICIES_RELATE_DE9IM_HPP
|