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1 /*
2 Copyright (c) 2003-2015 Erwin Coumans, Jakub Stepien
3 
4 This software is provided 'as-is', without any express or implied warranty.
5 In no event will the authors be held liable for any damages arising from the use of this software.
6 Permission is granted to anyone to use this software for any purpose,
7 including commercial applications, and to alter it and redistribute it freely,
8 subject to the following restrictions:
9 
10 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.
11 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
12 3. This notice may not be removed or altered from any source distribution.
13 */
14 
15 ///These spatial algebra classes are used for btMultiBody,
16 ///see BulletDynamics/Featherstone
17 
18 #ifndef BT_SPATIAL_ALGEBRA_H
19 #define BT_SPATIAL_ALGEBRA_H
20 
21 
22 #include "btMatrix3x3.h"
23 
24 struct btSpatialForceVector
25 {
26 	btVector3 m_topVec, m_bottomVec;
27 	//
btSpatialForceVectorbtSpatialForceVector28 	btSpatialForceVector() { setZero(); }
btSpatialForceVectorbtSpatialForceVector29 	btSpatialForceVector(const btVector3 &angular, const btVector3 &linear) : m_topVec(linear), m_bottomVec(angular) {}
btSpatialForceVectorbtSpatialForceVector30 	btSpatialForceVector(const btScalar &ax, const btScalar &ay, const btScalar &az, const btScalar &lx, const btScalar &ly, const btScalar &lz)
31 	{
32 		setValue(ax, ay, az, lx, ly, lz);
33 	}
34 	//
setVectorbtSpatialForceVector35 	void setVector(const btVector3 &angular, const btVector3 &linear) { m_topVec = linear; m_bottomVec = angular; }
setValuebtSpatialForceVector36 	void setValue(const btScalar &ax, const btScalar &ay, const btScalar &az, const btScalar &lx, const btScalar &ly, const btScalar &lz)
37 	{
38 		m_bottomVec.setValue(ax, ay, az); m_topVec.setValue(lx, ly, lz);
39 	}
40 	//
addVectorbtSpatialForceVector41 	void addVector(const btVector3 &angular, const btVector3 &linear) { m_topVec += linear; m_bottomVec += angular; }
addValuebtSpatialForceVector42 	void addValue(const btScalar &ax, const btScalar &ay, const btScalar &az, const btScalar &lx, const btScalar &ly, const btScalar &lz)
43 	{
44 		m_bottomVec[0] += ax; m_bottomVec[1] += ay; m_bottomVec[2] += az;
45 		m_topVec[0] += lx; m_topVec[1] += ly; m_topVec[2] += lz;
46 	}
47 	//
getLinearbtSpatialForceVector48 	const btVector3 & getLinear()  const { return m_topVec; }
getAngularbtSpatialForceVector49 	const btVector3 & getAngular() const { return m_bottomVec; }
50 	//
setLinearbtSpatialForceVector51 	void setLinear(const btVector3 &linear) { m_topVec = linear; }
setAngularbtSpatialForceVector52 	void setAngular(const btVector3 &angular) { m_bottomVec = angular; }
53 	//
addAngularbtSpatialForceVector54 	void addAngular(const btVector3 &angular) { m_bottomVec += angular; }
addLinearbtSpatialForceVector55 	void addLinear(const btVector3 &linear) { m_topVec += linear; }
56 	//
setZerobtSpatialForceVector57 	void setZero() { m_topVec.setZero(); m_bottomVec.setZero(); }
58 	//
59 	btSpatialForceVector & operator += (const btSpatialForceVector &vec) { m_topVec += vec.m_topVec; m_bottomVec += vec.m_bottomVec; return *this; }
