Package gaiasky.util.math

Class MathUtilsd

java.lang.Object
gaiasky.util.math.MathUtilsd
public final class MathUtilsd extends Object
Utility and fast math functions.

Thanks to Riven on JavaGaming.org for the basis of sin/cos/atan2/floor/ceil.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final double
    degRad
     
    static final double
    degreesToRadians
    multiply by this to convert from degrees to radians
    static final double
    E
     
    static final double
    FLOAT_ROUNDING_ERROR
     
    static final double
    nanoToSec
     
    static final double
    PI
     
    static final double
    PI2
     
    static final double
    radDeg
     
    static final double
    radiansToDegrees
    multiply by this to convert from radians to degrees
    static Random
    random
     

  • Constructor Summary

    Constructors
    Constructor
    Description
    MathUtilsd()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    static double
    atan2(double y, double x)
    Returns atan2 in radians, faster but less accurate than Math.atan2.
    static double
    clamp(double value, double min, double max)
     
    static float
    clamp(float value, float min, float max)
     
    static int
    clamp(int value, int min, int max)
     
    static short
    clamp(short value, short min, short max)
     
    static double
    cos(double radians)
    Returns the cosine in radians from a lookup table.
    static double
    cosDeg(double degrees)
    Returns the cosine in radians from a lookup table.
    static double
    distancePointLine(double x1, double y1, double z1, double x2, double y2, double z2, double x0, double y0, double z0)
    Gets the distance from the point x0 to the line denoted by x1-x2.
    Check this link
    static double
    distancePointSegment(double x1, double y1, double z1, double x2, double y2, double z2, double x0, double y0, double z0)
    Gets the distance from the point p0 to the segment denoted by p1-p2.
    Check this link.
    static double
    eint(double x, double x0, double x1, double y0, double y1, double exp)
    Does an exponential interpolation: y = y0 + (y1-y0) * 10 ^ (exp * (x-x0)/(x1-x0))
    static Vector3d
    getClosestPoint(double x1, double y1, double z1, double x2, double y2, double z2, double x0, double y0, double z0)
    Gets the closest point on the line p1-p2 from p0.
    Check this link.
    static Vector3d
    getClosestPoint2(double x1, double y1, double z1, double x2, double y2, double z2, double x0, double y0, double z0, Vector3d result)
     
    static boolean
    isEqual(double a, double b)
    Returns true if a is nearly equal to b.
    static boolean
    isEqual(double a, double b, double tolerance)
    Returns true if a is nearly equal to b.
    static boolean
    isZero(double value)
    Returns true if the value is zero (using the default tolerance as upper bound)
    static boolean
    isZero(double value, double tolerance)
    Returns true if the value is zero.
    static double
    lerp(double x, double y, double a)
     
    static float
    lerp(float x, float y, float a)
     
    static long
    lerp(long x, long y, long a)
     
    static double
    lint(double x, double x0, double x1, double y0, double y1)
    Linear interpolation
    static float
    lint(float x, float x0, float x1, float y0, float y1)
    Linear interpolation
    static float
    lint(long x, long x0, long x1, float y0, float y1)
    Linear interpolation
    static Vector3d
    perpendicular(Vector3d in, Vector3d out)
    Gets perpendicular vector to in vector
    static double
    random()
    Returns random number between 0.0 (inclusive) and 1.0 (exclusive).
    static double
    random(double range)
    Returns a random number between 0 (inclusive) and the specified value (exclusive).
    static double
    random(double start, double end)
    Returns a random number between start (inclusive) and end (exclusive).
    static int
    random(int range)
    Returns a random number between 0 (inclusive) and the specified value (inclusive).
    static int
    random(int start, int end)
    Returns a random number between start (inclusive) and end (inclusive).
    static long
    random(long range)
    Returns a random number between 0 (inclusive) and the specified value (inclusive).
    static long
    random(long start, long end)
    Returns a random number between start (inclusive) and end (inclusive).
    static boolean
    randomBoolean()
    Returns a random boolean value.
    static boolean
    randomBoolean(double chance)
    Returns true if a random value between 0 and 1 is less than the specified value.
    static int
    randomSign()
    Returns -1 or 1, randomly.
    static double
    randomTriangular()
    Returns a triangularly distributed random number between -1.0 (exclusive) and 1.0 (exclusive), where values around zero are more likely.
    static double
    randomTriangular(double max)
    Returns a triangularly distributed random number between -max (exclusive) and max (exclusive), where values around zero are more likely.
    static double
    randomTriangular(double min, double max)
    Returns a triangularly distributed random number between min (inclusive) and max (exclusive), where the mode argument defaults to the midpoint between the bounds, giving a symmetric distribution.
    static double
    randomTriangular(double min, double max, double mode)
    Returns a triangularly distributed random number between min (inclusive) and max (exclusive), where values around mode are more likely.
    static double
    roundAvoid(double value, int places)
    Rounds the double value to a number of decimal places
    static double
    sin(double radians)
    Returns the sine in radians from a lookup table.
    static double
    sinDeg(double degrees)
    Returns the sine in radians from a lookup table.
    static double
    sqrt(double value)
    Fast sqrt method.

