Module org.bzdev.anim2d

Package org.bzdev.anim2d

Class AnimationPath2D

java.lang.Object

org.bzdev.devqsim.SimObject

org.bzdev.anim2d.AnimationObject2D

org.bzdev.anim2d.AnimationPath2D

All Implemented Interfaces:

Graph.Graphic, NamedObjectOps

public class AnimationPath2D
extends AnimationObject2D

Class defining a path for animation objects. Some animation objects can follow a path. This class defines an animation object that can provide such a path and, if necessary, display it as part of an animation (displaying a path is useful for debugging).

Constructor Summary

Constructors

Constructor	Description
AnimationPath2D(Animation2D animation, String name, boolean intern)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	addTo(Graph graph, Graphics2D g2d, Graphics2D g2dgcs)	Add this object to a graph.
boolean	canDelete()	Determine if this named object can be deleted.
protected Object	clone()	Creates and returns a copy of this object.
double	curvature(double u)	Compute the curvature given path parameter.
double	d2xDu2(double u)	Get the second derivative of the x coordinate with respect to the path parameter for a given value of the parameter.
double	d2yDu2(double u)	Get the second derivative of the y coordinate with respect to the path parameter.
final boolean	delete()	Delete an object.
final boolean	deletePending()	Determine if an object is being deleted.
double	dsDu(double u)	Get the derivative of the path length with respect to the path parameter for a given value of the parameter.
double	dxDu(double u)	Get the derivative of the x coordinate with respect to the path parameter for a given value of the parameter.
double	dyDu(double u)	Get the derivative of the y coordinate with respect to the path parameter.
Color	getColor()	Get the color for a line drawing this path when addTo is called.
double	getDistance(double u1, double u2)	Get the distance traversed on a subpath.
boolean	getGcsMode()	Get GCS mode.
double	getInversionLimit()	Get the inversion limit for the path.
double	getMaxParameter()	Get the maximum value of the path parameter.
final String	getName()	Get an object's name.
protected Simulation	getObjectNamer()	Get the object namer for a named object.
BasicSplinePath2D	getPath()	Get the current path.
double	getPathLength()	Get the total length of the path.
double	getPathLength(double u1, double u2)	Get the length of a subpath.
Point2D	getPoint(double u)	Get the point on a path corresponding to a given value of the path parameter.
Stroke	getStroke()	Get the stroke for a line drawing this path when addTo is called.
double	getX(double u)	Get the x coordinate for a given value of the path parameter.
double	getY(double u)	Get the y coordinate for a given value of the parameter.
void	initPath()	Initialize the path with a default winding rule.
boolean	isClosed()	Determine if the path is a closed path.
final boolean	isDeleted()	Determine if an object has been deleted.
boolean	isInterned()	Determine if an object is interned in a object namer's tables.
void	printConfiguration(String iPrefix, String prefix, boolean printName, PrintWriter out)	Print this simulation object's configuration.
double	s(double u)	Get the distance along a path from its start for a specified path parameter.
void	setColor(Color color)	Set the color for a line drawing this path when addTo is called.
void	setGcsMode(boolean gcsMode)	Set GCS mode.
void	setInversionLimit(double limit)	Set the inversion limit.
void	setPath(BasicSplinePath2D spath)	Set the path.
void	setStroke(Stroke stroke)	Set the stroke for a line drawing this path when addTo is called.
void	showSegments(boolean mode, double radius)	Configure this path so that it will draw the end of each path segment when visible and when GCS mode is false.
double	u(double s)	Get the path parameter corresponding to a specified distance along a path from its start.

