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
|
/**#include <config.h>
* \file src/snapped-line.cpp
* SnappedLine class.
*
* Authors:
* Diederik van Lierop <mail@diedenrezi.nl>
*
* Released under GNU GPL, read the file 'COPYING' for more information.
*/
#include "snapped-line.h"
Inkscape::SnappedLineSegment::SnappedLineSegment(Geom::Point const &snapped_point, Geom::Coord const &snapped_distance, SnapSourceType const &source, long source_num, SnapTargetType const &target, Geom::Coord const &snapped_tolerance, bool const &always_snap, Geom::Point const &start_point_of_line, Geom::Point const &end_point_of_line)
: _start_point_of_line(start_point_of_line), _end_point_of_line(end_point_of_line)
{
_point = snapped_point;
_source = source;
_source_num = source_num;
_target = target;
_distance = snapped_distance;
_tolerance = std::max(snapped_tolerance, 1.0);
_always_snap = always_snap;
_at_intersection = false;
_second_distance = Geom::infinity();
_second_tolerance = 1;
_second_always_snap = false;
}
Inkscape::SnappedLineSegment::SnappedLineSegment()
{
_start_point_of_line = Geom::Point(0,0);
_end_point_of_line = Geom::Point(0,0);
_point = Geom::Point(0,0);
_source = SNAPSOURCE_UNDEFINED;
_source_num = -1;
_target = SNAPTARGET_UNDEFINED;
_distance = Geom::infinity();
_tolerance = 1;
_always_snap = false;
_at_intersection = false;
_second_distance = Geom::infinity();
_second_tolerance = 1;
_second_always_snap = false;
}
Inkscape::SnappedLineSegment::~SnappedLineSegment()
{
}
Inkscape::SnappedPoint Inkscape::SnappedLineSegment::intersect(SnappedLineSegment const &line) const
{
Geom::OptCrossing inters = Geom::OptCrossing(); // empty by default
try
{
inters = Geom::intersection(getLineSegment(), line.getLineSegment());
}
catch (Geom::InfiniteSolutions &e)
{
// We're probably dealing with parallel lines, so they don't really cross
inters = Geom::OptCrossing();
}
if (inters) {
Geom::Point inters_pt = getLineSegment().pointAt((*inters).ta);
/* If a snapper has been told to "always snap", then this one should be preferred
* over the other, if that other one has not been told so. (The preferred snapper
* will be labeled "primary" below)
*/
bool const c1 = this->getAlwaysSnap() && !line.getAlwaysSnap(); //do not use _tolerance directly!
/* If neither or both have been told to "always snap", then cast a vote based on
* the snapped distance. For this we should consider the distance to the snapped
* line, not the distance to the intersection.
* See the comment in Inkscape::SnappedLine::intersect
*/
bool const c2 = _distance < line.getSnapDistance();
bool const use_this_as_primary = c1 || c2;
Inkscape::SnappedLineSegment const *primarySLS = use_this_as_primary ? this : &line;
Inkscape::SnappedLineSegment const *secondarySLS = use_this_as_primary ? &line : this;
Geom::Coord primaryDist = use_this_as_primary ? Geom::L2(inters_pt - this->getPoint()) : Geom::L2(inters_pt - line.getPoint());
Geom::Coord secondaryDist = use_this_as_primary ? Geom::L2(inters_pt - line.getPoint()) : Geom::L2(inters_pt - this->getPoint());
return SnappedPoint(inters_pt, SNAPSOURCE_UNDEFINED, primarySLS->getSourceNum(), SNAPTARGET_PATH_INTERSECTION, primaryDist, primarySLS->getTolerance(), primarySLS->getAlwaysSnap(), true, false, true,
secondaryDist, secondarySLS->getTolerance(), secondarySLS->getAlwaysSnap());
}
// No intersection
return SnappedPoint(Geom::Point(Geom::infinity(), Geom::infinity()), SNAPSOURCE_UNDEFINED, 0, SNAPTARGET_UNDEFINED, Geom::infinity(), 0, false, false, false, false, Geom::infinity(), 0, false);
};