    Methods inherited from class java.lang.Object

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

  • Field Details

  • Constructor Details

    • MathUtilsd

      public MathUtilsd()

  • Method Details

    • sin

      public static double sin(double radians)
      Returns the sine in radians from a lookup table.

    • cos

      public static double cos(double radians)
      Returns the cosine in radians from a lookup table.

    • sinDeg

      public static double sinDeg(double degrees)
      Returns the sine in radians from a lookup table.

    • cosDeg

      public static double cosDeg(double degrees)
      Returns the cosine in radians from a lookup table.

    • atan2

      public static double atan2(double y, double x)
      Returns atan2 in radians, faster but less accurate than Math.atan2. Average error of 0.00231 radians (0.1323 degrees), largest error of 0.00488 radians (0.2796 degrees).

    • random

      public static int random(int range)
      Returns a random number between 0 (inclusive) and the specified value (inclusive).

    • random

      public static int random(int start, int end)
      Returns a random number between start (inclusive) and end (inclusive).

    • random

      public static long random(long range)
      Returns a random number between 0 (inclusive) and the specified value (inclusive).

    • random

      public static long random(long start, long end)
      Returns a random number between start (inclusive) and end (inclusive).

    • randomBoolean

      public static boolean randomBoolean()
      Returns a random boolean value.

    • randomBoolean

      public static boolean randomBoolean(double chance)
      Returns true if a random value between 0 and 1 is less than the specified value.

    • random

      public static double random()
      Returns random number between 0.0 (inclusive) and 1.0 (exclusive).

    • random

      public static double random(double range)
      Returns a random number between 0 (inclusive) and the specified value (exclusive).

    • random

      public static double random(double start, double end)
      Returns a random number between start (inclusive) and end (exclusive).

    • randomSign

      public static int randomSign()
      Returns -1 or 1, randomly.

    • randomTriangular

      public static double randomTriangular()
      Returns a triangularly distributed random number between -1.0 (exclusive) and 1.0 (exclusive), where values around zero are more likely.

      This is an optimized version of randomTriangular(-1, 1, 0)

    • randomTriangular

      public static double randomTriangular(double max)
      Returns a triangularly distributed random number between -max (exclusive) and max (exclusive), where values around zero are more likely.

      This is an optimized version of randomTriangular(-max, max, 0)

      Parameters:
      max - the upper limit

    • randomTriangular

      public static double randomTriangular(double min, double max)
      Returns a triangularly distributed random number between min (inclusive) and max (exclusive), where the mode argument defaults to the midpoint between the bounds, giving a symmetric distribution.

      This method is equivalent of randomTriangular(min, max, (min + max) * .5f)

      Parameters:
      min - the lower limit
      max - the upper limit

    • randomTriangular

      public static double randomTriangular(double min, double max, double mode)
      Returns a triangularly distributed random number between min (inclusive) and max (exclusive), where values around mode are more likely.
      Parameters:
      min - the lower limit
      max - the upper limit
      mode - the point around which the values are more likely

    • clamp

      public static int clamp(int value, int min, int max)

    • clamp

      public static short clamp(short value, short min, short max)

    • clamp

      public static float clamp(float value, float min, float max)

    • clamp

      public static double clamp(double value, double min, double max)

    • isZero

      public static boolean isZero(double value)
      Returns true if the value is zero (using the default tolerance as upper bound)

    • isZero

      public static boolean isZero(double value, double tolerance)
      Returns true if the value is zero.
      Parameters:
      tolerance - represent an upper bound below which the value is considered zero.

