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EGSnrc C++ class library
Report PIRS-898 (2021)
Iwan Kawrakow, Ernesto Mainegra-Hing, Frederic Tessier, Reid Townson and Blake Walters
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A class to represent a polygon in a plane (a 2D polygon). More...
#include <egs_polygon.h>
Public Member Functions | |
| EGS_2DPolygon (vector< EGS_2DVector > &points, bool Open=false) | |
| Construct a polygon from the 2D points points. More... | |
| ~EGS_2DPolygon () | |
| Destructor. | |
| int | getN () const |
| Get the number of points (vertices) in this polygon object. | |
| bool | isConvex () const |
| Is the polygon convex ? | |
| EGS_2DVector | getNormal (int j) const |
| Get a line normal to the j'th polygon edge. | |
| EGS_Float | hownear (bool in, const EGS_2DVector &x) const |
| Get the nearest distance from x to the polygon. More... | |
| bool | isInside (const EGS_2DVector &x) const |
| Is the 2D point x inside the polygon ? | |
| bool | howfar (bool in, const EGS_2DVector &x, const EGS_2DVector &u, EGS_Float &t, EGS_2DVector *normal=0) |
| Will the line defined by position x and direction u intersect the polygon ? More... | |
| EGS_2DVector | getPoint (int j) const |
| Get the j'th point of this polygon. | |
A class to represent a polygon in a plane (a 2D polygon).
The EGS_2DPolygon class represents a polygon in a plane. It provides various functions which are useful for the implementation of the required geometry methods of prisms and pyramids.
Definition at line 59 of file egs_polygon.h.
| EGS_2DPolygon::EGS_2DPolygon | ( | vector< EGS_2DVector > & | points, |
| bool | Open = false |
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| ) |
Construct a polygon from the 2D points points.
The optional Open argument has only a meaning for polygons with 3 points (triangles) and makes the triangle to be 'open', i.e. extend to infinity between the lines defined by the first and second point and the first and third point.
Definition at line 67 of file egs_polygon.cpp.
| EGS_Float EGS_2DPolygon::hownear | ( | bool | in, |
| const EGS_2DVector & | x | ||
| ) | const |
Get the nearest distance from x to the polygon.
The argument in must be true, if the 2D position x is inside the polygon, false otherwise.
Definition at line 100 of file egs_polygon.h.
References veryFar.
| bool EGS_2DPolygon::howfar | ( | bool | in, |
| const EGS_2DVector & | x, | ||
| const EGS_2DVector & | u, | ||
| EGS_Float & | t, | ||
| EGS_2DVector * | normal = 0 |
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| ) |
Will the line defined by position x and direction u intersect the polygon ?
This function returns true, if the line defined by position x and direction u intersects the polygon and false otherwise. If an intersection exists, t is set to the distance between x and the intersection point. In addition, if normal is not null, it is set to the normal to the edge being intersected. The argument in must be set to true, if x is inside the ploygon and to false otherwise.
Definition at line 189 of file egs_polygon.h.
References epsilon.
1.8.5