public Trackball()
{
_transform = new Transform3DGroup();
_transform.Children.Add(_scale);
_transform.Children.Add(new RotateTransform3D(_rotation));
_currentOrientation = Quaternion.Identity;
_persistentOrientation = Quaternion.Identity;
IoC.Get<IPropertyGrid>().SelectedObject = _rotation;
}
private void Track(Point currentPosition)
{
Vector3D currentPosition3D = ProjectToTrackball(EventSource.ActualWidth, EventSource.ActualHeight, currentPosition);
IoC.Get<IOutput>().Append("New trackball position: " + currentPosition3D);
// Because our sphere is centered at the origin, we may interpret our points as vectors. Doing so it is trivial
// to find the axis and angle of rotation using the cross product dot product respectively.
Vector3D axis = Vector3D.Cross(_initialPosition3D, currentPosition3D);
float angle = Vector3D.AngleBetween(_initialPosition3D, currentPosition3D);
// We negate the angle because we are rotating the camera (if we were rotating the scene, we wouldn't do this).
Quaternion delta = new Quaternion(axis, -angle);
// Get the initial orientation.
Quaternion q = _persistentOrientation;
// Compose the delta with the previous orientation
q *= delta;
// Store the new orientation.
_rotation.Axis = q.Axis;
_rotation.Angle = q.Angle;
_currentOrientation = q;
//_previousPosition3D = currentPosition3D;
}
public static bool IsNan(Quaternion q)
{
return float.IsNaN(q.X) || float.IsNaN(q.Y) || float.IsNaN(q.Z) || float.IsNaN(q.W);
}
private void OnMouseDown(object sender, MouseEventArgs e)
{
IoC.Get<IOutput>().Append("Mouse down");
Mouse.Capture(EventSource, CaptureMode.Element);
_previousPosition2D = e.GetPosition(EventSource);
_initialPosition3D = ProjectToTrackball(
EventSource.ActualWidth,
EventSource.ActualHeight,
_previousPosition2D);
_currentOrientation = _persistentOrientation;
_mouseDown = true;
}
public static Quaternion CreateFromRotationMatrix(Matrix3D matrix)
{
float num8 = (matrix.M11 + matrix.M22) + matrix.M33;
Quaternion quaternion = new Quaternion();
if (num8 > 0f)
{
float num = (float)Math.Sqrt((double)(num8 + 1f));
quaternion.W = num * 0.5f;
num = 0.5f / num;
quaternion.X = (matrix.M23 - matrix.M32) * num;
quaternion.Y = (matrix.M31 - matrix.M13) * num;
quaternion.Z = (matrix.M12 - matrix.M21) * num;
return quaternion;
}
if ((matrix.M11 >= matrix.M22) && (matrix.M11 >= matrix.M33))
{
float num7 = (float)Math.Sqrt((double)(((1f + matrix.M11) - matrix.M22) - matrix.M33));
float num4 = 0.5f / num7;
quaternion.X = 0.5f * num7;
quaternion.Y = (matrix.M12 + matrix.M21) * num4;
quaternion.Z = (matrix.M13 + matrix.M31) * num4;
quaternion.W = (matrix.M23 - matrix.M32) * num4;
return quaternion;
}
if (matrix.M22 > matrix.M33)
{
float num6 = (float)Math.Sqrt((double)(((1f + matrix.M22) - matrix.M11) - matrix.M33));
float num3 = 0.5f / num6;
quaternion.X = (matrix.M21 + matrix.M12) * num3;
quaternion.Y = 0.5f * num6;
quaternion.Z = (matrix.M32 + matrix.M23) * num3;
quaternion.W = (matrix.M31 - matrix.M13) * num3;
return quaternion;
}
float num5 = (float)Math.Sqrt((double)(((1f + matrix.M33) - matrix.M11) - matrix.M22));
float num2 = 0.5f / num5;
quaternion.X = (matrix.M31 + matrix.M13) * num2;
quaternion.Y = (matrix.M32 + matrix.M23) * num2;
quaternion.Z = 0.5f * num5;
quaternion.W = (matrix.M12 - matrix.M21) * num2;
return quaternion;
}