1 // Boost.Polygon library segment_concept.hpp header file
3 // Copyright (c) Intel Corporation 2008.
4 // Copyright (c) 2008-2012 Simonson Lucanus.
5 // Copyright (c) 2012-2012 Andrii Sydorchuk.
7 // See http://www.boost.org for updates, documentation, and revision history.
8 // Use, modification and distribution is subject to the Boost Software License,
9 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
10 // http://www.boost.org/LICENSE_1_0.txt)
12 #ifndef BOOST_POLYGON_SEGMENT_CONCEPT_HPP
13 #define BOOST_POLYGON_SEGMENT_CONCEPT_HPP
15 #include "isotropy.hpp"
16 #include "segment_traits.hpp"
17 #include "rectangle_concept.hpp"
22 struct segment_concept {};
24 template <typename ConceptType>
25 struct is_segment_concept {
30 struct is_segment_concept<segment_concept> {
34 template <typename ConceptType>
35 struct is_mutable_segment_concept {
40 struct is_mutable_segment_concept<segment_concept> {
44 template <typename GeometryType, typename BoolType>
45 struct segment_distance_type_by_concept {
49 template <typename GeometryType>
50 struct segment_distance_type_by_concept<GeometryType, gtl_yes> {
51 typedef typename coordinate_traits<
52 typename segment_traits<GeometryType>::coordinate_type
53 >::coordinate_distance type;
56 template <typename GeometryType>
57 struct segment_distance_type {
58 typedef typename segment_distance_type_by_concept<
60 typename is_segment_concept<
61 typename geometry_concept<GeometryType>::type
66 template <typename GeometryType, typename BoolType>
67 struct segment_point_type_by_concept {
71 template <typename GeometryType>
72 struct segment_point_type_by_concept<GeometryType, gtl_yes> {
73 typedef typename segment_traits<GeometryType>::point_type type;
76 template <typename GeometryType>
77 struct segment_point_type {
78 typedef typename segment_point_type_by_concept<
80 typename is_segment_concept<
81 typename geometry_concept<GeometryType>::type
86 template <typename GeometryType, typename BoolType>
87 struct segment_coordinate_type_by_concept {
91 template <typename GeometryType>
92 struct segment_coordinate_type_by_concept<GeometryType, gtl_yes> {
93 typedef typename segment_traits<GeometryType>::coordinate_type type;
96 template <typename GeometryType>
97 struct segment_coordinate_type {
98 typedef typename segment_coordinate_type_by_concept<
100 typename is_segment_concept<
101 typename geometry_concept<GeometryType>::type
106 struct y_s_get : gtl_yes {};
108 template <typename Segment>
112 typename is_segment_concept<
113 typename geometry_concept<Segment>::type
116 typename segment_point_type<Segment>::type>::type
117 get(const Segment& segment, direction_1d dir) {
118 return segment_traits<Segment>::get(segment, dir);
121 struct y_s_set : gtl_yes {};
123 template <typename Segment, typename Point>
127 typename is_mutable_segment_concept<
128 typename geometry_concept<Segment>::type
130 typename is_point_concept<
131 typename geometry_concept<Point>::type
134 void>::type set(Segment& segment, direction_1d dir, const Point& point) {
135 segment_mutable_traits<Segment>::set(segment, dir, point);
138 struct y_s_construct : gtl_yes {};
140 template <typename Segment, typename Point1, typename Point2>
144 typename is_mutable_segment_concept<
145 typename geometry_concept<Segment>::type
147 typename is_point_concept<
148 typename geometry_concept<Point1>::type
150 typename is_point_concept<
151 typename geometry_concept<Point2>::type
154 Segment>::type construct(const Point1& low, const Point2& high) {
155 return segment_mutable_traits<Segment>::construct(low, high);
158 struct y_s_copy_construct : gtl_yes {};
160 template <typename Segment1, typename Segment2>
164 typename is_mutable_segment_concept<
165 typename geometry_concept<Segment1>::type
167 typename is_segment_concept<
168 typename geometry_concept<Segment2>::type
