Poly2 (scad_ml.Scad

exception SelfIntersection of int

SelfIntersection i

Raised during polygon validation if a path is found to self-intersect. The index i refers to the culprit path (outer = 0, with holes increasing).

exception CrossIntersection of int * int

CrossIntersection (i, j)

Raised during polygon validation if two paths are found to intersect eachother. The indices i and j refer to the paths in question (outer = 0, with holes increasing).

exception DuplicatePoints

DuplicatePoints

Raised during polygon validation if there are any duplicate points across all of the paths contained within t.

type t = private {

`outer : Path2.t;`	(* outer perimeter *)
`holes : Path2.t list;`	(* inner paths to be subtracted from the outer shape *)

}

2-dimensional polygon

This type is kept private to force use of make, which performs validation by default, hopefully providing an early warning that the shape may have issues rendering in OpenSCAD.

Creation and Validation

val make : ?validate:bool -> ?holes:Path2.t list -> Path2.t -> t

make ?validate ?holes outer

Create a 2d polygon from an outer path (perimeter), and zero or more holes (default = []). If validate is true (as it is by default), validation is performed, raising exceptions if the defined polygon is not simple (and thus, may cause problems in CGAL).

val add_holes : ?validate:bool -> holes:V2.t list list -> t -> t

add_holes ?validate ~holes t

Add holes to t. If validate is true (as it is by default), validation is performed, raising exceptions if the defined polygon is not simple (and thus, may cause problems in CGAL).

val validation : ?eps:float -> t -> unit

validation ?eps t

Validate that t is a legal polygon, without self-intersections within paths, cross-intersections between paths, or any duplicate points. All checks are performed with the tolerance eps. If valid, unit will be returned, otherwise an exception will be raised.

raises SelfIntersection
if any paths in t self-intersect.

raises CrossIntersection
if any two paths in t intersect eachother.

raises DuplicatePoints
if there are any duplicate points in t.

val is_simple : ?eps:float -> t -> bool

is_simple ?eps t

Return true if t is a simple polygon, without self-intersections within paths, cross-intersections between paths, or any duplicate points. All checks are performed with the tolerance eps.

Basic Shapes

val circle : ?fn:int -> ?fa:float -> ?fs:float -> float -> t

circle ?fn ?fa ?fs r

Create a circle of radius r.

val wedge : 
  ?fn:int ->
  ?fa:float ->
  ?fs:float ->
  centre:V2.t ->
  radius:float ->
  start:float ->
  float ->
  t

wedge ?fn ?fa ?fs ~centre ~radius ~start a

Create an arcing path (as in Path2.arc), with the centre point included to close the path, forming a wedge.

val square : ?center:bool -> V2.t -> t

square ?center dims

Create a rectangular polygon with xy dims (e.g. width and height). If center is true then the path will be centred around the origin (default = false).

val ellipse : ?fn:int -> ?fa:float -> ?fs:float -> V2.t -> t

ellipse ?fn ?fa ?fs radii

Draw an ellipse with xy radii. The greater of the two radii is used for fragment/resolution calculation.

val star : r1:float -> r2:float -> int -> t

star ~r1 ~r2 n

Draw an n pointed star with inner radius r1 and outer radius r2.

val ring : ?fn:int -> ?fa:float -> ?fs:float -> thickness:V2.t -> V2.t -> t

ring ?fn ?fa ?fs ~thickness radii

Draw an empty elliptical ring of outer xy radii, with the given radial thickness (difference between outer and inner radii). For a circular ring, use equal x and y radii.

val box : ?center:bool -> thickness:V2.t -> V2.t -> t

box ?center ~thickness dims

Create a rectangular empty box of outer xy dimensions dims, with the given xy thickness (difference between outer and inner xy dimensions). If center is true, then the path will be centred around the origin (default = false).

Geometry

val bbox : t -> V2.bbox

bbox t

Compute the 2d bounding box of the polygon t.

val centroid : ?eps:float -> t -> V2.t

centroid ?eps t

Compute the centroid of the outer path of the polygon t. If t.outer is collinear or self-intersecting (within eps tolerance), an Invalid_argument exception is raised.

val area : ?signed:bool -> t -> float

area ?signed t

Compute the total area of the polygon t. If signed is true, then the signed areas of the outer and holes paths of t will be summed (keep in mind that this is dependent on winding direction, which should generally be opposite between outer and inner paths), otherwise the unsigned (positive) area of the holes will be subtracted (default = false).

Offset and Basic Transformations

val offset : 
  ?fn:int ->
  ?fs:float ->
  ?fa:float ->
  ?check_valid:[ `Quality of int | `No ] ->
  ?mode:[< `Chamfer | `Delta | `Radius Delta ] ->
  float ->
  t ->
  t

offset ?fn ?fs ?fa ?check_valid ?mode d t

Offset outer and inner paths of t by the specified distance d. The mode governs how d is used to create the new corners.

`Delta will create a new outline whose sides are a fixed distance d (+ve out, -ve in) from the original outline (this is the default behaviour).
`Chamfer fixed distance offset by d as with delta, but with corners chamfered.
`Radius creates a new outline as if a circle of some radius d is rotated around the exterior (d > 0) or interior (d < 0) original outline. fn, fs, and fa parameters govern the number of points that will be used for these arcs (they are ignored for delta and chamfer modes).
The check_valid default of `Quality 1 will check the validity of shifted line segments by checking whether their ends and n additional points spaced throughout are far enough from the original path. If there are no points that have been offset by the target d, a Failure exception will be raised. Checking can be turned off by setting this to `No.

val map : ( Path2.t -> Path2.t ) -> t -> t

map f t

Map the outer and inner paths of t with the function f.

val translate : V2.t -> t -> t

val xtrans : float -> t -> t

val ytrans : float -> t -> t

val rotate : ?about:V2.t -> float -> t -> t

val zrot : ?about:V2.t -> float -> t -> t

val scale : V2.t -> t -> t

val mirror : V2.t -> t -> t

val affine : Affine2.t -> t -> t

Output

val to_scad : ?convexity:int -> t -> Scad.d2

to_scad ?convexity t

Create a Scad.t from the polygon t, via Scad.polygon.