Methods inherited from class org.bzdev.anim2d.AnimationObject2D

addToFrame, addToFrame, getAnimation, getZorder, isVisible, printState, setVisible, setZorder, setZorder

Methods inherited from class org.bzdev.devqsim.SimObject

addSimulationListener, addTraceSet, bindCallable, bindCallable, bindCallable, bindCallable, bindRunnable, bindRunnable, bindRunnable, bindRunnable, callableObject, callableScript, callScriptFunction, callScriptMethod, clearTraceSets, evalScript, getEventListenerList, getScriptObject, getTraceSets, onDelete, printConfiguration, printConfiguration, printConfiguration, printConfiguration, printConfiguration, printConfiguration, printState, printState, printState, printState, printState, printState, putScriptObject, removeSimulationListener, removeTraceSet, runnableObject, runnableScript, scheduleCall, scheduleCall, scheduleCall, scheduleCall, scheduleCallObject, scheduleScript, scheduleTask, scheduleTask, scheduleTask, scheduleTask, scheduleTaskObject, scheduleTaskScript, startImmediateTask, startImmediateTask, trace, trace, unscheduledTaskThread, unscheduledTaskThread, update, update, usesTraceSet

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.bzdev.graphs.Graph.Graphic

boundingBox

Methods inherited from interface org.bzdev.obnaming.NamedObjectOps

canDelete, delete, deletePending, getName, isDeleted, isInterned

Constructor Details

AnimationPath2D

public AnimationPath2D(Animation2D animation,
 String name,
 boolean intern)

Constructor.

Parameters:

animation - the animation

name - the name of the object; null for an automatically generated name

intern - true if the object can be looked up by using the methods in Simulation; false otherwise.

Throws:

IllegalArgumentException - typically means a name is already in use

See Also:

• ObjectNamerOps.getObject(String,Class)

Method Details

setPath

public void setPath(BasicSplinePath2D spath)

Set the path.

Parameters:

spath - the path

initPath

public void initPath()

Initialize the path with a default winding rule.

getPath

public BasicSplinePath2D getPath()

Get the current path.

Returns:

the path

getMaxParameter

public double getMaxParameter()

Get the maximum value of the path parameter. This value is applicable for open paths, not closed paths. For closed paths, it represents the period at which the path is guaranteed to repeat. The returned value is numerically equal to the number of segments that make up the path.

Returns:

the maximum value of the parameter

Throws:

IllegalStateException - the path was not set

See Also:

• BasicSplinePath2D.getMaxParameter()

isClosed

public boolean isClosed()

Determine if the path is a closed path.

Returns:

true if it is closed; false if it is not closed

getX

public double getX(double u)
            throws IllegalStateException,
IllegalArgumentException

Get the x coordinate for a given value of the path parameter.

Parameters:

u - the parameter

Returns:

the x coordinate of the point on the path for the specified parameter

Throws:

IllegalStateException - the path is not a simple path or was not set

IllegalArgumentException - the parameter is out of bounds

See Also:

• BasicSplinePath2D.getX(double)

getY

public double getY(double u)
            throws IllegalStateException,
IllegalArgumentException

Get the y coordinate for a given value of the parameter.

Parameters:

u - the parameter

Returns:

the y coordinate of the point on the path for the specified parameter

Throws:

IllegalStateException - the path is not a simple path or was not set

IllegalArgumentException - the parameter is out of bounds

See Also:

• BasicSplinePath2D.getY(double)

getPoint

public Point2D getPoint(double u)
                 throws IllegalStateException,
IllegalArgumentException

Get the point on a path corresponding to a given value of the path parameter.

Parameters:

u - the parameter

Returns:

the point on the path corresponding to the specified parameter

Throws:

IllegalStateException - the path is not a simple path or was not set

IllegalArgumentException - the parameter is out of bounds

See Also:

• BasicSplinePath2D.getPoint(double)

dxDu

public double dxDu(double u)
            throws IllegalStateException,
IllegalArgumentException

Get the derivative of the x coordinate with respect to the path parameter for a given value of the parameter.

