Package org.eclipse.gef.geometry.planar

Class Polygon

java.lang.Object
org.eclipse.gef.geometry.planar.Polygon
All Implemented Interfaces:
Serializable, Cloneable, IGeometry, IRotatable<Polygon>, IScalable<Polygon>, IShape, ITranslatable<Polygon>
public class Polygon extends Object implements IShape
Represents the geometric shape of a convex polygon. Note that while all manipulations (e.g. within shrink, expand) within this class are based on double precision, all comparisons (e.g. within contains, intersects, equals, etc.) are based on a limited precision (with an accuracy defined within PrecisionUtils) to compensate for rounding effects.
See Also:

  • Constructor Details

    • Polygon

      public Polygon(double... coordinates)
      Constructs a new Polygon from a even-numbered sequence of coordinates.
      Parameters:
      coordinates - an alternating, even-numbered sequence of x and y coordinates, representing the Points from which the Polygon is to be created
      See Also:

    • Polygon

      public Polygon(Point... points)
      Constructs a new Polygon from the given sequence of Point s. The Polygon that is created will be automatically closed, i.e. it will not only contain a segment between succeeding points of the sequence but as well back from the last to the first point.
      Parameters:
      points - a sequence of points, from which the Polygon is to be created.

  • Method Details

    • contains

      public boolean contains(double x, double y)
      Checks whether the point that is represented by its x- and y-coordinates is contained within this Polygon.
      Parameters:
      x - the x-coordinate of the point to test
      y - the y-coordinate of the point to test
      Returns:
      true if the point represented by its coordinates if contained within this Polygon, false otherwise

    • contains

      public boolean contains(IGeometry g)
      Description copied from interface: IShape
      Tests whether the given IGeometry is fully contained by this IShape.
      Specified by:
      contains in interface IShape
      Parameters:
      g - The IGeometry to test for containment
      Returns:
      true if the given IGeometry is fully contained by this IShape, false otherwise.

    • contains

      public boolean contains(Line line)
      Checks whether the given Line is fully contained within this Polygon.
      Parameters:
      line - The Line to test for containment
      Returns:
      true if the given Line is fully contained, false otherwise

    • contains

      public boolean contains(Point p)
      Description copied from interface: IGeometry
      Returns whether the given Point is contained within this IGeometry. This includes the case that the Point lies on the border of this IGeometry.
      Specified by:
      contains in interface IGeometry
      Parameters:
      p - The Point being tested for containment
      Returns:
      true if the Point is contained within this IGeometry, false otherwise.
      See Also:

    • contains

      public boolean contains(Polygon p)
      Checks whether the given Polygon is fully contained within this Polygon.
      Parameters:
      p - The Polygon to test for containment
      Returns:
      true if the given Polygon is fully contained, false otherwise.

    • contains

      public boolean contains(Polyline p)
      Tests if the given Polyline p is contained in this Polygon.
      Parameters:
      p - The Polyline to test for containment.
      Returns:
      true if it is contained, false otherwise

    • contains

      public boolean contains(Rectangle r)
      Checks whether the given Rectangle is fully contained within this Polygon.
      Parameters:
      r - the Rectangle to test for containment
      Returns:
      true if the given Rectangle is fully contained, false otherwise.

    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class Object

    • equals

      public boolean equals(Point[] points)
      Checks whether this Polygon and the one that is indirectly given via the given array of points are regarded to be equal. The Polygons will be regarded equal, if they are characterized by the same segments. As a Polygon is always regarded to be closed, the list of points may not have to correspond in each index value, they may also be shifted by a certain offset. Moreover, the vertices of two equally Polygons may be reverted in order.
      Parameters:
      points - an array of Point characterizing a Polygon to be checked for equality
      Returns:
      true if the sequence of points that characterize this Polygon and the Polygon indirectly given via the array of points are regarded to form the same segments.

    • getArea

      public double getArea()
      Computes the area of this Polygon.
      Returns:
      the area of this Polygon

    • getCopy

      public Polygon getCopy()
      Returns a copy of this Polygon, which is made up by the same points.
      Specified by:
      getCopy in interface IGeometry
      Returns:
      a new Polygon with an identical set of points.

    • getOutline

      public Polyline getOutline()
      Description copied from interface: IShape
      Returns an ICurve representing the outline of this IShape .
      Specified by:
      getOutline in interface IShape
      Returns:
      An ICurve representing this IShape's outline.

