Class Envelope

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Comparable

    public class Envelope
    extends java.lang.Object
    implements java.lang.Comparable, java.io.Serializable
    Defines a rectangular region of the 2D coordinate plane. It is often used to represent the bounding box of a Geometry, e.g. the minimum and maximum x and y values of the Coordinates.

    Envelopes support infinite or half-infinite regions, by using the values of Double.POSITIVE_INFINITY and Double.NEGATIVE_INFINITY. Envelope objects may have a null value.

    When Envelope objects are created or initialized, the supplies extent values are automatically sorted into the correct order.

    Version:
    1.7
    See Also:
    Serialized Form
    • Constructor Summary

      Constructors 
      Constructor Description
      Envelope()
      Creates a null Envelope.
      Envelope​(double x1, double x2, double y1, double y2)
      Creates an Envelope for a region defined by maximum and minimum values.
      Envelope​(Coordinate p)
      Creates an Envelope for a region defined by a single Coordinate.
      Envelope​(Coordinate p1, Coordinate p2)
      Creates an Envelope for a region defined by two Coordinates.
      Envelope​(Envelope env)
      Create an Envelope from an existing Envelope.
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      Coordinate centre()
      Computes the coordinate of the centre of this envelope (as long as it is non-null
      int compareTo​(java.lang.Object o)
      Compares two envelopes using lexicographic ordering.
      boolean contains​(double x, double y)
      Tests if the given point lies in or on the envelope.
      boolean contains​(Coordinate p)
      Tests if the given point lies in or on the envelope.
      boolean contains​(Envelope other)
      Tests if the Envelope other lies wholely inside this Envelope (inclusive of the boundary).
      Envelope copy()
      Creates a copy of this envelope object.
      boolean covers​(double x, double y)
      Tests if the given point lies in or on the envelope.
      boolean covers​(Coordinate p)
      Tests if the given point lies in or on the envelope.
      boolean covers​(Envelope other)
      Tests if the Envelope other lies wholely inside this Envelope (inclusive of the boundary).
      boolean disjoint​(Envelope other)
      Tests if the region defined by other is disjoint from the region of this Envelope.
      double distance​(Envelope env)
      Computes the distance between this and another Envelope.
      boolean equals​(java.lang.Object other)  
      void expandBy​(double distance)
      Expands this envelope by a given distance in all directions.
      void expandBy​(double deltaX, double deltaY)
      Expands this envelope by a given distance in all directions.
      void expandToInclude​(double x, double y)
      Enlarges this Envelope so that it contains the given point.
      void expandToInclude​(Coordinate p)
      Enlarges this Envelope so that it contains the given Coordinate.
      void expandToInclude​(Envelope other)
      Enlarges this Envelope so that it contains the other Envelope.
      double getArea()
      Gets the area of this envelope.
      double getDiameter()
      Gets the length of the diameter (diagonal) of the envelope.
      double getHeight()
      Returns the difference between the maximum and minimum y values.
      double getMaxX()
      Returns the Envelopes maximum x-value.
      double getMaxY()
      Returns the Envelopes maximum y-value.
      double getMinX()
      Returns the Envelopes minimum x-value.
      double getMinY()
      Returns the Envelopes minimum y-value.
      double getWidth()
      Returns the difference between the maximum and minimum x values.
      int hashCode()  
      void init()
      Initialize to a null Envelope.
      void init​(double x1, double x2, double y1, double y2)
      Initialize an Envelope for a region defined by maximum and minimum values.
      void init​(Coordinate p)
      Initialize an Envelope to a region defined by a single Coordinate.
      void init​(Coordinate p1, Coordinate p2)
      Initialize an Envelope to a region defined by two Coordinates.
      void init​(Envelope env)
      Initialize an Envelope from an existing Envelope.
      Envelope intersection​(Envelope env)
      Computes the intersection of two Envelopes.
      boolean intersects​(double x, double y)
      Check if the point (x, y) intersects (lies inside) the region of this Envelope.
      boolean intersects​(Coordinate p)
      Tests if the point p intersects (lies inside) the region of this Envelope.
      boolean intersects​(Coordinate a, Coordinate b)
      Tests if the extent defined by two extremal points intersects the extent of this Envelope.
      static boolean intersects​(Coordinate p1, Coordinate p2, Coordinate q)
      Test the point q to see whether it intersects the Envelope defined by p1-p2
      static boolean intersects​(Coordinate p1, Coordinate p2, Coordinate q1, Coordinate q2)
      Tests whether the envelope defined by p1-p2 and the envelope defined by q1-q2 intersect.
      boolean intersects​(Envelope other)
      Tests if the region defined by other intersects the region of this Envelope.
      boolean isNull()
      Returns true if this Envelope is a "null" envelope.
      double maxExtent()
      Gets the maximum extent of this envelope across both dimensions.
      double minExtent()
      Gets the minimum extent of this envelope across both dimensions.
      boolean overlaps​(double x, double y)
      Deprecated.
      Use #intersects instead.
      boolean overlaps​(Coordinate p)
      Deprecated.
      Use #intersects instead.
      boolean overlaps​(Envelope other)
      Deprecated.
      Use #intersects instead.
      void setToNull()
      Makes this Envelope a "null" envelope, that is, the envelope of the empty geometry.
      java.lang.String toString()  
      void translate​(double transX, double transY)
      Translates this envelope by given amounts in the X and Y direction.
      • Methods inherited from class java.lang.Object

