api:dk11:activex:tatukgis_xdk11.itgis_shape.distance2part_itgis_point_double_integer_itgis_point
Table of Contents
ITGIS_Shape.Distance2Part method
DK for ActiveX | TatukGIS_XDK11.ITGIS_Shape.Distance2Part | Methods | Properties
Calculates distance from a point to the nearest element of a specific shape part and optionally returns the projection point.
Syntax
// C# public double Distance2Part( ITGIS_Point _ptg, double _prec, int _part, ref ITGIS_Point _proj );
' VisualBasic Public Function Distance2Part( ByVal _ptg As ITGIS_Point, ByVal _prec As Double, ByVal _part As Integer, ByRef _proj As ITGIS_Point ) As Double
// Oxygene public function Distance2Part( _ptg : ITGIS_Point; _prec : Double; _part : Integer; var _proj : ITGIS_Point ) : Double;
Parameters
| Name | Type | Description |
|---|---|---|
| _ptg | ITGIS_Point | Query point for which distance to the shape part is computed. |
| _prec | double Double | Precision threshold in map units. For polygons, a point inside the shape always returns a distance <= _prec. Negative _prec ignores inside/outside distinction. |
| _part | int Integer | Zero-based part index. Must be less than GetNumParts. |
| _proj | ITGIS_Point | Output point receiving the perpendicular projection of _ptg onto the nearest element of the specified shape part. |
Result
| Type | Description |
|---|---|
| double Double | Distance in map units, or -1 if the part index is invalid. |
Remarks
PURPOSE: Measure distance to a single part of a multipart geometry, such as one line in a MultiLineString or one ring in a polygon, and obtain the nearest projected point.
BEHAVIOR: Computes the shortest planar distance from _ptg to the specified part using the nearest vertex or segment and stores the closest point in _proj.
CONSTRAINTS: Returns -1 when _part is outside the valid range. This is a planar calculation and does not apply coordinate system transformation.
2026/07/05 01:25