teca_geometry Namespace Reference

Codes dealing with computational geometry. More...

Classes
struct	polygon

Functions
template<typename n_t >
bool	left (n_t e0x, n_t e0y, n_t e1x, n_t e1y, n_t px, n_t py)
	tests if a point is Left|On|Right of an infinite line. More...
template<typename n_t >
bool	point_in_poly (n_t px, n_t py, n_t *vx, n_t *vy, unsigned long nppts)

Detailed Description

Codes dealing with computational geometry.

Function Documentation

left()

template<typename n_t >

bool teca_geometry::left	(	n_t	e0x,
		n_t	e0y,
		n_t	e1x,
		n_t	e1y,
		n_t	px,
		n_t	py
	)

tests if a point is Left|On|Right of an infinite line.

point_in_poly()

template<typename n_t >

bool teca_geometry::point_in_poly	(	n_t	px,
		n_t	py,
		n_t *	vx,
		n_t *	vy,
		unsigned long	nppts
	)

Winding number test for a point in a polygon. The winding number is 0 when the point is outside. The polygon is defined a series of x, y points in counter clockwise order. Defining in clock wise order changes the sign of the winding number. the first and last point of the polygon are required to be the same.

Parameters

[in]	px	the x coordinate of the point.
[in]	py	the y coordinate of the point.
[in]	vx	the x coordinates of the polygon.
[in]	vy	the y coordinates of the polygon.
[in]	nppts	the number of points in the polygon.