1063 lines
26 KiB
C++
1063 lines
26 KiB
C++
/*
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Bullet Continuous Collision Detection and Physics Library
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Copyright (c) 2003-2014 Erwin Coumans https://bulletphysics.org
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This software is provided 'as-is', without any express or implied warranty.
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In no event will the authors be held liable for any damages arising from the
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use of this software.
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Permission is granted to anyone to use this software for any purpose,
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including commercial applications, and to alter it and redistribute it
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freely,
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subject to the following restrictions:
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1. The origin of this software must not be misrepresented; you must not
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claim that you wrote the original software. If you use this software in a
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product, an acknowledgment in the product documentation would be appreciated
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but is not required.
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2. Altered source versions must be plainly marked as such, and must not be
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misrepresented as being the original software.
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3. This notice may not be removed or altered from any source distribution.
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*/
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/*
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Initial GJK-EPA collision solver by Nathanael Presson, 2008
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Improvements and refactoring by Erwin Coumans, 2008-2014
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*/
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#ifndef BT_GJK_EPA3_H
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#define BT_GJK_EPA3_H
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#include "LinearMath/btTransform.h"
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#include "btGjkCollisionDescription.h"
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struct btGjkEpaSolver3
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{
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struct sResults
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{
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enum eStatus
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{
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Separated, /* Shapes doesnt penetrate */
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Penetrating, /* Shapes are penetrating */
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GJK_Failed, /* GJK phase fail, no big issue, shapes are probably just 'touching' */
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EPA_Failed /* EPA phase fail, bigger problem, need to save parameters, and debug */
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} status;
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btVector3 witnesses[2];
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btVector3 normal;
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btScalar distance;
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};
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};
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#if defined(DEBUG) || defined(_DEBUG)
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#include <stdio.h> //for debug printf
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#ifdef __SPU__
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#include <spu_printf.h>
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#define printf spu_printf
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#endif //__SPU__
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#endif
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// Config
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/* GJK */
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#define GJK_MAX_ITERATIONS 128
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#define GJK_ACCURARY ((btScalar)0.0001)
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#define GJK_MIN_DISTANCE ((btScalar)0.0001)
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#define GJK_DUPLICATED_EPS ((btScalar)0.0001)
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#define GJK_SIMPLEX2_EPS ((btScalar)0.0)
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#define GJK_SIMPLEX3_EPS ((btScalar)0.0)
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#define GJK_SIMPLEX4_EPS ((btScalar)0.0)
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/* EPA */
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#define EPA_MAX_VERTICES 64
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#define EPA_MAX_FACES (EPA_MAX_VERTICES * 2)
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#define EPA_MAX_ITERATIONS 255
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#define EPA_ACCURACY ((btScalar)0.0001)
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#define EPA_FALLBACK (10 * EPA_ACCURACY)
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#define EPA_PLANE_EPS ((btScalar)0.00001)
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#define EPA_INSIDE_EPS ((btScalar)0.01)
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// Shorthands
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typedef unsigned int U;
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typedef unsigned char U1;
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// MinkowskiDiff
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template <typename btConvexTemplate>
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struct MinkowskiDiff
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{
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const btConvexTemplate* m_convexAPtr;