60 	btSpatialForceVector & operator -= (const btSpatialForceVector &vec) { m_topVec -= vec.m_topVec; m_bottomVec -= vec.m_bottomVec; return *this; }
61 	btSpatialForceVector operator - (const btSpatialForceVector &vec) const { return btSpatialForceVector(m_bottomVec - vec.m_bottomVec, m_topVec - vec.m_topVec); }
62 	btSpatialForceVector operator + (const btSpatialForceVector &vec) const { return btSpatialForceVector(m_bottomVec + vec.m_bottomVec, m_topVec + vec.m_topVec); }
63 	btSpatialForceVector operator - () const { return btSpatialForceVector(-m_bottomVec, -m_topVec); }
64 	btSpatialForceVector operator * (const btScalar &s) const { return btSpatialForceVector(s * m_bottomVec, s * m_topVec); }
65 	//btSpatialForceVector & operator = (const btSpatialForceVector &vec) { m_topVec = vec.m_topVec; m_bottomVec = vec.m_bottomVec; return *this; }
66 };
67 
68 struct btSpatialMotionVector
69 {
70 	btVector3 m_topVec, m_bottomVec;
71 	//
btSpatialMotionVectorbtSpatialMotionVector72 	btSpatialMotionVector() { setZero(); }
btSpatialMotionVectorbtSpatialMotionVector73 	btSpatialMotionVector(const btVector3 &angular, const btVector3 &linear) : m_topVec(angular), m_bottomVec(linear) {}
74 	//
setVectorbtSpatialMotionVector75 	void setVector(const btVector3 &angular, const btVector3 &linear) { m_topVec = angular; m_bottomVec = linear; }
setValuebtSpatialMotionVector76 	void setValue(const btScalar &ax, const btScalar &ay, const btScalar &az, const btScalar &lx, const btScalar &ly, const btScalar &lz)
77 	{
78 		m_topVec.setValue(ax, ay, az); m_bottomVec.setValue(lx, ly, lz);
79 	}
80 	//
addVectorbtSpatialMotionVector81 	void addVector(const btVector3 &angular, const btVector3 &linear) { m_topVec += linear; m_bottomVec += angular; }
addValuebtSpatialMotionVector82 	void addValue(const btScalar &ax, const btScalar &ay, const btScalar &az, const btScalar &lx, const btScalar &ly, const btScalar &lz)
83 	{
84 		m_topVec[0] += ax; m_topVec[1] += ay; m_topVec[2] += az;
85 		m_bottomVec[0] += lx; m_bottomVec[1] += ly; m_bottomVec[2] += lz;
86 	}
87 	//
getAngularbtSpatialMotionVector88 	const btVector3 & getAngular() const { return m_topVec; }
getLinearbtSpatialMotionVector89 	const btVector3 & getLinear() const { return m_bottomVec; }
90 	//
setAngularbtSpatialMotionVector91 	void setAngular(const btVector3 &angular) { m_topVec = angular; }
setLinearbtSpatialMotionVector92 	void setLinear(const btVector3 &linear) { m_bottomVec = linear; }
93 	//
addAngularbtSpatialMotionVector94 	void addAngular(const btVector3 &angular) { m_topVec += angular; }
addLinearbtSpatialMotionVector95 	void addLinear(const btVector3 &linear) { m_bottomVec += linear; }
96 	//
setZerobtSpatialMotionVector97 	void setZero() { m_topVec.setZero(); m_bottomVec.setZero(); }
98 	//
dotbtSpatialMotionVector99 	btScalar dot(const btSpatialForceVector &b) const
100 	{
101 		return m_bottomVec.dot(b.m_topVec) + m_topVec.dot(b.m_bottomVec);
102 	}
103 	//
104 	template<typename SpatialVectorType>
crossbtSpatialMotionVector105 	void cross(const SpatialVectorType &b, SpatialVectorType &out) const
106 	{
107 		out.m_topVec = m_topVec.cross(b.m_topVec);
