-- File:	Vrml.cdl
-- Created:	Mon Dec 23 10:38:06 1996
-- Author:	Alexander BRIVIN and Dmitry TARASOV
--		<brivin@minox.nizhny.matra-dtv.fr>
---Copyright:	 Matra Datavision 1996


package Vrml 

	---Purpose: Vrml package  implements the specification  of the
	--          VRML ( Virtual  Reality Modeling Language ).  VRML
	--          is a standard  language for describing interactive
	--          3-D objects and  worlds delivered across Internet.
	--          Actual version of Vrml package have made for objects 
	--          of VRML version 1.0.  
        --          This package is used by VrmlConverter package.   
    	--          The developer should  already be familiar with VRML 
        --          specification before using this package.

    	--                     Coordinate System

    	--  VRML uses a Cartesian, right-handed, 3-dimensional coordinate system.  
    	--  By default, objects are projected onto a 2-dimensional device by projecting  
    	--  them in the direction of the positive Z axis, with the positive X axis to  
    	--  the right and the positive Y axis up. A camera or modeling transformation  
    	--  may be used to alter this default  projection. 
    	--  The standard unit for lengths and distances specified is meters.  
    	--  The standard unit for angles is radians.

    	--                           Fields

    	--  There are two general classes of fields; fields that contain a single value  
    	--  (where a value may be a single number, a vector, or even an image), and fields that  
    	--  contain multiple values. Single-valued fields all have names that begin with "SF",  
    	--  multiple-valued fields have names that begin with "MF". Each field type defines  
    	--  the format for the values it writes.  

    	--                            Nodes

    	--  VRML defines several different classes of nodes. Most of the nodes can be classified  
    	--  into one of three categories;  shape, property or group. Shape nodes define the geometry  
    	--  in the world. Conceptually, they are the only nodes  that draw anything. Property nodes  
    	--  affect the way shapes are drawn. And grouping nodes gather other nodes together, allowing  
    	--  collections of nodes to be treated as a single object. Some group nodes also control  
    	--  whether or not their children are drawn. 
    	--  Nodes may contain zero or more fields. Each node type defines the type, name, and default  
    	--  value for each of its fields. The default value for the field is used if a value for  
    	--  the field is not specified in the VRML file. 

    	--                             Instancing

	--  A node may be the child of more than one group. This is called "instancing" (using the same  
    	--  instance of a node multiple times, called "aliasing" or "multiple references" by other  
    	--  systems), and is accomplished by using the "USE" and  "DEF  keywords. 

uses

    TColStd,
    TColgp, 
    MMgt,
    Quantity, 
    gp, 
    TCollection

is
    

    	---Category: Classes of VRML field types.
	---Purpose: qualifies all types of VRML fields.


   --  Notes: 
   --         SFBitMask  VRML type == enumeration
   --         SFBool     VRML type == Boolean                from  Standard 
   --         SFColor    VRML type == Color                  from  Quantity
   --         SFEnum     VRML type == enumeration 
   --         SFFloat    VRML type == Real                   from  Standard 
   --         SFLong     VRML type == Integer                from  Standard
   --         SFMatrix   VRML type == Trsf                   from  gp
   --         SFString   VRML type == AsciiSting             from  TCollection 
   --         SFVec2f    VRML type == Vec2d                  from  gp
   --         SFVec3f    VRML type == Vec                    from  gp
   --         MFColor    VRML type == HArray1OfColor         from  Quantity
   --         MFLong     VRML type == HArray1OfInteger       from  TColStd
   --         MFFloat    VRML type == HArray1OfReal          from  TColStd  
   --         MFString   VRML type == HArray1OfAsciiString   from  TColStd  
   --         MFVec2f    VRML type == HArray1OfVec2d         from  TColgp
   --         MFVec3f    VRML type == HArray1OfVec           from  TColgp


  ---Purpose:  defines SFImage type of VRML field types.
    class SFImage;
  ---Purpose:  defines SFRotation type of VRML field types.
    class SFRotation;
 

    -- Enumeration for field representating a number of components 
    -- in the image per pixel for a SFImage type
    --  
  
    -- One-component  image  will  have  one-bite  hexadecimal  values 
    -- presenting  the  intensity  of  the  image 
    -- Ex:  0xFF  is full  intensity,  0x00 is  no  intensity   

    -- A  two-component  image  puts  the  intensity  in  the  first (hight)  byte 
    -- and  the  transparency  in  the  second  (low)  byte 

    -- Pixels  in  a  three-component  image  have  the  red  component  in  the  first (hight)  byte, 
    -- followed by  green  and  blue  components.  Ex:  0xFF0000  is  red.

    -- Four-component  images  put  transparency  byte  after  red/green/blue 
    -- Ex:  0x0000FF80  is  semi-transparent  blue.  A  value  of  1.0  is  completely transparent,  
    -- 0.0  is  completely  opaque.
    
    enumeration SFImageNumber  
      is  	  
      	 NULL,
         ONE,    
         TWO,
         THREE,
         FOUR  
    end SFImageNumber;


    	---Category: Classes of VRML nodes specifying geometry shapes.
	---Purpose: qualifies VRML geometry shapes.