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const btConvexTemplate* m_convexBPtr;
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btMatrix3x3 m_toshape1;
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btTransform m_toshape0;
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bool m_enableMargin;
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MinkowskiDiff(const btConvexTemplate& a, const btConvexTemplate& b)
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: m_convexAPtr(&a),
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m_convexBPtr(&b)
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{
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}
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void EnableMargin(bool enable)
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{
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m_enableMargin = enable;
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}
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inline btVector3 Support0(const btVector3& d) const
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{
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return m_convexAPtr->getLocalSupportWithMargin(d);
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}
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inline btVector3 Support1(const btVector3& d) const
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{
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return m_toshape0 * m_convexBPtr->getLocalSupportWithMargin(m_toshape1 * d);
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}
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inline btVector3 Support(const btVector3& d) const
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{
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return (Support0(d) - Support1(-d));
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}
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btVector3 Support(const btVector3& d, U index) const
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{
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if (index)
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return (Support1(d));
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else
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return (Support0(d));
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}
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};
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enum eGjkStatus
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{
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eGjkValid,
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eGjkInside,
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eGjkFailed
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};
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// GJK
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template <typename btConvexTemplate>
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struct GJK
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{
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/* Types */
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struct sSV
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{
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btVector3 d, w;
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};
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struct sSimplex
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{
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sSV* c[4];
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btScalar p[4];
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U rank;
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};
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/* Fields */
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MinkowskiDiff<btConvexTemplate> m_shape;
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btVector3 m_ray;
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btScalar m_distance;
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sSimplex m_simplices[2];
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sSV m_store[4];
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sSV* m_free[4];
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U m_nfree;
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U m_current;
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sSimplex* m_simplex;
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eGjkStatus m_status;
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/* Methods */
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GJK(const btConvexTemplate& a, const btConvexTemplate& b)
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: m_shape(a, b)
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{
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Initialize();
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}
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void Initialize()
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{
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m_ray = btVector3(0, 0, 0);
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m_nfree = 0;
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m_status = eGjkFailed;
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m_current = 0;
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m_distance = 0;
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}
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eGjkStatus Evaluate(const MinkowskiDiff<btConvexTemplate>& shapearg, const btVector3& guess)
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{
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U iterations = 0;
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btScalar sqdist = 0;
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btScalar alpha = 0;
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btVector3 lastw[4];
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U clastw = 0;
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/* Initialize solver */
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m_free[0] = &m_store[0];
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m_free[1] = &m_store[1];
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m_free[2] = &m_store[2];
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m_free[3] = &m_store[3];