108 		out.m_bottomVec = m_bottomVec.cross(b.m_topVec) + m_topVec.cross(b.m_bottomVec);
109 	}
110 	template<typename SpatialVectorType>
crossbtSpatialMotionVector111 	SpatialVectorType cross(const SpatialVectorType &b) const
112 	{
113 		SpatialVectorType out;
114 		out.m_topVec = m_topVec.cross(b.m_topVec);
115 		out.m_bottomVec = m_bottomVec.cross(b.m_topVec) + m_topVec.cross(b.m_bottomVec);
116 		return out;
117 	}
118 	//
119 	btSpatialMotionVector & operator += (const btSpatialMotionVector &vec) { m_topVec += vec.m_topVec; m_bottomVec += vec.m_bottomVec; return *this; }
120 	btSpatialMotionVector & operator -= (const btSpatialMotionVector &vec) { m_topVec -= vec.m_topVec; m_bottomVec -= vec.m_bottomVec; return *this; }
121 	btSpatialMotionVector & operator *= (const btScalar &s) { m_topVec *= s; m_bottomVec *= s; return *this; }
122 	btSpatialMotionVector operator - (const btSpatialMotionVector &vec) const { return btSpatialMotionVector(m_topVec - vec.m_topVec, m_bottomVec - vec.m_bottomVec); }
123 	btSpatialMotionVector operator + (const btSpatialMotionVector &vec) const { return btSpatialMotionVector(m_topVec + vec.m_topVec, m_bottomVec + vec.m_bottomVec); }
124 	btSpatialMotionVector operator - () const { return btSpatialMotionVector(-m_topVec, -m_bottomVec); }
125 	btSpatialMotionVector operator * (const btScalar &s) const { return btSpatialMotionVector(s * m_topVec, s * m_bottomVec); }
126 };
127 
128 struct btSymmetricSpatialDyad
129 {
130 	btMatrix3x3 m_topLeftMat, m_topRightMat, m_bottomLeftMat;
131 	//
btSymmetricSpatialDyadbtSymmetricSpatialDyad132 	btSymmetricSpatialDyad() { setIdentity(); }
btSymmetricSpatialDyadbtSymmetricSpatialDyad133 	btSymmetricSpatialDyad(const btMatrix3x3 &topLeftMat, const btMatrix3x3 &topRightMat, const btMatrix3x3 &bottomLeftMat) { setMatrix(topLeftMat, topRightMat, bottomLeftMat); }
134 	//
setMatrixbtSymmetricSpatialDyad135 	void setMatrix(const btMatrix3x3 &topLeftMat, const btMatrix3x3 &topRightMat, const btMatrix3x3 &bottomLeftMat)
136 	{
137 		m_topLeftMat = topLeftMat;
138 		m_topRightMat = topRightMat;
139 		m_bottomLeftMat = bottomLeftMat;
140 	}
141 	//
addMatrixbtSymmetricSpatialDyad142 	void addMatrix(const btMatrix3x3 &topLeftMat, const btMatrix3x3 &topRightMat, const btMatrix3x3 &bottomLeftMat)
143 	{
144 		m_topLeftMat += topLeftMat;
145 		m_topRightMat += topRightMat;
146 		m_bottomLeftMat += bottomLeftMat;
147 	}
148 	//
setIdentitybtSymmetricSpatialDyad149 	void setIdentity() { m_topLeftMat.setIdentity(); m_topRightMat.setIdentity(); m_bottomLeftMat.setIdentity();  }
150 	//
151 	btSymmetricSpatialDyad & operator -= (const btSymmetricSpatialDyad &mat)
152 	{
153 		m_topLeftMat -= mat.m_topLeftMat;
154 		m_topRightMat -= mat.m_topRightMat;
155 		m_bottomLeftMat -= mat.m_bottomLeftMat;
156 		return *this;
157 	}
158 	//
159 	btSpatialForceVector operator * (const btSpatialMotionVector &vec)
160 	{
161 		return btSpatialForceVector(m_bottomLeftMat * vec.m_topVec + m_topLeftMat.transpose() * vec.m_bottomVec, m_topLeftMat * vec.m_topVec + m_topRightMat * vec.m_bottomVec);
162 	}
163 };
164 
165 struct btSpatialTransformationMatrix
166 {
