1 /*
2  * Copyright (C) 2011 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 /* $Id: db_utilities_rotation.h,v 1.2 2010/09/03 12:00:11 bsouthall Exp $ */
18 
19 #ifndef DB_UTILITIES_ROTATION
20 #define DB_UTILITIES_ROTATION
21 
22 #include "db_utilities.h"
23 
24 
25 
26 /*****************************************************************
27 *    Lean and mean begins here                                   *
28 *****************************************************************/
29 /*!
30  * \defgroup LMRotation (LM) Rotation Utilities (quaternions, orthonormal)
31  */
32 /*\{*/
33 /*!
34  Takes a unit quaternion and gives its corresponding rotation matrix.
35  \param R rotation matrix (out)
36  \param q quaternion
37  */
db_QuaternionToRotation(double R[9],const double q[4])38 inline void db_QuaternionToRotation(double R[9],const double q[4])
39 {
40     double q0q0,q0qx,q0qy,q0qz,qxqx,qxqy,qxqz,qyqy,qyqz,qzqz;
41 
42     q0q0=q[0]*q[0];
43     q0qx=q[0]*q[1];
44     q0qy=q[0]*q[2];
45     q0qz=q[0]*q[3];
46     qxqx=q[1]*q[1];
47     qxqy=q[1]*q[2];
48     qxqz=q[1]*q[3];
49     qyqy=q[2]*q[2];
50     qyqz=q[2]*q[3];
51     qzqz=q[3]*q[3];
52 
53     R[0]=q0q0+qxqx-qyqy-qzqz; R[1]=2.0*(qxqy-q0qz);     R[2]=2.0*(qxqz+q0qy);
54     R[3]=2.0*(qxqy+q0qz);     R[4]=q0q0-qxqx+qyqy-qzqz; R[5]=2.0*(qyqz-q0qx);
55     R[6]=2.0*(qxqz-q0qy);     R[7]=2.0*(qyqz+q0qx);     R[8]=q0q0-qxqx-qyqy+qzqz;
56 }
57 
58 /*\}*/
59 #endif /* DB_UTILITIES_ROTATION */
60