Package com.badlogic.gdx.math

Class BSpline<T extends Vector<T>>

  • All Implemented Interfaces:
    Path<T>
    public class BSpline<T extends Vector<T>>
extends java.lang.Object
implements Path<T>

    • Constructor Summary

      Constructors 
      Constructor Description
      BSpline()  
      BSpline​(T[] controlPoints, int degree, boolean continuous)  

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method 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, int degree, boolean continuous, T tmp)
      Calculates the n-degree b-spline value for the given position (t).
      static <T extends Vector<T>>
      T      		 calculate​(T out, int i, float u, T[] points, int degree, boolean continuous, T tmp)
      Calculates the n-degree b-spline value for the given span (i) at the given position (u).
      static <T extends Vector<T>>
      T      		 cubic​(T out, float t, T[] points, boolean continuous, T tmp)
      Calculates the cubic b-spline value for the given position (t).
      static <T extends Vector<T>>
      T      		 cubic​(T out, int i, float u, T[] points, boolean continuous, T tmp)
      Calculates the cubic b-spline value for the given span (i) at the given position (u).
      static <T extends Vector<T>>
      T      		 cubic_derivative​(T out, float t, T[] points, boolean continuous, T tmp)
      Calculates the cubic b-spline derivative for the given position (t).
      static <T extends Vector<T>>
      T      		 cubic_derivative​(T out, int i, float u, T[] points, boolean continuous, T tmp)
      Calculates the cubic b-spline derivative for the given span (i) at the given position (u).
      static <T extends Vector<T>>
      T      		 derivative​(T out, float t, T[] points, int degree, boolean continuous, T tmp)
      Calculates the n-degree b-spline derivative for the given position (t).
      static <T extends Vector<T>>
      T      		 derivative​(T out, int i, float u, T[] points, int degree, boolean continuous, T tmp)
      Calculates the n-degree b-spline derivative 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)  
      BSpline set​(T[] controlPoints, int degree, boolean continuous)  
      T valueAt​(T out, float t)  
      T valueAt​(T out, int span, float u)  

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • controlPoints

        public T extends Vector<T>[] controlPoints

      • degree

        public int degree

      • continuous

        public boolean continuous

      • spanCount

        public int spanCount

    • Constructor Detail

      • BSpline

        public BSpline()

      • BSpline

        public BSpline​(T[] controlPoints,
               int degree,
               boolean continuous)

    • Method Detail

      • cubic

        public static <T extends Vector<T>> T cubic​(T out,
                                            float t,
                                            T[] points,
                                            boolean continuous,
                                            T tmp)
        Calculates the cubic b-spline 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

      • cubic_derivative

        public static <T extends Vector<T>> T cubic_derivative​(T out,
                                                       float t,
                                                       T[] points,
                                                       boolean continuous,
                                                       T tmp)
        Calculates the cubic b-spline derivative 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

      • cubic

        public static <T extends Vector<T>> T cubic​(T out,
                                            int i,
                                            float u,
                                            T[] points,
                                            boolean continuous,
                                            T tmp)
        Calculates the cubic b-spline 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

      • cubic_derivative

        public static <T extends Vector<T>> T cubic_derivative​(T out,
                                                       int i,
                                                       float u,
                                                       T[] points,
                                                       boolean continuous,
                                                       T tmp)
        Calculates the cubic b-spline derivative 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

      • calculate

        public static <T extends Vector<T>> T calculate​(T out,
                                                float t,
                                                T[] points,
                                                int degree,
                                                boolean continuous,
                                                T tmp)
        Calculates the n-degree b-spline 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
        degree - The degree of the b-spline
        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,
                                                 int degree,
                                                 boolean continuous,
                                                 T tmp)
        Calculates the n-degree b-spline derivative 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
        degree - The degree of the b-spline
        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,
                                                int degree,
                                                boolean continuous,
                                                T tmp)
        Calculates the n-degree b-spline 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
        degree - The degree of the b-spline, only 3 is supported
        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,
                                                 int degree,
                                                 boolean continuous,
                                                 T tmp)
        Calculates the n-degree b-spline derivative 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
        degree - The degree of the b-spline, only 3 is supported
        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 BSpline set​(T[] controlPoints,
                   int degree,
                   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,
                      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.