167 	btMatrix3x3 m_rotMat; //btMatrix3x3 m_trnCrossMat;
168 	btVector3 m_trnVec;
169 	//
170 	enum eOutputOperation
171 	{
172 		None = 0,
173 		Add = 1,
174 		Subtract = 2
175 	};
176 	//
177 	template<typename SpatialVectorType>
178 	void transform(	const SpatialVectorType &inVec,
179                       SpatialVectorType &outVec,
180 					eOutputOperation outOp = None)
181 	{
182 		if(outOp == None)
183 		{
184 			outVec.m_topVec = m_rotMat * inVec.m_topVec;
185 			outVec.m_bottomVec = -m_trnVec.cross(outVec.m_topVec) + m_rotMat * inVec.m_bottomVec;
186 		}
187 		else if(outOp == Add)
188 		{
189 			outVec.m_topVec += m_rotMat * inVec.m_topVec;
190 			outVec.m_bottomVec += -m_trnVec.cross(outVec.m_topVec) + m_rotMat * inVec.m_bottomVec;
191 		}
192 		else if(outOp == Subtract)
193 		{
194 			outVec.m_topVec -= m_rotMat * inVec.m_topVec;
195 			outVec.m_bottomVec -= -m_trnVec.cross(outVec.m_topVec) + m_rotMat * inVec.m_bottomVec;
196 		}
197 
198 	}
199 
200 	template<typename SpatialVectorType>
201 	void transformRotationOnly(	const SpatialVectorType &inVec,
202 								SpatialVectorType &outVec,
203 								eOutputOperation outOp = None)
204 	{
205 		if(outOp == None)
206 		{
207 			outVec.m_topVec = m_rotMat * inVec.m_topVec;
208 			outVec.m_bottomVec = m_rotMat * inVec.m_bottomVec;
209 		}
210 		else if(outOp == Add)
211 		{
212 			outVec.m_topVec += m_rotMat * inVec.m_topVec;
213 			outVec.m_bottomVec += m_rotMat * inVec.m_bottomVec;
214 		}
215 		else if(outOp == Subtract)
216 		{
217 			outVec.m_topVec -= m_rotMat * inVec.m_topVec;
218 			outVec.m_bottomVec -= m_rotMat * inVec.m_bottomVec;
219 		}
220 
221 	}
222 
223 	template<typename SpatialVectorType>
224 	void transformInverse(	const SpatialVectorType &inVec,
225 							SpatialVectorType &outVec,
226 							eOutputOperation outOp = None)
227 	{
228 		if(outOp == None)
229 		{
230 			outVec.m_topVec = m_rotMat.transpose() * inVec.m_topVec;
231 			outVec.m_bottomVec = m_rotMat.transpose() * (inVec.m_bottomVec + m_trnVec.cross(inVec.m_topVec));
232 		}
233 		else if(outOp == Add)
234 		{
235 			outVec.m_topVec += m_rotMat.transpose() * inVec.m_topVec;
236 			outVec.m_bottomVec += m_rotMat.transpose() * (inVec.m_bottomVec + m_trnVec.cross(inVec.m_topVec));
237 		}
238 		else if(outOp == Subtract)
239 		{
240 			outVec.m_topVec -= m_rotMat.transpose() * inVec.m_topVec;
241 			outVec.m_bottomVec -= m_rotMat.transpose() * (inVec.m_bottomVec + m_trnVec.cross(inVec.m_topVec));
242 		}
243 	}
244 
245 	template<typename SpatialVectorType>
246 	void transformInverseRotationOnly(	const SpatialVectorType &inVec,
247 										SpatialVectorType &outVec,
248 										eOutputOperation outOp = None)
249 	{
250 		if(outOp == None)
251 		{
252 			outVec.m_topVec = m_rotMat.transpose() * inVec.m_topVec;
253 			outVec.m_bottomVec = m_rotMat.transpose() * inVec.m_bottomVec;
254 		}
255 		else if(outOp == Add)
256 		{
257 			outVec.m_topVec += m_rotMat.transpose() * inVec.m_topVec;
258 			outVec.m_bottomVec += m_rotMat.transpose() * inVec.m_bottomVec;
259 		}
260 		else if(outOp == Subtract)
261 		{
262 			outVec.m_topVec -= m_rotMat.transpose() * inVec.m_topVec;
