dali-physics/third-party/bullet3/src/BulletCollision/CollisionShapes/btTriangleMeshShape.cpp

   1 /*
   2 Bullet Continuous Collision Detection and Physics Library
   3 Copyright (c) 2003-2009 Erwin Coumans  http://bulletphysics.org
   4
   5 This software is provided 'as-is', without any express or implied warranty.
   6 In no event will the authors be held liable for any damages arising from the use of this software.
   7 Permission is granted to anyone to use this software for any purpose,
   8 including commercial applications, and to alter it and redistribute it freely,
   9 subject to the following restrictions:
  10
  11 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.
  12 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
  13 3. This notice may not be removed or altered from any source distribution.
  14 */
  15
  16 #include "btTriangleMeshShape.h"
  17 #include "LinearMath/btVector3.h"
  18 #include "LinearMath/btQuaternion.h"
  19 #include "btStridingMeshInterface.h"
  20 #include "LinearMath/btAabbUtil2.h"
  21 #include "BulletCollision/CollisionShapes/btCollisionMargin.h"
  22
  23 btTriangleMeshShape::btTriangleMeshShape(btStridingMeshInterface* meshInterface)
  24         : btConcaveShape(), m_meshInterface(meshInterface)
  25 {
  26         m_shapeType = TRIANGLE_MESH_SHAPE_PROXYTYPE;
  27         if (meshInterface->hasPremadeAabb())
  28         {
  29                 meshInterface->getPremadeAabb(&m_localAabbMin, &m_localAabbMax);
  30         }
  31         else
  32         {
  33                 recalcLocalAabb();
  34         }
  35 }
  36
  37 btTriangleMeshShape::~btTriangleMeshShape()
  38 {
  39 }
  40
  41 void btTriangleMeshShape::getAabb(const btTransform& trans, btVector3& aabbMin, btVector3& aabbMax) const
  42 {
  43         btVector3 localHalfExtents = btScalar(0.5) * (m_localAabbMax - m_localAabbMin);
  44         localHalfExtents += btVector3(getMargin(), getMargin(), getMargin());
  45         btVector3 localCenter = btScalar(0.5) * (m_localAabbMax + m_localAabbMin);
  46
  47         btMatrix3x3 abs_b = trans.getBasis().absolute();
  48
  49         btVector3 center = trans(localCenter);
  50
  51         btVector3 extent = localHalfExtents.dot3(abs_b[0], abs_b[1], abs_b[2]);
  52         aabbMin = center - extent;
  53         aabbMax = center + extent;
  54 }
  55
  56 void btTriangleMeshShape::recalcLocalAabb()
  57 {
  58         for (int i = 0; i < 3; i++)
  59         {
  60                 btVector3 vec(btScalar(0.), btScalar(0.), btScalar(0.));
  61                 vec[i] = btScalar(1.);
  62                 btVector3 tmp = localGetSupportingVertex(vec);
  63                 m_localAabbMax[i] = tmp[i] + m_collisionMargin;
  64                 vec[i] = btScalar(-1.);
  65                 tmp = localGetSupportingVertex(vec);
  66                 m_localAabbMin[i] = tmp[i] - m_collisionMargin;
  67         }
  68 }
  69
  70 class SupportVertexCallback : public btTriangleCallback
  71 {
  72         btVector3 m_supportVertexLocal;
  73
  74 public:
  75         btTransform m_worldTrans;
  76         btScalar m_maxDot;
  77         btVector3 m_supportVecLocal;
  78
  79         SupportVertexCallback(const btVector3& supportVecWorld, const btTransform& trans)
  80                 : m_supportVertexLocal(btScalar(0.), btScalar(0.), btScalar(0.)), m_worldTrans(trans), m_maxDot(btScalar(-BT_LARGE_FLOAT))
  81
  82         {
  83                 m_supportVecLocal = supportVecWorld * m_worldTrans.getBasis();
  84         }
  85
  86         virtual void processTriangle(btVector3* triangle, int partId, int triangleIndex)
  87         {
  88                 (void)partId;
  89                 (void)triangleIndex;
  90                 for (int i = 0; i < 3; i++)
  91                 {
  92                         btScalar dot = m_supportVecLocal.dot(triangle[i]);
  93                         if (dot > m_maxDot)
  94                         {
  95                                 m_maxDot = dot;
  96                                 m_supportVertexLocal = triangle[i];
  97                         }
  98                 }
  99         }
 100
 101         btVector3 GetSupportVertexWorldSpace()
 102         {
 103                 return m_worldTrans(m_supportVertexLocal);
 104         }
 105
 106         btVector3 GetSupportVertexLocal()
 107         {
 108                 return m_supportVertexLocal;
 109         }
 110 };
 111
 112 void btTriangleMeshShape::setLocalScaling(const btVector3& scaling)
 113 {
 114         m_meshInterface->setScaling(scaling);
 115         recalcLocalAabb();
 116 }
 117
 118 const btVector3& btTriangleMeshShape::getLocalScaling() const
 119 {
 120         return m_meshInterface->getScaling();
 121 }
 122
 123 //#define DEBUG_TRIANGLE_MESH
 124
 125 void btTriangleMeshShape::processAllTriangles(btTriangleCallback* callback, const btVector3& aabbMin, const btVector3& aabbMax) const
 126 {
 127         struct FilteredCallback : public btInternalTriangleIndexCallback
 128         {
 129                 btTriangleCallback* m_callback;
 130                 btVector3 m_aabbMin;
 131                 btVector3 m_aabbMax;
 132
 133                 FilteredCallback(btTriangleCallback* callback, const btVector3& aabbMin, const btVector3& aabbMax)
 134                         : m_callback(callback),
 135                           m_aabbMin(aabbMin),
 136                           m_aabbMax(aabbMax)
 137                 {
 138                 }
 139
 140                 virtual void internalProcessTriangleIndex(btVector3* triangle, int partId, int triangleIndex)
 141                 {
 142                         if (TestTriangleAgainstAabb2(&triangle[0], m_aabbMin, m_aabbMax))
 143                         {
 144                                 //check aabb in triangle-space, before doing this
 145                                 m_callback->processTriangle(triangle, partId, triangleIndex);
 146                         }
 147                 }
 148         };
 149
 150         FilteredCallback filterCallback(callback, aabbMin, aabbMax);
 151
 152         m_meshInterface->InternalProcessAllTriangles(&filterCallback, aabbMin, aabbMax);
 153 }
 154
 155 void btTriangleMeshShape::calculateLocalInertia(btScalar mass, btVector3& inertia) const
 156 {
 157         (void)mass;
 158         //moving concave objects not supported
 159         btAssert(0);
 160         inertia.setValue(btScalar(0.), btScalar(0.), btScalar(0.));
 161 }
 162
 163 btVector3 btTriangleMeshShape::localGetSupportingVertex(const btVector3& vec) const
 164 {
 165         btVector3 supportVertex;
 166
 167         btTransform ident;
 168         ident.setIdentity();
 169
 170         SupportVertexCallback supportCallback(vec, ident);
 171
 172         btVector3 aabbMax(btScalar(BT_LARGE_FLOAT), btScalar(BT_LARGE_FLOAT), btScalar(BT_LARGE_FLOAT));
 173
 174         processAllTriangles(&supportCallback, -aabbMax, aabbMax);
 175
 176         supportVertex = supportCallback.GetSupportVertexLocal();
 177
 178         return supportVertex;
 179 }