Module Hugin_gg.Box2

Axis-aligned boxes.

A box is a closed rectangle of the plane with sides parallel to the axes, possibly of zero width or height. There is no empty box: a function whose result may enclose nothing, such as Hugin_gg.Path.bounds, returns an option. Boxes are what bounds report and what layout places panels in.

Types

#type t

The type for boxes. Invariant: the corners are finite, minx <= maxx and miny <= maxy.

Constructors

#val v : float -> float -> float -> float -> t

v x y w h is the box with corner (x, y), width w and height h: it spans [x;x +. w] by [y;y +. h].

Raises Invalid_argument if w or h is negative, or if x, y, x +. w or y +. h is not finite.

#val of_pts : P2.t -> P2.t -> t

of_pts p q is the smallest box containing p and q, which are any two opposite corners.

Raises Invalid_argument if a coordinate of p or q is not finite.

Accessors

#val minx : t -> float

minx b is the smallest x of b.

#val miny : t -> float

miny b is the smallest y of b, its top edge on screen.

#val maxx : t -> float

maxx b is the largest x of b.

#val maxy : t -> float

maxy b is the largest y of b, its bottom edge on screen.

#val w : t -> float

w b is maxx b -. minx b, possibly infinity.

#val h : t -> float

h b is maxy b -. miny b, possibly infinity.

#val mid : t -> P2.t

mid b is the centre of b.

Combining and transforming

#val union : t -> t -> t

union a b is the smallest box containing a and b.

#val inter : t -> t -> t option

inter a b is the box of the points in both a and b, or None if they have none. Boxes that touch along an edge or at a corner meet in a box of zero width or height.

#val grow : float -> t -> t

grow d b is b with each side moved outwards by d, inwards if d is negative.

Raises Invalid_argument if a corner of the result is not finite or if d shrinks a side past the opposite one.

#val transform : Affine.t -> t -> t

transform m b is the smallest box containing the images of b's four corners under m. Under a rotation it is larger than the rotated box.

Raises Invalid_argument if an image is not finite.

Comparing and formatting

#val equal : t -> t -> bool

equal a b is true iff a and b have equal corners.

#val compare : t -> t -> int

compare a b orders boxes lexicographically by minx, miny, maxx and maxy.

#val pp : Stdlib.Format.formatter -> t -> unit

pp ppf b formats b's corners for debugging.