-- File: Box2d.cdl -- Created: Mon Jan 28 11:51:08 1991 -- Author: Remi Lequette -- ---Copyright: Matra Datavision 1991, 1992 class Box2d from Bnd ---Purpose: Describes a bounding box in 2D space. -- A bounding box is parallel to the axes of the coordinates -- system. If it is finite, it is defined by the two intervals: -- - [ Xmin,Xmax ], and -- - [ Ymin,Ymax ]. -- A bounding box may be infinite (i.e. open) in one or more -- directions. It is said to be: -- - OpenXmin if it is infinite on the negative side of the "X Direction"; -- - OpenXmax if it is infinite on the positive side of the "X Direction"; -- - OpenYmin if it is infinite on the negative side of the "Y Direction"; -- - OpenYmax if it is infinite on the positive side of the "Y Direction"; -- - WholeSpace if it is infinite in all four directions. In -- this case, any point of the space is inside the box; -- - Void if it is empty. In this case, there is no point included in the box. -- A bounding box is defined by four bounds (Xmin, Xmax, Ymin and Ymax) which -- limit the bounding box if it is finite, six flags (OpenXmin, OpenXmax, OpenYmin, -- OpenYmax, WholeSpace and Void) which describe the bounding box if it is infinite or empty, and -- - a gap, which is included on both sides in any direction when consulting the finite bounds of the box. uses Pnt2d from gp, Dir2d from gp, Lin2d from gp, Trsf2d from gp raises ConstructionError from Standard is Create returns Box2d from Bnd; ---Purpose: Creates an empty 2D bounding box. -- The constructed box is qualified Void. Its gap is null. ---C++: inline SetWhole(me : in out) is static; ---Purpose: Sets this bounding box so that it covers the whole 2D -- space, i.e. it is infinite in all directions. ---C++: inline SetVoid(me : in out) is static; ---Purpose: Sets this 2D bounding box so that it is empty. All points are outside a void box. ---C++: inline Set(me : in out; P : Pnt2d) is static; ---Purpose: Sets this 2D bounding box so that it bounds -- the point P. This involves first setting this bounding box -- to be void and then adding the point PThe rectangle bounds the point

. ---C++: inline Set(me : in out; P : Pnt2d; D : Dir2d) is static; ---Purpose: Sets this 2D bounding box so that it bounds -- the half-line defined by point P and direction D, i.e. all -- points M defined by M=P+u*D, where u is greater than -- or equal to 0, are inside the bounding area. This involves -- first setting this 2D box to be void and then adding the half-line. ---C++: inline Update(me : in out; aXmin, aYmin, aXmax, aYmax : Real) ---Purpose: Enlarges this 2D bounding box, if required, so that it -- contains at least: -- - interval [ aXmin,aXmax ] in the "X Direction", -- - interval [ aYmin,aYmax ] in the "Y Direction" is static; Update(me : in out; X,Y : Real) ---Purpose: Adds a point of coordinates (X,Y) to this bounding box. is static; GetGap(me) returns Real ---Purpose: Returns the gap of this 2D bounding box. ---C++: inline is static; SetGap(me : in out; Tol : Real) ---Purpose: Set the gap of this 2D bounding box to abs(Tol). ---C++: inline is static; Enlarge(me : in out; Tol : Real) ---Purpose: Enlarges the box with a tolerance value. -- This means that the minimum values of its X and Y -- intervals of definition, when they are finite, are reduced by -- the absolute value of Tol, while the maximum values are -- increased by the same amount. ---C++: inline is static; Get(me; aXmin, aYmin, aXmax, aYmax : out Real) ---Purpose: Returns the bounds of this 2D bounding box. -- The gap is included. If this bounding box is infinite (i.e. "open"), returned values -- may be equal to +/- Precision::Infinite(). raises ConstructionError -- if IsVoid() is static; OpenXmin(me : in out) ---Purpose: The Box will be infinitely long in the Xmin direction. ---Level: Public ---C++: inline is static; OpenXmax(me : in out) ---Purpose: The Box will be infinitely long in the Xmax direction. ---Level: Public ---C++: inline is static; OpenYmin(me : in out) ---Purpose: The Box will be infinitely long in the Ymin direction. ---Level: Public ---C++: inline is static; OpenYmax(me : in out) ---Purpose: The Box will be infinitely long in the Ymax direction. ---Level: Public ---C++: inline is static; IsOpenXmin(me) returns Boolean ---Purpose: Returns true if this bounding box is open in the Xmin direction. ---C++: inline is static; IsOpenXmax(me) returns Boolean ---Purpose: Returns true if this bounding box is open in the Xmax direction. ---C++: inline is static; IsOpenYmin(me) returns Boolean ---Purpose: Returns true if this bounding box is open in the Ymin direction. ---C++: inline is static; IsOpenYmax(me) returns Boolean ---Purpose: Returns true if this bounding box is open in the Ymax direction. ---C++: inline is static; IsWhole(me) returns Boolean is static; ---Purpose: -- Returns true if this bounding box is infinite in all 4 -- directions (Whole Space flag). ---C++: inline IsVoid(me) returns Boolean is static; ---Purpose: -- Returns true if this 2D bounding box is empty (Void flag). ---C++: inline Transformed(me; T : Trsf2d from gp) ---Purpose: Returns a bounding box which is the result of applying the -- transformation T to this bounding box. -- Warning -- Applying a geometric transformation (for example, a -- rotation) to a bounding box generally increases its -- dimensions. This is not optimal for algorithms which use it. returns Box2d from Bnd is static; Add(me : in out; Other : Box2d) is static; ---Purpose: Adds the 2d box to . ---Level: Public Add(me : in out; P : Pnt2d) is static; ---Purpose: Adds the 2d pnt

to . ---Level: Public ---C++: inline Add(me : in out; P : Pnt2d; D : Dir2d) is static; ---Purpose: Extends from the Pnt

in the direction . ---Level: Public ---C++: inline Add(me : in out; D : Dir2d) is static; ---Purpose: Extends the Box in the given Direction, i.e. adds -- a half-line. The box may become infinite in 1 or 2 -- directions. ---Level: Public IsOut(me; P : Pnt2d) returns Boolean is static; ---Purpose: Returns True if the 2d pnt

is out . ---Level: Public IsOut(me; Other : Box2d) returns Boolean is static; ---Purpose: Returns True if is out . ---Level: Public IsOut(me; Other : Box2d; T : Trsf2d from gp) returns Boolean is static; ---Purpose: Returns True if transformed is out . ---Level: Public ---C++: inline IsOut(me; T1 : Trsf2d from gp; Other : Box2d; T2 : Trsf2d from gp) returns Boolean is static; ---Purpose: Compares a transformed bounding with a transformed -- bounding. The default implementation is to make a copy -- of and , to transform them and to test. ---Level: Public ---C++: inline Dump(me) is static; fields Xmin : Real; Xmax : Real; Ymin : Real; Ymax : Real; Gap : Real; Flags : Integer; -- 6 flags end Box2d;