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api:dk11:delphi:gisinterfaces.igis_viewer.locate_tgis_point_double

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IGIS_Viewer.Locate(TGIS_Point; Double) method

DK11 for Delphi | GisInterfaces.IGIS_Viewer.Locate | Overloads | Methods | Properties

Locate a shape that is near _ptg, but is closer than _prec distance.

Available also on: .NET | Java | ActiveX.

Syntax

// Delphi
public
  function Locate(
    const _ptg : TGIS_Point;
    const _prec : Double
  ) : TGIS_ShapeAbstract; overload;
// C++ Builder
public:
  TGIS_ShapeAbstract* Locate(
    TGIS_Point* const _ptg,
    const double _prec
  ) = 0 /* overload */;

Parameters

Name Type Description
_ptg TGIS_Point reference point /searching point/
_prec Double precision /not a longer distance than/; for points inside the polygon (if _prec >= 0) the distance will be multiply by 0.95 (to prefer points inside the polygon) but will not be bigger then _prec; for point distance will be multiplied by 0.9 to prefer points over lines and polygons; precision is express in map units

Result

Type Description
TGIS_ShapeAbstract Located shape or nil

Remarks

To improve performance sections visibility can be used to choose layer to call its Locate method. If locate is called upon active paint operations then result could be null. But Locate and paint process are using the same vector enumerator context.

It is recommended to check InPaint property before calling this Locate.

2018/02/17 00:05