--
-- File      :  View.cdl
-- Created   :  Mon 11 Jan 1993
-- Author    : CKY / Contract Toubro-Larsen ( Niraj RANGWALA )
--
---Copyright : MATRA-DATAVISION  1993
--

class View from IGESDraw  inherits ViewKindEntity

        ---Purpose : defines IGES View Entity, Type <410> Form <0>
        --           in package IGESDraw
        --
        --           Used to define a framework for specifying a viewing
        --           orientation of an object in three dimensional model
        --           space (X,Y,Z). The framework is also used to support
        --           the projection of all or part of model space onto a
        --           view volume.

uses

        TransfEntity     from IGESData,
        Plane            from IGESGeom,
	XYZ              from gp

raises OutOfRange

is

        Create returns mutable View;

        -- Specific Methods pertaining to the class

        Init (me           : mutable;
              aViewNum     : Integer;
              aScale       : Real;
              aLeftPlane   : Plane;
              aTopPlane    : Plane;
              aRightPlane  : Plane;
              aBottomPlane : Plane;
              aBackPlane   : Plane;
              aFrontPlane  : Plane);
        ---Purpose : This method is used to set fields of the class View
        --       - aViewNum     : View number
        --       - aScale       : Scale factor
        --       - aLeftPlane   : Left   plane of view volume
        --       - aTopPlane    : Top    plane of view volume
        --       - aRightPlane  : Right  plane of view volume
        --       - aBottomPlane : Bottom plane of view volume
        --       - aBackPlane   : Back   plane of view volume
        --       - aFrontPlane  : Front  plane of view volume

    	IsSingle (me) returns Boolean;
	---Purpose : Returns True (for a single view)

    	NbViews (me) returns Integer;
	---Purpose : Returns 1 (single view)

    	ViewItem (me; num : Integer) returns ViewKindEntity  raises OutOfRange;
	---Purpose : For a single view, returns <me> whatever <num>

        ViewNumber (me) returns Integer;
        ---Purpose : returns integer number identifying view orientation

        ScaleFactor (me) returns Real;
        ---Purpose : returns the scale factor(Default = 1.0)

        HasLeftPlane (me) returns Boolean;
        ---Purpose : returns False if left side of view volume is not present

        LeftPlane (me) returns Plane;
        ---Purpose : returns the left side of view volume, or null handle

        HasTopPlane (me) returns Boolean;
        ---Purpose : returns False if top of view volume is not present

        TopPlane (me) returns Plane;
        ---Purpose : returns the top of view volume, or null handle

        HasRightPlane (me) returns Boolean;
        ---Purpose : returns False if right side of view volume is not present

        RightPlane (me) returns Plane;
        ---Purpose : returns the right side of view volume, or null handle

        HasBottomPlane (me) returns Boolean;
        ---Purpose : returns False if bottom of view volume is not present

        BottomPlane (me) returns Plane;
        ---Purpose : returns the bottom of view volume, or null handle

        HasBackPlane (me) returns Boolean;
        ---Purpose : returns False if back of view volume is not present

        BackPlane (me) returns Plane;
        ---Purpose : returns the back of view volume, or null handle

        HasFrontPlane (me) returns Boolean;
        ---Purpose : returns False if front of view volume is not present

        FrontPlane (me) returns Plane;
        ---Purpose : returns the front of view volume, or null handle

        ViewMatrix (me) returns TransfEntity;
        ---Purpose : returns the Transformation Matrix

        ModelToView (me; coords : XYZ) returns XYZ;
        ---Purpose : returns XYZ from the Model space to the View space by
        -- applying the View Matrix

fields

--
-- Class    : IGESDraw_View
--
-- Purpose  : Declaration of the variables specific to a View.
--
-- Reminder : A  View Entity is defined by :
--                  - a view number for identifying the view orientation
--                  - a scale factor, and
--                  - a view volume to control the projection of the view into
--                    a 2-D drawing space specified by a Drawing Entity.
--                    The view volume is a rectangular parallelepiped with
--                    limits specified by Plane Entities.
--

        theViewNumber  : Integer;

        theScaleFactor : Real;

        theLeftPlane   : Plane;

        theTopPlane    : Plane;

        theRightPlane  : Plane;

        theBottomPlane : Plane;

        theBackPlane   : Plane;

        theFrontPlane  : Plane;

end View;