Back to FabImage Library website

You are here: Start » Function Reference » Region » Region Basics » CreatePolygonRegion

CreatePolygonRegion


Header: FIL.h
Namespace: fil
Module: FoundationLite

Creates a polygonal region corresponding to a given closed path.

Syntax

C++
C#
 
void fil::CreatePolygonRegion
(
	const fil::Path& inPolygon,
	ftl::Optional<const fil::CoordinateSystem2D&> inPolygonAlignment,
	int inFrameWidth,
	int inFrameHeight,
	fil::Region& outRegion,
	ftl::Optional<fil::Path&> outAlignedPolygon = ftl::NIL
)

Parameters

Name Type Range Default Description
Input value
 inPolygon const Path&
Input value
 inPolygonAlignment Optional<const CoordinateSystem2D&> NIL Adjusts the polygon to the position of the inspected object
Input value
 inFrameWidth int 0 - 65535 Width of the created region's frame
Input value
 inFrameHeight int 0 - 65535 Height of the created region's frame
Output value
 outRegion Region& Output region
Output value
 outAlignedPolygon Optional<Path&> NIL The input polygon transformed to the absolute coordinate system

Optional Outputs

The computation of following outputs can be switched off by passing value ftl::NIL to these parameters: outAlignedPolygon.

Read more about Optional Outputs.

Description

The operation creates a region containing pixels lying inside the shape described by inPolygon.

The inFrameWidth and inFrameHeight parameters most often should be set equal to the dimensions of the image this region will be used with. If the input polygon exceeds these dimensions, the output region will be cropped.

Hints

  • Remember to set inFrameWidth and inFrameHeight inputs to specify the region frame.

Examples

Remarks

  • inPolygon has to be a closed path, otherwise an error with appropriate description occurs.

Errors

List of possible exceptions:

Error type Description
DomainError Open path on input in CreatePolygonRegion.

See Also

  • CreateBoxRegion – Creates a rectangular region corresponding to a given box.