IntelliPhoto  0.5
IntelliHelper.h
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1 #ifndef INTELLIHELPER_H
2 #define INTELLIHELPER_H
3 
4 #include <QPoint>
5 #include <vector>
6 
10 struct Triangle {
11  QPoint A,B,C;
12 };
13 
14 namespace IntelliHelper {
15 
23 inline float sign(QPoint& p1, QPoint& p2, QPoint& p3){
24  return (p1.x()-p3.x())*(p2.y()-p3.y())-(p2.x()-p3.x())*(p1.y()-p3.y());
25 }
26 
33 inline bool isInTriangle(Triangle& tri, QPoint& P){
34  float val1, val2, val3;
35  bool neg, pos;
36 
37  val1 = IntelliHelper::sign(P,tri.A,tri.B);
38  val2 = IntelliHelper::sign(P,tri.B,tri.C);
39  val3 = IntelliHelper::sign(P,tri.C,tri.A);
40 
41  neg = (val1<0.f) || (val2<0.f) || (val3<0.f);
42  pos = (val1>0.f) || (val2>0.f) || (val3>0.f);
43 
44  return !(neg && pos);
45 }
46 
52 std::vector<Triangle> calculateTriangles(std::vector<QPoint> polyPoints);
53 
60 bool isInPolygon(std::vector<Triangle> &triangles, QPoint &point);
61 }
62 
63 #endif
IntelliHelper::isInTriangle
bool isInTriangle(Triangle &tri, QPoint &P)
A function to check if a given point is in a triangle.
Definition: IntelliHelper.h:33
Triangle::B
QPoint B
Definition: IntelliHelper.h:11
Triangle::C
QPoint C
Definition: IntelliHelper.h:11
IntelliHelper
Definition: IntelliHelper.h:14
Triangle
The Triangle struct holds the 3 vertices of a triangle.
Definition: IntelliHelper.h:10
IntelliHelper::isInPolygon
bool isInPolygon(std::vector< Triangle > &triangles, QPoint &point)
A function to check if a point lies in a polygon by checking its spanning triangles.
Definition: IntelliHelper.cpp:116
Triangle::A
QPoint A
Definition: IntelliHelper.h:11
IntelliHelper::calculateTriangles
std::vector< Triangle > calculateTriangles(std::vector< QPoint > polyPoints)
A function to split a polygon in its spanning traingles by using Meisters Theorem of graph theory by ...
Definition: IntelliHelper.cpp:7
IntelliHelper::sign
float sign(QPoint &p1, QPoint &p2, QPoint &p3)
A function to get the 2*area of a traingle, using its determinat.
Definition: IntelliHelper.h:23