263 			outVec.m_bottomVec -= m_rotMat.transpose() * inVec.m_bottomVec;
264 		}
265 
266 	}
267 
268 	void transformInverse(	const btSymmetricSpatialDyad &inMat,
269 							btSymmetricSpatialDyad &outMat,
270 							eOutputOperation outOp = None)
271 	{
272 		const btMatrix3x3 r_cross(	0, -m_trnVec[2], m_trnVec[1],
273 								m_trnVec[2], 0, -m_trnVec[0],
274 								-m_trnVec[1], m_trnVec[0], 0);
275 
276 
277 		if(outOp == None)
278 		{
279 			outMat.m_topLeftMat = m_rotMat.transpose() * ( inMat.m_topLeftMat - inMat.m_topRightMat * r_cross ) * m_rotMat;
280 			outMat.m_topRightMat = m_rotMat.transpose() * inMat.m_topRightMat * m_rotMat;
281 			outMat.m_bottomLeftMat = m_rotMat.transpose() * (r_cross * (inMat.m_topLeftMat - inMat.m_topRightMat * r_cross) + inMat.m_bottomLeftMat - inMat.m_topLeftMat.transpose() * r_cross) * m_rotMat;
282 		}
283 		else if(outOp == Add)
284 		{
285 			outMat.m_topLeftMat += m_rotMat.transpose() * ( inMat.m_topLeftMat - inMat.m_topRightMat * r_cross ) * m_rotMat;
286 			outMat.m_topRightMat += m_rotMat.transpose() * inMat.m_topRightMat * m_rotMat;
287 			outMat.m_bottomLeftMat += m_rotMat.transpose() * (r_cross * (inMat.m_topLeftMat - inMat.m_topRightMat * r_cross) + inMat.m_bottomLeftMat - inMat.m_topLeftMat.transpose() * r_cross) * m_rotMat;
288 		}
289 		else if(outOp == Subtract)
290 		{
291 			outMat.m_topLeftMat -= m_rotMat.transpose() * ( inMat.m_topLeftMat - inMat.m_topRightMat * r_cross ) * m_rotMat;
292 			outMat.m_topRightMat -= m_rotMat.transpose() * inMat.m_topRightMat * m_rotMat;
293 			outMat.m_bottomLeftMat -= m_rotMat.transpose() * (r_cross * (inMat.m_topLeftMat - inMat.m_topRightMat * r_cross) + inMat.m_bottomLeftMat - inMat.m_topLeftMat.transpose() * r_cross) * m_rotMat;
294 		}
295 	}
296 
297 	template<typename SpatialVectorType>
298 	SpatialVectorType operator * (const SpatialVectorType &vec)
299 	{
300 		SpatialVectorType out;
301 		transform(vec, out);
302 		return out;
303 	}
304 };
305 
306 template<typename SpatialVectorType>
symmetricSpatialOuterProduct(const SpatialVectorType & a,const SpatialVectorType & b,btSymmetricSpatialDyad & out)307 void symmetricSpatialOuterProduct(const SpatialVectorType &a, const SpatialVectorType &b, btSymmetricSpatialDyad &out)
308 {
309 	//output op maybe?
310 
311 	out.m_topLeftMat = outerProduct(a.m_topVec, b.m_bottomVec);
312 	out.m_topRightMat = outerProduct(a.m_topVec, b.m_topVec);
313 	out.m_topLeftMat = outerProduct(a.m_bottomVec, b.m_bottomVec);
314 	//maybe simple a*spatTranspose(a) would be nicer?
315 }
316 
317 template<typename SpatialVectorType>
symmetricSpatialOuterProduct(const SpatialVectorType & a,const SpatialVectorType & b)318 btSymmetricSpatialDyad symmetricSpatialOuterProduct(const SpatialVectorType &a, const SpatialVectorType &b)
319 {
320 	btSymmetricSpatialDyad out;
321 
322 	out.m_topLeftMat = outerProduct(a.m_topVec, b.m_bottomVec);
323 	out.m_topRightMat = outerProduct(a.m_topVec, b.m_topVec);
324 	out.m_bottomLeftMat = outerProduct(a.m_bottomVec, b.m_bottomVec);
325 
326 	return out;
327 	//maybe simple a*spatTranspose(a) would be nicer?
328 }
329 
330 #endif //BT_SPATIAL_ALGEBRA_H
331 
332