    • isEqual

      public static boolean isEqual(double a, double b)
      Returns true if a is nearly equal to b. The function uses the default doubleing error tolerance.
      Parameters:
      a - the first value.
      b - the second value.

    • isEqual

      public static boolean isEqual(double a, double b, double tolerance)
      Returns true if a is nearly equal to b.
      Parameters:
      a - the first value.
      b - the second value.
      tolerance - represent an upper bound below which the two values are considered equal.

    • sqrt

      public static double sqrt(double value)
      Fast sqrt method. Default passes it through one round of Newton's method
      Parameters:
      value - The value
      Returns:
      The square root value

    • eint

      public static double eint(double x, double x0, double x1, double y0, double y1, double exp)
      Does an exponential interpolation: y = y0 + (y1-y0) * 10 ^ (exp * (x-x0)/(x1-x0))
      Parameters:
      x -
      x0 -
      x1 -
      y0 -
      y1 -
      exp -
      Returns:

    • lint

      public static double lint(double x, double x0, double x1, double y0, double y1)
      Linear interpolation
      Parameters:
      x - The value to interpolate
      x0 - Inferior limit to the independent value
      x1 - Superior limit to the independent value
      y0 - Inferior limit to the dependent value
      y1 - Superior limit to the dependent value
      Returns:
      The interpolated value

    • lerp

      public static double lerp(double x, double y, double a)

    • lint

      public static float lint(float x, float x0, float x1, float y0, float y1)
      Linear interpolation
      Parameters:
      x - The value to interpolate
      x0 - Inferior limit to the independent value
      x1 - Superior limit to the independent value
      y0 - Inferior limit to the dependent value
      y1 - Superior limit to the dependent value
      Returns:
      The interpolated value

    • lerp

      public static float lerp(float x, float y, float a)

    • lint

      public static float lint(long x, long x0, long x1, float y0, float y1)
      Linear interpolation
      Parameters:
      x - The value to interpolate
      x0 - Inferior limit to the independent value
      x1 - Superior limit to the independent value
      y0 - Inferior limit to the dependent value
      y1 - Superior limit to the dependent value
      Returns:
      The interpolated value

    • lerp

      public static long lerp(long x, long y, long a)

    • distancePointLine

      public static double distancePointLine(double x1, double y1, double z1, double x2, double y2, double z2, double x0, double y0, double z0)
      Gets the distance from the point x0 to the line denoted by x1-x2.
      Check this link
      Parameters:
      x1 - The first point in the line
      x2 - The second point in the line
      x0 - The point
      Returns:
      The Euclidean distance between the line (x1, x2) and x0

    • distancePointSegment

      public static double distancePointSegment(double x1, double y1, double z1, double x2, double y2, double z2, double x0, double y0, double z0)
      Gets the distance from the point p0 to the segment denoted by p1-p2.
      Check this link.
      Parameters:
      x1 - The first segment delimiter.
      x2 - The second segment delimiter.
      x0 - The point.
      Returns:
      The Euclidean distance between the segment (x1, x2)

    • getClosestPoint

      public static Vector3d getClosestPoint(double x1, double y1, double z1, double x2, double y2, double z2, double x0, double y0, double z0)
      Gets the closest point on the line p1-p2 from p0.
      Check this link.
      Parameters:
      x1 - The first segment delimiter.
      x2 - The second segment delimiter.
      x0 - The point.
      Returns:
      The vector with the closest point on the line to p0

    • getClosestPoint2

      public static Vector3d getClosestPoint2(double x1, double y1, double z1, double x2, double y2, double z2, double x0, double y0, double z0, Vector3d result)

    • perpendicular

      public static Vector3d perpendicular(Vector3d in, Vector3d out)
      Gets perpendicular vector to in vector
      Parameters:
      in -
      Returns:

    • roundAvoid

      public static double roundAvoid(double value, int places)
      Rounds the double value to a number of decimal places
      Parameters:
      value - The value to round
      places - The number of decimal places
      Returns:
      The rounded value