/// <summary>
/// Set the visual parent to a child.
/// </summary>
/// <param name="child">The child to which set the visual parent.</param>
/// <param name="parent">The parent of the child.</param>
protected static void SetVisualParent(UIElement child, UIElement parent)
{
if (child == null) throw new ArgumentNullException(nameof(child));
if (parent != null && child.VisualParent != null && parent != child.VisualParent)
throw new InvalidOperationException("The UI element 'Name=" + child.Name + "' has already as visual parent the element 'Name=" + child.VisualParent.Name + "'.");
child.VisualParent?.VisualChildrenCollection.Remove(child);
child.VisualParent = parent;
if (parent != null)
{
child.ResourceDictionary = parent.ResourceDictionary;
child.LayoutingContext = parent.layoutingContext;
parent.VisualChildrenCollection.Add(child);
}
}
/// <summary>
/// Propagate the collapsing to a child element <paramref name="element"/>.
/// </summary>
/// <param name="element">A child element to which propagate the collapse.</param>
/// <exception cref="InvalidOperationException"><paramref name="element"/> is not a child of this element.</exception>
protected void PropagateCollapseToChild(UIElement element)
{
if (element.VisualParent != this)
throw new InvalidOperationException("Element is not a child of this element.");
element.InvalidateMeasure();
element.CollapseOverride();
}
/// <summary>
/// Set the parent to a child.
/// </summary>
/// <param name="child">The child to which set the parent.</param>
/// <param name="parent">The parent of the child.</param>
protected static void SetParent(UIElement child, UIElement parent)
{
if (parent != null && child.Parent != null && parent != child.Parent)
throw new InvalidOperationException("The UI element 'Name="+child.Name+"' has already as parent the element 'Name="+child.Parent.Name+"'.");
child.Parent = parent;
}
public ElementRenderer GetRenderer(UIElement element)
{
return rendererManager.GetRenderer(element);
}
public void RegisterRenderer(UIElement element, ElementRenderer renderer)
{
rendererManager.RegisterRenderer(element, renderer);
}
private UIElement GetElementAtScreenPosition(UIElement rootElement, Vector2 position, ref Vector3 intersectionPoint)
{
// here we use a trick to take into the calculation the viewport => we multiply the screen position by the viewport ratio (easier than modifying the view matrix)
var positionForHitTest = Vector2.Demodulate(position, viewportTargetRatio) - new Vector2(0.5f);
// calculate the ray corresponding to the click
var rayDirectionView = Vector3.Normalize(new Vector3(positionForHitTest.X * viewParameters.FrustumHeight * viewParameters.AspectRatio, -positionForHitTest.Y * viewParameters.FrustumHeight, -1));
var clickRay = new Ray(viewParameters.ViewMatrixInverse.TranslationVector, Vector3.TransformNormal(rayDirectionView, viewParameters.ViewMatrixInverse));
// perform the hit test
UIElement clickedElement = null;
var smallestDepth = float.PositiveInfinity;
PerformRecursiveHitTest(rootElement, ref clickRay, ref clickedElement, ref intersectionPoint, ref smallestDepth);
return clickedElement;
}
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 UIElement FindCommonParent(UIElement element1, UIElement element2)
{
// build the list of the parents of the newly selected element
newlySelectedElementParents.Clear();
var newElementParent = element1;
while (newElementParent != null)
{
newlySelectedElementParents.Add(newElementParent);
newElementParent = newElementParent.VisualParent;
}
// find the common element into the previously and newly selected element hierarchy
var commonElement = element2;
while (commonElement != null && !newlySelectedElementParents.Contains(commonElement))
commonElement = commonElement.VisualParent;
return commonElement;
}
private void ThrowEnterAndLeaveTouchEvents(UIElement currentElement, UIElement previousElement, TouchEventArgs touchEvent)
{
var commonElement = FindCommonParent(currentElement, previousElement);
// raise leave events to the hierarchy: previousElt -> commonElementParent
var previousElementParent = previousElement;
while (previousElementParent != commonElement && previousElementParent != null)
{
if (previousElementParent.IsHierarchyEnabled && previousElementParent.IsTouched)
{
touchEvent.Handled = false; // reset 'handled' because it corresponds to another event
previousElementParent.RaiseTouchLeaveEvent(touchEvent);
}
previousElementParent = previousElementParent.VisualParent;
}
// raise enter events to the hierarchy: newElt -> commonElementParent
var newElementParent = currentElement;
while (newElementParent != commonElement && newElementParent != null)
{
if (newElementParent.IsHierarchyEnabled && !newElementParent.IsTouched)
{
