Package org.jbox2d.common

Class Settings

java.lang.Object
org.jbox2d.common.Settings
public class Settings extends Object
Global tuning constants based on MKS units and various integer maximums (vertices per shape, pairs, etc.).
Author:
Daniel Murphy

  • 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

    • FAST_POW

      public static boolean FAST_POW

    • 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 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 SinCosTest.

    • maxManifoldPoints

      public static int maxManifoldPoints
      The maximum number of contact points between two convex shapes.

    • maxPolygonVertices

      public static int maxPolygonVertices
      The maximum number of vertices on a convex polygon.

    • aabbExtension

      public static 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.

    • aabbMultiplier

      public static 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.

    • linearSlop

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

    • angularSlop

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

    • polygonRadius

      public static 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.

    • maxSubSteps

      public static int maxSubSteps
      Maximum number of sub-steps per contact in continuous physics simulation.

    • maxTOIContacts

      public static int maxTOIContacts
      Maximum number of contacts to be handled to solve a TOI island.

    • velocityThreshold

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

    • maxLinearCorrection

      public static float maxLinearCorrection
      The maximum linear position correction used when solving constraints. This helps to prevent overshoot.

    • maxAngularCorrection

      public static float maxAngularCorrection
      The maximum angular position correction used when solving constraints. This helps to prevent overshoot.

    • maxTranslation

      public static 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.

    • maxTranslationSquared

      public static float maxTranslationSquared

    • maxRotation

      public static 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.

    • maxRotationSquared

      public static float maxRotationSquared

    • baumgarte

      public static 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.

    • toiBaugarte

      public static float toiBaugarte

    • timeToSleep

      public static float timeToSleep
      The time that a body must be still before it will go to sleep.

    • linearSleepTolerance

      public static float linearSleepTolerance
      A body cannot sleep if its linear velocity is above this tolerance.

    • angularSleepTolerance

      public static float angularSleepTolerance
      A body cannot sleep if its angular velocity is above this tolerance.

    • invalidParticleIndex

      public static final int invalidParticleIndex
      A symbolic constant that stands for particle allocation error.
      See Also:

    • particleStride

      public static final float particleStride
      The standard distance between particles, divided by the particle radius.
      See Also:

    • minParticleWeight

      public static final float minParticleWeight
      The minimum particle weight that produces pressure.
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    • maxParticleWeight

      public static final float maxParticleWeight
      The upper limit for particle weight used in pressure calculation.
      See Also:

    • maxTriadDistance

      public static final int maxTriadDistance
      The maximum distance between particles in a triad, divided by the particle radius.
      See Also:

    • maxTriadDistanceSquared

      public static final int maxTriadDistanceSquared
      See Also:

    • minParticleBufferCapacity

      public static final int minParticleBufferCapacity
      The initial size of particle data buffers.
      See Also:

  • Constructor Details

    • Settings

      public Settings()

  • Method Details

    • mixFriction

      public static float mixFriction(float friction1, float friction2)
      Friction mixing law. Feel free to customize this. TODO djm: add customization

    • mixRestitution

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