-- File:	Aspect_CircularGrid.cdl
-- Created:	Fri Mar 17 08:21:04 1995
-- Author:	Mister rmi
--		<rmi@pernox>
---Copyright:	 Matra Datavision 1995

class CircularGrid from Aspect

inherits Grid from Aspect


uses
    PlaneAngle, Length from Quantity

raises 
    NegativeValue,NullValue,NumericError from Standard

is 

    Create(aRadiusStep: Length from Quantity;
	       aDivisionNumber: Integer from Standard;
               XOrigin: Length from Quantity = 0;
	       anYOrigin: Length from Quantity = 0;
               aRotationAngle: PlaneAngle from Quantity = 0)
    returns mutable CircularGrid from Aspect;
    ---Purpose: creates a new grid. By default this grid is not
    --          active.
    
---Category: grid definition methods


    SetRadiusStep(me: mutable; aStep: Length from Quantity) 
    ---Purpose: defines the x step of the grid.
    raises NegativeValue,NullValue from Standard
    ---Warning: raises an exception if <aStep> is not strictly positive.
    is static;

    SetDivisionNumber(me: mutable; aNumber: Integer from Standard)
    ---Purpose: defines the step of the grid.
    raises NegativeValue,NullValue from Standard
    ---Warning: raises an exception if <aNumber> is not strictly positive.
    is static;

    SetGridValues(me: mutable; XOrigin, YOrigin: Length from Quantity;
                               RadiusStep: Length from Quantity;
                               DivisionNumber: Integer from Standard;
                               RotationAngle: PlaneAngle from Quantity)
    raises NegativeValue,NullValue from Standard
    ---Warning: raises an exception if <RadiusStep> is not strictly positive.
    ---Warning: raises an exception if <DivisionNumber> is not strictly positive.
    is static;
 
   
---Category: Pick methods
--           
    Compute(me; X,Y: Length from Quantity; gridX, gridY : out Length from Quantity)
    ---Purpose: returns the point of the grid the closest to the point X,Y
    is static;
    

    
---Category: inquire methods

    RadiusStep(me) returns Length from Quantity
    ---Purpose: returns the x step of the grid.
    is static;

    DivisionNumber(me) returns Integer from Standard
    ---Purpose: returns the x step of the grid.
    is static;
    
---Category: private methods.

    
    Init(me: mutable)
    is redefined static;
    
fields

    myRadiusStep: Length from Quantity;
    myDivisionNumber: Integer from Standard;
    myAlpha: Real from Standard;
    myA1,myB1: Real from Standard;
    
end CircularGrid from Aspect;