Parameters:

u - the parameter

Returns:

the derivative

Throws:

IllegalStateException - the path is not a simple path or was not set

IllegalArgumentException - the parameter is out of bounds

See Also:

• BasicSplinePath2D.dxDu(double)

dyDu

public double dyDu(double u)
            throws IllegalStateException,
IllegalArgumentException

Get the derivative of the y coordinate with respect to the path parameter.

Parameters:

u - the parameter

Returns:

the derivative

Throws:

IllegalStateException - the path is not a simple path or was not set

IllegalArgumentException - the parameter is out of bounds

See Also:

• BasicSplinePath2D.dyDu(double)

d2xDu2

public double d2xDu2(double u)
              throws IllegalStateException,
IllegalArgumentException

Get the second derivative of the x coordinate with respect to the path parameter for a given value of the parameter.

Parameters:

u - the parameter

Returns:

the second derivative

Throws:

IllegalStateException - the path is not a simple path or the path was not set

IllegalArgumentException - the parameter is out of bounds

See Also:

• BasicSplinePath2D.d2xDu2(double)

d2yDu2

public double d2yDu2(double u)
              throws IllegalStateException,
IllegalArgumentException

Get the second derivative of the y coordinate with respect to the path parameter.

Parameters:

u - the parameter

Returns:

the derivative

Throws:

IllegalStateException - the path is not a simple path or the path was not set

IllegalArgumentException - the parameter is out of bounds

See Also:

• BasicSplinePath2D.d2yDu2(double)

curvature

public double curvature(double u)
                 throws IllegalStateException,
IllegalArgumentException

Compute the curvature given path parameter. The curvature is given by the expression

    (x'y" - y'x")/(xp2 + y'2)3/2
 

where the derivative are computed with respect to the path parameter, and is positive if the path turns counterclockwise as the parameter increases, is negative if the path turns clockwise, and is zero if the path follows a straight line. The radius of curvature is the multiplicative inverse of the absolute value of the curvature.

Parameters:

u - the path-segment parameter

Returns:

the curvature

Throws:

IllegalStateException - the path is not a simple path or the path was not set

IllegalArgumentException - the parameter is out of bounds

See Also:

• BasicSplinePath2D.curvature(double)

dsDu

public double dsDu(double u)
            throws IllegalStateException,
IllegalArgumentException

Get the derivative of the path length with respect to the path parameter for a given value of the parameter.

Parameters:

u - the parameter

Returns:

the derivative

Throws:

IllegalStateException - the path is not a simple path or the path was not set

IllegalArgumentException - the parameter is out of bounds

See Also:

• BasicSplinePath2D.dsDu(double)

getInversionLimit

public double getInversionLimit()

Get the inversion limit for the path. The inversion limit (a negative number indicates that the default should be used) is used by cubic splines used to map path distances to path parameters. The value supplied is used when a spline is created.

Computing the inverse for a cubic spline in most cases requires solving a cubic equation, with valid solutions being in the range [0, 1]. The inversion limit allows solutions in the range [-inversionLimit, 1+inversionLimit] to be accepted, with values outside of the interval [0, 1] replaced by 0 or 1, whichever is closer. The use of an inversion limit allows for round-off errors.

Returns:

the inversion limit

Throws:

IllegalStateException - the path was not set

See Also:

• BasicSplinePath2D.getInversionLimit()

setInversionLimit

public void setInversionLimit(double limit)

Set the inversion limit. The inversion limit (a negative number indicates that the default should be used) is used by cubic splines used to map path distances to path parameters. The value supplied is used when a spline is created.

Computing the inverse for a cubic spline in most cases requires solving a cubic equation, with valid solutions being in the range [0, 1]. The inversion limit allows solutions in the range [-inversionLimit, 1+inversionLimit] to be accepted, with values outside of the interval [0, 1] replaced by 0 or 1, whichever is closer. The use of an inversion limit allows for round-off errors.

Parameters:

limit - the inversion limit; or a negative number to indicate that the default will be used.