    • getOutlineSegments

      public Line[] getOutlineSegments()
      Returns a sequence of Lines, representing the segments that are obtained by linking each two successive point of this Polygon (including the last and the first one).
      Specified by:
      getOutlineSegments in interface IShape
      Returns:
      an array of Lines, representing the segments that make up this Polygon

    • getSignedArea

      public double getSignedArea()
      Computes the signed area of this Polygon. The sign of the area is negative for counter clockwise ordered vertices. It is positive for clockwise ordered vertices.
      Returns:
      the signed area of this Polygon

    • getTransformed

      public Polygon getTransformed(AffineTransform t)
      Default implementation returning a transformed Path representation of this IGeometry. Subclasses may override this method to return a more specific representation.
      Specified by:
      getTransformed in interface IGeometry
      Specified by:
      getTransformed in interface IShape
      Parameters:
      t - The AffineTransform to be applied
      Returns:
      a transformed Path representation of this IGeometry
      See Also:

    • getTriangulation

      public Polygon[] getTriangulation()
      Naive, recursive ear-clipping algorithm to triangulate this simple, planar Polygon.
      Returns:
      triangulation Polygons (triangles)

    • toPath

      public Path toPath()
      Description copied from interface: IGeometry
      Converts this IGeometry into a Path representation.
      Specified by:
      toPath in interface IGeometry
      Returns:
      A new Path representation for this IGeometry.
      See Also:

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • getBounds

      public final Rectangle getBounds()
      Description copied from interface: IGeometry
      Returns the smallest Rectangle fully enclosing this IGeometry.
      Specified by:
      getBounds in interface IGeometry
      Returns:
      A new Rectangle object that fully encloses this IGeometry

    • getCentroid

      public Point getCentroid()
      Computes the centroid of this AbstractPointListBasedGeometry. The centroid is the "center of gravity", i.e. assuming a Polygon is spanned by the Points of this AbstractPointListBasedGeometry and it is made of a material of constant density, then it is in a balanced state, if you put it on a pin that is placed exactly on its centroid.
      Returns:
      the center Point (or centroid) of this AbstractPointListBasedGeometry

    • getCoordinates

      public final double[] getCoordinates()
      Returns a double array which represents the sequence of coordinates of the Points that make up this AbstractPointListBasedGeometry.
      Returns:
      an array that alternately contains the x and y coordinates of this AbstractPointListBasedGeometry's points

    • getPoints

      public final Point[] getPoints()
      Returns a copy of the Points that make up this AbstractPointListBasedGeometry.
      Returns:
      an array of Points representing the Points that make up this AbstractPointListBasedGeometry

    • getRotatedCCW

      public Polygon getRotatedCCW(Angle alpha)
      Description copied from interface: IRotatable
      Rotates the calling object by specified Angle counter-clock-wise (CCW) around its center Point. Does not necessarily return an object of the same type.
      Specified by:
      getRotatedCCW in interface IRotatable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      alpha - rotation Angle
      Returns:
      an IGeometry representing the result of the rotation

    • getRotatedCCW

      public Polygon getRotatedCCW(Angle angle, double cx, double cy)
      Description copied from interface: IRotatable
      Rotates the calling object by the specified Angle counter-clock-wise (CCW) around the specified center Point (cx, cy). Does not necessarily return an object of the same type.
      Specified by:
      getRotatedCCW in interface IRotatable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      angle - rotation Angle
      cx - x-coordinate of the relative Point for the rotation
      cy - y-coordinate of the relative Point for the rotation
      Returns:
      an IGeometry representing the result of the rotation

    • getRotatedCCW

      public Polygon getRotatedCCW(Angle alpha, Point center)
      Description copied from interface: IRotatable
      Rotates the calling object by the specified Angle counter-clock-wise (CCW) around the specified center Point. Does not necessarily return an object of the same type.
      Specified by:
      getRotatedCCW in interface IRotatable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      alpha - rotation Angle
      center - relative Point for the rotation
      Returns:
      an IGeometry representing the result of the rotation

    • getRotatedCW

      public Polygon getRotatedCW(Angle alpha)
      Description copied from interface: IRotatable
      Rotates the calling object by specified Angle clock-wise (CW) around its center Point. Does not necessarily return an object of the same type.
      Specified by:
      getRotatedCW in interface IRotatable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      alpha - rotation Angle
      Returns:
      an IGeometry representing the result of the rotation

    • getRotatedCW

      public Polygon getRotatedCW(Angle angle, double cx, double cy)
      Description copied from interface: IRotatable
      Rotates the calling object by the specified Angle clock-wise (CW) around the specified center Point (cx, cy). Does not necessarily return an object of the same type.
      Specified by:
      getRotatedCW in interface IRotatable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      angle - rotation Angle
      cx - x-coordinate of the relative Point for the rotation
      cy - y-coordinate of the relative Point for the rotation
      Returns:
      an IGeometry representing the result of the rotation

