Module java.desktop
Package java.awt.geom

Class QuadCurve2D

java.lang.Object
java.awt.geom.QuadCurve2D
All Implemented Interfaces:
Shape, Cloneable
Direct Known Subclasses:
QuadCurve2D.Double, QuadCurve2D.Float
public abstract class QuadCurve2D extends Object implements Shape, Cloneable
The QuadCurve2D class defines a quadratic parametric curve segment in (x,y) coordinate space.

This class is only the abstract superclass for all objects that store a 2D quadratic curve segment. The actual storage representation of the coordinates is left to the subclass.

Since:
1.2

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static class 
    QuadCurve2D.Double
    A quadratic parametric curve segment specified with double coordinates.
    static class 
    QuadCurve2D.Float
    A quadratic parametric curve segment specified with float coordinates.

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
    QuadCurve2D()
    This is an abstract class that cannot be instantiated directly.

  • Method Summary

    Modifier and Type
    Method
    Description
    Object
    clone()
    Creates a new object of the same class and with the same contents as this object.
    boolean
    contains(double x, double y)
    Tests if the specified coordinates are inside the boundary of the Shape, as described by the definition of insideness.
    boolean
    contains(double x, double y, double w, double h)
    Tests if the interior of the Shape entirely contains the specified rectangular area.
    boolean
    contains(Point2D p)
    Tests if a specified Point2D is inside the boundary of the Shape, as described by the definition of insideness.
    boolean
    contains(Rectangle2D r)
    Tests if the interior of the Shape entirely contains the specified Rectangle2D.
    Rectangle
    getBounds()
    Returns an integer Rectangle that completely encloses the Shape.
    Rectangle2D
    getBounds2D()
    Returns a high precision and more accurate bounding box of the Shape than the getBounds method.
    abstract Point2D
    getCtrlPt()
    Returns the control point.
    abstract double
    getCtrlX()
    Returns the X coordinate of the control point in double precision.
    abstract double
    getCtrlY()
    Returns the Y coordinate of the control point in double precision.
    double
    getFlatness()
    Returns the flatness, or maximum distance of a control point from the line connecting the end points, of this QuadCurve2D.
    static double
    getFlatness(double[] coords, int offset)
    Returns the flatness, or maximum distance of a control point from the line connecting the end points, of the quadratic curve specified by the control points stored in the indicated array at the indicated index.
    static double
    getFlatness(double x1, double y1, double ctrlx, double ctrly, double x2, double y2)
    Returns the flatness, or maximum distance of a control point from the line connecting the end points, of the quadratic curve specified by the indicated control points.
    double
    getFlatnessSq()
    Returns the square of the flatness, or maximum distance of a control point from the line connecting the end points, of this QuadCurve2D.
    static double
    getFlatnessSq(double[] coords, int offset)
    Returns the square of the flatness, or maximum distance of a control point from the line connecting the end points, of the quadratic curve specified by the control points stored in the indicated array at the indicated index.
    static double
    getFlatnessSq(double x1, double y1, double ctrlx, double ctrly, double x2, double y2)
    Returns the square of the flatness, or maximum distance of a control point from the line connecting the end points, of the quadratic curve specified by the indicated control points.
    abstract Point2D
    getP1()
    Returns the start point.
    abstract Point2D
    getP2()
    Returns the end point.
    PathIterator
    getPathIterator(AffineTransform at)
    Returns an iteration object that defines the boundary of the shape of this QuadCurve2D.
    PathIterator
    getPathIterator(AffineTransform at, double flatness)
    Returns an iteration object that defines the boundary of the flattened shape of this QuadCurve2D.
    abstract double
    getX1()
    Returns the X coordinate of the start point in double in precision.
    abstract double
    getX2()
    Returns the X coordinate of the end point in double precision.
    abstract double
    getY1()
    Returns the Y coordinate of the start point in double precision.
    abstract double
    getY2()
    Returns the Y coordinate of the end point in double precision.
    boolean
    intersects(double x, double y, double w, double h)
    Tests if the interior of the Shape intersects the interior of a specified rectangular area.
    boolean
    intersects(Rectangle2D r)
    Tests if the interior of the Shape intersects the interior of a specified Rectangle2D.
    void
    setCurve(double[] coords, int offset)
    Sets the location of the end points and control points of this QuadCurve2D to the double coordinates at the specified offset in the specified array.
    abstract void
    setCurve(double x1, double y1, double ctrlx, double ctrly, double x2, double y2)
    Sets the location of the end points and control point of this curve to the specified double coordinates.
    void
    setCurve(Point2D[] pts, int offset)
    Sets the location of the end points and control points of this QuadCurve2D to the coordinates of the Point2D objects at the specified offset in the specified array.
    void
    setCurve(Point2D p1, Point2D cp, Point2D p2)
    Sets the location of the end points and control point of this QuadCurve2D to the specified Point2D coordinates.
    void
    setCurve(QuadCurve2D c)
    Sets the location of the end points and control point of this QuadCurve2D to the same as those in the specified QuadCurve2D.
    static int
    solveQuadratic(double[] eqn)
    Solves the quadratic whose coefficients are in the eqn array and places the non-complex roots back into the same array, returning the number of roots.
    static int
    solveQuadratic(double[] eqn, double[] res)
    Solves the quadratic whose coefficients are in the eqn array and places the non-complex roots into the res array, returning the number of roots.
    static void
    subdivide(double[] src, int srcoff, double[] left, int leftoff, double[] right, int rightoff)
    Subdivides the quadratic curve specified by the coordinates stored in the src array at indices srcoff through srcoff + 5 and stores the resulting two subdivided curves into the two result arrays at the corresponding indices.
    void
    subdivide(QuadCurve2D left, QuadCurve2D right)
    Subdivides this QuadCurve2D and stores the resulting two subdivided curves into the left and right curve parameters.
    static void
    subdivide(QuadCurve2D src, QuadCurve2D left, QuadCurve2D right)
    Subdivides the quadratic curve specified by the src parameter and stores the resulting two subdivided curves into the left and right curve parameters.

