/// <summary>
/// Returns the intersection info for the given rayHitResult. Intersection info
/// only exists for an InteractiveModelVisual3D, so if an InteractiveModelVisual3D
/// is not hit, then the return value is null.
/// </summary>
/// <param name="rayHitResult"></param>
/// <returns>
/// Returns ClosestIntersectionInfo if an InteractiveModelVisual3D is hit, otherwise
/// returns null.
/// </returns>
private ClosestIntersectionInfo GetIntersectionInfo(RayHitTestResult rayHitResult)
{
ClosestIntersectionInfo isectInfo = null;
// try to cast to a RaymeshGeometry3DHitTestResult
RayMeshGeometry3DHitTestResult rayMeshResult = rayHitResult as RayMeshGeometry3DHitTestResult;
if (rayMeshResult != null)
{
// see if we hit an InteractiveVisual3D
InteractiveVisual3D imv3D = rayMeshResult.VisualHit as InteractiveVisual3D;
if (imv3D != null)
{
// we can now extract the mesh and visual for the object we hit
MeshGeometry3D geom = rayMeshResult.MeshHit;
UIElement uiElem = imv3D.InternalVisual;
if (uiElem != null)
{
// pull the barycentric coordinates of the intersection point
double vertexWeight1 = rayMeshResult.VertexWeight1;
double vertexWeight2 = rayMeshResult.VertexWeight2;
double vertexWeight3 = rayMeshResult.VertexWeight3;
// the indices in to where the actual intersection occurred
int index1 = rayMeshResult.VertexIndex1;
int index2 = rayMeshResult.VertexIndex2;
int index3 = rayMeshResult.VertexIndex3;
// texture coordinates of the three vertices hit
// in the case that no texture coordinates are supplied we will simply
// treat it as if no intersection occurred
if (geom.TextureCoordinates != null &&
index1 < geom.TextureCoordinates.Count &&
index2 < geom.TextureCoordinates.Count &&
index3 < geom.TextureCoordinates.Count)
{
Point texCoord1 = geom.TextureCoordinates[index1];
Point texCoord2 = geom.TextureCoordinates[index2];
Point texCoord3 = geom.TextureCoordinates[index3];
// get the final uv values based on the barycentric coordinates
Point finalPoint = new Point(texCoord1.X * vertexWeight1 +
texCoord2.X * vertexWeight2 +
texCoord3.X * vertexWeight3,
texCoord1.Y * vertexWeight1 +
texCoord2.Y * vertexWeight2 +
texCoord3.Y * vertexWeight3);
// create and return a valid intersection info
isectInfo = new ClosestIntersectionInfo(finalPoint,
uiElem,
imv3D);
}
}
}
}
return(isectInfo);
}
/// <summary>
/// This function sets the passed in uiElem as the hidden visual, and aligns
/// it so that the point the uv coordinates map to on the visual are located
/// at the same location as mousePos.
/// </summary>
/// <param name="uiElem">The UIElement that should be the hidden visual</param>
/// <param name="uv">The uv coordinates on that UIElement that should be aligned with mousePos</param>
/// <param name="mousePos">The mouse location</param>
/// <param name="scaleHiddenVisual">Whether to scale the visual in addition to moving it</param>
/// <returns></returns>
private bool UpdateHiddenVisual(ClosestIntersectionInfo isectInfo, Point mousePos, bool scaleHiddenVisual)
{
bool needsMouseReSync = false;
double newOffsetX, newOffsetY;
// compute positioning information
if (isectInfo != null)
{
UIElement uiElem = isectInfo.UIElementHit;
// set our UIElement to be the one passed in
if (_hiddenVisual.Child != uiElem)
{
// we need to replace the old one with this new one
UIElement prevVisual = _hiddenVisual.Child;
// clear out uiElem from any of our hidden visuals
if (_oldHiddenVisual.Child == uiElem)
{
_oldHiddenVisual.Child = null;
}
if (_oldKeyboardFocusVisual.Child == uiElem)
{
_oldKeyboardFocusVisual.Child = null;
}
// also clear out prevVisual
if (_oldHiddenVisual.Child == prevVisual)
{
_oldHiddenVisual.Child = null;
}
if (_oldKeyboardFocusVisual.Child == prevVisual)
{
_oldKeyboardFocusVisual.Child = null;
}
// depending on whether or not it has focus, do two different things, either
// use the _oldKeyboardFocusVisual or the _oldHiddenVisual
Decorator _oldVisToUse = null;
if (prevVisual != null && prevVisual.IsKeyboardFocusWithin)
{
_oldVisToUse = _oldKeyboardFocusVisual;
}
else
{
_oldVisToUse = _oldHiddenVisual;
}
// now safely link everything up
_hiddenVisual.Child = uiElem;
_oldVisToUse.Child = prevVisual;
needsMouseReSync = true;
}
Point ptOnVisual = TextureCoordsToVisualCoords(isectInfo.PointHit, _hiddenVisual);
newOffsetX = mousePos.X - ptOnVisual.X;
newOffsetY = mousePos.Y - ptOnVisual.Y;
}
else
{
// because we didn't interesect with anything, we need to move the hidden visual off
// screen so that it can no longer be interacted with
newOffsetX = ActualWidth + 1;
newOffsetY = ActualHeight + 1;
}
// compute the scale needed
double newScale;
if (scaleHiddenVisual)
{
newScale = Math.Max(Viewport3D.RenderSize.Width,
Viewport3D.RenderSize.Height);
}
else
{
newScale = 1.0;
}
// do the actual positioning
needsMouseReSync |= PositionHiddenVisual(newOffsetX, newOffsetY, newScale, mousePos);
return(needsMouseReSync);
}
/// <summary>
/// Returns the intersection info for the given rayHitResult. Intersection info
/// only exists for an InteractiveModelVisual3D, so if an InteractiveModelVisual3D
/// is not hit, then the return value is null.