Throws:

IllegalStateException - the path was not set

See Also:

• BasicSplinePath2D.setInversionLimit(double)

getPathLength

public double getPathLength()
                     throws IllegalStateException,
IllegalArgumentException

Get the total length of the path.

Returns:

the path length

Throws:

IllegalStateException - the path is not a simple path or the path was not set

IllegalArgumentException - the parameter is out of bounds

See Also:

• BasicSplinePath2D.getPathLength()

getPathLength

public double getPathLength(double u1,
 double u2)
                     throws IllegalStateException,
IllegalArgumentException

Get the length of a subpath. The returned value is the same if u1 and u2 are exchanged: lengths are non-negative.

Parameters:

u1 - the parameter at the first end point of a subpath

u2 - the parameter at the second end point of a subpath

Returns:

the length of the subpath

Throws:

IllegalStateException - the path is not a simple path or the path was not set

IllegalArgumentException - the parameter is out of bounds

See Also:

• BasicSplinePath2D.getPathLength(double,double)

getDistance

public double getDistance(double u1,
 double u2)
                   throws IllegalStateException,
IllegalArgumentException

Get the distance traversed on a subpath. If u2 < u1, the value returned is negative.

This is intended for cases where direction is important.

Parameters:

u1 - the parameter at the first end point of a subpath

u2 - the parameter at the second end point of a subpath

Returns:

the distance traversed on a subpath

Throws:

IllegalStateException - the path is not a simple path

IllegalArgumentException - the parameter is out of bounds

s

public double s(double u)
         throws IllegalStateException,
IllegalArgumentException

Get the distance along a path from its start for a specified path parameter.

Parameters:

u - the path parameter

Returns:

the distance along a path from its start

Throws:

IllegalStateException - the path was not set

IllegalArgumentException

See Also:

• BasicSplinePath2D.s(double)

u

public double u(double s)
         throws IllegalStateException,
IllegalArgumentException

Get the path parameter corresponding to a specified distance along a path from its start.

Parameters:

s - the distance along a path from its start

Returns:

the path parameter

Throws:

IllegalStateException - the path was not set

IllegalArgumentException

See Also:

• BasicSplinePath2D.u(double)

setColor

public void setColor(Color color)

Set the color for a line drawing this path when addTo is called.

Parameters:

color - the color

getColor

public Color getColor()

Get the color for a line drawing this path when addTo is called.

Returns:

the color

setStroke

public void setStroke(Stroke stroke)

Set the stroke for a line drawing this path when addTo is called.

Parameters:

stroke - the stroke

getStroke

public Stroke getStroke()

Get the stroke for a line drawing this path when addTo is called.

Returns:

the stroke

setGcsMode

public void setGcsMode(boolean gcsMode)

Set GCS mode. When GCS mode is set the stroke's width and dash array are interpreted in graph coordinate space units; otherwise in user-space units (the default).

Parameters:

gcsMode - true if the stroke's units are in graph coordinate space units; false if they are in user space units.

getGcsMode

public boolean getGcsMode()

Get GCS mode. When GCS mode is set the stroke's width and dash array are interpreted in graph coordinate space units; otherwise in user-space units.

Returns:

true if in graph-coordinate-space mode; false if in user-space mode

showSegments

public void showSegments(boolean mode,
 double radius)

Configure this path so that it will draw the end of each path segment when visible and when GCS mode is false.

Parameters:

mode - true to draw the segment ends; false to just draw the path

radius - the radius of a circle representing the end of a segment

addTo

public void addTo(Graph graph,
 Graphics2D g2d,
 Graphics2D g2dgcs)

Description copied from interface: Graph.Graphic

Add this object to a graph. The drawing operation is assumed to be a complex one that might involve fills, etc.

Any modifications to g2d or g2dGCS made by an implementation of this method should be undone before this method returns. For classes provided by the org.bzdev.anim2d package, such modifications must be undone before this method returns.

