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EMDtool

Summary

SURFACE Class for representing elementary surfaces.

A Surface object represents a single surface with or without holes (i.e. a simply or multiply connected surface). Each surface is defined by

  • Its boundary. The boundary consists of segments, i.e. Curve objects representing either a line segment or circle arc joining two Point objects.

  • (Optional) Its holes, each a Surface themselves.

See for more details.

PROPERTIES

  • holes - Array of Surface objects inside this Surface.

  • Surface/is_closed is a property.

  • line_directions - Direction of each boundary segment (+1 / -1).

  • lines - Array of Curve objects defining the boundary of the geometry. Ordered.

  • name - Surface name.

Methods

Class methods are listed below. Inherited methods are not included.

* Surface Constructor.

this = Surface(name)

Create an empty surface with the specified name (string).

this = Surface(name, (Curve definitions))

Create a surface, and then pass all following arguments (Curve definitions) to this.add_curve.

* add_curve Add a curve to the surface boundary.

add_curve(this, geo.line, p1, p1)

Add a line segment, from Point p1 to p2.

If the geometry already contains a Curve linking p1 and p2, it is automatically added to this. If not, a new Curve object is created.

Curves must be added in order , i.e. the start Point of the current curve must equal the end Point of the previously added Curve.

add_curve(this, geo.arc, p1, pcenter, p2)

Add a circle Arc, from Point p1 to p2, with its center at Point pcenter.

add_curve(this, Curve)

Add a Curve object to the boundary. *TO BE IMPLEMENTED*

add_curve(this, geo.hole, surf1, surf2, ..)

Adds the surfaces surf1, surf2, .. as holes within this surface.

Note : multiple calls to add_curve can be chained together by simply passing all arguments to the method at once. However, the holes , if any, must be supplied last and not be followed by any Curves.

* add_hole Add one or more holes to the surface.

add_hole(this, surface_1, …)

* area Return surface area(2D).

Calculate the area of this surface (polygon). See this.points().

NOTE : after meshing the geometry, the area of the meshed surface may not exactly equal the number returned by area(this), especially if the surface contains Arc boundaries.

* fill Fill(-plot) surface

* Surface.from_line is a function.

this = from_line(l, direction)

* in_surface Point in surface?

bl = in_surface(this, X)

* Surface/is_ccw is a function.

is_ccw = is_ccw(this)

* plot Plot surface.

plot(this, args)

Plot surface with (args).

* points Surface boundary as an array of doubles.

X = points(this)

Returns the x- and y-coordinates of the Point objects defining the boundary of this surface.

X = points(this, dense) use denser points for Arcs

* reduce Reduce surface to the smallest possible area.

This method removes such holes (geo.hole) that share one or more boundary Curves with this surface. For instance, a square surface with a smaller square inside, tangenting on one edge, is reduced into a U-shaped surface.

new_boundary_curves = reduce(this, [Point_start, Point_end] )

where Point_start and Point_end specify some boundary Line segment. The method modifies the boundary of this surface accordingly, and additionally returns the new boundary curves.

NOTE The method works on counterclockwise oriented surfaces, so the start and end points must be selected accordingly.

WARNING : If Point_start and Point_end are joined by both a Line and one or more Arcs, the Line is selected.

NOTE This method must be called only after all boundary-sharing holes have been defined; the method cannot see the future.

* reset_curves Remove all lines.

* rotate_inplace Rotate surface in-place.

rotate_inplace(this, a) rotates all Points in this around the Origin by the angle a.