Changeset 7983 for code/branches/kicklib/src/external/bullet/LinearMath/btQuaternion.h

Timestamp:

Feb 27, 2011, 7:43:24 AM (14 years ago)

Author:

rgrieder

Message:

Updated Bullet Physics Engine from v2.74 to v2.77

File:

• code/branches/kicklib/src/external/bullet/LinearMath/btQuaternion.h (modified) (4 diffs)

code/branches/kicklib/src/external/bullet/LinearMath/btQuaternion.h

@@ -210 +210 @@
         }
 
-
-  /**@brief Return the inverse of this quaternion */
+        /**@brief Return the axis of the rotation represented by this quaternion */
+        btVector3 getAxis() const
+        {
+                btScalar s_squared = btScalar(1.) - btPow(m_floats[3], btScalar(2.));
+                if (s_squared < btScalar(10.) * SIMD_EPSILON) //Check for divide by zero
+                        return btVector3(1.0, 0.0, 0.0);  // Arbitrary
+                btScalar s = btSqrt(s_squared);
+                return btVector3(m_floats[0] / s, m_floats[1] / s, m_floats[2] / s);
+        }
+
+        /**@brief Return the inverse of this quaternion */
         btQuaternion inverse() const
         {
@@ -253 +262 @@
         }
 
+        /**@todo document this and it's use */
+        SIMD_FORCE_INLINE btQuaternion nearest( const btQuaternion& qd) const 
+        {
+                btQuaternion diff,sum;
+                diff = *this - qd;
+                sum = *this + qd;
+                if( diff.dot(diff) < sum.dot(sum) )
+                        return qd;
+                return (-qd);
+        }
+
+
   /**@brief Return the quaternion which is the result of Spherical Linear Interpolation between this and the other quaternion
    * @param q The other quaternion to interpolate with 
@@ -265 +286 @@
                         btScalar s0 = btSin((btScalar(1.0) - t) * theta);
                         btScalar s1 = btSin(t * theta);   
-                        return btQuaternion((m_floats[0] * s0 + q.x() * s1) * d,
-                                (m_floats[1] * s0 + q.y() * s1) * d,
-                                (m_floats[2] * s0 + q.z() * s1) * d,
-                                (m_floats[3] * s0 + q.m_floats[3] * s1) * d);
+                        if (dot(q) < 0) // Take care of long angle case see http://en.wikipedia.org/wiki/Slerp
+                          return btQuaternion((m_floats[0] * s0 + -q.x() * s1) * d,
+                                              (m_floats[1] * s0 + -q.y() * s1) * d,
+                                              (m_floats[2] * s0 + -q.z() * s1) * d,
+                                              (m_floats[3] * s0 + -q.m_floats[3] * s1) * d);
+                        else
+                          return btQuaternion((m_floats[0] * s0 + q.x() * s1) * d,
+                                              (m_floats[1] * s0 + q.y() * s1) * d,
+                                              (m_floats[2] * s0 + q.z() * s1) * d,
+                                              (m_floats[3] * s0 + q.m_floats[3] * s1) * d);
+                        
                 }
                 else
@@ -379 +407 @@
 
         if (d < -1.0 + SIMD_EPSILON)
-                return btQuaternion(0.0f,1.0f,0.0f,0.0f); // just pick any vector
+        {
+                btVector3 n,unused;
+                btPlaneSpace1(v0,n,unused);
+                return btQuaternion(n.x(),n.y(),n.z(),0.0f); // just pick any vector that is orthogonal to v0
+        }
 
         btScalar  s = btSqrt((1.0f + d) * 2.0f);