        getClass, notify, notifyAll, wait, wait, wait
    • Constructor Detail

      • Envelope

        public Envelope()
        Creates a null Envelope.
      • Envelope

        public Envelope​(double x1,
                        double x2,
                        double y1,
                        double y2)
        Creates an Envelope for a region defined by maximum and minimum values.
        Parameters:
        x1 - the first x-value
        x2 - the second x-value
        y1 - the first y-value
        y2 - the second y-value
      • Envelope

        public Envelope​(Coordinate p1,
                        Coordinate p2)
        Creates an Envelope for a region defined by two Coordinates.
        Parameters:
        p1 - the first Coordinate
        p2 - the second Coordinate
      • Envelope

        public Envelope​(Coordinate p)
        Creates an Envelope for a region defined by a single Coordinate.
        Parameters:
        p - the Coordinate
      • Envelope

        public Envelope​(Envelope env)
        Create an Envelope from an existing Envelope.
        Parameters:
        env - the Envelope to initialize from
    • Method Detail

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.Object
      • intersects

        public static boolean intersects​(Coordinate p1,
                                         Coordinate p2,
                                         Coordinate q)
        Test the point q to see whether it intersects the Envelope defined by p1-p2
        Parameters:
        p1 - one extremal point of the envelope
        p2 - another extremal point of the envelope
        q - the point to test for intersection
        Returns:
        true if q intersects the envelope p1-p2
      • intersects

        public static boolean intersects​(Coordinate p1,
                                         Coordinate p2,
                                         Coordinate q1,
                                         Coordinate q2)
        Tests whether the envelope defined by p1-p2 and the envelope defined by q1-q2 intersect.
        Parameters:
        p1 - one extremal point of the envelope P
        p2 - another extremal point of the envelope P
        q1 - one extremal point of the envelope Q
        q2 - another extremal point of the envelope Q
        Returns:
        true if Q intersects P
      • init

        public void init()
        Initialize to a null Envelope.
      • init

        public void init​(double x1,
                         double x2,
                         double y1,
                         double y2)
        Initialize an Envelope for a region defined by maximum and minimum values.
        Parameters:
        x1 - the first x-value
        x2 - the second x-value
        y1 - the first y-value
        y2 - the second y-value
      • copy

        public Envelope copy()
        Creates a copy of this envelope object.
        Returns:
        a copy of this envelope
      • init

        public void init​(Coordinate p1,
                         Coordinate p2)
        Initialize an Envelope to a region defined by two Coordinates.
        Parameters:
        p1 - the first Coordinate
        p2 - the second Coordinate
      • init

        public void init​(Coordinate p)
        Initialize an Envelope to a region defined by a single Coordinate.
        Parameters:
        p - the coordinate
      • init

        public void init​(Envelope env)
        Initialize an Envelope from an existing Envelope.
        Parameters:
        env - the Envelope to initialize from
      • setToNull

