Class Settings

java.lang.Object
org.jbox2d.common.Settings

public class Settings extends java.lang.Object
Global tuning constants based on MKS units and various integer maximums (vertices per shape, pairs, etc.).
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final float
    This is used to fatten AABBs in the dynamic tree.
    static final float
    This is used to fatten AABBs in the dynamic tree.
    static final float
    A body cannot sleep if its angular velocity is above this tolerance.
    static final float
    A small angle used as a collision and constraint tolerance.
    static final float
    This scale factor controls how fast overlap is resolved.
    static int
     
    static final float
    A "close to zero" float epsilon value for use
    static boolean
     
    static boolean
     
    static boolean
     
    static boolean
     
    static boolean
     
    static final float
    A body cannot sleep if its linear velocity is above this tolerance.
    static final float
    A small length used as a collision and constraint tolerance.
    static final float
    The maximum angular position correction used when solving constraints.
    static final float
    The maximum linear position correction used when solving constraints.
    static final int
    The maximum number of contact points between two convex shapes.
    static final int
    The maximum number of vertices on a convex polygon.
    static final float
    The maximum angular velocity of a body.
    static float
     
    static final int
    Maximum number of sub-steps per contact in continuous physics simulation.
    static final int
    Maximum number of contacts to be handled to solve a TOI island.
    static final float
    The maximum linear velocity of a body.
    static final float
     
    static final float
    Pi.
    static final float
    The radius of the polygon/edge shape skin.
    static boolean
     
    static final int
     
    static boolean
    Use if the table's precision is large (eg .006 or greater).
    static final float
    smaller the precision, the larger the table.
    static final float
    The time that a body must be still before it will go to sleep.
    static final float
     
    static final float
    A velocity threshold for elastic collisions.
  • Constructor Summary

    Constructors
    Constructor
    Description
     
  • Method Summary

    Modifier and Type
    Method
    Description
    static final float
    mixFriction(float friction1, float friction2)
    Friction mixing law.
    static final float
    mixRestitution(float restitution1, float restitution2)
    Restitution mixing law.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Field Details

    • EPSILON

      public static final float EPSILON
      A "close to zero" float epsilon value for use
      See Also:
    • PI

      public static final float PI
      Pi.
      See Also:
    • FAST_ABS

      public static boolean FAST_ABS
    • FAST_FLOOR

      public static boolean FAST_FLOOR
    • FAST_CEIL

      public static boolean FAST_CEIL
    • FAST_ROUND

      public static boolean FAST_ROUND
    • FAST_ATAN2

      public static boolean FAST_ATAN2
    • CONTACT_STACK_INIT_SIZE

      public static int CONTACT_STACK_INIT_SIZE
    • SINCOS_LUT_ENABLED

      public static boolean SINCOS_LUT_ENABLED
    • SINCOS_LUT_PRECISION

      public static final float SINCOS_LUT_PRECISION
      smaller the precision, the larger the table. If a small table is used (eg, precision is .006 or greater), make sure you set the table to lerp it's results. Accuracy chart is in the MathUtils source. Or, run the tests yourself in
      invalid reference
      SinCosTest
      .

      Good lerp precision values:
      • .0092
      • .008201
      • .005904
      • .005204
      • .004305
      • .002807
      • .001508
      • 9.32500E-4
      • 7.48000E-4
      • 8.47000E-4
      • .0005095
      • .0001098
      • 9.50499E-5
      • 6.08500E-5
      • 3.07000E-5
      • 1.53999E-5
      See Also:
    • SINCOS_LUT_LENGTH

      public static final int SINCOS_LUT_LENGTH
    • SINCOS_LUT_LERP

      public static boolean SINCOS_LUT_LERP
      Use if the table's precision is large (eg .006 or greater). Although it is more expensive, it greatly increases accuracy. Look in the MathUtils source for some test results on the accuracy and speed of lerp vs non lerp. Or, run the tests yourself in
      invalid reference
      SinCosTest
      .
    • maxManifoldPoints

      public static final int maxManifoldPoints
      The maximum number of contact points between two convex shapes.
      See Also:
    • maxPolygonVertices

      public static final int maxPolygonVertices
      The maximum number of vertices on a convex polygon.
      See Also:
    • aabbExtension

      public static final float aabbExtension
      This is used to fatten AABBs in the dynamic tree. This allows proxies to move by a small amount without triggering a tree adjustment. This is in meters.
      See Also:
    • aabbMultiplier

      public static final float aabbMultiplier
      This is used to fatten AABBs in the dynamic tree. This is used to predict the future position based on the current displacement. This is a dimensionless multiplier.
      See Also:
    • linearSlop

      public static final float linearSlop
      A small length used as a collision and constraint tolerance. Usually it is chosen to be numerically significant, but visually insignificant.
      See Also:
    • angularSlop

      public static final float angularSlop
      A small angle used as a collision and constraint tolerance. Usually it is chosen to be numerically significant, but visually insignificant.
      See Also:
    • polygonRadius

      public static final float polygonRadius
      The radius of the polygon/edge shape skin. This should not be modified. Making this smaller means polygons will have and insufficient for continuous collision. Making it larger may create artifacts for vertex collision.
      See Also:
    • maxSubSteps

      public static final int maxSubSteps
      Maximum number of sub-steps per contact in continuous physics simulation.
      See Also:
    • maxTOIContacts

      public static final int maxTOIContacts
      Maximum number of contacts to be handled to solve a TOI island.
      See Also:
    • velocityThreshold

      public static final float velocityThreshold
      A velocity threshold for elastic collisions. Any collision with a relative linear velocity below this threshold will be treated as inelastic.
      See Also:
    • maxLinearCorrection

      public static final float maxLinearCorrection
      The maximum linear position correction used when solving constraints. This helps to prevent overshoot.
      See Also:
    • maxAngularCorrection

      public static final float maxAngularCorrection
      The maximum angular position correction used when solving constraints. This helps to prevent overshoot.
      See Also:
    • maxTranslation

      public static final float maxTranslation
      The maximum linear velocity of a body. This limit is very large and is used to prevent numerical problems. You shouldn't need to adjust this.
      See Also:
    • maxTranslationSquared

      public static final float maxTranslationSquared
      See Also:
    • maxRotation

      public static final float maxRotation
      The maximum angular velocity of a body. This limit is very large and is used to prevent numerical problems. You shouldn't need to adjust this.
      See Also:
    • maxRotationSquared

      public static float maxRotationSquared
    • baumgarte

      public static final float baumgarte
      This scale factor controls how fast overlap is resolved. Ideally this would be 1 so that overlap is removed in one time step. However using values close to 1 often lead to overshoot.
      See Also:
    • toiBaugarte

      public static final float toiBaugarte
      See Also:
    • timeToSleep

      public static final float timeToSleep
      The time that a body must be still before it will go to sleep.
      See Also:
    • linearSleepTolerance

      public static final float linearSleepTolerance
      A body cannot sleep if its linear velocity is above this tolerance.
      See Also:
    • angularSleepTolerance

      public static final float angularSleepTolerance
      A body cannot sleep if its angular velocity is above this tolerance.
      See Also:
  • Constructor Details

    • Settings

      public Settings()
  • Method Details

    • mixFriction

      public static final float mixFriction(float friction1, float friction2)
      Friction mixing law. Feel free to customize this. TODO djm: add customization
      Parameters:
      friction1 -
      friction2 -
      Returns:
    • mixRestitution

      public static final float mixRestitution(float restitution1, float restitution2)
      Restitution mixing law. Feel free to customize this. TODO djm: add customization
      Parameters:
      restitution1 -
      restitution2 -
      Returns: