Package edu.wpi.first.math.geometry

Class Translation2d

java.lang.Object
edu.wpi.first.math.geometry.Translation2d
All Implemented Interfaces:
Interpolatable<Translation2d>, ProtobufSerializable, StructSerializable, WPISerializable
public class Translation2d extends Object implements Interpolatable<Translation2d>, ProtobufSerializable, StructSerializable
Represents a translation in 2D space. This object can be used to represent a point or a vector.

This assumes that you are using conventional mathematical axes. When the robot is at the origin facing in the positive X direction, forward is positive X and left is positive Y.

  • Field Details

    • kZero

      public static final Translation2d kZero
      A preallocated Translation2d representing the origin.

      This exists to avoid allocations for common translations.

    • proto

      public static final Translation2dProto proto
      Translation2d protobuf for serialization.

    • struct

      public static final Translation2dStruct struct
      Translation2d struct for serialization.

  • Constructor Details

    • Translation2d

      public Translation2d()
      Constructs a Translation2d with X and Y components equal to zero.

    • Translation2d

      public Translation2d(double x, double y)
      Constructs a Translation2d with the X and Y components equal to the provided values.
      Parameters:
      x - The x component of the translation.
      y - The y component of the translation.

    • Translation2d

      public Translation2d(double distance, Rotation2d angle)
      Constructs a Translation2d with the provided distance and angle. This is essentially converting from polar coordinates to Cartesian coordinates.
      Parameters:
      distance - The distance from the origin to the end of the translation.
      angle - The angle between the x-axis and the translation vector.

    • Translation2d

      public Translation2d(Distance x, Distance y)
      Constructs a Translation2d with the X and Y components equal to the provided values. The X and Y components will be converted to and tracked as meters.
      Parameters:
      x - The x component of the translation.
      y - The y component of the translation.

    • Translation2d

      public Translation2d(Vector<N2> vector)
      Constructs a Translation2d from a 2D translation vector. The values are assumed to be in meters.
      Parameters:
      vector - The translation vector.

  • Method Details

    • getDistance

      public double getDistance(Translation2d other)
      Calculates the distance between two translations in 2D space.

      The distance between translations is defined as √((x₂−x₁)²+(y₂−y₁)²).

      Parameters:
      other - The translation to compute the distance to.
      Returns:
      The distance between the two translations.

    • getSquaredDistance

      public double getSquaredDistance(Translation2d other)
      Calculates the square of the distance between two translations in 2D space. This is equivalent to squaring the result of getDistance(Translation2d), but avoids computing a square root.

      The square of the distance between translations is defined as (x₂−x₁)²+(y₂−y₁)².

      Parameters:
      other - The translation to compute the squared distance to.
      Returns:
      The square of the distance between the two translations, in square meters.

    • getX

      public double getX()
      Returns the X component of the translation.
      Returns:
      The X component of the translation.

    • getY

      public double getY()
      Returns the Y component of the translation.
      Returns:
      The Y component of the translation.

    • getMeasureX

      public Distance getMeasureX()
      Returns the X component of the translation in a measure.
      Returns:
      The x component of the translation in a measure.

    • getMeasureY

      public Distance getMeasureY()
      Returns the Y component of the translation in a measure.
      Returns:
      The y component of the translation in a measure.

    • toVector

      public Vector<N2> toVector()
      Returns a 2D translation vector representation of this translation.
      Returns:
      A 2D translation vector representation of this translation.

    • getNorm

      public double getNorm()
      Returns the norm, or distance from the origin to the translation.
      Returns:
      The norm of the translation.

    • getSquaredNorm

      public double getSquaredNorm()
      Returns the squared norm, or squared distance from the origin to the translation. This is equivalent to squaring the result of getNorm(), but avoids computing a square root.
      Returns:
      The squared norm of the translation, in square meters.

