public override void Update()
{
if (DisplayedObject.Entity != null)
{
//The reason for this complexity is that we're drawing the shape's location directly and interpolated buffers might be active.
//That means we can't rely solely on the collidable's world transform or the entity's world transform alone;
//we must rebuild it from the entity's world transform and the collidable's local position.
//TODO: This is awfully annoying. Could use some built-in convenience methods to ease the usage.
Vector3 translation = Matrix3x3.Transform(DisplayedObject.LocalPosition, DisplayedObject.Entity.BufferedStates.InterpolatedStates.OrientationMatrix);
translation += DisplayedObject.Entity.BufferedStates.InterpolatedStates.Position;
Matrix worldTransform = Matrix3x3.ToMatrix4X4(DisplayedObject.Entity.BufferedStates.InterpolatedStates.OrientationMatrix);
worldTransform.Translation = translation;
WorldTransform = MathConverter.Convert(worldTransform);
}
else
{
//Entityless EntityCollidables just go by what their current transform is.
WorldTransform = MathConverter.Convert(DisplayedObject.WorldTransform.Matrix);
}
}
/// <summary>
/// Updates the wheel's world transform for graphics.
/// Called automatically by the owning wheel at the end of each frame.
/// If the engine is updating asynchronously, you can call this inside of a space read buffer lock
/// and update the wheel transforms safely.
/// </summary>
public override void UpdateWorldTransform()
{
#if !WINDOWS
Vector3 newPosition = new Vector3();
#else
Vector3 newPosition;
#endif
Vector3 worldAttachmentPoint;
Vector3 localAttach;
Vector3.Add(ref wheel.suspension.localAttachmentPoint, ref wheel.vehicle.Body.CollisionInformation.localPosition, out localAttach);
worldTransform = Matrix3x3.ToMatrix4X4(wheel.vehicle.Body.BufferedStates.InterpolatedStates.OrientationMatrix);
Matrix.TransformNormal(ref localAttach, ref worldTransform, out worldAttachmentPoint);
worldAttachmentPoint += wheel.vehicle.Body.BufferedStates.InterpolatedStates.Position;
Vector3 worldDirection;
Matrix.Transform(ref wheel.suspension.localDirection, ref worldTransform, out worldDirection);
float length = wheel.suspension.currentLength - graphicalRadius;
newPosition.X = worldAttachmentPoint.X + worldDirection.X * length;
newPosition.Y = worldAttachmentPoint.Y + worldDirection.Y * length;
newPosition.Z = worldAttachmentPoint.Z + worldDirection.Z * length;
Matrix spinTransform;
Vector3 localSpinAxis;
Vector3.Cross(ref wheel.localForwardDirection, ref wheel.suspension.localDirection, out localSpinAxis);
Matrix.CreateFromAxisAngle(ref localSpinAxis, spinAngle, out spinTransform);
Matrix localTurnTransform;
Matrix.Multiply(ref localGraphicTransform, ref spinTransform, out localTurnTransform);
Matrix.Multiply(ref localTurnTransform, ref steeringTransform, out localTurnTransform);
//Matrix.Multiply(ref localTurnTransform, ref spinTransform, out localTurnTransform);
Matrix.Multiply(ref localTurnTransform, ref worldTransform, out worldTransform);
worldTransform.Translation += newPosition;
}