    Methods declared in class java.lang.Object

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

  • Constructor Details

    • QuadCurve2D

      protected QuadCurve2D()
      This is an abstract class that cannot be instantiated directly. Type-specific implementation subclasses are available for instantiation and provide a number of formats for storing the information necessary to satisfy the various accessor methods below.
      Since:
      1.2
      See Also:

  • Method Details

    • getX1

      public abstract double getX1()
      Returns the X coordinate of the start point in double in precision.
      Returns:
      the X coordinate of the start point.
      Since:
      1.2

    • getY1

      public abstract double getY1()
      Returns the Y coordinate of the start point in double precision.
      Returns:
      the Y coordinate of the start point.
      Since:
      1.2

    • getP1

      public abstract Point2D getP1()
      Returns the start point.
      Returns:
      a Point2D that is the start point of this QuadCurve2D.
      Since:
      1.2

    • getCtrlX

      public abstract double getCtrlX()
      Returns the X coordinate of the control point in double precision.
      Returns:
      X coordinate the control point
      Since:
      1.2

    • getCtrlY

      public abstract double getCtrlY()
      Returns the Y coordinate of the control point in double precision.
      Returns:
      the Y coordinate of the control point.
      Since:
      1.2

    • getCtrlPt

      public abstract Point2D getCtrlPt()
      Returns the control point.
      Returns:
      a Point2D that is the control point of this Point2D.
      Since:
      1.2

    • getX2

      public abstract double getX2()
      Returns the X coordinate of the end point in double precision.
      Returns:
      the x coordinate of the end point.
      Since:
      1.2

    • getY2

      public abstract double getY2()
      Returns the Y coordinate of the end point in double precision.
      Returns:
      the Y coordinate of the end point.
      Since:
      1.2

    • getP2

      public abstract Point2D getP2()
      Returns the end point.
      Returns:
      a Point object that is the end point of this Point2D.
      Since:
      1.2

    • setCurve

      public abstract void setCurve(double x1, double y1, double ctrlx, double ctrly, double x2, double y2)
      Sets the location of the end points and control point of this curve to the specified double coordinates.
      Parameters:
      x1 - the X coordinate of the start point
      y1 - the Y coordinate of the start point
      ctrlx - the X coordinate of the control point
      ctrly - the Y coordinate of the control point
      x2 - the X coordinate of the end point
      y2 - the Y coordinate of the end point
      Since:
      1.2

    • setCurve

      public void setCurve(double[] coords, int offset)
      Sets the location of the end points and control points of this QuadCurve2D to the double coordinates at the specified offset in the specified array.
      Parameters:
      coords - the array containing coordinate values
      offset - the index into the array from which to start getting the coordinate values and assigning them to this QuadCurve2D
      Since:
      1.2

    • setCurve

      public void setCurve(Point2D p1, Point2D cp, Point2D p2)
      Sets the location of the end points and control point of this QuadCurve2D to the specified Point2D coordinates.
      Parameters:
      p1 - the start point
      cp - the control point
      p2 - the end point
      Since:
      1.2

    • setCurve

      public void setCurve(Point2D[] pts, int offset)
      Sets the location of the end points and control points of this QuadCurve2D to the coordinates of the Point2D objects at the specified offset in the specified array.
      Parameters:
      pts - an array containing Point2D that define coordinate values
      offset - the index into pts from which to start getting the coordinate values and assigning them to this QuadCurve2D
      Since:
      1.2

    • setCurve

      public void setCurve(QuadCurve2D c)
      Sets the location of the end points and control point of this QuadCurve2D to the same as those in the specified QuadCurve2D.
      Parameters:
      c - the specified QuadCurve2D
      Since:
      1.2

    • getFlatnessSq

      public static double getFlatnessSq(double x1, double y1, double ctrlx, double ctrly, double x2, double y2)
      Returns the square of the flatness, or maximum distance of a control point from the line connecting the end points, of the quadratic curve specified by the indicated control points.
      Parameters:
      x1 - the X coordinate of the start point
      y1 - the Y coordinate of the start point
      ctrlx - the X coordinate of the control point
      ctrly - the Y coordinate of the control point
      x2 - the X coordinate of the end point
      y2 - the Y coordinate of the end point
      Returns:
      the square of the flatness of the quadratic curve defined by the specified coordinates.
      Since:
      1.2

    • getFlatness

      public static double getFlatness(double x1, double y1, double ctrlx, double ctrly, double x2, double y2)
      Returns the flatness, or maximum distance of a control point from the line connecting the end points, of the quadratic curve specified by the indicated control points.
      Parameters:
      x1 - the X coordinate of the start point
      y1 - the Y coordinate of the start point
      ctrlx - the X coordinate of the control point
      ctrly - the Y coordinate of the control point
      x2 - the X coordinate of the end point
      y2 - the Y coordinate of the end point
      Returns:
      the flatness of the quadratic curve defined by the specified coordinates.
      Since:
      1.2

    • getFlatnessSq

      public static double getFlatnessSq(double[] coords, int offset)
      Returns the square of the flatness, or maximum distance of a control point from the line connecting the end points, of the quadratic curve specified by the control points stored in the indicated array at the indicated index.
      Parameters:
      coords - an array containing coordinate values
      offset - the index into coords from which to to start getting the values from the array
      Returns:
      the flatness of the quadratic curve that is defined by the values in the specified array at the specified index.
      Since:
      1.2

    • getFlatness

      public static double getFlatness(double[] coords, int offset)
      Returns the flatness, or maximum distance of a control point from the line connecting the end points, of the quadratic curve specified by the control points stored in the indicated array at the indicated index.
      Parameters:
      coords - an array containing coordinate values
      offset - the index into coords from which to start getting the coordinate values
      Returns:
      the flatness of a quadratic curve defined by the specified array at the specified offset.
      Since:
      1.2

    • getFlatnessSq

      public double getFlatnessSq()
      Returns the square of the flatness, or maximum distance of a control point from the line connecting the end points, of this QuadCurve2D.
      Returns:
      the square of the flatness of this QuadCurve2D.
      Since:
      1.2

    • getFlatness

      public double getFlatness()
      Returns the flatness, or maximum distance of a control point from the line connecting the end points, of this QuadCurve2D.
      Returns:
      the flatness of this QuadCurve2D.
      Since:
      1.2

    • subdivide

      public void subdivide(QuadCurve2D left, QuadCurve2D right)
      Subdivides this QuadCurve2D and stores the resulting two subdivided curves into the left and right curve parameters. Either or both of the left and right objects can be the same as this QuadCurve2D or null.
      Parameters:
      left - the QuadCurve2D object for storing the left or first half of the subdivided curve
      right - the QuadCurve2D object for storing the right or second half of the subdivided curve
      Since:
      1.2

    • subdivide

      public static void subdivide(QuadCurve2D src, QuadCurve2D left, QuadCurve2D right)
      Subdivides the quadratic curve specified by the src parameter and stores the resulting two subdivided curves into the left and right curve parameters. Either or both of the left and right objects can be the same as the src object or null.
      Parameters:
      src - the quadratic curve to be subdivided
      left - the QuadCurve2D object for storing the left or first half of the subdivided curve
      right - the QuadCurve2D object for storing the right or second half of the subdivided curve
      Since:
      1.2

    • subdivide

      public static void subdivide(double[] src, int srcoff, double[] left, int leftoff, double[] right, int rightoff)
      Subdivides the quadratic curve specified by the coordinates stored in the src array at indices srcoff through srcoff + 5 and stores the resulting two subdivided curves into the two result arrays at the corresponding indices. Either or both of the left and right arrays can be null or a reference to the same array and offset as the src array. Note that the last point in the first subdivided curve is the same as the first point in the second subdivided curve. Thus, it is possible to pass the same array for left and right and to use offsets such that rightoff equals leftoff + 4 in order to avoid allocating extra storage for this common point.
      Parameters:
      src - the array holding the coordinates for the source curve
      srcoff - the offset into the array of the beginning of the the 6 source coordinates
      left - the array for storing the coordinates for the first half of the subdivided curve
      leftoff - the offset into the array of the beginning of the the 6 left coordinates
      right - the array for storing the coordinates for the second half of the subdivided curve
      rightoff - the offset into the array of the beginning of the the 6 right coordinates
      Since:
      1.2

    • solveQuadratic

      public static int solveQuadratic(double[] eqn)
      Solves the quadratic whose coefficients are in the eqn array and places the non-complex roots back into the same array, returning the number of roots. The quadratic solved is represented by the equation: 
           eqn = {C, B, A};
     ax^2 + bx + c = 0
      A return value of -1 is used to distinguish a constant equation, which might be always 0 or never 0, from an equation that has no zeroes.
      Parameters:
      eqn - the array that contains the quadratic coefficients
      Returns:
      the number of roots, or -1 if the equation is a constant
      Since:
      1.2

    • solveQuadratic

      public static int solveQuadratic(double[] eqn, double[] res)
      Solves the quadratic whose coefficients are in the eqn array and places the non-complex roots into the res array, returning the number of roots. The quadratic solved is represented by the equation: 
           eqn = {C, B, A};
     ax^2 + bx + c = 0
      A return value of -1 is used to distinguish a constant equation, which might be always 0 or never 0, from an equation that has no zeroes.
      Parameters:
      eqn - the specified array of coefficients to use to solve the quadratic equation
      res - the array that contains the non-complex roots resulting from the solution of the quadratic equation
      Returns:
      the number of roots, or -1 if the equation is a constant.
      Since:
      1.3

    • contains

      public boolean contains(double x, double y)
      Tests if the specified coordinates are inside the boundary of the Shape, as described by the definition of insideness.
      Specified by:
      contains in interface Shape
      Parameters:
      x - the specified X coordinate to be tested
      y - the specified Y coordinate to be tested
      Returns:
      true if the specified coordinates are inside the Shape boundary; false otherwise.
      Since:
      1.2

    • contains

      public boolean contains(Point2D p)
      Tests if a specified Point2D is inside the boundary of the Shape, as described by the definition of insideness.
      Specified by:
      contains in interface Shape
      Parameters:
      p - the specified Point2D to be tested
      Returns:
      true if the specified Point2D is inside the boundary of the Shape; false otherwise.
      Since:
      1.2

    • intersects

      public boolean intersects(double x, double y, double w, double h)
      Tests if the interior of the Shape intersects the interior of a specified rectangular area. The rectangular area is considered to intersect the Shape if any point is contained in both the interior of the Shape and the specified rectangular area.

