Update Files

lib/haxebullet/bullet/BulletDynamics/ConstraintSolver/btUniversalConstraint.cpp

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+/*
+Bullet Continuous Collision Detection and Physics Library, http://bulletphysics.org
+Copyright (C) 2006, 2007 Sony Computer Entertainment Inc. 
+
+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.
+*/
+
+
+
+#include "btUniversalConstraint.h"
+#include "BulletDynamics/Dynamics/btRigidBody.h"
+#include "LinearMath/btTransformUtil.h"
+
+
+
+#define UNIV_EPS btScalar(0.01f)
+
+
+// constructor
+// anchor, axis1 and axis2 are in world coordinate system
+// axis1 must be orthogonal to axis2
+btUniversalConstraint::btUniversalConstraint(btRigidBody& rbA, btRigidBody& rbB, const btVector3& anchor, const btVector3& axis1, const btVector3& axis2)
+: btGeneric6DofConstraint(rbA, rbB, btTransform::getIdentity(), btTransform::getIdentity(), true),
+ m_anchor(anchor),
+ m_axis1(axis1),
+ m_axis2(axis2)
+{
+	// build frame basis
+	// 6DOF constraint uses Euler angles and to define limits
+	// it is assumed that rotational order is :
+	// Z - first, allowed limits are (-PI,PI);
+	// new position of Y - second (allowed limits are (-PI/2 + epsilon, PI/2 - epsilon), where epsilon is a small positive number 
+	// used to prevent constraint from instability on poles;
+	// new position of X, allowed limits are (-PI,PI);
+	// So to simulate ODE Universal joint we should use parent axis as Z, child axis as Y and limit all other DOFs
+	// Build the frame in world coordinate system first
+	btVector3 zAxis = m_axis1.normalize();
+	btVector3 yAxis = m_axis2.normalize();
+	btVector3 xAxis = yAxis.cross(zAxis); // we want right coordinate system
+	btTransform frameInW;
+	frameInW.setIdentity();
+	frameInW.getBasis().setValue(	xAxis[0], yAxis[0], zAxis[0],	
+									xAxis[1], yAxis[1], zAxis[1],
+									xAxis[2], yAxis[2], zAxis[2]);
+	frameInW.setOrigin(anchor);
+	// now get constraint frame in local coordinate systems
+	m_frameInA = rbA.getCenterOfMassTransform().inverse() * frameInW;
+	m_frameInB = rbB.getCenterOfMassTransform().inverse() * frameInW;
+	// sei limits
+	setLinearLowerLimit(btVector3(0., 0., 0.));
+	setLinearUpperLimit(btVector3(0., 0., 0.));
+	setAngularLowerLimit(btVector3(0.f, -SIMD_HALF_PI + UNIV_EPS, -SIMD_PI + UNIV_EPS));
+	setAngularUpperLimit(btVector3(0.f,  SIMD_HALF_PI - UNIV_EPS,  SIMD_PI - UNIV_EPS));
+}
+
+void btUniversalConstraint::setAxis(const btVector3& axis1,const btVector3& axis2)
+{
+  m_axis1 = axis1;
+  m_axis2 = axis2;
+
+	btVector3 zAxis = axis1.normalized();
+	btVector3 yAxis = axis2.normalized();
+	btVector3 xAxis = yAxis.cross(zAxis); // we want right coordinate system
+
+	btTransform frameInW;
+	frameInW.setIdentity();
+	frameInW.getBasis().setValue(	xAxis[0], yAxis[0], zAxis[0],	
+                                xAxis[1], yAxis[1], zAxis[1],
+                                xAxis[2], yAxis[2], zAxis[2]);
+	frameInW.setOrigin(m_anchor);
+
+	// now get constraint frame in local coordinate systems
+	m_frameInA = m_rbA.getCenterOfMassTransform().inverse() * frameInW;
+	m_frameInB = m_rbB.getCenterOfMassTransform().inverse() * frameInW;
+
+  calculateTransforms();
+}
+
+