VS:PointAlongPoly

.VectorScript|VectorScript ..VS:Function Reference|Function Reference ..VS:Function_Reference_Appendix|Appendix

Description

Returns a point at the specified distance along the poly, and a vector tangent to the poly at that point.

FUNCTION PointAlongPoly(
             h             :HANDLE;
             dist          :REAL;
             VAR pt        :VECTOR;
             VAR tangent   :VECTOR) : BOOLEAN;

def vs.PointAlongPoly(h, dist):
    return (BOOLEAN, pt, tangent)

Parameters

h		HANDLE
dist		REAL
pt		VECTOR
tangent		VECTOR

Remarks

( _c_, 2022.01.18) In Vectorscript Python this returns a tuple with 3 items ( 0, 0, 0 ). This is relevant for usage in routines such as Vec2Ang, returning wrong values if the tuple is only bidimensional.

Example

Pascal

PROCEDURE Test;
VAR
    polyObj : HANDLE;
    dist : REAL;
    p, tangentVec : VECTOR;
	
BEGIN
    polyObj := FSActLayer;

    IF polyObj = NIL THEN
        AlrtDialog( 'Select a polygon' )
		
    ELSE BEGIN
        dist := 1m;
        IF PointAlongPoly( polyObj, dist, p, tangentVec ) THEN
            Locus( p.x, p.y );
    END;
END;
Run(Test);

Python

def Str2Num( inStr ):
    ok, num = vs.ValidNumStr( inStr )
    if ok:
        return num
    else:
        return 0

polyObj = vs.FSActLayer()

if polyObj == vs.Handle():
    vs.AlrtDialog( 'Select a polygon' )
else:
    dist = Str2Num( '1m' ) # convert string to dim
    ok, p, tangentVec = vs.PointAlongPoly( polyObj, dist )
    if ok:
        vs.Locus( p )
        vs.AlrtDialog( str( len(p)) ) # return a tuple with 3 items

Version

Availability: from Vectorworks 2014