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 "btCapsuleShape.h"
17
18 #include "LinearMath/btQuaternion.h"
19
btCapsuleShape(btScalar radius,btScalar height)20 btCapsuleShape::btCapsuleShape(btScalar radius, btScalar height) : btConvexInternalShape()
21 {
22 m_collisionMargin = radius;
23 m_shapeType = CAPSULE_SHAPE_PROXYTYPE;
24 m_upAxis = 1;
25 m_implicitShapeDimensions.setValue(radius, 0.5f * height, radius);
26 }
27
localGetSupportingVertexWithoutMargin(const btVector3 & vec0) const28 btVector3 btCapsuleShape::localGetSupportingVertexWithoutMargin(const btVector3& vec0) const
29 {
30 btVector3 supVec(0, 0, 0);
31
32 btScalar maxDot(btScalar(-BT_LARGE_FLOAT));
33
34 btVector3 vec = vec0;
35 btScalar lenSqr = vec.length2();
36 if (lenSqr < btScalar(0.0001))
37 {
38 vec.setValue(1, 0, 0);
39 }
40 else
41 {
42 btScalar rlen = btScalar(1.) / btSqrt(lenSqr);
43 vec *= rlen;
44 }
45
46 btVector3 vtx;
47 btScalar newDot;
48
49 {
50 btVector3 pos(0, 0, 0);
51 pos[getUpAxis()] = getHalfHeight();
52
53 vtx = pos;
54 newDot = vec.dot(vtx);
55 if (newDot > maxDot)
56 {
57 maxDot = newDot;
58 supVec = vtx;
59 }
60 }
61 {
62 btVector3 pos(0, 0, 0);
63 pos[getUpAxis()] = -getHalfHeight();
64
65 vtx = pos;
66 newDot = vec.dot(vtx);
67 if (newDot > maxDot)
68 {
69 maxDot = newDot;
70 supVec = vtx;
71 }
72 }
73
74 return supVec;
75 }
76
batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3 * vectors,btVector3 * supportVerticesOut,int numVectors) const77 void btCapsuleShape::batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3* vectors, btVector3* supportVerticesOut, int numVectors) const
78 {
79 for (int j = 0; j < numVectors; j++)
80 {
81 btScalar maxDot(btScalar(-BT_LARGE_FLOAT));
82 const btVector3& vec = vectors[j];
83
84 btVector3 vtx;
85 btScalar newDot;
86 {
87 btVector3 pos(0, 0, 0);
88 pos[getUpAxis()] = getHalfHeight();
89 vtx = pos;
90 newDot = vec.dot(vtx);
91 if (newDot > maxDot)
92 {
93 maxDot = newDot;
94 supportVerticesOut[j] = vtx;
95 }
96 }
97 {
98 btVector3 pos(0, 0, 0);
99 pos[getUpAxis()] = -getHalfHeight();
100 vtx = pos;
101 newDot = vec.dot(vtx);
102 if (newDot > maxDot)
103 {
104 maxDot = newDot;
105 supportVerticesOut[j] = vtx;
106 }
107 }
108 }
109 }
110
calculateLocalInertia(btScalar mass,btVector3 & inertia) const111 void btCapsuleShape::calculateLocalInertia(btScalar mass, btVector3& inertia) const
112 {
113 //as an approximation, take the inertia of the box that bounds the spheres
114
115 btTransform ident;
116 ident.setIdentity();
117
118 btScalar radius = getRadius();
119
120 btVector3 halfExtents(radius, radius, radius);
121 halfExtents[getUpAxis()] += getHalfHeight();
122
123 btScalar lx = btScalar(2.) * (halfExtents[0]);
124 btScalar ly = btScalar(2.) * (halfExtents[1]);
125 btScalar lz = btScalar(2.) * (halfExtents[2]);
126 const btScalar x2 = lx * lx;
127 const btScalar y2 = ly * ly;
128 const btScalar z2 = lz * lz;
129 const btScalar scaledmass = mass * btScalar(.08333333);
130
131 inertia[0] = scaledmass * (y2 + z2);
132 inertia[1] = scaledmass * (x2 + z2);
133 inertia[2] = scaledmass * (x2 + y2);
134 }
135
btCapsuleShapeX(btScalar radius,btScalar height)136 btCapsuleShapeX::btCapsuleShapeX(btScalar radius, btScalar height)
137 {
138 m_collisionMargin = radius;
139 m_upAxis = 0;
140 m_implicitShapeDimensions.setValue(0.5f * height, radius, radius);
141 }
142
btCapsuleShapeZ(btScalar radius,btScalar height)143 btCapsuleShapeZ::btCapsuleShapeZ(btScalar radius, btScalar height)
144 {
145 m_collisionMargin = radius;
146 m_upAxis = 2;
147 m_implicitShapeDimensions.setValue(radius, radius, 0.5f * height);
148 }
149