171 Segment1>::type copy_construct(const Segment2& segment) {
172 return construct<Segment1>(get(segment, LOW), get(segment, HIGH));
175 struct y_s_assign : gtl_yes {};
177 template <typename Segment1, typename Segment2>
181 typename is_mutable_segment_concept<
182 typename geometry_concept<Segment1>::type
184 typename is_segment_concept<
185 typename geometry_concept<Segment2>::type
188 Segment1>::type& assign(Segment1& segment1, const Segment2& segment2) {
189 return segment1 = copy_construct<Segment1>(segment2);
192 struct y_s_equivalence : gtl_yes {};
194 template <typename Segment1, typename Segment2>
198 typename is_segment_concept<
199 typename geometry_concept<Segment1>::type
201 typename is_segment_concept<
202 typename geometry_concept<Segment2>::type
205 bool>::type equivalence(const Segment1& segment1, const Segment2& segment2) {
206 return get(segment1, LOW) == get(segment2, LOW) &&
207 get(segment1, HIGH) == get(segment2, HIGH);
210 struct y_s_low : gtl_yes {};
212 template <typename Segment>
216 typename is_segment_concept<
217 typename geometry_concept<Segment>::type
220 typename segment_point_type<Segment>::type>::type low(const Segment& segment) {
221 return get(segment, LOW);
224 struct y_s_high : gtl_yes {};
226 template <typename Segment>
230 typename is_segment_concept<
231 typename geometry_concept<Segment>::type
234 typename segment_point_type<Segment>::type>::type high(const Segment& segment) {
235 return get(segment, HIGH);
238 struct y_s_center : gtl_yes {};
240 template <typename Segment>
244 typename is_segment_concept<
245 typename geometry_concept<Segment>::type
248 typename segment_point_type<Segment>::type>::type
249 center(const Segment& segment) {
250 return construct<typename segment_point_type<Segment>::type>(
251 (x(high(segment)) + x(low(segment)))/2,
252 (y(high(segment)) + y(low(segment)))/2);
255 struct y_s_low2 : gtl_yes {};
257 template <typename Segment, typename Point>
261 typename is_mutable_segment_concept<
262 typename geometry_concept<Segment>::type
264 typename is_point_concept<
265 typename geometry_concept<Point>::type
268 void>::type low(Segment& segment, const Point& point) {
269 set(segment, LOW, point);
272 struct y_s_high2 : gtl_yes {};
274 template <typename Segment, typename Point>
278 typename is_mutable_segment_concept<
279 typename geometry_concept<Segment>::type
281 typename is_point_concept<
282 typename geometry_concept<Point>::type
285 void>::type high(Segment& segment, const Point& point) {
286 set(segment, HIGH, point);
289 struct y_s_orientation1 : gtl_yes {};
291 // -1 for CW, 0 for collinear and 1 for CCW.
292 template <typename Segment1, typename Segment2>
296 typename is_segment_concept<
297 typename geometry_concept<Segment1>::type
299 typename is_segment_concept<
300 typename geometry_concept<Segment2>::type
303 int>::type orientation(const Segment1& segment1, const Segment2& segment2) {
304 typedef typename coordinate_traits<
305 typename segment_traits<Segment1>::coordinate_type
306 >::manhattan_area_type int_x2;
307 typedef typename coordinate_traits<
308 typename segment_traits<Segment1>::coordinate_type
309 >::unsigned_area_type uint_x2;
310 int_x2 a1 = (int_x2)x(high(segment1)) - (int_x2)x(low(segment1));
311 int_x2 b1 = (int_x2)y(high(segment1)) - (int_x2)y(low(segment1));
312 int_x2 a2 = (int_x2)x(high(segment2)) - (int_x2)x(low(segment2));
313 int_x2 b2 = (int_x2)y(high(segment2)) - (int_x2)y(low(segment2));
318 sign1 = ((a1 > 0) ^ (b2 > 0)) ? -1 : 1;
320 sign2 = ((a2 > 0) ^ (b1 > 0)) ? -1 : 1;
323 return (sign1 < sign2) ? -1 : 1;
324 uint_x2 a3 = (uint_x2)(a1 < 0 ? -a1 : a1) * (uint_x2)(b2 < 0 ? -b2 : b2);
325 uint_x2 b3 = (uint_x2)(b1 < 0 ? -b1 : b1) * (uint_x2)(a2 < 0 ? -a2 : a2);
328 return ((a3 < b3) ^ (sign1 == 1)) ? 1 : -1;
331 struct y_s_orientation2 : gtl_yes {};
333 // -1 for right, 0 for collinear and 1 for left.