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m_nfree = 4;
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m_current = 0;
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m_status = eGjkValid;
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m_shape = shapearg;
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m_distance = 0;
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/* Initialize simplex */
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m_simplices[0].rank = 0;
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m_ray = guess;
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const btScalar sqrl = m_ray.length2();
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appendvertice(m_simplices[0], sqrl > 0 ? -m_ray : btVector3(1, 0, 0));
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m_simplices[0].p[0] = 1;
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m_ray = m_simplices[0].c[0]->w;
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sqdist = sqrl;
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lastw[0] =
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lastw[1] =
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lastw[2] =
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lastw[3] = m_ray;
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/* Loop */
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do
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{
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const U next = 1 - m_current;
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sSimplex& cs = m_simplices[m_current];
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sSimplex& ns = m_simplices[next];
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/* Check zero */
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const btScalar rl = m_ray.length();
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if (rl < GJK_MIN_DISTANCE)
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{ /* Touching or inside */
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m_status = eGjkInside;
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break;
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}
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/* Append new vertice in -'v' direction */
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appendvertice(cs, -m_ray);
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const btVector3& w = cs.c[cs.rank - 1]->w;
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bool found = false;
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for (U i = 0; i < 4; ++i)
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{
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if ((w - lastw[i]).length2() < GJK_DUPLICATED_EPS)
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{
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found = true;
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break;
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}
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}
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if (found)
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{ /* Return old simplex */
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removevertice(m_simplices[m_current]);
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break;
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}
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else
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{ /* Update lastw */
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lastw[clastw = (clastw + 1) & 3] = w;
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}
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/* Check for termination */
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const btScalar omega = btDot(m_ray, w) / rl;
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alpha = btMax(omega, alpha);
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if (((rl - alpha) - (GJK_ACCURARY * rl)) <= 0)
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{ /* Return old simplex */
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removevertice(m_simplices[m_current]);
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break;
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}
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/* Reduce simplex */
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btScalar weights[4];
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U mask = 0;
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switch (cs.rank)
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{
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case 2:
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sqdist = projectorigin(cs.c[0]->w,
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cs.c[1]->w,
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weights, mask);
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break;
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case 3:
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sqdist = projectorigin(cs.c[0]->w,
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cs.c[1]->w,
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cs.c[2]->w,
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weights, mask);
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break;
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case 4:
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sqdist = projectorigin(cs.c[0]->w,
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cs.c[1]->w,
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cs.c[2]->w,
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cs.c[3]->w,
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weights, mask);
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break;
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}
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if (sqdist >= 0)
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{ /* Valid */
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ns.rank = 0;
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m_ray = btVector3(0, 0, 0);
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m_current = next;
