org.mdiutil.geom

Class GeometryRuler

java.lang.Object

org.mdiutil.geom.GeometryRuler

public class GeometryRuler
extends Object

This class computes areas and perimeters of any Shape.

Method Summary

Modifier and Type	Method and Description
float	getArc2DArea(Arc2D arc) Return an Arc2D area.
float	getArc2DLength(Arc2D arc) Return an Arc2D length.
float	getEllipse2DArea(Ellipse2D el) Return an Ellipse2D area.
float	getEllipse2DLength(Ellipse2D el) Return an Ellipse2D length (perimeter).
double	getFlatness() Return the flatness value.
float	getPolygon2DArea(Polygon2D pol) Return a Polygon area using the following formula: area = 1/2 * (x1*y2 - x2*y1 + x2*y3 - x3*y2
float	getPolygon2DLength(Polygon2D pol) Return a Polygon2D length;
float	getPolyline2DLength(Polyline2D pol) Return a Polyline2D length;
static GeometryRuler	getRuler() Return the unique GeometryRuler instance.
float	getShapeArea(Shape shape) This method compute the area of a shape.
float	getShapeArea(Shape shape, double flatness) Return the area of a Shape.
float	getShapeLength(Shape shape) This method compute the length (perimeter) of a shape.
float	getShapeLength(Shape shape, double flatness) Return the length of a Shape.
void	setFlatness(double flatness) Set the flatness value (which will be used to compute CubicCurves areas and perimeters.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getRuler

public static GeometryRuler getRuler()

Return the unique GeometryRuler instance.

Returns:

the unique GeometryRuler instance

setFlatness

public void setFlatness(double flatness)

Set the flatness value (which will be used to compute CubicCurves areas and perimeters.

Parameters:

flatness - the flatness value

getFlatness

public double getFlatness()

Return the flatness value.

Returns:

the flatness value

getShapeArea

public float getShapeArea(Shape shape,
                          double flatness)

Return the area of a Shape. This is a convenience method, equivalent to setting the flatness and calling the getShapeArea(Shape).

Parameters:

shape - the Shape

flatness - the flatness value (see setFlatness(double))

Returns:

the shape area

See Also:

getShapeArea(Shape)

getShapeArea

public float getShapeArea(Shape shape)

This method compute the area of a shape. The Shape can be:

• a complex Shape : the Shape will be transformed to a set of lines and Polylines, by using the ShapeNormalizer class. The area of the Shape is the sum of the areas of all the sub-Shapes computed by this class
• a Polygon2D : equivalent to getPolygon2DArea(Polygon2D)
• an Arc2D : equivalent to getArc2DArea(Arc2D)
• an Ellipse2D : equivalent to getEllipse2DArea(Ellipse2D)

Parameters:

shape - the shape

Returns:

the shape area

getArc2DArea

public float getArc2DArea(Arc2D arc)

Return an Arc2D area.

Parameters:

arc - the Arc2D

Returns:

the Arc2D area

getEllipse2DArea

public float getEllipse2DArea(Ellipse2D el)

Return an Ellipse2D area.

Parameters:

el - the Ellipse2D

Returns:

the Ellipse2D area

getPolygon2DArea

public float getPolygon2DArea(Polygon2D pol)

Return a Polygon area using the following formula:

 area = 1/2 * (x1*y2 - x2*y1 + x2*y3 - x3*y2 ...
        + xn-1*yn - xn*yn-1 + xn*y1 - x1*yn)
 

Parameters:

pol - the Polygon2D

Returns:

the Polygon2D area

getShapeLength

public float getShapeLength(Shape shape,
                            double flatness)

Return the length of a Shape. This is a convenience method, equivalent to setting the flatness and calling the getShapeLength(Shape).

Parameters:

shape - the Shape

flatness - the flatness value (see setFlatness(double))

Returns:

the Shape length

See Also:

getShapeLength(Shape)

getShapeLength

public float getShapeLength(Shape shape)

This method compute the length (perimeter) of a shape. The Shape can be:

• a complex Shape: the Shape will be transformed to a set of lines and Polylines, by using the ShapeNormalizer class. The legnth of the Shape is the sum of the lengts of all the sub-Shapes computed by this class
• a Polygon2D: equivalent to getPolygon2DLength(Polygon2D)
• a Polyline2D: equivalent to getPolyline2DLength(Polyline2D)
• a Line2D: equivalent to getPolyline2DLength(Polyline2D), the Polyline2D corresponding to the Line2D
• an Arc2D: equivalent to getArc2DLength(Arc2D)
• a Ellipse2D: equivalent to getEllipse2DLength(Ellipse2D)

Parameters:

shape - the Shape

Returns:

the Shape perimeter

getArc2DLength

public float getArc2DLength(Arc2D arc)

Return an Arc2D length.

Parameters:

arc - the Arc2D

Returns:

the Arc2D length

getEllipse2DLength

public float getEllipse2DLength(Ellipse2D el)

Return an Ellipse2D length (perimeter). The approximative formula used for the calculation is :

PI * sqrt(2*(a*a + b*b) - (a - b)*(a-b)/2)

where a and be are the major radius and minor radius of he ellipsis.

Parameters:

el - the Ellipse2D

Returns:

the Ellipse2D length

getPolygon2DLength

public float getPolygon2DLength(Polygon2D pol)

Return a Polygon2D length;

Parameters:

pol - the Polygon2D

Returns:

the Polygon2D length

getPolyline2DLength

public float getPolyline2DLength(Polyline2D pol)

Return a Polyline2D length;

Parameters:

pol - the Polyline2D

Returns:

the Polyline2D length