/// </summary>
/// <param name="rayHitResult"></param>
/// <returns>
/// Returns ClosestIntersectionInfo if an InteractiveModelVisual3D is hit, otherwise
/// returns null.
/// </returns>
private ClosestIntersectionInfo GetIntersectionInfo(RayHitTestResult rayHitResult)
{
ClosestIntersectionInfo isectInfo = null;
// try to cast to a RaymeshGeometry3DHitTestResult
RayMeshGeometry3DHitTestResult rayMeshResult = rayHitResult as RayMeshGeometry3DHitTestResult;
if (rayMeshResult != null)
{
// see if we hit an InteractiveVisual3D
InteractiveVisual3D imv3D = rayMeshResult.VisualHit as InteractiveVisual3D;
if (imv3D != null)
{
// we can now extract the mesh and visual for the object we hit
MeshGeometry3D geom = rayMeshResult.MeshHit;
UIElement uiElem = imv3D.InternalVisual;
if (uiElem != null)
{
// pull the barycentric coordinates of the intersection point
double vertexWeight1 = rayMeshResult.VertexWeight1;
double vertexWeight2 = rayMeshResult.VertexWeight2;
double vertexWeight3 = rayMeshResult.VertexWeight3;
// the indices in to where the actual intersection occurred
int index1 = rayMeshResult.VertexIndex1;
int index2 = rayMeshResult.VertexIndex2;
int index3 = rayMeshResult.VertexIndex3;
// texture coordinates of the three vertices hit
// in the case that no texture coordinates are supplied we will simply
// treat it as if no intersection occurred
if (geom.TextureCoordinates != null &&
index1 < geom.TextureCoordinates.Count &&
index2 < geom.TextureCoordinates.Count &&
index3 < geom.TextureCoordinates.Count)
{
Point texCoord1 = geom.TextureCoordinates[index1];
Point texCoord2 = geom.TextureCoordinates[index2];
Point texCoord3 = geom.TextureCoordinates[index3];
// get the final uv values based on the barycentric coordinates
Point finalPoint = new Point(texCoord1.X * vertexWeight1 +
texCoord2.X * vertexWeight2 +
texCoord3.X * vertexWeight3,
texCoord1.Y * vertexWeight1 +
texCoord2.Y * vertexWeight2 +
texCoord3.Y * vertexWeight3);
// create and return a valid intersection info
isectInfo = new ClosestIntersectionInfo(finalPoint,
uiElem,
imv3D);
}
}
}
}
return isectInfo;
}
/// <summary>
/// Finds the point in edges that is closest ot the mouse position. Updates closestIntersectionInfo
/// with the results of this calculation
/// </summary>
/// <param name="mousePos">The mouse position</param>
/// <param name="edges">The edges to test against</param>
/// <param name="imv3DHit">The model that has the visual on it with capture</param>
private void FindClosestIntersection(Point mousePos, List <HitTestEdge> edges, InteractiveVisual3D imv3DHit)
{
double closestDistance = Double.MaxValue;
Point closestIntersection = new Point(); // the uv of the closest intersection
// Find the closest point to the mouse position
for (int i = 0; i < edges.Count; i++)
{
Vector v1 = mousePos - edges[i]._p1Transformed;
Vector v2 = edges[i]._p2Transformed - edges[i]._p1Transformed;
Point currClosest;
double distance;
// calculate the distance from the mouse position to this edge
// The closest distance can be computed by projecting v1 on to v2. If the
// projectiong occurs between _p1Transformed and _p2Transformed, then this is the
// closest point. Otherwise, depending on which side it lies, it is either _p1Transformed
// or _p2Transformed.
//
// The projection equation is given as: (v1 DOT v2) / (v2 DOT v2) * v2.