    • getRotatedCW

      public Polygon getRotatedCW(Angle alpha, Point center)
      Description copied from interface: IRotatable
      Rotates the calling object by the specified Angle clock-wise (CW) around the specified center Point. Does not necessarily return an object of the same type.
      Specified by:
      getRotatedCW in interface IRotatable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      alpha - rotation Angle
      center - relative Point for the rotation
      Returns:
      an IGeometry representing the result of the rotation

    • getScaled

      public Polygon getScaled(double factor)
      Description copied from interface: IScalable
      Scales a copy of the calling object by the given factor relative to its center Point.
      Specified by:
      getScaled in interface IScalable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      factor - scale-factor
      Returns:
      the new, scaled object

    • getScaled

      public Polygon getScaled(double factorX, double factorY)
      Description copied from interface: IScalable
      Scales a copy of the calling object by the given factors relative to its center Point.
      Specified by:
      getScaled in interface IScalable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      factorX - x-scale-factor
      factorY - y-scale-factor
      Returns:
      the new, scaled object

    • getScaled

      public Polygon getScaled(double factor, double cx, double cy)
      Description copied from interface: IScalable
      Scales a copy of the calling object by the given factor relative to the given center Point (cx, cy).
      Specified by:
      getScaled in interface IScalable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      factor - scale-factor
      cx - x-coordinate of the relative Point for the scaling
      cy - y-coordinate of the relative Point for the scaling
      Returns:
      the new, scaled object

    • getScaled

      public Polygon getScaled(double fx, double fy, double cx, double cy)
      Description copied from interface: IScalable
      Scales a copy of the calling object by the given factors relative to the given center Point (cx, cy).
      Specified by:
      getScaled in interface IScalable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      fx - x-scale-factor
      fy - y-scale-factor
      cx - x-coordinate of the relative Point for the scaling
      cy - y-coordinate of the relative Point for the scaling
      Returns:
      the new, scaled object

    • getScaled

      public Polygon getScaled(double factorX, double factorY, Point center)
      Description copied from interface: IScalable
      Scales a copy of the calling object by the given factors relative to the given center Point.
      Specified by:
      getScaled in interface IScalable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      factorX - x-scale-factor
      factorY - y-scale-factor
      center - relative Point for the scaling
      Returns:
      the new, scaled object

    • getScaled

      public Polygon getScaled(double factor, Point center)
      Description copied from interface: IScalable
      Scales a copy of the calling object by the given factor relative to the given center Point.
      Specified by:
      getScaled in interface IScalable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      factor - scale-factor
      center - relative Point for the scaling
      Returns:
      the new, scaled object

    • getTranslated

      public Polygon getTranslated(double dx, double dy)
      Description copied from interface: ITranslatable
      Translates a copy of this object by the given values in x and y direction.
      Specified by:
      getTranslated in interface ITranslatable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      dx - x-translation
      dy - y-translation
      Returns:
      a new, translated object

    • getTranslated

      public Polygon getTranslated(Point pt)
      Description copied from interface: ITranslatable
      Translates a copy of this object by the given Point.
      Specified by:
      getTranslated in interface ITranslatable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      pt - translation Point
      Returns:
      a new, translated object

    • rotateCCW

      public Polygon rotateCCW(Angle alpha)
      Rotates this AbstractPointListBasedGeometry counter-clockwise (CCW) by the given Angle around its centroid (see getCentroid()).
      Parameters:
      alpha - the rotation Angle
      Returns:
      this for convenience
      See Also:

    • rotateCCW

      public Polygon rotateCCW(Angle alpha, double cx, double cy)
      Rotates this AbstractPointListBasedGeometry counter-clockwise (CCW) by the given Angle around the Point specified by the passed-in x and y coordinates.
      Parameters:
      alpha - the rotation Angle
      cx - the x coordinate of the Point to rotate around
      cy - the y coordinate of the Point to rotate around
      Returns:
      this for convenience
      See Also:

    • rotateCCW

      public Polygon rotateCCW(Angle alpha, Point center)
      Rotates this AbstractPointListBasedGeometry counter-clockwise (CCW) by the given Angle around the given Point. The rotation is done by
      1. translating this AbstractPointListBasedGeometry by the negated Point center
      2. rotating each Point of this AbstractPointListBasedGeometry counter-clockwise by the given Angle
      3. translating this AbstractPointListBasedGeometry back by the Point center
      Parameters:
      alpha - the rotation Angle
      center - the Point to rotate around
      Returns:
      this for convenience

