/*******************************************************************************
* Copyright (c) 2011, Daniel Murphy
* All rights reserved.
*
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* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
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* * Neither the name of the <organization> nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
******************************************************************************/
/*
* JBox2D - A Java Port of Erin Catto's Box2D
*
* JBox2D homepage: http://jbox2d.sourceforge.net/
* Box2D homepage: http://www.box2d.org
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/
package org.jbox2d.common;
//Updated to rev. 142 of b2Settings.cpp/.h
/**
* Global tuning constants based on MKS units and various integer maximums
* (vertices per shape, pairs, etc.).
*/
public class Settings {
/** A "close to zero" float epsilon value for use */
public static final float EPSILON = 1.1920928955078125E-7f;
/** Pi. */
public static final float PI = (float) Math.PI;
// JBox2D specific settings
/**
* needs to be final, or will slow down math methods
*/
public static final boolean FAST_MATH = true;
public static final boolean POOLING = true;
public static final int CONTACT_STACK_INIT_SIZE = 10;
public static final boolean SINCOS_LUT_ENABLED = false;
/**
* 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 {@link SinCosTest}.</br> </br> Good lerp precision
* values:
* <ul>
* <li>.0092</li>
* <li>.008201</li>
* <li>.005904</li>
* <li>.005204</li>
* <li>.004305</li>
* <li>.002807</li>
* <li>.001508</li>
* <li>9.32500E-4</li>
* <li>7.48000E-4</li>
* <li>8.47000E-4</li>
* <li>.0005095</li>
* <li>.0001098</li>
* <li>9.50499E-5</li>
* <li>6.08500E-5</li>
* <li>3.07000E-5</li>
* <li>1.53999E-5</li>
* </ul>
*/
public static final float SINCOS_LUT_PRECISION = .00011f;
public static final int SINCOS_LUT_LENGTH = (int) Math.ceil(Math.PI * 2 / SINCOS_LUT_PRECISION);
/**
* 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 {@link SinCosTest}.
*/
public static final boolean SINCOS_LUT_LERP = false;
// Collision
/**
* The maximum number of contact points between two convex shapes.
*/
public static int maxManifoldPoints = 2;
/**
* The maximum number of vertices on a convex polygon.
*/
public static int maxPolygonVertices = 8;
/**
* 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.
*/
public static float aabbExtension = 0.1f;
/**
* 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.
*/
public static float aabbMultiplier = 2.0f;
/**
* A small length used as a collision and constraint tolerance. Usually it
* is chosen to be numerically significant, but visually insignificant.
*/
public static float linearSlop = 0.005f;
/**
* A small angle used as a collision and constraint tolerance. Usually it is
* chosen to be numerically significant, but visually insignificant.
*/
public static float angularSlop = (2.0f / 180.0f * PI);
/**
* 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.
*/
public static float polygonRadius = (2.0f * linearSlop);
// Dynamics
/**
* Maximum number of contacts to be handled to solve a TOI island.
*/
public static int maxTOIContacts = 32;
/**
* A velocity threshold for elastic collisions. Any collision with a
* relative linear velocity below this threshold will be treated as
* inelastic.
*/
public static float velocityThreshold = 1.0f;
/**
* The maximum linear position correction used when solving constraints.
* This helps to prevent overshoot.
*/
public static float maxLinearCorrection = 0.2f;
/**
* The maximum angular position correction used when solving constraints.
* This helps to prevent overshoot.
*/
public static float maxAngularCorrection = (8.0f / 180.0f * PI);
/**
* 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.
*/
public static float maxTranslation = 2.0f;
public static float maxTranslationSquared = (maxTranslation * maxTranslation);
/**
* 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.
*/
public static float maxRotation = (0.5f * PI);
public static float maxRotationSquared = (maxRotation * maxRotation);
/**
* 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.
*/
public static float contactBaumgarte = 0.2f;
// Sleep
/**
* The time that a body must be still before it will go to sleep.
*/
public static float timeToSleep = 0.5f;
/**
* A body cannot sleep if its linear velocity is above this tolerance.
*/
public static float linearSleepTolerance = 0.01f;
/**
* A body cannot sleep if its angular velocity is above this tolerance.
*/
public static float angularSleepTolerance = (2.0f / 180.0f * PI);
/**
* Friction mixing law. Feel free to customize this.
* TODO djm: add customization
*
* @param friction1
* @param friction2
* @return
*/
public static final float mixFriction(float friction1, float friction2) {
return MathUtils.sqrt(friction1 * friction2);
}
/**
* Restitution mixing law. Feel free to customize this.
* TODO djm: add customization
*
* @param restitution1
* @param restitution2
* @return
*/
public static final float mixRestitution(float restitution1, float restitution2) {
return restitution1 > restitution2 ? restitution1 : restitution2;
}
}
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