/// <summary>
/// Convert this instance to an axis-angle representation.
/// </summary>
/// <returns>A TkVector4 that is the axis-angle representation of this quaternion.</returns>
public TkVector4 ToAxisAngle()
{
TkQuaternion q = this;
if (Math.Abs(q.W) > 1.0f)
{
q.Normalize();
}
TkVector4 result = new TkVector4();
result.W = 2.0f * (float)System.Math.Acos(q.W); // angle
float den = (float)System.Math.Sqrt(1.0 - q.W * q.W);
if (den > 0.0001f)
{
result.Xyz = q.Xyz / den;
}
else
{
// This occurs when the angle is zero.
// Not a problem: just set an arbitrary normalized axis.
result.Xyz = TkVector3.UnitX;
}
return(result);
}
/// <summary>
/// The new Half4 instance will convert the TkVector4 into 16-bit half-precision floating-point.
/// </summary>
/// <param name="v">OpenTK.TkVector4</param>
/// <param name="throwOnError">Enable checks that will throw if the conversion result is not meaningful.</param>
public TkVector4h(ref TkVector4 v, bool throwOnError)
{
X = new Half(v.X, throwOnError);
Y = new Half(v.Y, throwOnError);
Z = new Half(v.Z, throwOnError);
W = new Half(v.W, throwOnError);
}
/// <summary>
/// Convert the current quaternion to axis angle representation
/// </summary>
/// <param name="axis">The resultant axis</param>
/// <param name="angle">The resultant angle</param>
public void ToAxisAngle(out TkVector3 axis, out float angle)
{
TkVector4 result = ToAxisAngle();
axis = result.Xyz;
angle = result.W;
}
/// <summary>
/// The new Half4 instance will convert the TkVector4 into 16-bit half-precision floating-point.
/// This is the fastest constructor.
/// </summary>
/// <param name="v">OpenTK.TkVector4</param>
public TkVector4h(ref TkVector4 v)
{
X = new Half(v.X);
Y = new Half(v.Y);
Z = new Half(v.Z);
W = new Half(v.W);
}
