private int WalkTree(ControlCollection controls, RectF clip, Vector2 position, int depth, Func <Control, bool> predicate, float maxDistanceSquared)
{
var totalMatches = 0;
var ordered = controls.InDisplayOrder(Context.FrameIndex);
var stop = false;
for (int i = ordered.Count - 1; (i >= 0) && !stop; i--)
{
var control = ordered[i];
if (control.IsTransparent || control.Intangible)
{
continue;
}
var result = new Result {
Depth = depth,
Control = control,
Rect = control.GetRect(context: Context)
};
if (!result.Rect.Intersection(in clip, out result.ClippedRect))
{
continue;
}
var inside = result.ClippedRect.Contains(position);
stop = stop || inside;
int localMatches = 0;
var ifht = control as IFuzzyHitTestTarget;
if (ifht != null)
{
localMatches += ifht.WalkTree(Results, ref result, position, predicate, maxDistanceSquared);
}
if (ifht?.WalkChildren != false)
{
var icc = control as IControlContainer;
if (icc != null)
{
localMatches += WalkTree(icc.Children, result.ClippedRect, position, depth + 1, predicate, maxDistanceSquared);
}
}
totalMatches += localMatches;
if (localMatches > 0)
{
continue;
}
if ((predicate != null) && !predicate(control))
{
continue;
}
float distanceSquared;
if (inside)
{
result.Distance = distanceSquared = 0f;
result.ClosestPoint = position;
}
else
{
result.ClosestPoint = result.ClippedRect.Clamp(position);
distanceSquared = (position - result.ClosestPoint).LengthSquared();
if (distanceSquared > maxDistanceSquared)
{
continue;
}
result.Distance = (float)Math.Sqrt(distanceSquared);
}
var ipic = result.Control as IPartiallyIntangibleControl;
result.IsIntangibleAtClosestPoint = (ipic?.IsIntangibleAtPosition(result.ClosestPoint) == true);
Results.Add(result);
totalMatches += 1;
}
return(totalMatches);
}