Inkscape::SnappedLine::SnappedLine(Geom::Point const &snapped_point, Geom::Coord const &snapped_distance, SnapSourceType const &source, long source_num, SnapTargetType const &target, Geom::Coord const &snapped_tolerance, bool const &always_snap, Geom::Point const &normal_to_line, Geom::Point const &point_on_line)
: _normal_to_line(normal_to_line), _point_on_line(point_on_line)
{
_source = source;
_source_num = source_num;
_target = target;
_distance = snapped_distance;
_tolerance = std::max(snapped_tolerance, 1.0);
_always_snap = always_snap;
_second_distance = Geom::infinity();
_second_tolerance = 1;
_second_always_snap = false;
_point = snapped_point;
_at_intersection = false;
}
Inkscape::SnappedLine::SnappedLine()
{
_normal_to_line = Geom::Point(0,0);
_point_on_line = Geom::Point(0,0);
_source = SNAPSOURCE_UNDEFINED;
_source_num = -1;
_target = SNAPTARGET_UNDEFINED;
_distance = Geom::infinity();
_tolerance = 1;
_always_snap = false;
_second_distance = Geom::infinity();
_second_tolerance = 1;
_second_always_snap = false;
_point = Geom::Point(0,0);
_at_intersection = false;
}
Inkscape::SnappedLine::~SnappedLine()
{
}
Inkscape::SnappedPoint Inkscape::SnappedLine::intersect(SnappedLine const &line) const
{
// Calculate the intersection of two lines, which are both within snapping range
// One could be a grid line, whereas the other could be a guide line
// The point of intersection should be considered for snapping, but might be outside the snapping range
Geom::OptCrossing inters = Geom::OptCrossing(); // empty by default
try
{
inters = Geom::intersection(getLine(), line.getLine());
}
catch (Geom::InfiniteSolutions &e)
{
// We're probably dealing with parallel lines, so they don't really cross
inters = Geom::OptCrossing();
}
if (inters) {
Geom::Point inters_pt = getLine().pointAt((*inters).ta);
/* If a snapper has been told to "always snap", then this one should be preferred
* over the other, if that other one has not been told so. (The preferred snapper
* will be labelled "primary" below)
*/
bool const c1 = this->getAlwaysSnap() && !line.getAlwaysSnap();
/* If neither or both have been told to "always snap", then cast a vote based on
* the snapped distance. For this we should consider the distance to the snapped
* line or to the intersection
*/
bool const c2 = _distance < line.getSnapDistance();
bool const use_this_as_primary = c1 || c2;
Inkscape::SnappedLine const *primarySL = use_this_as_primary ? this : &line;
Inkscape::SnappedLine const *secondarySL = use_this_as_primary ? &line : this;
Geom::Coord primaryDist = use_this_as_primary ? Geom::L2(inters_pt - this->getPoint()) : Geom::L2(inters_pt - line.getPoint());
Geom::Coord secondaryDist = use_this_as_primary ? Geom::L2(inters_pt - line.getPoint()) : Geom::L2(inters_pt - this->getPoint());
return SnappedPoint(inters_pt, Inkscape::SNAPSOURCE_UNDEFINED, primarySL->getSourceNum(), Inkscape::SNAPTARGET_UNDEFINED, primaryDist, primarySL->getTolerance(), primarySL->getAlwaysSnap(), true, false, true,
secondaryDist, secondarySL->getTolerance(), secondarySL->getAlwaysSnap());
// The type of the snap target is yet undefined, as we cannot tell whether
// we're snapping to grid or the guide lines; must be set by on a higher level
}
// No intersection
return SnappedPoint(Geom::Point(Geom::infinity(), Geom::infinity()), SNAPSOURCE_UNDEFINED, 0, SNAPTARGET_UNDEFINED, Geom::infinity(), 0, false, false, false, false, Geom::infinity(), 0, false);
}
// search for the closest snapped line segment
bool getClosestSLS(std::list<Inkscape::SnappedLineSegment> const &list, Inkscape::SnappedLineSegment &result)
{
bool success = false;
for (std::list<Inkscape::SnappedLineSegment>::const_iterator i = list.begin(); i != list.end(); ++i) {
if ((i == list.begin()) || (*i).getSnapDistance() < result.getSnapDistance()) {