    • getAngle

      public Rotation2d getAngle()
      Returns the angle this translation forms with the positive X axis.
      Returns:
      The angle of the translation

    • rotateBy

      public Translation2d rotateBy(Rotation2d other)
      Applies a rotation to the translation in 2D space.

      This multiplies the translation vector by a counterclockwise rotation matrix of the given angle. 

       [x_new]   [other.cos, -other.sin][x]
 [y_new] = [other.sin,  other.cos][y]

      For example, rotating a Translation2d of <2, 0> by 90 degrees will return a Translation2d of <0, 2>.

      Parameters:
      other - The rotation to rotate the translation by.
      Returns:
      The new rotated translation.

    • rotateAround

      public Translation2d rotateAround(Translation2d other, Rotation2d rot)
      Rotates this translation around another translation in 2D space. 
       [x_new]   [rot.cos, -rot.sin][x - other.x]   [other.x]
 [y_new] = [rot.sin,  rot.cos][y - other.y] + [other.y]
      Parameters:
      other - The other translation to rotate around.
      rot - The rotation to rotate the translation by.
      Returns:
      The new rotated translation.

    • dot

      public double dot(Translation2d other)
      Computes the dot product between this translation and another translation in 2D space.

      The dot product between two translations is defined as x₁x₂+y₁y₂.

      Parameters:
      other - The translation to compute the dot product with.
      Returns:
      The dot product between the two translations, in square meters.

    • cross

      public double cross(Translation2d other)
      Computes the cross product between this translation and another translation in 2D space.

      The 2D cross product between two translations is defined as x₁y₂-x₂y₁.

      Parameters:
      other - The translation to compute the cross product with.
      Returns:
      The cross product between the two translations, in square meters.

    • plus

      public Translation2d plus(Translation2d other)
      Returns the sum of two translations in 2D space.

      For example, Translation3d(1.0, 2.5) + Translation3d(2.0, 5.5) = Translation3d{3.0, 8.0).

      Parameters:
      other - The translation to add.
      Returns:
      The sum of the translations.

    • minus

      public Translation2d minus(Translation2d other)
      Returns the difference between two translations.

      For example, Translation2d(5.0, 4.0) - Translation2d(1.0, 2.0) = Translation2d(4.0, 2.0).

      Parameters:
      other - The translation to subtract.
      Returns:
      The difference between the two translations.

    • unaryMinus

      public Translation2d unaryMinus()
      Returns the inverse of the current translation. This is equivalent to rotating by 180 degrees, flipping the point over both axes, or negating all components of the translation.
      Returns:
      The inverse of the current translation.

    • times

      public Translation2d times(double scalar)
      Returns the translation multiplied by a scalar.

      For example, Translation2d(2.0, 2.5) * 2 = Translation2d(4.0, 5.0).

      Parameters:
      scalar - The scalar to multiply by.
      Returns:
      The scaled translation.

    • div

      public Translation2d div(double scalar)
      Returns the translation divided by a scalar.

      For example, Translation3d(2.0, 2.5) / 2 = Translation3d(1.0, 1.25).

      Parameters:
      scalar - The scalar to multiply by.
      Returns:
      The reference to the new mutated object.

    • nearest

      public Translation2d nearest(Collection<Translation2d> translations)
      Returns the nearest Translation2d from a collection of translations.
      Parameters:
      translations - The collection of translations.
      Returns:
      The nearest Translation2d from the collection.

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • equals

      public boolean equals(Object obj)
      Checks equality between this Translation2d and another object.
      Overrides:
      equals in class Object
      Parameters:
      obj - The other object.
      Returns:
      Whether the two objects are equal or not.

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • interpolate

      public Translation2d interpolate(Translation2d endValue, double t)
      Description copied from interface: Interpolatable
      Return the interpolated value. This object is assumed to be the starting position, or lower bound.
      Specified by:
      interpolate in interface Interpolatable<Translation2d>
      Parameters:
      endValue - The upper bound, or end.
      t - How far between the lower and upper bound we are. This should be bounded in [0, 1].
      Returns:
      The interpolated value.