Package javax.media.j3d
Class PathInterpolator
- Direct Known Subclasses:
PositionPathInterpolator
,RotationPathInterpolator
,RotPosPathInterpolator
,RotPosScalePathInterpolator
PathInterpolator behavior. This class defines the base class for
all Path Interpolators. Subclasses have access to the
computePathInterpolation() method, which computes the
currentInterpolationValue given the current time and alpha.
The method also computes the currentKnotIndex, which is based on
the currentInterpolationValue.
The currentInterpolationValue is calculated
by linearly interpolating among a series of predefined knots
(using the value generated by the specified Alpha object).
The first knot must have a value of 0.0 and the last knot must have a
value of 1.0. An intermediate knot with index k must have a value
strictly greater than any knot with index less than k.
-
Field Summary
FieldsModifier and TypeFieldDescriptionprotected float
This value is the ratio between knot values indicated by the currentKnotIndex variable.protected int
This value is the index of the current base knot value, as determined by the alpha function.Fields inherited from class javax.media.j3d.TransformInterpolator
axis, axisInverse, target
Fields inherited from class javax.media.j3d.Interpolator
defaultWakeupCriterion
Fields inherited from class javax.media.j3d.Node
ALLOW_AUTO_COMPUTE_BOUNDS_READ, ALLOW_AUTO_COMPUTE_BOUNDS_WRITE, ALLOW_BOUNDS_READ, ALLOW_BOUNDS_WRITE, ALLOW_COLLIDABLE_READ, ALLOW_COLLIDABLE_WRITE, ALLOW_LOCAL_TO_VWORLD_READ, ALLOW_LOCALE_READ, ALLOW_PARENT_READ, ALLOW_PICKABLE_READ, ALLOW_PICKABLE_WRITE, ENABLE_COLLISION_REPORTING, ENABLE_PICK_REPORTING
-
Constructor Summary
ConstructorsConstructorDescriptionPathInterpolator
(Alpha alpha, float[] knots) Deprecated.PathInterpolator
(Alpha alpha, TransformGroup target, float[] knots) Constructs a new PathInterpolator object that interpolates between the knot values in the knots array.PathInterpolator
(Alpha alpha, TransformGroup target, Transform3D axisOfTransform, float[] knots) Constructs a new PathInterpolator object that interpolates between the knot values in the knots array. -
Method Summary
Modifier and TypeMethodDescriptionprotected void
Deprecated.As of Java 3D version 1.3, replaced bycomputePathInterpolation(float)
protected void
computePathInterpolation
(float alphaValue) Computes the base knot index and interpolation value given the specified value of alpha and the knots[] array.int
Retrieves the length of the knots array.float
getKnot
(int index) Retrieves the knot at the specified index.void
getKnots
(float[] knots) Copies the array of knots from this interpolator into the specified array.void
setKnot
(int index, float knot) Sets the knot at the specified index for this interpolator.protected void
setKnots
(float[] knots) Replaces the existing array of knot values with the specified array.Methods inherited from class javax.media.j3d.TransformInterpolator
computeTransform, getTarget, getTransformAxis, processStimulus, setTarget, setTransformAxis, updateNodeReferences
Methods inherited from class javax.media.j3d.Interpolator
getAlpha, initialize, setAlpha
Methods inherited from class javax.media.j3d.Behavior
getEnable, getNumSchedulingIntervals, getSchedulingBoundingLeaf, getSchedulingBounds, getSchedulingInterval, getView, getWakeupCondition, postId, setEnable, setSchedulingBoundingLeaf, setSchedulingBounds, setSchedulingInterval, wakeupOn
Methods inherited from class javax.media.j3d.Node
cloneNode, cloneTree, cloneTree, cloneTree, cloneTree, cloneTree, cloneTree, duplicateNode, getBounds, getBoundsAutoCompute, getCollidable, getLocale, getLocalToVworld, getLocalToVworld, getParent, getPickable, setBounds, setBoundsAutoCompute, setCollidable, setPickable
Methods inherited from class javax.media.j3d.SceneGraphObject
clearCapability, clearCapabilityIsFrequent, duplicateSceneGraphObject, getCapability, getCapabilityIsFrequent, getName, getUserData, isCompiled, isLive, setCapability, setCapabilityIsFrequent, setName, setUserData, toString
-
Field Details
-
currentInterpolationValue
protected float currentInterpolationValueThis value is the ratio between knot values indicated by the currentKnotIndex variable. So if a subclass wanted to interpolate between knot values, it would use the currentKnotIndex to get the bounding knots for the "real" value, then use the currentInterpolationValue to interpolate between the knots. To calculate this variable, a subclass needs to call thecomputePathInterpolation(alphaValue)
method from the subclass's computeTransform() method. Then this variable will hold a valid value which can be used in further calculations by the subclass. -
currentKnotIndex
protected int currentKnotIndexThis value is the index of the current base knot value, as determined by the alpha function. A subclass wishing to interpolate between bounding knots would use this index and the one following it, and would use the currentInterpolationValue variable as the ratio between these indices. To calculate this variable, a subclass needs to call thecomputePathInterpolation(alphaValue)
method from the subclass's computeTransform() method. Then this variable will hold a valid value which can be used in further calculations by the subclass.