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for (U i = 0, ni = cs.rank; i < ni; ++i)
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{
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if (mask & (1 << i))
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{
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ns.c[ns.rank] = cs.c[i];
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ns.p[ns.rank++] = weights[i];
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m_ray += cs.c[i]->w * weights[i];
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}
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else
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{
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m_free[m_nfree++] = cs.c[i];
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}
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}
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if (mask == 15) m_status = eGjkInside;
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}
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else
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{ /* Return old simplex */
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removevertice(m_simplices[m_current]);
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break;
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}
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m_status = ((++iterations) < GJK_MAX_ITERATIONS) ? m_status : eGjkFailed;
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} while (m_status == eGjkValid);
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m_simplex = &m_simplices[m_current];
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switch (m_status)
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{
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case eGjkValid:
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m_distance = m_ray.length();
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break;
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case eGjkInside:
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m_distance = 0;
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break;
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default:
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{
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}
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}
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return (m_status);
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}
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bool EncloseOrigin()
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{
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switch (m_simplex->rank)
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{
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case 1:
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{
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for (U i = 0; i < 3; ++i)
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{
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btVector3 axis = btVector3(0, 0, 0);
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axis[i] = 1;
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appendvertice(*m_simplex, axis);
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if (EncloseOrigin()) return (true);
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removevertice(*m_simplex);
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appendvertice(*m_simplex, -axis);
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if (EncloseOrigin()) return (true);
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removevertice(*m_simplex);
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}
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}
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break;
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case 2:
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{
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const btVector3 d = m_simplex->c[1]->w - m_simplex->c[0]->w;
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for (U i = 0; i < 3; ++i)
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{
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btVector3 axis = btVector3(0, 0, 0);
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axis[i] = 1;
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const btVector3 p = btCross(d, axis);
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if (p.length2() > 0)
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{
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appendvertice(*m_simplex, p);
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if (EncloseOrigin()) return (true);
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removevertice(*m_simplex);
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appendvertice(*m_simplex, -p);
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if (EncloseOrigin()) return (true);
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removevertice(*m_simplex);
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}
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}
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}
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break;
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case 3:
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{
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const btVector3 n = btCross(m_simplex->c[1]->w - m_simplex->c[0]->w,
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m_simplex->c[2]->w - m_simplex->c[0]->w);
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if (n.length2() > 0)
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{
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appendvertice(*m_simplex, n);
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if (EncloseOrigin()) return (true);
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removevertice(*m_simplex);
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appendvertice(*m_simplex, -n);
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if (EncloseOrigin()) return (true);
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removevertice(*m_simplex);
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}
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}