    • rotateCW

      public Polygon rotateCW(Angle alpha)
      Rotates this AbstractPointListBasedGeometry clockwise (CW) by the given Angle around its centroid (see getCentroid()).
      Parameters:
      alpha - the rotation Angle
      Returns:
      this for convenience
      See Also:

    • rotateCW

      public Polygon rotateCW(Angle alpha, double cx, double cy)
      Rotates this AbstractPointListBasedGeometry clockwise (CW) by the given Angle around the Point specified by the passed-in x and y coordinates.
      Parameters:
      alpha - the rotation Angle
      cx - the x coordinate of the Point to rotate around
      cy - the y coordinate of the Point to rotate around
      Returns:
      this for convenience
      See Also:

    • rotateCW

      public Polygon rotateCW(Angle alpha, Point center)
      Rotates this AbstractPointListBasedGeometry clockwise (CW) by the given Angle around the given Point. The rotation is done by
      1. translating this AbstractPointListBasedGeometry by the negated Point center
      2. rotating each Point of this AbstractPointListBasedGeometry clockwise by the given Angle
      3. translating this AbstractPointListBasedGeometry back by the Point center
      Parameters:
      alpha - the rotation Angle
      center - the Point to rotate around
      Returns:
      this for convenience

    • scale

      public Polygon scale(double factor)
      Description copied from interface: IScalable
      Scales the calling object by the given factor relative to its center Point.
      Specified by:
      scale in interface IScalable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      factor - scale-factor
      Returns:
      this for convenience

    • scale

      public Polygon scale(double fx, double fy)
      Description copied from interface: IScalable
      Scales the calling object by the given factors relative to the given center Point.
      Specified by:
      scale in interface IScalable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      fx - x-scale-factor
      fy - y-scale-factor
      Returns:
      this for convenience

    • scale

      public Polygon scale(double factor, double cx, double cy)
      Description copied from interface: IScalable
      Scales the calling object by the given factor relative to the given center Point (cx, cy).
      Specified by:
      scale in interface IScalable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      factor - scale-factor
      cx - x-coordinate of the relative Point for the scaling
      cy - y-coordinate of the relative Point for the scaling
      Returns:
      this for convenience

    • scale

      public Polygon scale(double fx, double fy, double cx, double cy)
      Description copied from interface: IScalable
      Scales the calling object by the given factors relative to the given center Point (cx, cy).
      Specified by:
      scale in interface IScalable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      fx - x-scale-factor
      fy - y-scale-factor
      cx - x-coordinate of the relative Point for the scaling
      cy - y-coordinate of the relative Point for the scaling
      Returns:
      this for convenience

    • scale

      public Polygon scale(double fx, double fy, Point center)
      Description copied from interface: IScalable
      Scales the calling object by the given factors relative to the given center Point.
      Specified by:
      scale in interface IScalable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      fx - x-scale-factor
      fy - y-scale-factor
      center - relative Point for the scaling
      Returns:
      this for convenience

    • scale

      public Polygon scale(double factor, Point center)
      Description copied from interface: IScalable
      Scales the calling object by the given factor relative to the given center Point.
      Specified by:
      scale in interface IScalable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      factor - scale-factor
      center - relative Point for the scaling
      Returns:
      this for convenience

    • translate

      public Polygon translate(double dx, double dy)
      Description copied from interface: ITranslatable
      Translates the object by the given values in x and y direction.
      Specified by:
      translate in interface ITranslatable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      dx - x-translation
      dy - y-translation
      Returns:
      this for convenience

    • translate

      public Polygon translate(Point p)
      Description copied from interface: ITranslatable
      Translates the object by the given Point.
      Specified by:
      translate in interface ITranslatable<T extends org.eclipse.gef.geometry.planar.AbstractPointListBasedGeometry<?>>
      Parameters:
      p - translation Point
      Returns:
      this for convenience

    • clone

      public Object clone()
      Overridden with public visibility as recommended within Cloneable .
      Overrides:
      clone in class Object

    • hashCode

      public final int hashCode()
      Overrides:
      hashCode in class Object
      See Also:

    • touches

      public boolean touches(IGeometry g)
      Description copied from interface: IGeometry
      Returns true if the input IGeometry touches this IGeometry, i.e. there is at least one common point.
      Specified by:
      touches in interface IGeometry
      Parameters:
      g - The IGeometry for the intersection test
      Returns:
      true if the input IGeometry and this IGeometry have at least one common point.