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
|
#include "clipping.hpp"
#include "rect_intersect.hpp"
#include "std/vector.hpp"
namespace m2
{
using AddPoligonPoint = function<void(m2::PointD const &)>;
int GetRectSideIndex(int code)
{
if (code == m2::detail::LEFT)
return 0;
if (code == m2::detail::TOP)
return 1;
if (code == m2::detail::RIGHT)
return 2;
return 3;
}
void InsertCorners(vector<m2::PointD> const & corners,
m2::PointD const & p1, m2::PointD const & p2, m2::PointD const & p3,
AddPoligonPoint const & addPoligonPoint, int code1, int code2)
{
int cornerInd = GetRectSideIndex(code1);
int endCornerInd = GetRectSideIndex(code2);
if (!IsPointInsideTriangle(corners[cornerInd], p1, p2, p3))
{
if (!IsPointInsideTriangle(corners[endCornerInd], p1, p2, p3))
return;
swap(cornerInd, endCornerInd);
}
while (cornerInd != endCornerInd)
{
addPoligonPoint(corners[cornerInd]);
cornerInd = (cornerInd + 1) % 4;
}
}
bool IntersectEdge(m2::RectD const & rect, vector<m2::PointD> const & corners,
m2::PointD const & pp1, m2::PointD const & pp2, m2::PointD const & pp3,
AddPoligonPoint const & addPoligonPoint,
int prevClipCode, int nextClipCode, int & firstClipCode, int & lastClipCode)
{
m2::PointD p1 = pp1;
m2::PointD p2 = pp2;
if (m2::Intersect(rect, p1, p2, firstClipCode, lastClipCode))
{
if (firstClipCode != 0 && prevClipCode != 0 && ((firstClipCode & prevClipCode) == 0))
InsertCorners(corners, pp1, pp2, pp3, addPoligonPoint, prevClipCode, firstClipCode);
addPoligonPoint(p1);
addPoligonPoint(p2);
if (lastClipCode != 0 && nextClipCode != 0 && ((lastClipCode & nextClipCode) == 0) &&
firstClipCode != lastClipCode && prevClipCode != nextClipCode)
InsertCorners(corners, pp1, pp2, pp3, addPoligonPoint, lastClipCode, nextClipCode);
return true;
}
else if (prevClipCode != 0 && nextClipCode != 0)
{
InsertCorners(corners, pp1, pp2, pp3, addPoligonPoint, prevClipCode, nextClipCode);
}
return false;
}
void ClipTriangleByRect(m2::RectD const & rect, m2::PointD const & p1,
m2::PointD const & p2, m2::PointD const & p3,
ClipTriangleByRectResultIt const & resultIterator)
{
if (resultIterator == nullptr)
return;
if (rect.IsPointInside(p1) && rect.IsPointInside(p2) && rect.IsPointInside(p3))
{
resultIterator(p1, p2, p3);
return;
}
const double kEps = 1e-8;
vector<m2::PointD> poligon;
auto const addPoligonPoint = [&poligon, kEps](m2::PointD const & pt)
{
if (poligon.empty() || !poligon.back().EqualDxDy(pt, kEps))
poligon.push_back(pt);
};
vector<m2::PointD> const corners = { rect.LeftTop(), rect.RightTop(), rect.RightBottom(), rect.LeftBottom() };
int firstClipCode[3];
int lastClipCode[3];
bool intersected[3];
intersected[0] = IntersectEdge(rect, corners, p1, p2, p3, addPoligonPoint,
0, 0, firstClipCode[0], lastClipCode[0]);
intersected[1] = IntersectEdge(rect, corners, p2, p3, p1, addPoligonPoint,
lastClipCode[0], 0, firstClipCode[1], lastClipCode[1]);
intersected[2] = IntersectEdge(rect, corners, p3, p1, p2, addPoligonPoint,
lastClipCode[1] != 0 ? lastClipCode[1] : lastClipCode[0],
firstClipCode[0] != 0 ? firstClipCode[0] : firstClipCode[1],
firstClipCode[2], lastClipCode[2]);
int const intersectCount = intersected[0] + intersected[1] + intersected[2];
if (intersectCount == 0)
{
if (IsPointInsideTriangle(rect.Center(), p1, p2, p3))
{
resultIterator(rect.LeftTop(), rect.RightTop(), rect.RightBottom());
resultIterator(rect.RightBottom(), rect.LeftBottom(), rect.LeftTop());
}
return;
}
if (intersectCount == 1 && intersected[2])
InsertCorners(corners, p1, p2, p3, addPoligonPoint, lastClipCode[2], firstClipCode[2]);
if (!poligon.empty() && poligon.back().EqualDxDy(poligon[0], kEps))
poligon.pop_back();
if (poligon.size() < 3)
return;
for (size_t i = 0; i < poligon.size() - 2; ++i)
resultIterator(poligon[0], poligon[i + 1], poligon[i + 2]);
}
vector<m2::SharedSpline> ClipSplineByRect(m2::RectD const & rect, m2::SharedSpline const & spline)
{
vector<m2::SharedSpline> result;
vector<m2::PointD> const & path = spline->GetPath();
if (path.size() < 2)
return result;
m2::RectD splineRect;
for (m2::PointD const & p : path)
splineRect.Add(p);
// Check for spline is inside.
if (rect.IsRectInside(splineRect))
{
result.push_back(spline);
return result;
}
// Check for spline is outside.
if (!rect.IsIntersect(splineRect))
return result;
// Divide spline into parts.
result.reserve(2);
m2::PointD p1, p2;
int code1 = 0;
int code2 = 0;
m2::SharedSpline s;
s.Reset(new m2::Spline(path.size()));
for (size_t i = 0; i < path.size() - 1; i++)
{
p1 = path[i];
p2 = path[i + 1];
if (m2::Intersect(rect, p1, p2, code1, code2))
{
if ((p1 - p2).IsAlmostZero())
continue;
if (s.IsNull())
s.Reset(new m2::Spline(path.size() - i));
s->AddPoint(p1);
if (code2 != 0 || i + 2 == path.size())
{
s->AddPoint(p2);
result.push_back(s);
s.Reset(nullptr);
}
}
}
return result;
}
} // namespace m2;
|