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break;
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case 4:
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{
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if (btFabs(det(m_simplex->c[0]->w - m_simplex->c[3]->w,
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m_simplex->c[1]->w - m_simplex->c[3]->w,
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m_simplex->c[2]->w - m_simplex->c[3]->w)) > 0)
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return (true);
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}
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break;
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}
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return (false);
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}
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/* Internals */
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void getsupport(const btVector3& d, sSV& sv) const
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{
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sv.d = d / d.length();
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sv.w = m_shape.Support(sv.d);
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}
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void removevertice(sSimplex& simplex)
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{
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m_free[m_nfree++] = simplex.c[--simplex.rank];
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}
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void appendvertice(sSimplex& simplex, const btVector3& v)
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{
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simplex.p[simplex.rank] = 0;
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simplex.c[simplex.rank] = m_free[--m_nfree];
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getsupport(v, *simplex.c[simplex.rank++]);
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}
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static btScalar det(const btVector3& a, const btVector3& b, const btVector3& c)
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{
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return (a.y() * b.z() * c.x() + a.z() * b.x() * c.y() -
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a.x() * b.z() * c.y() - a.y() * b.x() * c.z() +
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a.x() * b.y() * c.z() - a.z() * b.y() * c.x());
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}
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static btScalar projectorigin(const btVector3& a,
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const btVector3& b,
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btScalar* w, U& m)
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{
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const btVector3 d = b - a;
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const btScalar l = d.length2();
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if (l > GJK_SIMPLEX2_EPS)
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{
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const btScalar t(l > 0 ? -btDot(a, d) / l : 0);
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if (t >= 1)
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{
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w[0] = 0;
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w[1] = 1;
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m = 2;
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return (b.length2());
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}
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else if (t <= 0)
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{
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w[0] = 1;
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w[1] = 0;
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m = 1;
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return (a.length2());
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}
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else
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{
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w[0] = 1 - (w[1] = t);
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m = 3;
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return ((a + d * t).length2());
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}
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}
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return (-1);
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}
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static btScalar projectorigin(const btVector3& a,
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const btVector3& b,
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const btVector3& c,
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btScalar* w, U& m)
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{
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static const U imd3[] = {1, 2, 0};
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const btVector3* vt[] = {&a, &b, &c};
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const btVector3 dl[] = {a - b, b - c, c - a};
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const btVector3 n = btCross(dl[0], dl[1]);
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const btScalar l = n.length2();
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if (l > GJK_SIMPLEX3_EPS)
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{
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btScalar mindist = -1;
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btScalar subw[2] = {0.f, 0.f};
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U subm(0);
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for (U i = 0; i < 3; ++i)
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{
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if (btDot(*vt[i], btCross(dl[i], n)) > 0)
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{
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const U j = imd3[i];
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const btScalar subd(projectorigin(*vt[i], *vt[j], subw, subm));
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if ((mindist < 0) || (subd < mindist))
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{
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mindist = subd;
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m = static_cast<U>(((subm & 1) ? 1 << i : 0) + ((subm & 2) ? 1 << j : 0));
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w[i] = subw[0];
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w[j] = subw[1];
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w[imd3[j]] = 0;
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}
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}
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}
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if (mindist < 0)
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{
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const btScalar d = btDot(a, n);
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const btScalar s = btSqrt(l);
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const btVector3 p = n * (d / l);
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mindist = p.length2();
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m = 7;
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w[0] = (btCross(dl[1], b - p)).length() / s;
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w[1] = (btCross(dl[2], c - p)).length() / s;
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w[2] = 1 - (w[0] + w[1]);
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}
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return (mindist);
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}
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return (-1);
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}
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static btScalar projectorigin(const btVector3& a,
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const btVector3& b,
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const btVector3& c,
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const btVector3& d,
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btScalar* w, U& m)
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{
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static const U imd3[] = {1, 2, 0};
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const btVector3* vt[] = {&a, &b, &c, &d};
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const btVector3 dl[] = {a - d, b - d, c - d};
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const btScalar vl = det(dl[0], dl[1], dl[2]);
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const bool ng = (vl * btDot(a, btCross(b - c, a - b))) <= 0;
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if (ng && (btFabs(vl) > GJK_SIMPLEX4_EPS))
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{
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btScalar mindist = -1;
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btScalar subw[3] = {0.f, 0.f, 0.f};
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U subm(0);
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for (U i = 0; i < 3; ++i)
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{
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const U j = imd3[i];
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const btScalar s = vl * btDot(d, btCross(dl[i], dl[j]));
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if (s > 0)
|
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{
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const btScalar subd = projectorigin(*vt[i], *vt[j], d, subw, subm);
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if ((mindist < 0) || (subd < mindist))
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{
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mindist = subd;
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m = static_cast<U>((subm & 1 ? 1 << i : 0) +
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(subm & 2 ? 1 << j : 0) +
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(subm & 4 ? 8 : 0));
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w[i] = subw[0];
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w[j] = subw[1];
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w[imd3[j]] = 0;
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w[3] = subw[2];
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}
|
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}
|
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}
|
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if (mindist < 0)
|
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{
|
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mindist = 0;
|
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m = 15;
|
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w[0] = det(c, b, d) / vl;
|
|
w[1] = det(a, c, d) / vl;
|
|
w[2] = det(b, a, d) / vl;
|
|
w[3] = 1 - (w[0] + w[1] + w[2]);
|
|
}
|
|
return (mindist);
|
|
}
|
|
return (-1);
|
|
}
|
|
};
|
|
|
|
enum eEpaStatus
|
|
{
|
|
eEpaValid,
|
|
eEpaTouching,
|
|
eEpaDegenerated,
|
|
eEpaNonConvex,
|
|
eEpaInvalidHull,
|
|
eEpaOutOfFaces,
|
|
eEpaOutOfVertices,
|
|
eEpaAccuraryReached,
|
|
eEpaFallBack,
|
|
eEpaFailed
|
|
};
|
|
|
|
// EPA
|
|
template <typename btConvexTemplate>
|
|
struct EPA
|
|
{
|
|
/* Types */
|
|
|
|
struct sFace
|
|
{
|
|
btVector3 n;
|
|
btScalar d;
|
|
typename GJK<btConvexTemplate>::sSV* c[3];
|
|
sFace* f[3];
|
|
sFace* l[2];
|
|
U1 e[3];
|
|
U1 pass;
|
|
};
|
|
struct sList
|
|
{
|
|
sFace* root;
|
|
U count;
|
|
sList() : root(0), count(0) {}
|
|
};
|
|
struct sHorizon
|
|
{
|
|
sFace* cf;
|
|
sFace* ff;
|
|
U nf;
|
|
sHorizon() : cf(0), ff(0), nf(0) {}
|
|
};
|
|
|
|
/* Fields */
|
|
eEpaStatus m_status;
|
|
typename GJK<btConvexTemplate>::sSimplex m_result;
|
|
btVector3 m_normal;
|
|
btScalar m_depth;
|
|
typename GJK<btConvexTemplate>::sSV m_sv_store[EPA_MAX_VERTICES];
|
|
sFace m_fc_store[EPA_MAX_FACES];
|
|
U m_nextsv;
|
|
sList m_hull;
|
|
sList m_stock;
|
|
/* Methods */
|
|
EPA()
|
|
{
|
|
Initialize();
|
|
}
|
|
|
|
static inline void bind(sFace* fa, U ea, sFace* fb, U eb)
|
|
{
|
|
fa->e[ea] = (U1)eb;
|
|
fa->f[ea] = fb;
|
|
fb->e[eb] = (U1)ea;
|
|
fb->f[eb] = fa;
|
|
}
|
|
static inline void append(sList& list, sFace* face)
|
|
{
|
|
face->l[0] = 0;
|
|
