9c7697dc83d87dc72d204c7d843ba3ef4631004a
1 /**
2 * \file src/snapped-line.cpp
3 * \brief SnappedInfiniteLine class.
4 *
5 * Authors:
6 * Diederik van Lierop <mail@diedenrezi.nl>
7 *
8 * Released under GNU GPL, read the file 'COPYING' for more information.
9 */
11 #include "snapped-line.h"
12 #include "geom.h"
13 #include "libnr/nr-values.h"
15 Inkscape::SnappedLine::SnappedLine(NR::Point snapped_point, NR::Coord snapped_distance, NR::Point start_point_of_line, NR::Point end_point_of_line)
16 : _start_point_of_line(start_point_of_line), _end_point_of_line(end_point_of_line)
17 {
18 _distance = snapped_distance;
19 _point = snapped_point;
20 _at_intersection = false;
21 }
23 Inkscape::SnappedLine::SnappedLine()
24 {
25 _start_point_of_line = NR::Point(0,0);
26 _end_point_of_line = NR::Point(0,0);
27 _distance = NR_HUGE;
28 _point = NR::Point(0,0);
29 _at_intersection = false;
30 }
33 Inkscape::SnappedLine::~SnappedLine()
34 {
35 }
37 Inkscape::SnappedPoint Inkscape::SnappedLine::intersect(SnappedLine const &line) const
38 {
39 //TODO: Diederik, implement the intersection
40 NR::Point const intersection = NR::Point(NR_HUGE, NR_HUGE);
42 //if (result == INTERSECTS) {
43 /* The relevant snapped distance is the distance to the closest snapped line, not the
44 distance to the intersection. For example, when a box is almost aligned with a grid
45 in both horizontal and vertical directions, the distance to the intersection of the
46 grid lines will always be larger then the distance to a grid line. We will be snapping
47 to the closest snapped point however, so if we ever want to snap to the intersection
48 then the distance to it should at least be equal to the other distance, not greater
49 than it, as that would rule the intersection out
50 */
51 NR::Coord distance = std::min(_distance, line.getDistance());
52 //}
53 return SnappedPoint(intersection, distance);
54 };
58 Inkscape::SnappedInfiniteLine::SnappedInfiniteLine(NR::Point snapped_point, NR::Coord snapped_distance, NR::Point normal_to_line, NR::Point point_on_line)
59 : _normal_to_line(normal_to_line), _point_on_line(point_on_line)
60 {
61 _distance = snapped_distance;
62 _point = snapped_point;
63 _at_intersection = false;
64 }
66 Inkscape::SnappedInfiniteLine::SnappedInfiniteLine()
67 {
68 _normal_to_line = NR::Point(0,0);
69 _point_on_line = NR::Point(0,0);
70 _distance = NR_HUGE;
71 _point = NR::Point(0,0);
72 _at_intersection = false;
73 }
75 Inkscape::SnappedInfiniteLine::~SnappedInfiniteLine()
76 {
77 }
79 Inkscape::SnappedPoint Inkscape::SnappedInfiniteLine::intersect(SnappedInfiniteLine const &line) const
80 {
81 // Calculate the intersection of to infinite lines, which are both within snapping range
82 // The point of intersection should be considered for snapping, but might be outside the snapping range
84 NR::Point intersection = NR::Point(NR_HUGE, NR_HUGE);
85 NR::Coord distance = NR_HUGE;
87 IntersectorKind result = intersector_line_intersection(getNormal(), getConstTerm(),
88 line.getNormal(), line.getConstTerm(), intersection);
90 /*std::cout << "n0 = " << getNormal() << std::endl;
91 std::cout << "n1 = " << line.getNormal() << std::endl;
92 std::cout << "c0 = " << getConstTerm() << std::endl;
93 std::cout << "c1 = " << line.getConstTerm() << std::endl;*/
95 if (result == INTERSECTS) {
96 /* The relevant snapped distance is the distance to the closest snapped line, not the
97 distance to the intersection. For example, when a box is almost aligned with a grid
98 in both horizontal and vertical directions, the distance to the intersection of the
99 grid lines will always be larger then the distance to a grid line. We will be snapping
100 to the closest snapped point however, so if we ever want to snap to the intersection
101 then the distance to it should at least be equal to the other distance, not greater
102 than it, as that would rule the intersection out
103 */
104 distance = std::min(_distance, line.getDistance());
105 //std::cout << "Intersected nicely, now getSIL distance = " << distance << std::endl;
106 }
108 //std::cout << "getSIL distance = " << distance << std::endl;
110 return SnappedPoint(intersection, distance, result == INTERSECTS);
111 }
113 // search for the closest snapped infinite line
114 bool getClosestSIL(std::list<Inkscape::SnappedInfiniteLine> &list, Inkscape::SnappedInfiniteLine &result)
115 {
116 bool success = false;
118 for (std::list<Inkscape::SnappedInfiniteLine>::const_iterator i = list.begin(); i != list.end(); i++) {
119 if ((i == list.begin()) || (*i).getDistance() < result.getDistance()) {
120 result = *i;
121 success = true;
122 }
123 }
125 return success;
126 }
128 // search for the closest intersection of two snapped infinite lines, which are both member of the same collection
129 bool getClosestIntersectionSIL(std::list<Inkscape::SnappedInfiniteLine> &list, Inkscape::SnappedPoint &result)
130 {
131 bool success = false;
133 for (std::list<Inkscape::SnappedInfiniteLine>::const_iterator i = list.begin(); i != list.end(); i++) {
134 std::list<Inkscape::SnappedInfiniteLine>::const_iterator j = i;
135 j++;
136 for (; j != list.end(); j++) {
137 Inkscape::SnappedPoint sp = (*i).intersect(*j);
138 if (sp.getAtIntersection()) {
139 if (!success || sp.getDistance() < result.getDistance()) {
140 // !success because the first intersection cannot be compared to a previous one
141 result = sp;
142 success = true;
143 }
144 }
145 }
146 }
148 return success;
149 }
151 // search for the closest intersection of two snapped infinite lines, which are in two different collections
152 bool getClosestIntersectionSIL(std::list<Inkscape::SnappedInfiniteLine> &list1, std::list<Inkscape::SnappedInfiniteLine> &list2, Inkscape::SnappedPoint &result)
153 {
154 bool success = false;
156 for (std::list<Inkscape::SnappedInfiniteLine>::const_iterator i = list1.begin(); i != list1.end(); i++) {
157 for (std::list<Inkscape::SnappedInfiniteLine>::const_iterator j = list2.begin(); j != list2.end(); j++) {
158 Inkscape::SnappedPoint sp = (*i).intersect(*j);
159 if (sp.getAtIntersection()) {
160 if (!success || sp.getDistance() < result.getDistance()) {
161 // !success because the first intersection cannot be compared to a previous one
162 result = sp;
163 success = true;
164 }
165 }
166 }
167 }
169 return success;
170 }
172 /*
173 Local Variables:
174 mode:c++
175 c-file-style:"stroustrup"
176 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
177 indent-tabs-mode:nil
178 fill-column:99
179 End:
180 */
181 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :