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.
Modifier and Type | Class and Description |
---|---|
static class |
QuadCurve2D.Double A quadratic parametric curve segment specified with |
static class |
QuadCurve2D.Float A quadratic parametric curve segment specified with |
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.
QuadCurve2D.Float
, QuadCurve2D.Double
public abstract double getX1()
Returns the X coordinate of the start point in double
in precision.
public abstract double getY1()
Returns the Y coordinate of the start point in double
precision.
public abstract Point2D getP1()
Returns the start point.
Point2D
that is the start point of this QuadCurve2D
.public abstract double getCtrlX()
Returns the X coordinate of the control point in double
precision.
public abstract double getCtrlY()
Returns the Y coordinate of the control point in double
precision.
public abstract Point2D getCtrlPt()
Returns the control point.
Point2D
that is the control point of this Point2D
.public abstract double getX2()
Returns the X coordinate of the end point in double
precision.
public abstract double getY2()
Returns the Y coordinate of the end point in double
precision.
public abstract Point2D getP2()
Returns the end point.
Point
object that is the end point of this Point2D
.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.
x1
- the X coordinate of the start pointy1
- the Y coordinate of the start pointctrlx
- the X coordinate of the control pointctrly
- the Y coordinate of the control pointx2
- the X coordinate of the end pointy2
- the Y coordinate of the end pointpublic 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.
coords
- the array containing coordinate valuesoffset
- the index into the array from which to start getting the coordinate values and assigning them to this QuadCurve2D
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.
p1
- the start pointcp
- the control pointp2
- the end pointpublic 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.
pts
- an array containing Point2D
that define coordinate valuesoffset
- the index into pts
from which to start getting the coordinate values and assigning them to this QuadCurve2D
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
.
c
- the specified QuadCurve2D
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.
x1
- the X coordinate of the start pointy1
- the Y coordinate of the start pointctrlx
- the X coordinate of the control pointctrly
- the Y coordinate of the control pointx2
- the X coordinate of the end pointy2
- the Y coordinate of the end pointpublic 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.
x1
- the X coordinate of the start pointy1
- the Y coordinate of the start pointctrlx
- the X coordinate of the control pointctrly
- the Y coordinate of the control pointx2
- the X coordinate of the end pointy2
- the Y coordinate of the end pointpublic 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.
coords
- an array containing coordinate valuesoffset
- the index into coords
from which to to start getting the values from the arraypublic 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.
coords
- an array containing coordinate valuesoffset
- the index into coords
from which to start getting the coordinate valuespublic 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
.
QuadCurve2D
.public double getFlatness()
Returns the flatness, or maximum distance of a control point from the line connecting the end points, of this QuadCurve2D
.
QuadCurve2D
.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
.
left
- the QuadCurve2D
object for storing the left or first half of the subdivided curveright
- the QuadCurve2D
object for storing the right or second half of the subdivided curvepublic 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
.
src
- the quadratic curve to be subdividedleft
- the QuadCurve2D
object for storing the left or first half of the subdivided curveright
- the QuadCurve2D
object for storing the right or second half of the subdivided curvepublic 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.
src
- the array holding the coordinates for the source curvesrcoff
- the offset into the array of the beginning of the the 6 source coordinatesleft
- the array for storing the coordinates for the first half of the subdivided curveleftoff
- the offset into the array of the beginning of the the 6 left coordinatesright
- the array for storing the coordinates for the second half of the subdivided curverightoff
- the offset into the array of the beginning of the the 6 right coordinatespublic 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 = 0A 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. eqn
- the array that contains the quadratic coefficients-1
if the equation is a constantpublic 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 = 0A 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. eqn
- the specified array of coefficients to use to solve the quadratic equationres
- the array that contains the non-complex roots resulting from the solution of the quadratic equation-1
if the equation is a constant.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.
contains
in interface Shape
x
- the specified X coordinate to be testedy
- the specified Y coordinate to be testedtrue
if the specified coordinates are inside the Shape
boundary; false
otherwise.public boolean contains(Point2D p)
Tests if a specified Point2D
is inside the boundary of the Shape
, as described by the definition of insideness.
contains
in interface Shape
p
- the specified Point2D
to be testedtrue
if the specified Point2D
is inside the boundary of the Shape
; false
otherwise.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:
Shape
intersect, but 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.intersects
in interface Shape
x
- the X coordinate of the upper-left corner of the specified rectangular areay
- the Y coordinate of the upper-left corner of the specified rectangular areaw
- the width of the specified rectangular areah
- the height of the specified rectangular areatrue
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.Area
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:
Rectangle2D
and the Shape
intersect, but 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. intersects
in interface Shape
r
- the specified Rectangle2D
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.Shape.intersects(double, double, double, double)
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:
intersect
method returns true
and Shape
entirely contains the rectangular area are prohibitively expensive. 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.contains
in interface Shape
x
- the X coordinate of the upper-left corner of the specified rectangular areay
- the Y coordinate of the upper-left corner of the specified rectangular areaw
- the width of the specified rectangular areah
- the height of the specified rectangular areatrue
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.Area
, Shape.intersects(double, double, double, double)
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:
intersect
method returns true
and Shape
entirely contains the Rectangle2D
are prohibitively expensive. 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. contains
in interface Shape
r
- The specified Rectangle2D
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.Shape.contains(double, double, double, double)
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)
getBounds
in interface Shape
Rectangle
that completely encloses the Shape
.Shape.getBounds2D()
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.
getPathIterator
in interface Shape
at
- an optional AffineTransform
to apply to the shape boundaryPathIterator
object that defines the boundary of the shape.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.
getPathIterator
in interface Shape
at
- an optional AffineTransform
to apply to the boundary of the shapeflatness
- 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.PathIterator
object that defines the flattened boundary of the shape.public Object clone()
Creates a new object of the same class and with the same contents as this object.
clone
in class Object
OutOfMemoryError
- if there is not enough memory.Cloneable
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