GEOcountIntersectLineSpline

Count the intersection of line and Spline.

With this routine the intersections are counted between line and Spline. Runs of the Spline several times by the same point and cuts the line this point, the intersection is also counted several times.

The line is cut only with coarse interpolations of the sections and is cut only with cut with a refinement of the suitable sections again.

Parametre

lsx (stands in) [IN]

lsy (stands in) [IN]

Starting point of the line.

lex (stands in) [IN]

ley (stands in) [IN]

Terminator point of the line

x [] (stands in) [IN]

y [] (stands in) [IN]

Field with the Splinepunkten.

scount (int) [IN]

Number of the Splinepunkte in the field.

Result

(int) [OUT]

As a result the number of the intersections is determined. There are special cases which are described under remarks.

Declaration

#include "basic.h"

int DLLENTRY GEOcountIntersectLineSpline (

stand in lsx,

stand in lsy,

stand in lex,

stand in ley,

stand in x [],

stand in y [],

int scount

);

Related functions

GEOintersectLineSpline

Remarks

The return value–3 can appear if the Spline has degenerated, exists i.e. only of two points, or if a section of the Splines is approximated by a line.

Return value–2 means mistake.

With the return value–1 the calculation was broken off on account of a special case of the simplicity half, the 'point in the polygon test' can call the function then with changed distance again.

0 count tangential intersection.