      The Shape.intersects() method allows a Shape implementation to conservatively return true when:

      • there is a high probability that the rectangular area and the Shape intersect, but
      • the calculations to accurately determine this intersection are prohibitively expensive.
      This means that for some Shapes this method might return true even though the rectangular area does not intersect the Shape. The Area class performs more accurate computations of geometric intersection than most Shape objects and therefore can be used if a more precise answer is required.
      Specified by:
      intersects in interface Shape
      Parameters:
      x - the X coordinate of the upper-left corner of the specified rectangular area
      y - the Y coordinate of the upper-left corner of the specified rectangular area
      w - the width of the specified rectangular area
      h - the height of the specified rectangular area
      Returns:
      true if the interior of the Shape and the interior of the rectangular area intersect, or are both highly likely to intersect and intersection calculations would be too expensive to perform; false otherwise.
      Since:
      1.2
      See Also:

    • intersects

      public boolean intersects(Rectangle2D r)
      Tests if the interior of the Shape intersects the interior of a specified Rectangle2D. The Shape.intersects() method allows a Shape implementation to conservatively return true when:
      • there is a high probability that the Rectangle2D and the Shape intersect, but
      • the calculations to accurately determine this intersection are prohibitively expensive.
      This means that for some Shapes this method might return true even though the Rectangle2D does not intersect the Shape. The Area class performs more accurate computations of geometric intersection than most Shape objects and therefore can be used if a more precise answer is required.
      Specified by:
      intersects in interface Shape
      Parameters:
      r - the specified Rectangle2D
      Returns:
      true if the interior of the Shape and the interior of the specified Rectangle2D intersect, or are both highly likely to intersect and intersection calculations would be too expensive to perform; false otherwise.
      Since:
      1.2
      See Also:

    • contains

      public boolean contains(double x, double y, double w, double h)
      Tests if the interior of the Shape entirely contains the specified rectangular area. All coordinates that lie inside the rectangular area must lie within the Shape for the entire rectangular area to be considered contained within the Shape.

      The Shape.contains() method allows a Shape implementation to conservatively return false when:

      • the intersect method returns true and
      • the calculations to determine whether or not the Shape entirely contains the rectangular area are prohibitively expensive.
      This means that for some Shapes this method might return false even though the Shape contains the rectangular area. The Area class performs more accurate geometric computations than most Shape objects and therefore can be used if a more precise answer is required.
      Specified by:
      contains in interface Shape
      Parameters:
      x - the X coordinate of the upper-left corner of the specified rectangular area
      y - the Y coordinate of the upper-left corner of the specified rectangular area
      w - the width of the specified rectangular area
      h - the height of the specified rectangular area
      Returns:
      true if the interior of the Shape entirely contains the specified rectangular area; false otherwise or, if the Shape contains the rectangular area and the intersects method returns true and the containment calculations would be too expensive to perform.
      Since:
      1.2
      See Also:

    • contains

      public boolean contains(Rectangle2D r)
      Tests if the interior of the Shape entirely contains the specified Rectangle2D. The Shape.contains() method allows a Shape implementation to conservatively return false when:
      • the intersect method returns true and
      • the calculations to determine whether or not the Shape entirely contains the Rectangle2D are prohibitively expensive.
      This means that for some Shapes this method might return false even though the Shape contains the Rectangle2D. The Area class performs more accurate geometric computations than most Shape objects and therefore can be used if a more precise answer is required.
      Specified by:
      contains in interface Shape
      Parameters:
      r - The specified Rectangle2D
      Returns:
      true if the interior of the Shape entirely contains the Rectangle2D; false otherwise or, if the Shape contains the Rectangle2D and the intersects method returns true and the containment calculations would be too expensive to perform.
      Since:
      1.2
      See Also:

