| 255 | 
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       return rotation angle from -PI to PI  | 
| 256 | 
  | 
    */ | 
| 257 | 
  | 
    inline Real get_rotation_angle() const{ | 
| 258 | 
< | 
      if( w < (Real)0.0 ) | 
| 258 | 
> | 
      if( w() < (Real)0.0 ) | 
| 259 | 
  | 
        return 2.0*atan2(-sqrt( x()*x() + y()*y() + z()*z() ), -w() ); | 
| 260 | 
  | 
      else | 
| 261 | 
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        return 2.0*atan2( sqrt( x()*x() + y()*y() + z()*z() ),  w() ); | 
| 313 | 
  | 
                               c.z()); | 
| 314 | 
  | 
 | 
| 315 | 
  | 
      this->normalize();    // if "from" or "to" not unit, normalize quat | 
| 316 | 
< | 
      w += 1.0f;            // reducing angle to halfangle | 
| 317 | 
< | 
      if( w <= 1e-6 ) {     // angle close to PI | 
| 316 | 
> | 
      w() += 1.0f;            // reducing angle to halfangle | 
| 317 | 
> | 
      if( w() <= 1e-6 ) {     // angle close to PI | 
| 318 | 
  | 
        if( ( from.z()*from.z() ) > ( from.x()*from.x() ) ) { | 
| 319 | 
< | 
          this->data_[0] =  w;     | 
| 319 | 
> | 
          this->data_[0] =  w();     | 
| 320 | 
  | 
          this->data_[1] =  0.0;       //cross(from , Vector3d(1,0,0)) | 
| 321 | 
  | 
          this->data_[2] =  from.z(); | 
| 322 | 
  | 
          this->data_[3] = -from.y(); | 
| 323 | 
  | 
        } else { | 
| 324 | 
< | 
          this->data_[0] =  w; | 
| 324 | 
> | 
          this->data_[0] =  w(); | 
| 325 | 
  | 
          this->data_[1] =  from.y();  //cross(from, Vector3d(0,0,1)) | 
| 326 | 
  | 
          this->data_[2] = -from.x(); | 
| 327 | 
  | 
          this->data_[3] =  0.0; |