face->l[1] = list.root;
|
|
if (list.root) list.root->l[0] = face;
|
|
list.root = face;
|
|
++list.count;
|
|
}
|
|
static inline void remove(sList& list, sFace* face)
|
|
{
|
|
if (face->l[1]) face->l[1]->l[0] = face->l[0];
|
|
if (face->l[0]) face->l[0]->l[1] = face->l[1];
|
|
if (face == list.root) list.root = face->l[1];
|
|
--list.count;
|
|
}
|
|
|
|
void Initialize()
|
|
{
|
|
m_status = eEpaFailed;
|
|
m_normal = btVector3(0, 0, 0);
|
|
m_depth = 0;
|
|
m_nextsv = 0;
|
|
for (U i = 0; i < EPA_MAX_FACES; ++i)
|
|
{
|
|
append(m_stock, &m_fc_store[EPA_MAX_FACES - i - 1]);
|
|
}
|
|
}
|
|
eEpaStatus Evaluate(GJK<btConvexTemplate>& gjk, const btVector3& guess)
|
|
{
|
|
typename GJK<btConvexTemplate>::sSimplex& simplex = *gjk.m_simplex;
|
|
if ((simplex.rank > 1) && gjk.EncloseOrigin())
|
|
{
|
|
/* Clean up */
|
|
while (m_hull.root)
|
|
{
|
|
sFace* f = m_hull.root;
|
|
remove(m_hull, f);
|
|
append(m_stock, f);
|
|
}
|
|
m_status = eEpaValid;
|
|
m_nextsv = 0;
|
|
/* Orient simplex */
|
|
if (gjk.det(simplex.c[0]->w - simplex.c[3]->w,
|
|
simplex.c[1]->w - simplex.c[3]->w,
|
|
simplex.c[2]->w - simplex.c[3]->w) < 0)
|
|
{
|
|
btSwap(simplex.c[0], simplex.c[1]);
|
|
btSwap(simplex.p[0], simplex.p[1]);
|
|
}
|
|
/* Build initial hull */
|
|
sFace* tetra[] = {newface(simplex.c[0], simplex.c[1], simplex.c[2], true),
|
|
newface(simplex.c[1], simplex.c[0], simplex.c[3], true),
|
|
newface(simplex.c[2], simplex.c[1], simplex.c[3], true),
|
|
newface(simplex.c[0], simplex.c[2], simplex.c[3], true)};
|
|
if (m_hull.count == 4)
|
|
{
|
|
sFace* best = findbest();
|
|
sFace outer = *best;
|
|
U pass = 0;
|
|
U iterations = 0;
|
|
bind(tetra[0], 0, tetra[1], 0);
|
|
bind(tetra[0], 1, tetra[2], 0);
|
|
bind(tetra[0], 2, tetra[3], 0);
|
|
bind(tetra[1], 1, tetra[3], 2);
|
|
bind(tetra[1], 2, tetra[2], 1);
|
|
bind(tetra[2], 2, tetra[3], 1);
|
|
m_status = eEpaValid;
|
|
for (; iterations < EPA_MAX_ITERATIONS; ++iterations)
|
|
{
|
|
if (m_nextsv < EPA_MAX_VERTICES)
|
|
{
|
|
sHorizon horizon;
|
|
typename GJK<btConvexTemplate>::sSV* w = &m_sv_store[m_nextsv++];
|
|
bool valid = true;
|
|
best->pass = (U1)(++pass);
|
|
gjk.getsupport(best->n, *w);
|
|
const btScalar wdist = btDot(best->n, w->w) - best->d;
|
|
if (wdist > EPA_ACCURACY)
|
|
{
|
|
for (U j = 0; (j < 3) && valid; ++j)
|
|
{
|
|
valid &= expand(pass, w,
|
|
best->f[j], best->e[j],
|
|
horizon);
|
|
}
|
|
if (valid && (horizon.nf >= 3))
|
|
{
|
|
bind(horizon.cf, 1, horizon.ff, 2);
|
|
remove(m_hull, best);
|
|
append(m_stock, best);
|
|
best = findbest();
|
|
outer = *best;
|
|
}
|
|
else
|
|
{
|
|
m_status = eEpaInvalidHull;
|
|
break;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
m_status = eEpaAccuraryReached;
|
|
break;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
m_status = eEpaOutOfVertices;
|
|
break;
|
|
}
|
|
}
|
|
const btVector3 projection = outer.n * outer.d;
|
|
m_normal = outer.n;
|
|
m_depth = outer.d;
|
|
m_result.rank = 3;
|
|
m_result.c[0] = outer.c[0];
|
|
m_result.c[1] = outer.c[1];
|
|
m_result.c[2] = outer.c[2];
|
|
m_result.p[0] = btCross(outer.c[1]->w - projection,
|
|
outer.c[2]->w - projection)
|
|
.length();
|
|
m_result.p[1] = btCross(outer.c[2]->w - projection,
|
|
outer.c[0]->w - projection)
|
|
.length();
|
|
m_result.p[2] = btCross(outer.c[0]->w - projection,
|
|
outer.c[1]->w - projection)
|
|
.length();
|
|
const btScalar sum = m_result.p[0] + m_result.p[1] + m_result.p[2];
|
|
m_result.p[0] /= sum;
|
|
m_result.p[1] /= sum;
|
|
m_result.p[2] /= sum;
|
|
return (m_status);
|
|
}
|
|
}
|
|
/* Fallback */
|
|
m_status = eEpaFallBack;
|
|
m_normal = -guess;
|
|
const btScalar nl = m_normal.length();
|
|
if (nl > 0)
|
|
m_normal = m_normal / nl;
|
|
else
|
|
m_normal = btVector3(1, 0, 0);
|
|
m_depth = 0;
|
|
m_result.rank = 1;
|
|
m_result.c[0] = simplex.c[0];
|
|
m_result.p[0] = 1;
|
|
return (m_status);
|
|
}
|
|
bool getedgedist(sFace* face, typename GJK<btConvexTemplate>::sSV* a, typename GJK<btConvexTemplate>::sSV* b, btScalar& dist)
|
|
{
|
|
const btVector3 ba = b->w - a->w;
|
|
const btVector3 n_ab = btCross(ba, face->n); // Outward facing edge normal direction, on triangle plane
|
|
const btScalar a_dot_nab = btDot(a->w, n_ab); // Only care about the sign to determine inside/outside, so not normalization required
|
|
|
|
if (a_dot_nab < 0)
|
|
{
|
|
// Outside of edge a->b
|
|
|
|
const btScalar ba_l2 = ba.length2();
|
|
const btScalar a_dot_ba = btDot(a->w, ba);
|
|
const btScalar b_dot_ba = btDot(b->w, ba);
|
|
|
|
if (a_dot_ba > 0)
|
|
{
|
|
// Pick distance vertex a
|
|
dist = a->w.length();
|
|
}
|
|
else if (b_dot_ba < 0)
|
|
{
|
|
// Pick distance vertex b
|
|
dist = b->w.length();
|
|
}
|
|
else
|
|
{
|
|
// Pick distance to edge a->b
|
|
const btScalar a_dot_b = btDot(a->w, b->w);
|
|
dist = btSqrt(btMax((a->w.length2() * b->w.length2() - a_dot_b * a_dot_b) / ba_l2, (btScalar)0));
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
sFace* newface(typename GJK<btConvexTemplate>::sSV* a, typename GJK<btConvexTemplate>::sSV* b, typename GJK<btConvexTemplate>::sSV* c, bool forced)
|
|
{
|
|
if (m_stock.root)
|
|
{
|
|
sFace* face = m_stock.root;
|
|
remove(m_stock, face);
|
|
append(m_hull, face);
|
|
face->pass = 0;
|
|
face->c[0] = a;
|
|
face->c[1] = b;
|
|
face->c[2] = c;
|
|
face->n = btCross(b->w - a->w, c->w - a->w);
|
|
const btScalar l = face->n.length();
|
|
const bool v = l > EPA_ACCURACY;
|
|
|
|
if (v)
|
|
{
|
|
if (!(getedgedist(face, a, b, face->d) ||
|
|
getedgedist(face, b, c, face->d) ||
|
|
getedgedist(face, c, a, face->d)))
|
|
{
|
|
// Origin projects to the interior of the triangle
|
|
// Use distance to triangle plane
|
|
face->d = btDot(a->w, face->n) / l;
|
|
}
|
|
|
|
face->n /= l;
|
|
if (forced || (face->d >= -EPA_PLANE_EPS))
|
|
{
|
|
return face;
|
|
}
|
|
else
|
|
m_status = eEpaNonConvex;
|
|
}
|
|
else
|
|
m_status = eEpaDegenerated;
|
|
|
|
remove(m_hull, face);
|
|
append(m_stock, face);
|
|
return 0;
|
|
}
|
|
m_status = m_stock.root ? eEpaOutOfVertices : eEpaOutOfFaces;
|
|
return 0;
|
|
}
|
|
sFace* findbest()
|
|
{
|
|
sFace* minf = m_hull.root;
|
|
btScalar mind = minf->d * minf->d;
|
|
for (sFace* f = minf->l[1]; f; f = f->l[1])
|
|
{
|
|
const btScalar sqd = f->d * f->d;
|
|
if (sqd < mind)
|
|
{
|
|
minf = f;
|
|
mind = sqd;
|
|
}
|
|
}
|
|
return (minf);
|
|
}
|
|
bool expand(U pass, typename GJK<btConvexTemplate>::sSV* w, sFace* f, U e, sHorizon& horizon)
|
|
{
|
|