        public void setToNull()
        Makes this Envelope a "null" envelope, that is, the envelope of the empty geometry.
      • isNull

        public boolean isNull()
        Returns true if this Envelope is a "null" envelope.
        Returns:
        true if this Envelope is uninitialized or is the envelope of the empty geometry.
      • getWidth

        public double getWidth()
        Returns the difference between the maximum and minimum x values.
        Returns:
        max x - min x, or 0 if this is a null Envelope
      • getHeight

        public double getHeight()
        Returns the difference between the maximum and minimum y values.
        Returns:
        max y - min y, or 0 if this is a null Envelope
      • getDiameter

        public double getDiameter()
        Gets the length of the diameter (diagonal) of the envelope.
        Returns:
        the diameter length
      • getMinX

        public double getMinX()
        Returns the Envelopes minimum x-value. min x > max x indicates that this is a null Envelope.
        Returns:
        the minimum x-coordinate
      • getMaxX

        public double getMaxX()
        Returns the Envelopes maximum x-value. min x > max x indicates that this is a null Envelope.
        Returns:
        the maximum x-coordinate
      • getMinY

        public double getMinY()
        Returns the Envelopes minimum y-value. min y > max y indicates that this is a null Envelope.
        Returns:
        the minimum y-coordinate
      • getMaxY

        public double getMaxY()
        Returns the Envelopes maximum y-value. min y > max y indicates that this is a null Envelope.
        Returns:
        the maximum y-coordinate
      • getArea

        public double getArea()
        Gets the area of this envelope.
        Returns:
        the area of the envelope
      • minExtent

        public double minExtent()
        Gets the minimum extent of this envelope across both dimensions.
        Returns:
        the minimum extent of this envelope
      • maxExtent

        public double maxExtent()
        Gets the maximum extent of this envelope across both dimensions.
        Returns:
        the maximum extent of this envelope
      • expandToInclude

        public void expandToInclude​(Coordinate p)
        Enlarges this Envelope so that it contains the given Coordinate. Has no effect if the point is already on or within the envelope.
        Parameters:
        p - the Coordinate to expand to include
      • expandBy

        public void expandBy​(double distance)
        Expands this envelope by a given distance in all directions. Both positive and negative distances are supported.
        Parameters:
        distance - the distance to expand the envelope
      • expandBy

        public void expandBy​(double deltaX,
                             double deltaY)
        Expands this envelope by a given distance in all directions. Both positive and negative distances are supported.
        Parameters:
        deltaX - the distance to expand the envelope along the the X axis
        deltaY - the distance to expand the envelope along the the Y axis
      • expandToInclude

        public void expandToInclude​(double x,
                                    double y)
        Enlarges this Envelope so that it contains the given point. Has no effect if the point is already on or within the envelope.
        Parameters:
        x - the value to lower the minimum x to or to raise the maximum x to
        y - the value to lower the minimum y to or to raise the maximum y to
      • expandToInclude

        public void expandToInclude​(Envelope other)
        Enlarges this Envelope so that it contains the other Envelope. Has no effect if other is wholly on or within the envelope.
        Parameters:
        other - the Envelope to expand to include
      • translate

        public void translate​(double transX,
                              double transY)
        Translates this envelope by given amounts in the X and Y direction.
        Parameters:
        transX - the amount to translate along the X axis
        transY - the amount to translate along the Y axis
      • centre

        public Coordinate centre()
        Computes the coordinate of the centre of this envelope (as long as it is non-null
        Returns:
        the centre coordinate of this envelope null if the envelope is null
      • intersection

        public Envelope intersection​(Envelope env)
        Computes the intersection of two Envelopes.
        Parameters:
        env - the envelope to intersect with
        Returns:
        a new Envelope representing the intersection of the envelopes (this will be the null envelope if either argument is null, or they do not intersect
      • intersects

        public boolean intersects​(Envelope other)
        Tests if the region defined by other intersects the region of this Envelope.
        Parameters:
        other - the Envelope which this Envelope is being checked for intersecting
        Returns:
        true if the Envelopes intersect
      • intersects