Two graphics contexts are provided as arguments. g2d will typically be used as the first argument to the graph's draw or fill methods. In this case, the shape of an object is described in graph coordinate space but the widths of strokes drawn by fill operations, gradient paint, etc., have user-space units. The result is that line widths as they appear in an image are not sensitive to the mapping from graph coordinate space to user space. One should use the draw and fill methods specified by Graph, using g2d as their first argument. By contrast, if a line width, etc., should be in graph-coordinate space units, one can use the g2dGCS argument directly. This will rarely be done when plotting a graph but is useful in animations.

Parameters:

graph - the graph on which this object should be drawn

g2d - the user-space Graphics2D to use to draw the Graphic

g2dgcs - the graph-coordinate space Graphics2D to use to draw the Graphic

printConfiguration

public void printConfiguration(String iPrefix,
 String prefix,
 boolean printName,
 PrintWriter out)

Print this simulation object's configuration. Documentation for the use of this method is provided by the documentation for the SimObject method SimObject.printConfiguration(String,String,boolean,PrintWriter).

When the second argument has a value of true, the object name and class name will be printed in a standard format with its indentation provided by the iPrefix argument. In addition, the configuration that is printed includes the following items.

Defined in AnimationObject2D:

• the Z-order.
• whether or not this object is visible.

Defined in AnimationPath2D:

• the configuration for a BasicSplinePath2D, provided by calling this path's method BasicSplinePath2D.printTable(String,Appendable).

Overrides:

printConfiguration in class AnimationObject2D

Parameters:

iPrefix - the prefix to use for an initial line when printName is true with null treated as an empty string

prefix - a prefix string (typically whitespace) to put at the start of each line other than the initial line that is printed when printName is true

printName - requests printing the name of an object

out - the output print writer

clone

protected Object clone()
                throws CloneNotSupportedException

Creates and returns a copy of this object. This method will throw the exception CloneNotSupportedException if the object is interned.

Overrides:

clone in class Object

Throws:

CloneNotSupportedException - a clone could not be created

See Also:

• Object.clone()

isInterned

public boolean isInterned()

Determine if an object is interned in a object namer's tables.

Specified by:

isInterned in interface NamedObjectOps

Returns:

true if the object is interned; false if not

getObjectNamer

protected Simulation getObjectNamer()

Get the object namer for a named object.

Returns:

the object namer for this named object

getName

public final String getName()

Get an object's name.

Specified by:

getName in interface NamedObjectOps

Returns:

the name of the object

canDelete

public boolean canDelete()

Determine if this named object can be deleted. A named object can be deleted if the method delete has not been called and if the object is not in a state that prevents the object from being deleted. Subclasses that override this method must call canDelete() for their superclasses and return false if the superclass' canDelete method returns false. The default method returns true if delete() has not been called and returned true.

Specified by:

canDelete in interface NamedObjectOps

Returns:

true if this object can be deleted; false otherwise

delete

public final boolean delete()

Delete an object. An object can only be deleted once. If this method returns true, the object (if interned) will have been removed from the object namer tables.

The implementations provided by DefaultNamedObect and generated because of a @NamedObject annotation provide a protected method named onDelete. A subclass that overrides onDelete() must call the onDelete method of its superclass after it's onDelete method has been called and any cleanup actions performed. In some cases, this may happen at a later time (e.g., if a thread is used for some of the cleanup operations or if it is otherwise necessary to wait).

Specified by:

delete in interface NamedObjectOps

Returns:

true if the deletion request was accepted; false otherwise

isDeleted

public final boolean isDeleted()

Determine if an object has been deleted. An object is deleted if the method delete() has been called and returned true.

Specified by:

isDeleted in interface NamedObjectOps

Returns:

true if deleted; false otherwise

deletePending

public final boolean deletePending()

Determine if an object is being deleted. An deletion is pending if the method delete() has been called and returned true but the deletion has not been completed.

Specified by:

deletePending in interface NamedObjectOps

Returns:

true if deletion is pending; false otherwise