Class MathUtils

java.lang.Object
com.blackrook.gui.struct.MathUtils
public final class MathUtils extends Object
A class with static methods that perform "other" types of mathematics.

A bunch of the collision/intersection algorithms found in this class are adapted from Real-Time Collision Detection by Christer Ericson (ISBN-13: 978-1-55860-732-3).

Author:
Matthew Tropiano

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final double
    PI_OVER_TWO
    PI over Two.
    static final double
    THREE_PI_OVER_TWO
    Three PI over Two.
    static final double
    TWO_PI
    Two PI.

  • Constructor Summary

    Constructors
    Constructor
    Description
    MathUtils()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    static double
    clampValue(double val, double lo, double hi)
    Coerces a double to the range bounded by lo and hi.
    static float
    clampValue(float val, float lo, float hi)
    Coerces a float to the range bounded by lo and hi.
    static int
    clampValue(int val, int lo, int hi)
    Coerces an integer to the range bounded by lo and hi.
    static short
    clampValue(short val, short lo, short hi)
    Coerces a short to the range bounded by lo and hi.
    static double
    degToRad(double degrees)
    Converts degrees to radians.
    static double
    getInterpolationFactor(double value, double lo, double hi)
    Gets a scalar factor that equals how "far along" a value is along an interval.
    static boolean
    getIntersectionBox(double spx, double spy, double shw, double shh, double tpx, double tpy, double thw, double thh)
    Tests if two boxes intersect.
    static boolean
    getIntersectionCircleBox(double ccx, double ccy, double crad, double bcx, double bcy, double bhw, double bhh)
    Returns if a circle and box intersect.
    static double
    getLineLength(double x0, double y0, double x1, double y1)
    Returns the length of a line by the coordinates of the two points that comprise it.
    static double
    getLineLengthSquared(double x0, double y0, double x1, double y1)
    Returns the squared length of a line by the coordinates of the two points that comprise it.
    static double
    getVectorLengthSquared(double x, double y)
    Returns the squared length of a vector by its components.
    static double
    linearInterpolate(double factor, double x, double y)
    Gives a value that is the result of a linear interpolation between two values.
    static double
    radToDeg(double radians)
    Converts radians to degrees.

    Methods inherited from class Object

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

  • Field Details

  • Constructor Details

    • MathUtils

      public MathUtils()

  • Method Details

    • radToDeg

      public static double radToDeg(double radians)
      Converts radians to degrees.
      Parameters:
      radians - the input angle in radians.
      Returns:
      the resultant angle in degrees.

    • degToRad

      public static double degToRad(double degrees)
      Converts degrees to radians.
      Parameters:
      degrees - the input angle in degrees.
      Returns:
      the resultant angle in radians.

    • clampValue

      public static int clampValue(int val, int lo, int hi)
      Coerces an integer to the range bounded by lo and hi.
      Example: clampValue(32,-16,16) returns 16.
      Example: clampValue(4,-16,16) returns 4.
      Example: clampValue(-1000,-16,16) returns -16.
      Parameters:
      val - the integer.
      lo - the lower bound.
      hi - the upper bound.
      Returns:
      the value after being "forced" into the range.

    • clampValue

      public static short clampValue(short val, short lo, short hi)
      Coerces a short to the range bounded by lo and hi.
      Example: clampValue(32,-16,16) returns 16.
      Example: clampValue(4,-16,16) returns 4.
      Example: clampValue(-1000,-16,16) returns -16.
      Parameters:
      val - the short.
      lo - the lower bound.
      hi - the upper bound.
      Returns:
      the value after being "forced" into the range.

    • clampValue

      public static float clampValue(float val, float lo, float hi)
      Coerces a float to the range bounded by lo and hi.
      Example: clampValue(32,-16,16) returns 16.
      Example: clampValue(4,-16,16) returns 4.
      Example: clampValue(-1000,-16,16) returns -16.
      Parameters:
      val - the float.
      lo - the lower bound.
      hi - the upper bound.
      Returns:
      the value after being "forced" into the range.

    • clampValue

      public static double clampValue(double val, double lo, double hi)
      Coerces a double to the range bounded by lo and hi.
      Example: clampValue(32,-16,16) returns 16.
      Example: clampValue(4,-16,16) returns 4.
      Example: clampValue(-1000,-16,16) returns -16.
      Parameters:
      val - the double.
      lo - the lower bound.
      hi - the upper bound.
      Returns:
      the value after being "forced" into the range.

    • linearInterpolate

      public static double linearInterpolate(double factor, double x, double y)
      Gives a value that is the result of a linear interpolation between two values.
      Parameters:
      factor - the interpolation factor.
      x - the first value.
      y - the second value.
      Returns:
      the interpolated value.

    • getInterpolationFactor

      public static double getInterpolationFactor(double value, double lo, double hi)
      Gets a scalar factor that equals how "far along" a value is along an interval.
      Parameters:
      value - the value to test.
      lo - the lower value of the interval.
      hi - the higher value of the interval.
      Returns:
      a value between 0 and 1 describing this distance (0 = beginning or less, 1 = end or greater), or 0 if lo and hi are equal.

    • getLineLength

      public static double getLineLength(double x0, double y0, double x1, double y1)
      Returns the length of a line by the coordinates of the two points that comprise it.
      Parameters:
      x0 - the first point's x-component.
      y0 - the first point's y-component.
      x1 - the second point's x-component.
      y1 - the second point's y-component.
      Returns:
      the length of the line.

    • getLineLengthSquared

      public static double getLineLengthSquared(double x0, double y0, double x1, double y1)
      Returns the squared length of a line by the coordinates of the two points that comprise it.
      Parameters:
      x0 - the first point's x-component.
      y0 - the first point's y-component.
      x1 - the second point's x-component.
      y1 - the second point's y-component.
      Returns:
      the length of the line.

    • getIntersectionCircleBox

      public static boolean getIntersectionCircleBox(double ccx, double ccy, double crad, double bcx, double bcy, double bhw, double bhh)
      Returns if a circle and box intersect.
      Parameters:
      ccx - the circle center, x-coordinate.
      ccy - the circle center, y-coordinate.
      crad - the circle radius.
      bcx - the box center, x-coordinate.
      bcy - the box center, y-coordinate.
      bhw - the box half width.
      bhh - the box half height.
      Returns:
      if an intersection occurred.

    • getIntersectionBox

      public static boolean getIntersectionBox(double spx, double spy, double shw, double shh, double tpx, double tpy, double thw, double thh)
      Tests if two boxes intersect.
      Parameters:
      spx - the first box center, x-coordinate.
      spy - the first box center, y-coordinate.
      shw - the first box half width.
      shh - the first box half height.
      tpx - the second box center, x-coordinate.
      tpy - the second box center, y-coordinate.
      thw - the second box half width.
      thh - the second box half height.
      Returns:
      true if an intersection occurred, false if not.

    • getVectorLengthSquared

      public static double getVectorLengthSquared(double x, double y)
      Returns the squared length of a vector by its components.
      Parameters:
      x - the x-component.
      y - the y-component.
      Returns:
      the length of the vector.