    • getBounds2D

      public Rectangle2D getBounds2D()
      Returns a high precision and more accurate bounding box of the Shape than the getBounds method. Note that there is no guarantee that the returned Rectangle2D is the smallest bounding box that encloses the Shape, only that the Shape lies entirely within the indicated Rectangle2D. The bounding box returned by this method is usually tighter than that returned by the getBounds method and never fails due to overflow problems since the return value can be an instance of the Rectangle2D that uses double precision values to store the dimensions.

      Note that the definition of insideness can lead to situations where points on the defining outline of the shape may not be considered contained in the returned bounds object, but only in cases where those points are also not considered contained in the original shape.

      If a point is inside the shape according to the contains(point) method, then it must be inside the returned Rectangle2D bounds object according to the contains(point) method of the bounds. Specifically:

      shape.contains(p) requires bounds.contains(p)

      If a point is not inside the shape, then it might still be contained in the bounds object:

      bounds.contains(p) does not imply shape.contains(p)

      Specified by:
      getBounds2D in interface Shape
      Returns:
      an instance of Rectangle2D that is a high-precision bounding box of the Shape.
      Since:
      1.2
      See Also:

    • getBounds

      public Rectangle getBounds()
      Returns an integer Rectangle that completely encloses the Shape. Note that there is no guarantee that the returned Rectangle is the smallest bounding box that encloses the Shape, only that the Shape lies entirely within the indicated Rectangle. The returned Rectangle might also fail to completely enclose the Shape if the Shape overflows the limited range of the integer data type. The getBounds2D method generally returns a tighter bounding box due to its greater flexibility in representation.

      Note that the definition of insideness can lead to situations where points on the defining outline of the shape may not be considered contained in the returned bounds object, but only in cases where those points are also not considered contained in the original shape.

      If a point is inside the shape according to the contains(point) method, then it must be inside the returned Rectangle bounds object according to the contains(point) method of the bounds. Specifically:

      shape.contains(x,y) requires bounds.contains(x,y)

      If a point is not inside the shape, then it might still be contained in the bounds object:

      bounds.contains(x,y) does not imply shape.contains(x,y)

      Specified by:
      getBounds in interface Shape
      Returns:
      an integer Rectangle that completely encloses the Shape.
      Since:
      1.2
      See Also:

    • getPathIterator

      public PathIterator getPathIterator(AffineTransform at)
      Returns an iteration object that defines the boundary of the shape of this QuadCurve2D. The iterator for this class is not multi-threaded safe, which means that this QuadCurve2D class does not guarantee that modifications to the geometry of this QuadCurve2D object do not affect any iterations of that geometry that are already in process.
      Specified by:
      getPathIterator in interface Shape
      Parameters:
      at - an optional AffineTransform to apply to the shape boundary
      Returns:
      a PathIterator object that defines the boundary of the shape.
      Since:
      1.2

    • getPathIterator

      public PathIterator getPathIterator(AffineTransform at, double flatness)
      Returns an iteration object that defines the boundary of the flattened shape of this QuadCurve2D. The iterator for this class is not multi-threaded safe, which means that this QuadCurve2D class does not guarantee that modifications to the geometry of this QuadCurve2D object do not affect any iterations of that geometry that are already in process.
      Specified by:
      getPathIterator in interface Shape
      Parameters:
      at - an optional AffineTransform to apply to the boundary of the shape
      flatness - the maximum distance that the control points for a subdivided curve can be with respect to a line connecting the end points of this curve before this curve is replaced by a straight line connecting the end points.
      Returns:
      a PathIterator object that defines the flattened boundary of the shape.
      Since:
      1.2

    • clone

      public Object clone()
      Creates a new object of the same class and with the same contents as this object.
      Overrides:
      clone in class Object
      Returns:
      a clone of this instance.
      Throws:
      OutOfMemoryError - if there is not enough memory.
      Since:
      1.2
      See Also: