Since: 1.2
java.awt.geom
public abstract class CubicCurve2D extends Object implements Shape, Cloneable
Since: 1.2
| Nested Class Summary | |
|---|---|
| static class | CubicCurve2D.Double
A two-dimensional curve that is parameterized with a cubic
function and stores coordinate values in double-precision
floating-point format.
|
| static class | CubicCurve2D.Float
A two-dimensional curve that is parameterized with a cubic
function and stores coordinate values in single-precision
floating-point format.
|
| Constructor Summary | |
|---|---|
| protected | CubicCurve2D()
Constructs a new CubicCurve2D. |
| Method Summary | |
|---|---|
| Object | clone()
Create a new curve with the same contents as this one.
|
| boolean | contains(double x, double y)
Determines whether a position lies inside the area bounded
by the curve and the straight line connecting its end points.
|
| boolean | contains(Point2D p)
Determines whether a point lies inside the area bounded
by the curve and the straight line connecting its end points.
|
| boolean | contains(double x, double y, double w, double h)
Determine whether a rectangle is entirely inside the area that is bounded
by the curve and the straight line connecting its end points.
|
| boolean | contains(Rectangle2D r)
Determine whether a Rectangle2D is entirely inside the area that is
bounded by the curve and the straight line connecting its end points.
|
| Rectangle | getBounds()
Determines the smallest rectangle that encloses the
curve’s start, end and control points. |
| abstract Point2D | getCtrlP1()
Returns the curve’s first control point. |
| abstract Point2D | getCtrlP2()
Returns the curve’s second control point. |
| abstract double | getCtrlX1()
Returns the x coordinate of the curve’s first
control point. |
| abstract double | getCtrlX2()
Returns the x coordinate of the curve’s second
control point. |
| abstract double | getCtrlY1()
Returns the y coordinate of the curve’s first
control point. |
| abstract double | getCtrlY2()
Returns the y coordinate of the curve’s second
control point. |
| static double | getFlatness(double x1, double y1, double cx1, double cy1, double cx2, double cy2, double x2, double y2)
Calculates the flatness of a cubic curve, directly specifying
each coordinate value. |
| static double | getFlatness(double[] coords, int offset)
Calculates the flatness of a cubic curve, specifying the
coordinate values in an array. |
| double | getFlatness()
Calculates the flatness of this curve. |
| static double | getFlatnessSq(double x1, double y1, double cx1, double cy1, double cx2, double cy2, double x2, double y2)
Calculates the squared flatness of a cubic curve, directly
specifying each coordinate value. |
| static double | getFlatnessSq(double[] coords, int offset)
Calculates the squared flatness of a cubic curve, specifying the
coordinate values in an array. |
| double | getFlatnessSq()
Calculates the squared flatness of this curve. |
| abstract Point2D | getP1()
Returns the curve’s start point. |
| abstract Point2D | getP2()
Returns the curve’s end point. |
| PathIterator | getPathIterator(AffineTransform at) |
| PathIterator | getPathIterator(AffineTransform at, double flatness) |
| abstract double | getX1()
Returns the x coordinate of the curve’s start
point. |
| abstract double | getX2()
Returns the x coordinate of the curve’s end
point. |
| abstract double | getY1()
Returns the y coordinate of the curve’s start
point. |
| abstract double | getY2()
Returns the y coordinate of the curve’s end
point. |
| boolean | intersects(double x, double y, double w, double h)
Determines whether any part of a rectangle is inside the area bounded
by the curve and the straight line connecting its end points.
|
| boolean | intersects(Rectangle2D r)
Determines whether any part of a Rectangle2D is inside the area bounded
by the curve and the straight line connecting its end points. |
| abstract void | setCurve(double x1, double y1, double cx1, double cy1, double cx2, double cy2, double x2, double y2)
Changes the curve geometry, separately specifying each coordinate
value.
|
| void | setCurve(double[] coords, int offset)
Changes the curve geometry, specifying coordinate values in an
array.
|
| void | setCurve(Point2D p1, Point2D c1, Point2D c2, Point2D p2)
Changes the curve geometry, specifying coordinate values in
separate Point objects.
|
| void | setCurve(Point2D[] pts, int offset)
Changes the curve geometry, specifying coordinate values in an
array of Point objects.
|
| void | setCurve(CubicCurve2D c)
Changes the curve geometry to that of another curve.
|
| static int | solveCubic(double[] eqn)
Finds the non-complex roots of a cubic equation, placing the
results into the same array as the equation coefficients. |
| static int | solveCubic(double[] eqn, double[] res)
Finds the non-complex roots of a cubic equation. |
| void | subdivide(CubicCurve2D left, CubicCurve2D right)
Subdivides this curve into two halves.
|
| static void | subdivide(CubicCurve2D src, CubicCurve2D left, CubicCurve2D right)
Subdivides a cubic curve into two halves.
|
| static void | subdivide(double[] src, int srcOff, double[] left, int leftOff, double[] right, int rightOff)
Subdivides a cubic curve into two halves, passing all coordinates
in an array.
|
Returns: the clone.
