com.badlogic.gdx.math

Class CatmullRomSpline<T extends Vector<T>>

java.lang.Object

com.badlogic.gdx.math.CatmullRomSpline<T>

All Implemented Interfaces:

Path<T>

public class CatmullRomSpline<T extends Vector<T>>
extends Object
implements Path<T>

Author:

Xoppa

Field Summary

Fields

Modifier and Type	Field and Description
boolean	continuous
T[]	controlPoints
int	spanCount

Constructor Summary

Constructors

Constructor and Description
CatmullRomSpline()
CatmullRomSpline(T[] controlPoints, boolean continuous)

Method Summary

Modifier and Type	Method and Description
float	approximate(T v)
float	approximate(T in, int near)
float	approximate(T in, int start, int count)
float	approxLength(int samples)
static <T extends Vector<T>> T	calculate(T out, float t, T[] points, boolean continuous, T tmp) Calculates the catmullrom value for the given position (t).
static <T extends Vector<T>> T	calculate(T out, int i, float u, T[] points, boolean continuous, T tmp) Calculates the catmullrom value for the given span (i) at the given position (u).
static <T extends Vector<T>> T	derivative(T out, float t, T[] points, boolean continuous, T tmp) Calculates the derivative of the catmullrom spline for the given position (t).
static <T extends Vector<T>> T	derivative(T out, int i, float u, T[] points, boolean continuous, T tmp) Calculates the derivative of the catmullrom spline for the given span (i) at the given position (u).
T	derivativeAt(T out, float t)
T	derivativeAt(T out, int span, float u)
float	locate(T v)
int	nearest(T in)
int	nearest(T in, int start, int count)
CatmullRomSpline	set(T[] controlPoints, boolean continuous)
T	valueAt(T out, float t)
T	valueAt(T out, int span, float u)

Methods inherited from class java.lang.Object

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

Field Detail

controlPoints

public T extends Vector<T>[] controlPoints

continuous

public boolean continuous

spanCount

public int spanCount

Constructor Detail

CatmullRomSpline

public CatmullRomSpline()

CatmullRomSpline

public CatmullRomSpline(T[] controlPoints,
                        boolean continuous)

Method Detail

calculate

public static <T extends Vector<T>> T calculate(T out,
                                                float t,
                                                T[] points,
                                                boolean continuous,
                                                T tmp)

Calculates the catmullrom value for the given position (t).

Parameters:

out - The Vector to set to the result.

t - The position (0<=t<=1) on the spline

points - The control points

continuous - If true the b-spline restarts at 0 when reaching 1

tmp - A temporary vector used for the calculation

Returns:

The value of out

calculate

public static <T extends Vector<T>> T calculate(T out,
                                                int i,
                                                float u,
                                                T[] points,
                                                boolean continuous,
                                                T tmp)

Calculates the catmullrom value for the given span (i) at the given position (u).

Parameters:

out - The Vector to set to the result.

i - The span (0<=i

u - The position (0<=u<=1) on the span

points - The control points

continuous - If true the b-spline restarts at 0 when reaching 1

tmp - A temporary vector used for the calculation

Returns:

The value of out

derivative

public static <T extends Vector<T>> T derivative(T out,
                                                 float t,
                                                 T[] points,
                                                 boolean continuous,
                                                 T tmp)

Calculates the derivative of the catmullrom spline for the given position (t).

Parameters:

out - The Vector to set to the result.

t - The position (0<=t<=1) on the spline

points - The control points

continuous - If true the b-spline restarts at 0 when reaching 1

tmp - A temporary vector used for the calculation

Returns:

The value of out

derivative

public static <T extends Vector<T>> T derivative(T out,
                                                 int i,
                                                 float u,
                                                 T[] points,
                                                 boolean continuous,
                                                 T tmp)

Calculates the derivative of the catmullrom spline for the given span (i) at the given position (u).

Parameters:

out - The Vector to set to the result.

i - The span (0<=i

u - The position (0<=u<=1) on the span

points - The control points

continuous - If true the b-spline restarts at 0 when reaching 1

tmp - A temporary vector used for the calculation

Returns:

The value of out

set

public CatmullRomSpline set(T[] controlPoints,
                            boolean continuous)

valueAt

public T valueAt(T out,
                 float t)

Specified by:

valueAt in interface Path<T extends Vector<T>>

Returns:

The value of the path at t where 0<=t<=1

valueAt

public T valueAt(T out,
                 int span,
                 float u)

Returns:

The value of the spline at position u of the specified span

derivativeAt

public T derivativeAt(T out,
                      float t)

Specified by:

derivativeAt in interface Path<T extends Vector<T>>

derivativeAt

public T derivativeAt(T out,
                      int span,
                      float u)

Returns:

The derivative of the spline at position u of the specified span

nearest

public int nearest(T in)

Returns:

The span closest to the specified value

nearest

public int nearest(T in,
                   int start,
                   int count)

Returns:

The span closest to the specified value, restricting to the specified spans.

approximate

public float approximate(T v)

Specified by:

approximate in interface Path<T extends Vector<T>>

Returns:

The approximated value (between 0 and 1) on the path which is closest to the specified value. Note that the implementation of this method might be optimized for speed against precision, see Path.locate(Object) for a more precise (but more intensive) method.

approximate

public float approximate(T in,
                         int start,
                         int count)

approximate

public float approximate(T in,
                         int near)

locate

public float locate(T v)

Specified by:

locate in interface Path<T extends Vector<T>>

Returns:

The precise location (between 0 and 1) on the path which is closest to the specified value. Note that the implementation of this method might be CPU intensive, see Path.approximate(Object) for a faster (but less precise) method.

approxLength

public float approxLength(int samples)

Specified by:

approxLength in interface Path<T extends Vector<T>>

Parameters:

samples - The amount of divisions used to approximate length. Higher values will produce more precise results, but will be more CPU intensive.

Returns:

An approximated length of the spline through sampling the curve and accumulating the euclidean distances between the sample points.