src/BulletCollision/CollisionShapes/btCapsuleShape.h

   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 #ifndef BT_CAPSULE_SHAPE_H
  17 #define BT_CAPSULE_SHAPE_H
  18
  19 #include "btConvexInternalShape.h"
  20 #include "BulletCollision/BroadphaseCollision/btBroadphaseProxy.h" // for the types
  21
  22
  23 ///The btCapsuleShape represents a capsule around the Y axis, there is also the btCapsuleShapeX aligned around the X axis and btCapsuleShapeZ around the Z axis.
  24 ///The total height is height+2*radius, so the height is just the height between the center of each 'sphere' of the capsule caps.
  25 ///The btCapsuleShape is a convex hull of two spheres. The btMultiSphereShape is a more general collision shape that takes the convex hull of multiple sphere, so it can also represent a capsule when just using two spheres.
  26 class btCapsuleShape : public btConvexInternalShape
  27 {
  28 protected:
  29         int     m_upAxis;
  30
  31 protected:
  32         ///only used for btCapsuleShapeZ and btCapsuleShapeX subclasses.
  33         btCapsuleShape() : btConvexInternalShape() {m_shapeType = CAPSULE_SHAPE_PROXYTYPE;};
  34
  35 public:
  36         btCapsuleShape(btScalar radius,btScalar height);
  37
  38         ///CollisionShape Interface
  39         virtual void    calculateLocalInertia(btScalar mass,btVector3& inertia) const;
  40
  41         /// btConvexShape Interface
  42         virtual btVector3       localGetSupportingVertexWithoutMargin(const btVector3& vec)const;
  43
  44         virtual void    batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3* vectors,btVector3* supportVerticesOut,int numVectors) const;
  45
  46         virtual void setMargin(btScalar collisionMargin)
  47         {
  48                 //correct the m_implicitShapeDimensions for the margin
  49                 btVector3 oldMargin(getMargin(),getMargin(),getMargin());
  50                 btVector3 implicitShapeDimensionsWithMargin = m_implicitShapeDimensions+oldMargin;
  51
  52                 btConvexInternalShape::setMargin(collisionMargin);
  53                 btVector3 newMargin(getMargin(),getMargin(),getMargin());
  54                 m_implicitShapeDimensions = implicitShapeDimensionsWithMargin - newMargin;
  55
  56         }
  57
  58         virtual void getAabb (const btTransform& t, btVector3& aabbMin, btVector3& aabbMax) const
  59         {
  60                         btVector3 halfExtents(getRadius(),getRadius(),getRadius());
  61                         halfExtents[m_upAxis] = getRadius() + getHalfHeight();
  62                         halfExtents += btVector3(getMargin(),getMargin(),getMargin());
  63                         btMatrix3x3 abs_b = t.getBasis().absolute();
  64                         btVector3 center = t.getOrigin();
  65                         btVector3 extent = btVector3(abs_b[0].dot(halfExtents),abs_b[1].dot(halfExtents),abs_b[2].dot(halfExtents));
  66
  67                         aabbMin = center - extent;
  68                         aabbMax = center + extent;
  69         }
  70
  71         virtual const char*     getName()const
  72         {
  73                 return "CapsuleShape";
  74         }
  75
  76         int     getUpAxis() const
  77         {
  78                 return m_upAxis;
  79         }
  80
  81         btScalar        getRadius() const
  82         {
  83                 int radiusAxis = (m_upAxis+2)%3;
  84                 return m_implicitShapeDimensions[radiusAxis];
  85         }
  86
  87         btScalar        getHalfHeight() const
  88         {
  89                 return m_implicitShapeDimensions[m_upAxis];
  90         }
  91
  92         virtual void    setLocalScaling(const btVector3& scaling)
  93         {
  94                 btVector3 oldMargin(getMargin(),getMargin(),getMargin());
  95                 btVector3 implicitShapeDimensionsWithMargin = m_implicitShapeDimensions+oldMargin;
  96                 btVector3 unScaledImplicitShapeDimensionsWithMargin = implicitShapeDimensionsWithMargin / m_localScaling;
  97
  98                 btConvexInternalShape::setLocalScaling(scaling);
  99
 100                 m_implicitShapeDimensions = (unScaledImplicitShapeDimensionsWithMargin * m_localScaling) - oldMargin;
 101
 102         }
 103
 104         virtual int     calculateSerializeBufferSize() const;
 105
 106         ///fills the dataBuffer and returns the struct name (and 0 on failure)
 107         virtual const char*     serialize(void* dataBuffer, btSerializer* serializer) const;
 108
 109
 110 };
 111
 112 ///btCapsuleShapeX represents a capsule around the Z axis
 113 ///the total height is height+2*radius, so the height is just the height between the center of each 'sphere' of the capsule caps.
 114 class btCapsuleShapeX : public btCapsuleShape
 115 {
 116 public:
 117
 118         btCapsuleShapeX(btScalar radius,btScalar height);
 119
 120         //debugging
 121         virtual const char*     getName()const
 122         {
 123                 return "CapsuleX";
 124         }
 125
 126
 127
 128 };
 129
 130 ///btCapsuleShapeZ represents a capsule around the Z axis
 131 ///the total height is height+2*radius, so the height is just the height between the center of each 'sphere' of the capsule caps.
 132 class btCapsuleShapeZ : public btCapsuleShape
 133 {
 134 public:
 135         btCapsuleShapeZ(btScalar radius,btScalar height);
 136
 137                 //debugging
 138         virtual const char*     getName()const
 139         {
 140                 return "CapsuleZ";
 141         }
 142
 143
 144 };
 145
 146 ///do not change those serialization structures, it requires an updated sBulletDNAstr/sBulletDNAstr64
 147 struct  btCapsuleShapeData
 148 {
 149         btConvexInternalShapeData       m_convexInternalShapeData;
 150
 151         int     m_upAxis;
 152
 153         char    m_padding[4];
 154 };
 155
 156 SIMD_FORCE_INLINE       int     btCapsuleShape::calculateSerializeBufferSize() const
 157 {
 158         return sizeof(btCapsuleShapeData);
 159 }
 160
 161         ///fills the dataBuffer and returns the struct name (and 0 on failure)
 162 SIMD_FORCE_INLINE       const char*     btCapsuleShape::serialize(void* dataBuffer, btSerializer* serializer) const
 163 {
 164         btCapsuleShapeData* shapeData = (btCapsuleShapeData*) dataBuffer;
 165
 166         btConvexInternalShape::serialize(&shapeData->m_convexInternalShapeData,serializer);
 167
 168         shapeData->m_upAxis = m_upAxis;
 169
 170         return "btCapsuleShapeData";
 171 }
 172
 173 #endif //BT_CAPSULE_SHAPE_H