The above drawing illustrates in which area points are considered “inside” a CubicCurve2D.
The above drawing illustrates in which area points are considered “inside” a CubicCurve2D.
The above drawing illustrates in which area points are considered “inside” a CubicCurve2D.
See Also: CubicCurve2D
The above drawing illustrates in which area points are considered “inside” a CubicCurve2D.
See Also: CubicCurve2D
In the above drawing, the straight line connecting start point P1 and end point P2 is depicted in gray. In comparison to C1, control point C2 is father away from the gray line. Therefore, the result will be the distance between C2 and the gray line, i.e. the length of the red line.
Parameters: x1 the x coordinate of the start point P1. y1 the y coordinate of the start point P1. cx1 the x coordinate of the first control point C1. cy1 the y coordinate of the first control point C1. cx2 the x coordinate of the second control point C2. cy2 the y coordinate of the second control point C2. x2 the x coordinate of the end point P2. y2 the y coordinate of the end point P2.
In the above drawing, the straight line connecting start point P1 and end point P2 is depicted in gray. In comparison to C1, control point C2 is father away from the gray line. Therefore, the result will be the distance between C2 and the gray line, i.e. the length of the red line.
Parameters: coords an array containing the coordinate values. The
x coordinate of the start point P1 is located at
coords[offset], its y coordinate at
coords[offset + 1]. The x coordinate of the
first control point C1 is located at coords[offset +
2], its y coordinate at coords[offset +
3]. The x coordinate of the second control point C2
is located at coords[offset + 4], its y
coordinate at coords[offset + 5]. The x
coordinate of the end point P2 is located at coords[offset
+ 6], its y coordinate at coords[offset +
7].
offset the offset of the first coordinate value in
coords.
In the above drawing, the straight line connecting start point P1 and end point P2 is depicted in gray. In comparison to C1, control point C2 is father away from the gray line. Therefore, the result will be the distance between C2 and the gray line, i.e. the length of the red line.
In the above drawing, the straight line connecting start point P1 and end point P2 is depicted in gray. In comparison to C1, control point C2 is father away from the gray line. Therefore, the result will be the square of the distance between C2 and the gray line, i.e. the squared length of the red line.
Parameters: x1 the x coordinate of the start point P1. y1 the y coordinate of the start point P1. cx1 the x coordinate of the first control point C1. cy1 the y coordinate of the first control point C1. cx2 the x coordinate of the second control point C2. cy2 the y coordinate of the second control point C2. x2 the x coordinate of the end point P2. y2 the y coordinate of the end point P2.
In the above drawing, the straight line connecting start point P1 and end point P2 is depicted in gray. In comparison to C1, control point C2 is father away from the gray line. Therefore, the result will be the square of the distance between C2 and the gray line, i.e. the squared length of the red line.
Parameters: coords an array containing the coordinate values. The
x coordinate of the start point P1 is located at
coords[offset], its y coordinate at
coords[offset + 1]. The x coordinate of the
first control point C1 is located at coords[offset +
2], its y coordinate at coords[offset +
3]. The x coordinate of the second control point C2
is located at coords[offset + 4], its y
coordinate at coords[offset + 5]. The x
coordinate of the end point P2 is located at coords[offset
+ 6], its y coordinate at coords[offset +
7].
offset the offset of the first coordinate value in
coords.
In the above drawing, the straight line connecting start point P1 and end point P2 is depicted in gray. In comparison to C1, control point C2 is father away from the gray line. Therefore, the result will be the square of the distance between C2 and the gray line, i.e. the squared length of the red line.
The above drawing illustrates in which area points are considered “inside” in a CubicCurve2D.
