Changeset 1799Tweet

Timestamp:

Aug 23, 2012, 5:51:20 PM (8 years ago)

Author:

Jnat

Message:

Added Slerp method to Quat

Location:

trunk/src

Files:

• lol/math/vector.h (modified) (1 diff)
• math/vector.cpp (modified) (1 diff)

trunk/src/lol/math/vector.h

@@ -935 +935 @@
     static Quat<T> rotate(T angle, T x, T y, T z);
     static Quat<T> rotate(T angle, Vec3<T> const &v);
+        static Quat<T> slerp(Quat<T> QuatA,Quat<T> QuatB, float const &Scalar);
 
     /* Convert from Euler angles. The axes in fromeuler_xyx are

trunk/src/math/vector.cpp

@@ -485 +485 @@
 {
     return quat::rotate(angle, vec3(x, y, z));
+}
+
+template<> quat quat::slerp(quat QuatA, quat QuatB, float const &Scalar)
+{
+        float magnitude = lol::sqrt(sqlength(QuatA) * sqlength(QuatB));
+        //btAssert(magnitude > btScalar(0));
+
+        float product = lol::dot(QuatA,QuatB) / magnitude;
+        if (product != 1.0f)
+        {
+                // Take care of long angle case see http://en.wikipedia.org/wiki/Slerp
+                const float sign = (product < 0.0f) ? -1.0f : 1.0f;
+
+                const float theta = lol::acos(sign * product);
+                const float s1 = lol::sin(sign * Scalar * theta);   
+                const float d = 1.0f / lol::sin(theta);
+                const float s0 = lol::sin((1.0f - Scalar) * theta);
+
+                return quat(
+                        (QuatA.w * s0 + QuatB.w * s1) * d,
+                        (QuatA.x * s0 + QuatB.x * s1) * d,
+                        (QuatA.y * s0 + QuatB.y * s1) * d,
+                        (QuatA.z * s0 + QuatB.z * s1) * d);
+        }
+        else
+        {
+                return QuatA;
+        }
 }