-
-
Constructor Details
-
PathInterpolator
Deprecated.As of Java 3D version 1.3, replaced byPathInterpolator(Alpha, TransformGroup, float[])
Constructs a new PathInterpolator object that interpolates between the knot values in the knots array. The array of knots is copied into this PathInterpolator object.- Parameters:
alpha
- the alpha object for this interpolator.knots
- an array of knot values that specify interpolation points.
-
PathInterpolator
Constructs a new PathInterpolator object that interpolates between the knot values in the knots array. The array of knots is copied into this PathInterpolator object.- Parameters:
alpha
- the alpha object for this interpolator.target
- the transformgroup node effected by this pathInterpolatorknots
- an array of knot values that specify interpolation points.- Since:
- Java 3D 1.3
-
PathInterpolator
public PathInterpolator(Alpha alpha, TransformGroup target, Transform3D axisOfTransform, float[] knots) Constructs a new PathInterpolator object that interpolates between the knot values in the knots array. The array of knots is copied into this PathInterpolator object.- Parameters:
alpha
- the alpha object for this interpolator.target
- the transform node effected by this positionInterpolatoraxisOfTransform
- the transform that defines the local coordinateknots
- an array of knot values that specify interpolation points.- Since:
- Java 3D 1.3
-
-
Method Details
-
getArrayLengths
public int getArrayLengths()Retrieves the length of the knots array.- Returns:
- the array length
-
setKnot
public void setKnot(int index, float knot) Sets the knot at the specified index for this interpolator.- Parameters:
index
- the index to be changedknot
- the new knot value
-
getKnot
public float getKnot(int index) Retrieves the knot at the specified index.- Parameters:
index
- the index of the value requested- Returns:
- the interpolator's knot value at the associated index
-
setKnots
protected void setKnots(float[] knots) Replaces the existing array of knot values with the specified array. The array of knots is copied into this interpolator object. Prior to calling this method, subclasses should verify that the lengths of the new knots array and subclass-specific parameter arrays are the same.- Parameters:
knots
- a new array of knot values that specify interpolation points.- Since:
- Java 3D 1.2
-
getKnots
public void getKnots(float[] knots) Copies the array of knots from this interpolator into the specified array. The array must be large enough to hold all of the knots.- Parameters:
knots
- array that will receive the knots.- Since:
- Java 3D 1.2
-
computePathInterpolation
protected void computePathInterpolation(float alphaValue) Computes the base knot index and interpolation value given the specified value of alpha and the knots[] array. If the index is 0 and there should be no interpolation, both the index variable and the interpolation variable are set to 0. Otherwise, currentKnotIndex is set to the lower index of the two bounding knot points and the currentInterpolationValue variable is set to the ratio of the alpha value between these two bounding knot points.- Parameters:
alphaValue
- alpha value between 0.0 and 1.0- Since:
- Java 3D 1.3
-
computePathInterpolation
protected void computePathInterpolation()Deprecated.As of Java 3D version 1.3, replaced bycomputePathInterpolation(float)
-
PathInterpolator(Alpha, TransformGroup, float[])