334 template <typename Segment, typename Point>
338 typename is_segment_concept<
339 typename geometry_concept<Segment>::type
341 typename is_point_concept<
342 typename geometry_concept<Point>::type
345 int>::type orientation(const Segment& segment, const Point& point) {
346 Segment segment2 = construct<Segment>(high(segment), point);
347 return orientation(segment, segment2);
350 struct y_s_contains : gtl_yes {};
352 template <typename Segment, typename Point>
356 typename is_segment_concept<
357 typename geometry_concept<Segment>::type
359 typename is_point_concept<
360 typename geometry_concept<Point>::type
363 bool>::type contains(const Segment& segment,
364 const Point& point, bool consider_touch = true ) {
365 if (orientation(segment, point))
367 rectangle_data<typename segment_coordinate_type<Segment>::type> rect;
368 set_points(rect, low(segment), high(segment));
369 if (!contains(rect, point, true))
371 if (!consider_touch &&
372 (equivalence(low(segment), point) ||
373 equivalence(high(segment), point)))
378 struct y_s_contains2 : gtl_yes {};
380 template <typename Segment1, typename Segment2>
384 typename is_segment_concept<
385 typename geometry_concept<Segment1>::type
387 typename is_segment_concept<
388 typename geometry_concept<Segment2>::type
391 bool>::type contains(const Segment1& segment1,
392 const Segment2& segment2, bool consider_touch = true) {
393 return contains(segment1, get(segment2, LOW), consider_touch) &&
394 contains(segment1, get(segment2, HIGH), consider_touch);
397 struct y_s_length : gtl_yes {};
399 template <typename Segment>
403 typename is_segment_concept<
404 typename geometry_concept<Segment>::type
407 typename segment_distance_type<Segment>::type>::type
408 length(const Segment& segment) {
409 return euclidean_distance(low(segment), high(segment));
412 struct y_s_scale_up : gtl_yes {};
414 template <typename Segment>
418 typename is_mutable_segment_concept<
419 typename geometry_concept<Segment>::type
422 Segment>::type& scale_up(Segment& segment,
423 typename coordinate_traits<
424 typename segment_coordinate_type<Segment>::type
425 >::unsigned_area_type factor) {
426 typename segment_point_type<Segment>::type l = low(segment);
427 typename segment_point_type<Segment>::type h = high(segment);
428 low(segment, scale_up(l, factor));
429 high(segment, scale_up(h, factor));
433 struct y_s_scale_down : gtl_yes {};
435 template <typename Segment>
439 typename is_mutable_segment_concept<
440 typename geometry_concept<Segment>::type
443 Segment>::type& scale_down(Segment& segment,
444 typename coordinate_traits<
445 typename segment_coordinate_type<Segment>::type
446 >::unsigned_area_type factor) {
447 typename segment_point_type<Segment>::type l = low(segment);
448 typename segment_point_type<Segment>::type h = high(segment);
449 low(segment, scale_down(l, factor));
450 high(segment, scale_down(h, factor));
454 struct y_s_scale : gtl_yes {};
456 template <typename Segment, typename Scale>
460 typename is_mutable_segment_concept<
461 typename geometry_concept<Segment>::type
464 Segment>::type& scale(Segment& segment, const Scale& sc) {
465 typename segment_point_type<Segment>::type l = low(segment);
466 typename segment_point_type<Segment>::type h = high(segment);
467 low(segment, scale(l, sc));
468 high(segment, scale(h, sc));
472 struct y_s_transform : gtl_yes {};
474 template <typename Segment, typename Transform>
478 typename is_mutable_segment_concept<
479 typename geometry_concept<Segment>::type
482 Segment>::type& transform(Segment& segment, const Transform& tr) {
483 typename segment_point_type<Segment>::type l = low(segment);
484 typename segment_point_type<Segment>::type h = high(segment);
485 low(segment, transform(l, tr));
486 high(segment, transform(h, tr));
490 struct y_s_move : gtl_yes {};
492 template <typename Segment>
496 typename is_mutable_segment_concept<
497 typename geometry_concept<Segment>::type
500 Segment>::type& move(Segment& segment, orientation_2d orient,
501 typename segment_coordinate_type<Segment>::type displacement) {
502 typename segment_point_type<Segment>::type l = low(segment);
503 typename segment_point_type<Segment>::type h = high(segment);
504 low(segment, move(l, orient, displacement));
505 high(segment, move(h, orient, displacement));
509 struct y_s_convolve : gtl_yes {};
511 template <typename Segment, typename Point>
515 typename is_mutable_segment_concept<
516 typename geometry_concept<Segment>::type
518 typename is_point_concept<
519 typename geometry_concept<Point>::type