static const U i1m3[] = {1, 2, 0};
|
|
static const U i2m3[] = {2, 0, 1};
|
|
if (f->pass != pass)
|
|
{
|
|
const U e1 = i1m3[e];
|
|
if ((btDot(f->n, w->w) - f->d) < -EPA_PLANE_EPS)
|
|
{
|
|
sFace* nf = newface(f->c[e1], f->c[e], w, false);
|
|
if (nf)
|
|
{
|
|
bind(nf, 0, f, e);
|
|
if (horizon.cf)
|
|
bind(horizon.cf, 1, nf, 2);
|
|
else
|
|
horizon.ff = nf;
|
|
horizon.cf = nf;
|
|
++horizon.nf;
|
|
return (true);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
const U e2 = i2m3[e];
|
|
f->pass = (U1)pass;
|
|
if (expand(pass, w, f->f[e1], f->e[e1], horizon) &&
|
|
expand(pass, w, f->f[e2], f->e[e2], horizon))
|
|
{
|
|
remove(m_hull, f);
|
|
append(m_stock, f);
|
|
return (true);
|
|
}
|
|
}
|
|
}
|
|
return (false);
|
|
}
|
|
};
|
|
|
|
template <typename btConvexTemplate>
|
|
static void Initialize(const btConvexTemplate& a, const btConvexTemplate& b,
|
|
btGjkEpaSolver3::sResults& results,
|
|
MinkowskiDiff<btConvexTemplate>& shape)
|
|
{
|
|
/* Results */
|
|
results.witnesses[0] =
|
|
results.witnesses[1] = btVector3(0, 0, 0);
|
|
results.status = btGjkEpaSolver3::sResults::Separated;
|
|
/* Shape */
|
|
|
|
shape.m_toshape1 = b.getWorldTransform().getBasis().transposeTimes(a.getWorldTransform().getBasis());
|
|
shape.m_toshape0 = a.getWorldTransform().inverseTimes(b.getWorldTransform());
|
|
}
|
|
|
|
//
|
|
// Api
|
|
//
|
|
|
|
//
|
|
template <typename btConvexTemplate>
|
|
bool btGjkEpaSolver3_Distance(const btConvexTemplate& a, const btConvexTemplate& b,
|
|
const btVector3& guess,
|
|
btGjkEpaSolver3::sResults& results)
|
|
{
|
|
MinkowskiDiff<btConvexTemplate> shape(a, b);
|
|
Initialize(a, b, results, shape);
|
|
GJK<btConvexTemplate> gjk(a, b);
|
|
eGjkStatus gjk_status = gjk.Evaluate(shape, guess);
|
|
if (gjk_status == eGjkValid)
|
|
{
|
|
btVector3 w0 = btVector3(0, 0, 0);
|
|
btVector3 w1 = btVector3(0, 0, 0);
|
|
for (U i = 0; i < gjk.m_simplex->rank; ++i)
|
|
{
|
|
const btScalar p = gjk.m_simplex->p[i];
|
|
w0 += shape.Support(gjk.m_simplex->c[i]->d, 0) * p;
|
|
w1 += shape.Support(-gjk.m_simplex->c[i]->d, 1) * p;
|
|
}
|
|
results.witnesses[0] = a.getWorldTransform() * w0;
|
|
results.witnesses[1] = a.getWorldTransform() * w1;
|
|
results.normal = w0 - w1;
|
|
results.distance = results.normal.length();
|
|
results.normal /= results.distance > GJK_MIN_DISTANCE ? results.distance : 1;
|
|
return (true);
|
|
}
|
|
else
|
|
{
|
|
results.status = gjk_status == eGjkInside ? btGjkEpaSolver3::sResults::Penetrating : btGjkEpaSolver3::sResults::GJK_Failed;
|
|
return (false);
|
|
}
|
|
}
|
|
|
|
template <typename btConvexTemplate>
|
|
bool btGjkEpaSolver3_Penetration(const btConvexTemplate& a,
|
|
const btConvexTemplate& b,
|
|
const btVector3& guess,
|
|
btGjkEpaSolver3::sResults& results)
|
|
{
|
|
MinkowskiDiff<btConvexTemplate> shape(a, b);
|
|
Initialize(a, b, results, shape);
|
|
GJK<btConvexTemplate> gjk(a, b);
|
|
eGjkStatus gjk_status = gjk.Evaluate(shape, -guess);
|
|
switch (gjk_status)
|
|
{
|
|
case eGjkInside:
|
|
{
|
|
EPA<btConvexTemplate> epa;
|
|
eEpaStatus epa_status = epa.Evaluate(gjk, -guess);
|
|
if (epa_status != eEpaFailed)
|
|
{
|
|
btVector3 w0 = btVector3(0, 0, 0);
|
|
for (U i = 0; i < epa.m_result.rank; ++i)
|
|
{
|
|
w0 += shape.Support(epa.m_result.c[i]->d, 0) * epa.m_result.p[i];
|
|
}
|
|
results.status = btGjkEpaSolver3::sResults::Penetrating;
|
|
results.witnesses[0] = a.getWorldTransform() * w0;
|
|
results.witnesses[1] = a.getWorldTransform() * (w0 - epa.m_normal * epa.m_depth);
|
|
results.normal = -epa.m_normal;
|
|
results.distance = -epa.m_depth;
|
|
return (true);
|
|
}
|
|
else
|
|
results.status = btGjkEpaSolver3::sResults::EPA_Failed;
|
|
}
|
|
break;
|
|
case eGjkFailed:
|
|
results.status = btGjkEpaSolver3::sResults::GJK_Failed;
|
|
break;
|
|
default:
|
|
{
|
|
}
|
|
}
|
|
return (false);
|
|
}
|
|
|
|
#if 0
|
|
int btComputeGjkEpaPenetration2(const btCollisionDescription& colDesc, btDistanceInfo* distInfo)
|
|
{
|
|
btGjkEpaSolver3::sResults results;
|
|
btVector3 guess = colDesc.m_firstDir;
|
|
|
|
bool res = btGjkEpaSolver3::Penetration(colDesc.m_objA,colDesc.m_objB,
|
|
colDesc.m_transformA,colDesc.m_transformB,
|
|
colDesc.m_localSupportFuncA,colDesc.m_localSupportFuncB,
|
|
guess,
|
|
results);
|
|
if (res)
|
|
{
|
|
if ((results.status==btGjkEpaSolver3::sResults::Penetrating) || results.status==GJK::eStatus::Inside)
|
|
{
|
|
//normal could be 'swapped'
|
|
|
|
distInfo->m_distance = results.distance;
|
|
distInfo->m_normalBtoA = results.normal;
|
|
btVector3 tmpNormalInB = results.witnesses[1]-results.witnesses[0];
|
|
btScalar lenSqr = tmpNormalInB.length2();
|
|
if (lenSqr <= (SIMD_EPSILON*SIMD_EPSILON))
|
|
{
|
|
tmpNormalInB = results.normal;
|
|
lenSqr = results.normal.length2();
|
|
}
|
|
|
|
if (lenSqr > (SIMD_EPSILON*SIMD_EPSILON))
|
|
{
|
|
tmpNormalInB /= btSqrt(lenSqr);
|
|
btScalar distance2 = -(results.witnesses[0]-results.witnesses[1]).length();
|
|
//only replace valid penetrations when the result is deeper (check)
|
|
//if ((distance2 < results.distance))
|
|
{
|
|
distInfo->m_distance = distance2;
|
|
distInfo->m_pointOnA= results.witnesses[0];
|
|
distInfo->m_pointOnB= results.witnesses[1];
|
|
distInfo->m_normalBtoA= tmpNormalInB;
|
|
return 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
#endif
|
|
|
|
template <typename btConvexTemplate, typename btDistanceInfoTemplate>
|
|
int btComputeGjkDistance(const btConvexTemplate& a, const btConvexTemplate& b,
|
|
const btGjkCollisionDescription& colDesc, btDistanceInfoTemplate* distInfo)
|
|
{
|
|
btGjkEpaSolver3::sResults results;
|
|
btVector3 guess = colDesc.m_firstDir;
|
|
|
|
bool isSeparated = btGjkEpaSolver3_Distance(a, b,
|
|
guess,
|
|
results);
|
|
if (isSeparated)
|
|
{
|
|
distInfo->m_distance = results.distance;
|
|
distInfo->m_pointOnA = results.witnesses[0];
|
|
distInfo->m_pointOnB = results.witnesses[1];
|
|
distInfo->m_normalBtoA = results.normal;
|
|
return 0;
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
/* Symbols cleanup */
|
|
|
|
#undef GJK_MAX_ITERATIONS
|
|
#undef GJK_ACCURARY
|
|
#undef GJK_MIN_DISTANCE
|
|
#undef GJK_DUPLICATED_EPS
|
|
#undef GJK_SIMPLEX2_EPS
|
|
#undef GJK_SIMPLEX3_EPS
|
|
#undef GJK_SIMPLEX4_EPS
|
|
|
|
#undef EPA_MAX_VERTICES
|
|
#undef EPA_MAX_FACES
|
|
#undef EPA_MAX_ITERATIONS
|
|
#undef EPA_ACCURACY
|
|
#undef EPA_FALLBACK
|
|
#undef EPA_PLANE_EPS
|
|
#undef EPA_INSIDE_EPS
|
|
|
|
#endif //BT_GJK_EPA3_H
|