    --  a SFBitMask type for Parts field of a Cone node
    enumeration ConeParts 
      is 
    	    ConeSIDES,       -- The conical part
    	    ConeBOTTOM,      -- The bottom circular face
    	    ConeALL          -- All parts

    end ConeParts;


    --  a SFEnum VRML type for Justification field of a AsciiText node
    enumeration AsciiTextJustification 
      is  
    	    LEFT,      -- Align left edge of text to origin
   	    CENTER,    -- Align center of text to origin
   	    RIGHT      -- Align right edge of text to origin  

    end AsciiTextJustification;


    --  a SFBitMask type for Parts field of a Cylinder node
    enumeration CylinderParts 
      is 
    	    CylinderSIDES,   -- The tubular part
    	    CylinderTOP,     -- The top circular face 
    	    CylinderBOTTOM,  -- The bottom circular face
    	    CylinderALL      -- All parts
   
    end CylinderParts;

    class AsciiText;
    class Cone;
    class Cube;
    class Cylinder;
    class IndexedFaceSet;
    class IndexedLineSet;
    class PointSet;
    class Sphere;


	---Category: Classes of VRML nodes specifying properties of geometry
	---          and its appearance. 
	---Purpose: qualifies properties of geometry and its appearance.



    --  a SFBitMask type for Family field of a FontStyle node
    enumeration FontStyleFamily 
      is 
            SERIF,	     -- Serif style (such as TimesRoman)
            SANS,	     -- Sans-serif style (such as Helvetica)
	    TYPEWRITER	     -- Fixed pitch style (such as Courier) 

    end FontStyleFamily;


    --  a SFEnum VRML type for Style field of a FontStyle node
    enumeration FontStyleStyle 
      is  

  	    NONE,			-- No modifications to family
	    BOLD,			-- Embolden family
	    ITALIC 			-- Italicize or slant family
 
    end FontStyleStyle; 
     
    
    --  a SFEnum VRML type for Value field of a MaterialBinding  
    --        and NormalBinding  nodes
    enumeration MaterialBindingAndNormalBinding 
      is  
    	    DEFAULT,
	    OVERALL,
	    PER_PART,
	    PER_PART_INDEXED,
	    PER_FACE,
	    PER_FACE_INDEXED,
	    PER_VERTEX,
	    PER_VERTEX_INDEXED

    end MaterialBindingAndNormalBinding;


    --  a SFEnum VRML type for wrapS and wrapT fields  of a Texture2 node
    enumeration Texture2Wrap   --Texture wrap type
     is 
	  REPEAT,     -- Repeats texture outside 0-1 texture coordinate range
	  CLAMP       -- Clamps texture coordinates  to lie within 0-1 range
     
    end Texture2Wrap;

     --  a SFEnum VRML type for VertexOrdering field of a ShapeHints node
    enumeration VertexOrdering
      is 
	UNKNOWN_ORDERING,
	CLOCKWISE,
	COUNTERCLOCKWISE

    end  VertexOrdering;


     --  a SFEnum VRML type for ShapeType field of a ShapeHints node
    enumeration ShapeType
      is 
	UNKNOWN_SHAPE_TYPE,
	SOLID

    end  ShapeType;

     --  a SFEnum VRML type for FaceType field of a ShapeHints node
    enumeration FaceType
      is 
	UNKNOWN_FACE_TYPE,
	CONVEX

    end  FaceType;

    class Coordinate3;
    class FontStyle;
    class Info;
    class LOD;
    class Material;
    class MaterialBinding;
    class Normal;
    class NormalBinding;
    class Texture2;
    class Texture2Transform;
    class TextureCoordinate2;
    class ShapeHints;



	---Category: Classes of VRML nodes specifying matrix and transform
	---          properties. 
	---Purpose: qualifies matrix and transform properties.  

    class MatrixTransform;
    class Rotation;
    class Scale;
    class Transform;
    class Translation;


	---Category: Classes of VRML nodes specifying properties of cameras
	---          and lights. 
	---Purpose: qualifies properties of cameras and lights. 

    class OrthographicCamera;
    class PerspectiveCamera;
    class DirectionalLight;
    class PointLight;
    class SpotLight;

        
	---Category: Classes of VRML nodes specifying group properties. 
	---Purpose: qualifies group properties.



     --  a SFEnum VRML type for RenderCulling field of a Separator node-
     enumeration SeparatorRenderCulling  -- Possible values for culling
      is 
	OFF,			-- Never cull
	ON,			-- Always cull
	AUTO			-- Decide based on some heuristic
     end  SeparatorRenderCulling;

    
      --  a SFEnum VRML type for Map field of a WWWAnchor node
    enumeration  WWWAnchorMap
      is 
	MAP_NONE,	  -- Leave URL name alone
	POINT	          -- Add object coords to URL name

    end WWWAnchorMap;


    class Group;
    class Separator;
    class Switch;
    class TransformSeparator;
    class WWWAnchor;
    class WWWInline; 

    class Instancing; 
    
	---Category: Methods to write commentaries in anOStream (VRML file).

        ---Purpose: Writes a header in anOStream (VRML file).
    	
    VrmlHeaderWriter  ( anOStream: in out OStream from Standard )
    	    returns OStream from Standard;
    ---C++:  return  & 
    	
        ---Purpose: Writes one line of commentary in  anOStream (VRML file).

    CommentWriter  ( aComment   :        CString from Standard;   
    	    	     anOStream  : in out OStream from Standard )
    	    returns OStream from Standard;
    ---C++:  return  & 
    	        	
end Vrml;