Package org.gephi.lib.gleem.linalg

Class Rotf

  • public class Rotf
extends Object
    Represents a rotation with single-precision components

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private static float EPSILON  
      private float q0  
      private float q1  
      private float q2  
      private float q3  

    • Constructor Summary

      Constructors 
      Constructor Description
      Rotf()
      Default constructor initializes to the identity quaternion
      Rotf​(Rotf arg)  
      Rotf​(Vec3f axis, float angle)
      Axis does not need to be normalized but must not be the zero vector.
      Rotf​(Vec3f from, Vec3f to)
      Creates a rotation which will rotate vector "from" into vector "to".

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void fromMatrix​(Mat4f mat)
      Turns the upper left 3x3 of the passed matrix into a rotation.
      float get​(Vec3f axis)
      Returns angle (in radians) and mutates the given vector to be the axis.
      void init()
      Re-initialize this quaternion to be the identity quaternion "e" (i.e., no rotation)
      Rotf inverse()
      Returns inverse of this rotation; creates new rotation
      void invert()
      Mutate this quaternion to be its inverse.
      float length()
      Length of this quaternion in four-space
      float lengthSquared()
      This dotted with this
      void mul​(Rotf a, Rotf b)
      Compose two rotations: this = A * B in that order.
      void normalize()
      Make this quaternion a unit quaternion again.
      Vec3f rotateVector​(Vec3f src)
      Rotate a vector by this quaternion, returning newly-allocated result.
      void rotateVector​(Vec3f src, Vec3f dest)
      Rotate a vector by this quaternion.
      void set​(Rotf arg)  
      void set​(Vec3f axis, float angle)
      Axis does not need to be normalized but must not be the zero vector.
      void set​(Vec3f from, Vec3f to)
      Sets this rotation to that which will rotate vector "from" into vector "to".
      private void setQ​(int i, float val)  
      Rotf times​(Rotf b)
      Returns this * b, in that order; creates new rotation
      void toMatrix​(Mat4f mat)
      Turns this rotation into a 3x3 rotation matrix.
      String toString()  
      boolean withinEpsilon​(Rotf arg, float epsilon)
      Test for "approximate equality" -- performs componentwise test to see whether difference between all components is less than epsilon.

    • Field Detail

      • q0

        private float q0

      • q1

        private float q1

      • q2

        private float q2

      • q3

        private float q3

    • Constructor Detail

      • Rotf

        public Rotf()
        Default constructor initializes to the identity quaternion

      • Rotf

        public Rotf​(Rotf arg)

      • Rotf

        public Rotf​(Vec3f axis,
            float angle)
        Axis does not need to be normalized but must not be the zero vector. Angle is in radians.

      • Rotf

        public Rotf​(Vec3f from,
            Vec3f to)
        Creates a rotation which will rotate vector "from" into vector "to".

    • Method Detail

      • init

        public void init()
        Re-initialize this quaternion to be the identity quaternion "e" (i.e., no rotation)

      • withinEpsilon

        public boolean withinEpsilon​(Rotf arg,
                             float epsilon)
        Test for "approximate equality" -- performs componentwise test to see whether difference between all components is less than epsilon.

      • set

        public void set​(Vec3f axis,
                float angle)
        Axis does not need to be normalized but must not be the zero vector. Angle is in radians.

      • set

        public void set​(Rotf arg)

      • set

        public void set​(Vec3f from,
                Vec3f to)
        Sets this rotation to that which will rotate vector "from" into vector "to". from and to do not have to be the same length.

      • get

        public float get​(Vec3f axis)
        Returns angle (in radians) and mutates the given vector to be the axis.

      • inverse

        public Rotf inverse()
        Returns inverse of this rotation; creates new rotation

      • invert

        public void invert()
        Mutate this quaternion to be its inverse. This is equivalent to the conjugate of the quaternion.

      • length

        public float length()
        Length of this quaternion in four-space

      • lengthSquared

        public float lengthSquared()
        This dotted with this

      • normalize

        public void normalize()
        Make this quaternion a unit quaternion again. If you are composing dozens of quaternions you probably should call this periodically to ensure that you have a valid rotation.

      • times

        public Rotf times​(Rotf b)
        Returns this * b, in that order; creates new rotation

      • mul

        public void mul​(Rotf a,
                Rotf b)
        Compose two rotations: this = A * B in that order. NOTE that because we assume a column vector representation that this implies that a vector rotated by the cumulative rotation will be rotated first by B, then A. NOTE: "this" must be different than both a and b.

      • toMatrix

        public void toMatrix​(Mat4f mat)
        Turns this rotation into a 3x3 rotation matrix. NOTE: only mutates the upper-left 3x3 of the passed Mat4f. Implementation from B. K. P. Horn's Robot Vision textbook.

      • rotateVector

        public void rotateVector​(Vec3f src,
                         Vec3f dest)
        Rotate a vector by this quaternion. Implementation is from Horn's Robot Vision. NOTE: src and dest must be different vectors.

      • rotateVector

        public Vec3f rotateVector​(Vec3f src)
        Rotate a vector by this quaternion, returning newly-allocated result.

      • setQ

        private void setQ​(int i,
                  float val)