See Also: CubicCurve2D
See Also: CubicCurve2D
Parameters: x1 the x coordinate of the curve’s new start point. y1 the y coordinate of the curve’s new start point. cx1 the x coordinate of the curve’s new first control point. cy1 the y coordinate of the curve’s new first control point. cx2 the x coordinate of the curve’s new second control point. cy2 the y coordinate of the curve’s new second control point. x2 the x coordinate of the curve’s new end point. y2 the y coordinate of the curve’s new end point.
Parameters: coords an array containing the new coordinate values. The
x coordinate of the new start point is located at
coords[offset], its y coordinate at
coords[offset + 1]. The x coordinate of the
new first control point is located at coords[offset +
2], its y coordinate at coords[offset +
3]. The x coordinate of the new second control
point is located at coords[offset + 4], its y
coordinate at coords[offset + 5]. The x
coordinate of the new end point is located at coords[offset
+ 6], its y coordinate at coords[offset +
7].
offset the offset of the first coordinate value in
coords.
The curve does not keep any reference to the passed point
objects. Therefore, a later change to p1,
c1, c2 or p2 will not
affect the curve geometry.
Parameters: p1 the new start point. c1 the new first control point. c2 the new second control point. p2 the new end point.
The curve does not keep references to the passed point
objects. Therefore, a later change to the pts array
or any of its elements will not affect the curve geometry.
Parameters: pts an array containing the points. The new start point
is located at pts[offset], the new first control
point at pts[offset + 1], the new second control
point at pts[offset + 2], and the new end point
at pts[offset + 3].
offset the offset of the start point in pts.
Parameters: c the curve whose coordinates will be copied.
eqn[3]· x3 +eqn[2]· x2 +eqn[1]· x +eqn[0]= 0
For some background about solving cubic equations, see the article “Cubic Formula” in PlanetMath. For an extensive library of numerical algorithms written in the C programming language, see the GNU Scientific Library, from which this implementation was adapted.
Parameters: eqn an array with the coefficients of the equation. When
this procedure has returned, eqn will contain the
non-complex solutions of the equation, in no particular order.
Returns: the number of non-complex solutions. A result of 0 indicates that the equation has no non-complex solutions. A result of -1 indicates that the equation is constant (i.e., always or never zero).
See Also: (double[], double[]) (double[],double[])
eqn[3]· x3 +eqn[2]· x2 +eqn[1]· x +eqn[0]= 0
For some background about solving cubic equations, see the article “Cubic Formula” in PlanetMath. For an extensive library of numerical algorithms written in the C programming language, see the GNU Scientific Library, from which this implementation was adapted.
Parameters: eqn an array with the coefficients of the equation.
res an array into which the non-complex roots will be
stored. The results may be in an arbitrary order. It is safe to
pass the same array object reference for both eqn
and res.
Returns: the number of non-complex solutions. A result of 0 indicates that the equation has no non-complex solutions. A result of -1 indicates that the equation is constant (i.e., always or never zero).
See Also: (double[],double[])
Parameters: left a curve whose geometry will be set to the left half
of this curve, or null if the caller is not
interested in the left half.
right a curve whose geometry will be set to the right half
of this curve, or null if the caller is not
interested in the right half.
Parameters: src the curve to be subdivided.
left a curve whose geometry will be set to the left half
of src, or null if the caller is not
interested in the left half.
right a curve whose geometry will be set to the right half
of src, or null if the caller is not
interested in the right half.
The left end point and the right start point will always be
identical. Memory-concious programmers thus may want to pass the
same array for both left and right, and
set rightOff to leftOff + 6.
Parameters: src an array containing the coordinates of the curve to be
subdivided. The x coordinate of the start point P1 is
located at src[srcOff], its y at
src[srcOff + 1]. The x coordinate of the
first control point C1 is located at src[srcOff +
2], its y at src[srcOff + 3]. The
x coordinate of the second control point C2 is located at
src[srcOff + 4], its y at src[srcOff +
5]. The x coordinate of the end point is located at
src[srcOff + 6], its y at src[srcOff +
7].
srcOff an offset into src, specifying
the index of the start point’s x coordinate.
left an array that will receive the coordinates of the
left half of src. It is acceptable to pass
src. A caller who is not interested in the left half
can pass null.
leftOff an offset into left, specifying the
index where the start point’s x coordinate will be
stored.
right an array that will receive the coordinates of the
right half of src. It is acceptable to pass
src or left. A caller who is not
interested in the right half can pass null.
rightOff an offset into right, specifying the
index where the start point’s x coordinate will be
stored.