522 Segment>::type& convolve(Segment& segment, const Point& point) {
523 typename segment_point_type<Segment>::type l = low(segment);
524 typename segment_point_type<Segment>::type h = high(segment);
525 low(segment, convolve(l, point));
526 high(segment, convolve(h, point));
530 struct y_s_deconvolve : gtl_yes {};
532 template <typename Segment, typename Point>
536 typename is_mutable_segment_concept<
537 typename geometry_concept<Segment>::type
539 typename is_point_concept<
540 typename geometry_concept<Point>::type
543 Segment>::type& deconvolve(Segment& segment, const Point& point) {
544 typename segment_point_type<Segment>::type l = low(segment);
545 typename segment_point_type<Segment>::type h = high(segment);
546 low(segment, deconvolve(l, point));
547 high(segment, deconvolve(h, point));
551 struct y_s_abuts1 : gtl_yes {};
553 template <typename Segment1, typename Segment2>
557 typename is_segment_concept<
558 typename geometry_concept<Segment1>::type
560 typename is_segment_concept<
561 typename geometry_concept<Segment2>::type
564 bool>::type abuts(const Segment1& segment1,
565 const Segment2& segment2, direction_1d dir) {
566 return dir.to_int() ? equivalence(low(segment2) , high(segment1)) :
567 equivalence(low(segment1) , high(segment2));
570 struct y_s_abuts2 : gtl_yes {};
572 template <typename Segment1, typename Segment2>
576 typename is_segment_concept<
577 typename geometry_concept<Segment1>::type
579 typename is_segment_concept<
580 typename geometry_concept<Segment2>::type
583 bool>::type abuts(const Segment1& segment1, const Segment2& segment2) {
584 return abuts(segment1, segment2, HIGH) || abuts(segment1, segment2, LOW);
587 struct y_s_e_intersects : gtl_yes {};
589 template <typename Segment1, typename Segment2>
593 typename is_segment_concept<
594 typename geometry_concept<Segment1>::type
596 typename is_segment_concept<
597 typename geometry_concept<Segment2>::type
601 >::type intersects(const Segment1& segment1, const Segment2& segment2,
602 bool consider_touch = true) {
603 rectangle_data<typename segment_coordinate_type<Segment1>::type> rect1, rect2;
604 set_points(rect1, low(segment1), high(segment1));
605 set_points(rect2, low(segment2), high(segment2));
606 // Check if axis-parallel rectangles containing segments intersect.
607 if (!intersects(rect1, rect2, true))
609 int or1_1 = orientation(segment1, low(segment2));
610 int or1_2 = orientation(segment1, high(segment2));
611 if (or1_1 * or1_2 > 0)
613 int or2_1 = orientation(segment2, low(segment1));
614 int or2_2 = orientation(segment2, high(segment1));
615 if (or2_1 * or2_2 > 0)
617 if (consider_touch || (or1_1 && or1_2) || (or2_1 && or2_2))
621 return intersects(vertical(rect1), vertical(rect2), false) ||
622 intersects(horizontal(rect1), horizontal(rect2), false);
625 struct y_s_e_dist : gtl_yes {};
627 template <typename Segment, typename Point>
631 typename is_segment_concept<
632 typename geometry_concept<Segment>::type
634 typename is_point_concept<
635 typename geometry_concept<Point>::type
638 typename segment_distance_type<Segment>::type>::type
639 euclidean_distance(const Segment& segment, const Point& point) {
640 typedef typename segment_distance_type<Segment>::type Unit;
641 Unit x1 = x(low(segment));
642 Unit y1 = y(low(segment));
643 Unit x2 = x(high(segment));
644 Unit y2 = y(high(segment));
651 Unit param = (A * C + B * D);
652 Unit length_sq = C * C + D * D;
653 if (param > length_sq) {
654 return euclidean_distance(high(segment), point);
655 } else if (param < 0.0) {
656 return euclidean_distance(low(segment), point);
658 if (length_sq == 0.0)
660 Unit denom = std::sqrt(length_sq);
661 Unit result = (A * D - C * B) / denom;
662 return (result < 0.0) ? -result : result;
665 struct y_s_e_dist2 : gtl_yes {};
667 template <typename Segment1, typename Segment2>
671 typename is_segment_concept<
672 typename geometry_concept<Segment1>::type
674 typename is_segment_concept<
675 typename geometry_concept<Segment2>::type
678 typename segment_distance_type<Segment1>::type>::type
679 euclidean_distance(const Segment1& segment1, const Segment2& segment2) {
680 if (intersects(segment1, segment2))
682 typename segment_distance_type<Segment1>::type
683 result1 = euclidean_distance(segment1, low(segment2)),
684 result2 = euclidean_distance(segment1, high(segment2)),
685 result3 = euclidean_distance(segment2, low(segment1)),
686 result4 = euclidean_distance(segment2, high(segment1));
687 if (result2 < result1)
689 if (result4 < result3)
691 return (result1 < result3) ? result1 : result3;
696 #endif // BOOST_POLYGON_SEGMENT_CONCEPT_HPP