private static void PerformRecursiveHitTest(UIElement element, ref Ray ray, ref Matrix worldViewProj, ICollection<HitTestResult> results)
{
// if the element is not visible, we also remove all its children
if (!element.IsVisible)
return;
var canBeHit = element.CanBeHitByUser;
if (canBeHit || element.ClipToBounds)
{
Vector3 intersection;
var intersect = element.Intersects(ref ray, out intersection);
// don't perform the hit test on children if clipped and parent no hit
if (element.ClipToBounds && !intersect)
return;
// Calculate the depth of the element with the depth bias so that hit test corresponds to visuals.
Vector4 projectedIntersection;
var intersection4 = new Vector4(intersection, 1);
Vector4.Transform(ref intersection4, ref worldViewProj, out projectedIntersection);
// update the hit results
if (canBeHit && intersect)
{
results.Add(new HitTestResult(element.DepthBias, element, intersection));
}
}
// test the children
foreach (var child in element.HitableChildren)
PerformRecursiveHitTest(child, ref ray, ref worldViewProj, results);
}
private void PerformRecursiveHitTest(UIElement element, ref Ray ray, ref UIElement clickedElement, ref Vector3 intersectionPoint, ref float smallestDepth)
{
// if the element is not visible, we also remove all its children
if (!element.IsVisible)
return;
if (element.ClipToBounds || element.CanBeHitByUser)
{
Vector3 intersection;
var intersect = element.Intersects(ref ray, out intersection);
// don't perform the hit test on children if clipped and parent no hit
if (element.ClipToBounds && !intersect)
return;
// Calculate the depth of the element with the depth bias so that hit test corresponds to visuals.
Vector4 projectedIntersection;
var intersection4 = new Vector4(intersection, 1);
Vector4.Transform(ref intersection4, ref viewParameters.ViewProjectionMatrix, out projectedIntersection);
var depthWithBias = projectedIntersection.Z / projectedIntersection.W - element.DepthBias * BatchBase<int>.DepthBiasShiftOneUnit;
// update the closest element hit
if (element.CanBeHitByUser && intersect && depthWithBias < smallestDepth)
{
smallestDepth = depthWithBias;
intersectionPoint = intersection;
clickedElement = element;
}
}
// render the children
foreach (var child in element.HitableChildren)
PerformRecursiveHitTest(child, ref ray, ref clickedElement, ref intersectionPoint, ref smallestDepth);
}
private static void PerformRecursiveHitTest(UIElement element, ref Ray ray, ref Matrix worldViewProj, ref UIElement hitElement, ref Vector3 intersectionPoint, ref float smallestDepth, ref float highestDepthBias)
{
// if the element is not visible, we also remove all its children
if (!element.IsVisible)
return;
var canBeHit = element.CanBeHitByUser;
if (canBeHit || element.ClipToBounds)
{
Vector3 intersection;
var intersect = element.Intersects(ref ray, out intersection);
// don't perform the hit test on children if clipped and parent no hit
if (element.ClipToBounds && !intersect)
return;
// Calculate the depth of the element with the depth bias so that hit test corresponds to visuals.
Vector4 projectedIntersection;
var intersection4 = new Vector4(intersection, 1);
Vector4.Transform(ref intersection4, ref worldViewProj, out projectedIntersection);
var depth = projectedIntersection.Z/projectedIntersection.W;
// update the closest element hit
if (canBeHit && intersect)
{
if (depth < smallestDepth || (depth == smallestDepth && element.DepthBias > highestDepthBias))
{
smallestDepth = depth;
highestDepthBias = element.DepthBias;
intersectionPoint = intersection;
hitElement = element;
}
}
}
// test the children
foreach (var child in element.HitableChildren)
PerformRecursiveHitTest(child, ref ray, ref worldViewProj, ref hitElement, ref intersectionPoint, ref smallestDepth, ref highestDepthBias);
}