touchEvent.Handled = false; // reset 'handled' because it corresponds to another event
newElementParent.RaiseTouchEnterEvent(touchEvent);
}
newElementParent = newElementParent.VisualParent;
}
}
public HitTestResult(float depthBias, UIElement element, Vector3 intersection)
{
DepthBias = depthBias;
Element = element;
IntersectionPoint = intersection;
}
private void ReccursiveDrawWithClipping(RenderContext context, UIElement element)
{
// if the element is not visible, we also remove all its children
if (!element.IsVisible)
return;
var renderer = rendererManager.GetRenderer(element);
renderingContext.DepthBias = element.DepthBias;
// render the clipping region of the element
if (element.ClipToBounds)
{
// flush current elements
batch.End();
// render the clipping region
batch.Begin(ref viewParameters.ViewProjectionMatrix, context.GraphicsDevice.BlendStates.ColorDisabled, uiSystem.IncreaseStencilValueState, renderingContext.StencilTestReferenceValue);
renderer.RenderClipping(element, renderingContext);
batch.End();
// update context and restart the batch
renderingContext.StencilTestReferenceValue += 1;
batch.Begin(ref viewParameters.ViewProjectionMatrix, context.GraphicsDevice.BlendStates.AlphaBlend, uiSystem.KeepStencilValueState, renderingContext.StencilTestReferenceValue);
}
// render the design of the element
renderer.RenderColor(element, renderingContext);
// render the children
foreach (var child in element.VisualChildrenCollection)
ReccursiveDrawWithClipping(context, child);
// clear the element clipping region from the stencil buffer
if (element.ClipToBounds)
{
// flush current elements
batch.End();
renderingContext.DepthBias = element.MaxChildrenDepthBias;
// render the clipping region
batch.Begin(ref viewParameters.ViewProjectionMatrix, context.GraphicsDevice.BlendStates.ColorDisabled, uiSystem.DecreaseStencilValueState, renderingContext.StencilTestReferenceValue);
renderer.RenderClipping(element, renderingContext);
batch.End();
// update context and restart the batch
renderingContext.StencilTestReferenceValue -= 1;
batch.Begin(ref viewParameters.ViewProjectionMatrix, context.GraphicsDevice.BlendStates.AlphaBlend, uiSystem.KeepStencilValueState, renderingContext.StencilTestReferenceValue);
}
}
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 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);
}
/// <summary>
/// Gets all elements that the given <paramref name="ray"/> intersects.
/// </summary>
/// <param name="rootElement">The root <see cref="UIElement"/> from which it should test</param>
/// <param name="ray"><see cref="Ray"/> from the click in object space of the ui component in (-Resolution.X/2 .. Resolution.X/2, -Resolution.Y/2 .. Resolution.Y/2) range</param>
/// <param name="worldViewProj"></param>
/// <returns>A collection of all elements hit by this ray, or an empty collection if no hit.</returns>
public static ICollection<HitTestResult> GetElementsAtPosition(UIElement rootElement, ref Ray ray, ref Matrix worldViewProj)
{
var results = new List<HitTestResult>();
PerformRecursiveHitTest(rootElement, ref ray, ref worldViewProj, results);
return results;
}
/// <summary>
/// Gets the element with which the clickRay intersects, or null if none is found
/// </summary>
/// <param name="rootElement">The root <see cref="UIElement"/> from which it should test</param>
/// <param name="clickRay"><see cref="Ray"/> from the click in object space of the ui component in (-Resolution.X/2 .. Resolution.X/2, -Resolution.Y/2 .. Resolution.Y/2) range</param>
/// <param name="worldViewProj"></param>
/// <param name="intersectionPoint">Intersection point between the ray and the element</param>
/// <returns>The <see cref="UIElement"/> with which the ray intersects</returns>
public static UIElement GetElementAtScreenPosition(UIElement rootElement, ref Ray clickRay, ref Matrix worldViewProj, ref Vector3 intersectionPoint)
{
UIElement clickedElement = null;
var smallestDepth = float.PositiveInfinity;
var highestDepthBias = -1.0f;
PerformRecursiveHitTest(rootElement, ref clickRay, ref worldViewProj, ref clickedElement, ref intersectionPoint, ref smallestDepth, ref highestDepthBias);
return clickedElement;
}
// Create a button that can toggle on/off the light shadow map
private Button CreateShadowButton(UIElement parentButton, LightComponent component)
{
var button = new Button
{
Margin = new Thickness(20, 5, 5, 5),
Name = "Shadow Button " + component.Entity.Name,
Opacity = component.Enabled ? 1.0f : 0.3f,
CanBeHitByUser = component.Enabled,
Content = new TextBlock
{
Font = Font,
TextAlignment = TextAlignment.Right,
Text = GetButtonTextOnOffShadow(component),
},
};
button.Click += ToggleShadowMap;
button.DependencyProperties.Set(LightKey, component);
parentButton.DependencyProperties.Set(ShadowButtonKey, button);
return button;
}