GeometryDifference (Function)

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GeometryDifference (Function)

In french: GéométrieDifférence

Returns a geometry representing the difference between two geometries.

Example:

Input A and B geometries

Difference

Example

o2DPolygon_1 is Polygon2D
Linestring2DAddPoint(o2DPolygon_1.Outline, 2.00, 2.00)
Linestring2DAddPoint(o2DPolygon_1.Outline, 2.00, -2.00)
Linestring2DAddPoint(o2DPolygon_1.Outline, -2.00, -2.00)
Linestring2DAddPoint(o2DPolygon_1.Outline, -2.00, 2.00)
// The last point of the polygon is the same as the first
Linestring2DAddPoint(o2DPolygon_1.Outline, 2.00, 2.00)
// Corrects the new geometry
o2DPolygon_1 = GeometryCorrect(o2DPolygon_1)

o2DPolygon_2 is Polygon2D
Linestring2DAddPoint(o2DPolygon_2.Outline, 3.00, 1.00)
Linestring2DAddPoint(o2DPolygon_2.Outline, 3.00, -1.00)
Linestring2DAddPoint(o2DPolygon_2.Outline, 1.00, -1.00)
Linestring2DAddPoint(o2DPolygon_2.Outline, 1.00, 1.00)
// The last point of the polygon is the same as the first
Linestring2DAddPoint(o2DPolygon_2.Outline, 3.00, 1.00)
// Corrects the new geometry
o2DPolygon_2 = GeometryCorrect(o2DPolygon_2)

// The difference is a 2D polygon
// The difference between two polygons is always a MultiPolygon
Difference is MultiPolygon2D = GeometryDifference(o2DPolygon_1, o2DPolygon_2)

Syntax

<Result> = GeometryDifference(<Geometry A> , <Geometry B>)

<Result>: Variable of type MultiPoint2D, MultiPointGeo, MultiLinestring2D, MultiLinestringGeo, MultiPolygon2D or MultiPolygonGeo

Difference. This geometry contains a collection of geometries of a given type:
MultiPoint2D or MultiPointGeo,
MultiLinestring2D or MultiLinestringGeo,
MultiPolygon2D or MultiPolygonGeo.
If the difference between two geometries consists of a single element, the collection will contain a single element.
If the difference is empty (e.g., difference between identical geometries), the collection will be empty.
If the result of the difference is disjoint (e.g. by splitting a polygon into two), the collection will contain several elements.

<Geometry A>: Variable containing spatial data

Geometry against which geometry B will be compared. This geometry can correspond to one of the following variable types:
PointGeo.
Point2D.
LinestringGeo.
Linestring2D.
PolygonGeo.
Polygon2D.
MultiPointGeo.
MultiPoint2D.
MultiLinestringGeo.
MultiLinestring2D.
MultiPolygonGeo.
MultiPolygon2D.

<Geometry B>: Variable containing spatial data

Geometry to be compared against geometry A. This geometry can correspond to one of the following variable types:
PointGeo.
Point2D.
LinestringGeo.
Linestring2D.
PolygonGeo.
Polygon2D.
MultiPointGeo.
MultiPoint2D.
MultiLinestringGeo.
MultiLinestring2D.
MultiPolygonGeo.
MultiPolygon2D.

Business / UI classification: Business Logic

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