/// <summary>
/// Attempts to calculate and update the transform.
/// </summary>
/// <param name="force">
/// <c>true</c> to force an update even if the same parent option is
/// selected. The default is <c>false</c>.
/// </param>
public virtual void UpdateTransform(bool force = false)
{
// If there are no parent options, nothing to do
if (parentOptions.Count == 0)
{
State = AlignmentState.Inhibited;
Debug.LogWarning($"{nameof(MultiParentAlignment)}: No parent options to select from.");
return;
}
// Validate the parent options
ValidateParentOptions();
// Use virtual method to select the best parent option
ParentAlignmentOptions parentOption = SelectParent();
// If no option could be found, fail
if (parentOption == null)
{
State = AlignmentState.Inhibited;
Debug.LogWarning($"{nameof(MultiParentAlignment)}: No parent could be found that meets the minimum criteria.");
return;
}
else
{
// Actually apply the parent
ApplyParent(parentOption, force: force);
// Resolved
State = AlignmentState.Tracking;
}
}
/// <summary>
/// Applies the specified parent options to this object.
/// </summary>
/// <param name="parentOption">
/// The parent options to apply.
/// </param>
/// <param name="force">
/// <c>true</c> to force an update even if reusing the same option.
/// The default is <c>false</c>.
/// </param>
/// <remarks>
/// The default implementation of this method parents the transform
/// and applies position, rotation and scale modifications.
/// </remarks>
protected virtual void ApplyParent(ParentAlignmentOptions parentOption, bool force = false)
{
// Validate
if (parentOption == null)
{
throw new ArgumentNullException(nameof(parentOption));
}
if (parentOption.Frame == null)
{
throw new InvalidOperationException($"{nameof(parentOption.Frame)} cannot be null.");
}
// If already parented to this object, no additional work needed
if ((!force) && (currentParent == parentOption))
{
return;
}
// Make our transform a child of the frame
this.transform.SetParent(parentOption.Frame.transform, worldPositionStays: false);
// Apply transform modifications
this.transform.localPosition = parentOption.Position;
this.transform.localRotation = Quaternion.Euler(parentOption.Rotation);
this.transform.localScale = parentOption.Scale;
// Notify of parent change
CurrentParent = parentOption;
// Done!
}
/// <summary>
/// Attempts to select the best parent option based on current settings.
/// </summary>
/// <returns>
/// The <see cref="ParentAlignmentOptions"/> that represent the best parent,
/// if found; otherwise <see langword = "null" />.
/// </returns>
/// <remarks>
/// The default implementation examines all options where
/// <see cref="ParentAlignmentOptions.IsValidTarget">IsValidTarget</see>
/// returns <c>true</c> and selects the top option sorted by
/// <see cref="ParentAlignmentOptions.SortOrder(Transform)">SortOrder</see>.
/// </remarks>
protected virtual ParentAlignmentOptions SelectParent()
{
// Attempt to get the reference transform
Transform reference = GetReferenceTransform();
// If no transform, can't continue
if (reference == null)
{
return(null);
}
// Placeholder
ParentAlignmentOptions parentOption = null;
// If only one parent option, always use that
if (parentOptions.Count == 1)
{
// Use only parent option, if valid
parentOption = (parentOptions[0].IsValidTarget() ? parentOptions[0] : null);
}
else
{
// Find the best valid parent, sorted by logic in the ParentAlignmentOption itself
parentOption = (from o in ParentOptions
where o.IsValidTarget()
orderby o.SortOrder(reference)
select o
).FirstOrDefault();
}
// Done searching
return(parentOption);
}
