CrystalSpace

Public API Reference

csgeom/quaternion.h

Go to the documentation of this file.
00001 /*
00002     Copyright (C) 2000 by Norman Kramer
00003 
00004     This library is free software; you can redistribute it and/or
00005     modify it under the terms of the GNU Library General Public
00006     License as published by the Free Software Foundation; either
00007     version 2 of the License, or (at your option) any later version.
00008 
00009     This library is distributed in the hope that it will be useful,
00010     but WITHOUT ANY WARRANTY; without even the implied warranty of
00011     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012     Library General Public License for more details.
00013 
00014     You should have received a copy of the GNU Library General Public
00015     License along with this library; if not, write to the Free
00016     Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
00017 */
00018 
00019 #ifndef __CS_QUATERNION_H__
00020 #define __CS_QUATERNION_H__
00021 
00029 #include "csextern.h"
00030 #include "csqsqrt.h"
00031 
00032 #include "csgeom/vector3.h"
00033 
00034 class csMatrix3;
00035 
00039 class CS_CRYSTALSPACE_EXPORT csQuaternion
00040 {
00041 public:
00043   inline void Init (float theR, float theX, float theY, float theZ)
00044   { r = theR; x = theX; y = theY; z = theZ; }
00045 
00047   csQuaternion () { Init(0, 0, 0, 0 ); }
00049   csQuaternion (float theR, float theX=0.0, float theY=0.0, float theZ=0.0)
00050   { Init (theR, theX, theY, theZ ); }
00052   csQuaternion (const csQuaternion& q) { Init (q.r, q.x, q.y, q.z); }
00054   csQuaternion (const csVector3& q) { Init (0, q.x, q.y, q.z); }
00055 
00057   csQuaternion (const csMatrix3& smat);
00058 
00060   inline friend csQuaternion operator+ (const csQuaternion& q1,
00061         const csQuaternion& q2)
00062   {
00063     return csQuaternion (q1.r + q2.r, q1.x + q2.x, q1.y + q2.y, q1.z + q2.z );
00064   }
00065 
00067   inline friend csQuaternion operator- (const csQuaternion& q1,
00068         const csQuaternion& q2)
00069   {
00070     return csQuaternion (q1.r - q2.r, q1.x - q2.x, q1.y - q2.y, q1.z - q2.z );
00071   }
00072 
00074   inline friend csQuaternion operator* (const csQuaternion& q1,
00075         const csQuaternion& q2)
00076   {
00077     return csQuaternion (q1.r*q2.r -  q1.x*q2.x - q1.y*q2.y - q1.z*q2.z,
00078              q1.y*q2.z -  q1.z*q2.y + q1.r*q2.x + q1.x*q2.r,
00079              q1.z*q2.x -  q1.x*q2.z + q1.r*q2.y + q1.y*q2.r,
00080              q1.x*q2.y -  q1.y*q2.x + q1.r*q2.z + q1.z*q2.r);
00081   }
00082 
00084   csQuaternion& operator*= (const csQuaternion& q2)
00085   {
00086     Init (r*q2.r -  x*q2.x - y*q2.y - z*q2.z,
00087       y*q2.z -  z*q2.y + r*q2.x + x*q2.r,
00088       z*q2.x -  x*q2.z + r*q2.y + y*q2.r,
00089       x*q2.y -  y*q2.x + r*q2.z + z*q2.r);
00090     return *this;
00091   }
00092 
00094   void Conjugate () { Init (r, -x, -y, -z); }
00095 
00097   void Negate () { Init(-r, -x, -y, -z); }
00098 
00100   void Invert();
00101 
00107   void GetAxisAngle(csVector3& axis, float& phi) const;
00108 
00114   void SetWithAxisAngle(csVector3 axis, float phi);
00115 
00121   void PrepRotation (float angle, csVector3 vec)
00122   {
00123     double theSin = sin (angle / 2.0f);
00124     Init ((float) cos (angle / 2.0f), vec.x * theSin, vec.y * theSin,
00125         vec.z * theSin);
00126   }
00127 
00129   csVector3 Rotate (csVector3 vec)
00130   {
00131     csQuaternion p (vec);
00132     csQuaternion qConj (r, -x, -y, -z);
00133 
00134     p = *this * p;
00135     p *= qConj;
00136     return csVector3 (p.x, p.y, p.z);
00137   }
00138 
00140   void Normalize ()
00141   {
00142     float dist, square;
00143     square = x * x + y * y + z * z + r * r;
00144 
00145     if (square > 0.0) dist = (float)csQisqrt(square);
00146     else dist = 1;
00147 
00148     x *= dist;
00149     y *= dist;
00150     z *= dist;
00151     r *= dist;
00152 
00153     /*if(x*x + y*y + z*z > .999)
00154     {
00155       // Severe problems...
00156       float inverselen = 1.0f / (x*x + y*y + z*z);
00157       x *= inverselen;
00158       y *= inverselen;
00159       z *= inverselen;
00160       if(r > 0) r = -1 + r;
00161       else r = 1 + r;
00162     }
00163     else
00164     {
00165       r = csQsqrt(1.0f - x*x - y*y - z*z);
00166       }*/
00167   }
00168 
00174   void SetWithEuler (const csVector3 &rot);
00175 
00180   void GetEulerAngles (csVector3& angles, bool radians = false);
00181 
00185   csQuaternion ToAxisAngle () const;
00186 
00192   csQuaternion Slerp (const csQuaternion &quat2, float slerp) const;
00193 
00194   //csQuaternion Lerp(const csQuaternion& quat2, float ratio) const;
00195 
00196   float r,x,y,z;
00197 };
00198 
00201 #endif // __CS_QUATERNION_H__
00202 

Generated for Crystal Space by doxygen 1.4.6