result = *i;
success = true;
}
}
return success;
}
// search for the closest intersection of two snapped line segments, which are both member of the same collection
bool getClosestIntersectionSLS(std::list<Inkscape::SnappedLineSegment> const &list, Inkscape::SnappedPoint &result)
{
bool success = false;
for (std::list<Inkscape::SnappedLineSegment>::const_iterator i = list.begin(); i != list.end(); ++i) {
std::list<Inkscape::SnappedLineSegment>::const_iterator j = i;
++j;
for (; j != list.end(); ++j) {
Inkscape::SnappedPoint sp = (*i).intersect(*j);
if (sp.getAtIntersection()) {
// if it's the first point
bool const c1 = !success;
// or, if it's closer
bool const c2 = sp.getSnapDistance() < result.getSnapDistance();
// or, if it's just then look at the other distance
// (only relevant for snapped points which are at an intersection
bool const c3 = (sp.getSnapDistance() == result.getSnapDistance()) && (sp.getSecondSnapDistance() < result.getSecondSnapDistance());
// then prefer this point over the previous one
if (c1 || c2 || c3) {
result = sp;
success = true;
}
}
}
}
return success;
}
// search for the closest snapped line
bool getClosestSL(std::list<Inkscape::SnappedLine> const &list, Inkscape::SnappedLine &result)
{
bool success = false;
for (std::list<Inkscape::SnappedLine>::const_iterator i = list.begin(); i != list.end(); ++i) {
if ((i == list.begin()) || (*i).getSnapDistance() < result.getSnapDistance()) {
result = *i;
success = true;
}
}
return success;
}
// search for the closest intersection of two snapped lines, which are both member of the same collection
bool getClosestIntersectionSL(std::list<Inkscape::SnappedLine> const &list, Inkscape::SnappedPoint &result)
{
bool success = false;
for (std::list<Inkscape::SnappedLine>::const_iterator i = list.begin(); i != list.end(); ++i) {
std::list<Inkscape::SnappedLine>::const_iterator j = i;
++j;
for (; j != list.end(); ++j) {
Inkscape::SnappedPoint sp = (*i).intersect(*j);
if (sp.getAtIntersection()) {
// if it's the first point
bool const c1 = !success;
// or, if it's closer
bool const c2 = sp.getSnapDistance() < result.getSnapDistance();
// or, if it's just then look at the other distance
// (only relevant for snapped points which are at an intersection
bool const c3 = (sp.getSnapDistance() == result.getSnapDistance()) && (sp.getSecondSnapDistance() < result.getSecondSnapDistance());
// then prefer this point over the previous one
if (c1 || c2 || c3) {
result = sp;
success = true;
}
}
}
}
return success;
}
// search for the closest intersection of two snapped lines, which are in two different collections
bool getClosestIntersectionSL(std::list<Inkscape::SnappedLine> const &list1, std::list<Inkscape::SnappedLine> const &list2, Inkscape::SnappedPoint &result)
{
bool success = false;
for (std::list<Inkscape::SnappedLine>::const_iterator i = list1.begin(); i != list1.end(); ++i) {
for (std::list<Inkscape::SnappedLine>::const_iterator j = list2.begin(); j != list2.end(); ++j) {
Inkscape::SnappedPoint sp = (*i).intersect(*j);
if (sp.getAtIntersection()) {
// if it's the first point
bool const c1 = !success;
// or, if it's closer
bool const c2 = sp.getSnapDistance() < result.getSnapDistance();
// or, if it's just then look at the other distance
// (only relevant for snapped points which are at an intersection
bool const c3 = (sp.getSnapDistance() == result.getSnapDistance()) && (sp.getSecondSnapDistance() < result.getSecondSnapDistance());
// then prefer this point over the previous one
if (c1 || c2 || c3) {
result = sp;
success = true;
}
}
}
}
return success;
}
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
|