mirror of
https://github.com/bulletphysics/bullet3
synced 2024-12-14 05:40:05 +00:00
b1863f7ce2
to the rest of the Bullet code base. This code will replace the original GJK/EPA in a future commit. Added btMprPenetration, an implementation of Minkowski Portal Refinement by Daniel Fiser. Original MPR idea is by Gary Snethen, and the first implementation is here: https://github.com/erwincoumans/xenocollide It is an alternative to EPA, although computing the local penetration depth. EPA computes the global penetration depth. In many cases, MPR is sufficient and performs better than EPA.
58 lines
2.4 KiB
C
58 lines
2.4 KiB
C
/*
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Bullet Continuous Collision Detection and Physics Library
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Copyright (c) 2003-2014 Erwin Coumans http://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 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 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 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.
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2. Altered source versions must be plainly marked as such, and must not be 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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#ifndef SPHERE_SPHERE_COLLISION_H
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#define SPHERE_SPHERE_COLLISION_H
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#include "LinearMath/btTransform.h" // Note that btVector3 might be double precision...
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#include "btDistanceInfo.h"
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struct btSphereSphereCollisionDescription
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{
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btTransform m_sphereTransformA;
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btTransform m_sphereTransformB;
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btScalar m_radiusA;
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btScalar m_radiusB;
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};
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///compute the distance between two spheres, where the distance is zero when the spheres are touching
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///positive distance means the spheres are separate and negative distance means penetration
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///point A and pointB are witness points, and normalOnB points from sphere B to sphere A
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inline int btComputeSphereSphereCollision(const btSphereSphereCollisionDescription& input, btDistanceInfo* distInfo)
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{
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btVector3 diff = input.m_sphereTransformA.getOrigin()- input.m_sphereTransformB.getOrigin();
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btScalar len = diff.length();
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btScalar radiusA = input.m_radiusA;
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btScalar radiusB = input.m_radiusB;
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///distance (negative means penetration)
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btScalar dist = len - (radiusA+radiusB);
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btVector3 normalOnSurfaceB(1,0,0);
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if (len > SIMD_EPSILON)
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{
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normalOnSurfaceB = diff / len;
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}
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distInfo->m_distance = dist;
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distInfo->m_normalBtoA = normalOnSurfaceB;
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distInfo->m_pointOnA = input.m_sphereTransformA.getOrigin()-input.m_radiusA*normalOnSurfaceB;
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distInfo->m_pointOnB = input.m_sphereTransformB.getOrigin()+input.m_radiusB*normalOnSurfaceB;
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return 0;//sphere-sphere cannot fail
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}
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#endif //SPHERE_SPHERE_COLLISION_H
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