        public boolean intersects​(Coordinate a,
                                  Coordinate b)
        Tests if the extent defined by two extremal points intersects the extent of this Envelope.
        Parameters:
        a - a point
        b - another point
        Returns:
        true if the extents intersect
      • disjoint

        public boolean disjoint​(Envelope other)
        Tests if the region defined by other is disjoint from the region of this Envelope.
        Parameters:
        other - the Envelope being checked for disjointness
        Returns:
        true if the Envelopes are disjoint
        See Also:
        intersects(Envelope)
      • overlaps

        public boolean overlaps​(Envelope other)
        Deprecated.
        Use #intersects instead. In the future, #overlaps may be changed to be a true overlap check; that is, whether the intersection is two-dimensional.
      • intersects

        public boolean intersects​(Coordinate p)
        Tests if the point p intersects (lies inside) the region of this Envelope.
        Parameters:
        p - the Coordinate to be tested
        Returns:
        true if the point intersects this Envelope
      • overlaps

        public boolean overlaps​(Coordinate p)
        Deprecated.
        Use #intersects instead.
      • intersects

        public boolean intersects​(double x,
                                  double y)
        Check if the point (x, y) intersects (lies inside) the region of this Envelope.
        Parameters:
        x - the x-ordinate of the point
        y - the y-ordinate of the point
        Returns:
        true if the point overlaps this Envelope
      • overlaps

        public boolean overlaps​(double x,
                                double y)
        Deprecated.
        Use #intersects instead.
      • contains

        public boolean contains​(Envelope other)
        Tests if the Envelope other lies wholely inside this Envelope (inclusive of the boundary).

        Note that this is not the same definition as the SFS contains, which would exclude the envelope boundary.

        Parameters:
        other - the Envelope to check
        Returns:
        true if other is contained in this Envelope
        See Also:
        covers(Envelope)
      • contains

        public boolean contains​(Coordinate p)
        Tests if the given point lies in or on the envelope.

        Note that this is not the same definition as the SFS contains, which would exclude the envelope boundary.

        Parameters:
        p - the point which this Envelope is being checked for containing
        Returns:
        true if the point lies in the interior or on the boundary of this Envelope.
        See Also:
        covers(Coordinate)
      • contains

        public boolean contains​(double x,
                                double y)
        Tests if the given point lies in or on the envelope.

        Note that this is not the same definition as the SFS contains, which would exclude the envelope boundary.

        Parameters:
        x - the x-coordinate of the point which this Envelope is being checked for containing
        y - the y-coordinate of the point which this Envelope is being checked for containing
        Returns:
        true if (x, y) lies in the interior or on the boundary of this Envelope.
        See Also:
        covers(double, double)
      • covers

        public boolean covers​(double x,
                              double y)
        Tests if the given point lies in or on the envelope.
        Parameters:
        x - the x-coordinate of the point which this Envelope is being checked for containing
        y - the y-coordinate of the point which this Envelope is being checked for containing
        Returns:
        true if (x, y) lies in the interior or on the boundary of this Envelope.
      • covers

        public boolean covers​(Coordinate p)
        Tests if the given point lies in or on the envelope.
        Parameters:
        p - the point which this Envelope is being checked for containing
        Returns:
        true if the point lies in the interior or on the boundary of this Envelope.
      • covers

        public boolean covers​(Envelope other)
        Tests if the Envelope other lies wholely inside this Envelope (inclusive of the boundary).
        Parameters:
        other - the Envelope to check
        Returns:
        true if this Envelope covers the other
      • distance

        public double distance​(Envelope env)
        Computes the distance between this and another Envelope. The distance between overlapping Envelopes is 0. Otherwise, the distance is the Euclidean distance between the closest points.
      • equals

        public boolean equals​(java.lang.Object other)
        Overrides:
        equals in class java.lang.Object
      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object
      • compareTo

        public int compareTo​(java.lang.Object o)
        Compares two envelopes using lexicographic ordering. The ordering comparison is based on the usual numerical comparison between the sequence of ordinates. Null envelopes are less than all non-null envelopes.
        Specified by:
        compareTo in interface java.lang.Comparable
        Parameters:
        o - an Envelope object