METHODS

Constructors

$obj->new( [%options], [@polygons], %options )
$class->new( [%options], [@polygons], %options )

You may merge %options with @polygons. You may also use the "outer" and "inner" options.

Each polygon is a references to an ARRAY of points, each an ARRAY of X and Y, but better pass Math::Polygon objects.

Option Default

inner

[]

outer

undef

inner => \@polygons
The inner polygons, zero or more Math::Polygon objects.
outer => $polygon
The outer polygon, a Math::Polygon.
» Error: surface requires outer polygon

Attributes

$obj->inner

Returns a list (often empty) of inner polygons.

$obj->outer

Returns the outer polygon.

Simple calculations

area

Returns the area enclosed by the outer polygon, minus the areas of the inner polygons. See method Math::Polygon::area().

$obj->bbox

Returns a list with four elements: (xmin, ymin, xmax, ymax), which describe the bounding box of the surface, which is the bbox of the outer polygon. See method Math::Polygon::bbox().

$obj->perimeter

The length of the border: sums outer and inner perimeters. See method Math::Polygon::perimeter().

Clipping

$obj->fillClip1( $box )

Clipping a polygon into rectangles can be done in various ways. With this algorithm, the parts of the polygon which are outside the $box are mapped on the borders.

All polygons are treated separately.

$obj->lineClip( $box )

Returned is a list of ARRAYS-OF-POINTS containing line pieces from the input surface. Lines from outer and inner polygons are undistinguishable. See method Math::Polygon::lineClip().

$obj->string

Translate the surface structure into some string. Use Geo::WKT if you need a standardized format.

Returned is a single string possibly containing multiple lines. The first line is the outer, the other lines represent the inner polygons.