// v2 DOT v2 will always be positive. Thus, if v1 DOT v2 is negative, we know the projection
// will occur before _p1Transformed (and so it is the closest point). If (v1 DOT v2) is greater
// than (v2 DOT v2), then we have gone passed _p2Transformed and so it is the closest point.
// Otherwise the projection gives us this value.
//
double denom = v2 * v2;
if (denom == 0)
{
currClosest = edges[i]._p1Transformed;
distance = v1.Length;
}
else
{
double numer = v2 * v1;
if (numer < 0)
{
currClosest = edges[i]._p1Transformed;
}
else
{
if (numer > denom)
{
currClosest = edges[i]._p2Transformed;
}
else
{
currClosest = edges[i]._p1Transformed + (numer / denom) * v2;
}
}
distance = (mousePos - currClosest).Length;
}
// see if we found a new closest distance
if (distance < closestDistance)
{
closestDistance = distance;
if (denom != 0)
{
closestIntersection = ((currClosest - edges[i]._p1Transformed).Length / Math.Sqrt(denom) *
(edges[i]._uv2 - edges[i]._uv1)) + edges[i]._uv1;
}
else
{
closestIntersection = edges[i]._uv1;
}
}
}
if (closestDistance != Double.MaxValue)
{
UIElement uiElemWCapture = (UIElement)Mouse.Captured;
UIElement uiElemOnMesh = imv3DHit.InternalVisual;
Rect contBounds = VisualTreeHelper.GetDescendantBounds(uiElemWCapture);
Point ptOnVisual = TextureCoordsToVisualCoords(closestIntersection, uiElemOnMesh);
Point ptRelToCapture = uiElemOnMesh.TransformToDescendant(uiElemWCapture).Transform(ptOnVisual);
// we want to "ring" around the outside so things like buttons are not pressed
// this code here does that - the +BUFFER_SIZE and -BUFFER_SIZE are to give a bit of a
// buffer for any numerical issues
if (ptRelToCapture.X <= contBounds.Left + 1)
{
ptRelToCapture.X -= BUFFER_SIZE;
}
if (ptRelToCapture.Y <= contBounds.Top + 1)
{
ptRelToCapture.Y -= BUFFER_SIZE;
}
if (ptRelToCapture.X >= contBounds.Right - 1)
{
ptRelToCapture.X += BUFFER_SIZE;
}
if (ptRelToCapture.Y >= contBounds.Bottom - 1)
{
ptRelToCapture.Y += BUFFER_SIZE;
}
Point finalVisualPoint = uiElemWCapture.TransformToAncestor(uiElemOnMesh).Transform(ptRelToCapture);
_closestIntersectInfo = new ClosestIntersectionInfo(VisualCoordsToTextureCoords(finalVisualPoint, uiElemOnMesh),
imv3DHit.InternalVisual,
imv3DHit);
}
}
/// <summary>
/// This function sets the passed in uiElem as the hidden visual, and aligns
/// it so that the point the uv coordinates map to on the visual are located
/// at the same location as mousePos.
/// </summary>
/// <param name="uiElem">The UIElement that should be the hidden visual</param>
/// <param name="uv">The uv coordinates on that UIElement that should be aligned with mousePos</param>
/// <param name="mousePos">The mouse location</param>
/// <param name="scaleHiddenVisual">Whether to scale the visual in addition to moving it</param>
/// <returns></returns>
private bool UpdateHiddenVisual(ClosestIntersectionInfo isectInfo, Point mousePos, bool scaleHiddenVisual)
{
bool needsMouseReSync = false;
double newOffsetX, newOffsetY;
// compute positioning information
if (isectInfo != null)
{
UIElement uiElem = isectInfo.UIElementHit;
// set our UIElement to be the one passed in
if (_hiddenVisual.Child != uiElem)
{
// we need to replace the old one with this new one
UIElement prevVisual = _hiddenVisual.Child;
// clear out uiElem from any of our hidden visuals
if (_oldHiddenVisual.Child == uiElem) _oldHiddenVisual.Child = null;
if (_oldKeyboardFocusVisual.Child == uiElem) _oldKeyboardFocusVisual.Child = null;
// also clear out prevVisual
if (_oldHiddenVisual.Child == prevVisual) _oldHiddenVisual.Child = null;
if (_oldKeyboardFocusVisual.Child == prevVisual) _oldKeyboardFocusVisual.Child = null;
// depending on whether or not it has focus, do two different things, either
// use the _oldKeyboardFocusVisual or the _oldHiddenVisual
Decorator _oldVisToUse = null;
if (prevVisual != null && prevVisual.IsKeyboardFocusWithin)
{
_oldVisToUse = _oldKeyboardFocusVisual;
}
else
{
_oldVisToUse = _oldHiddenVisual;
}
// now safely link everything up
_hiddenVisual.Child = uiElem;
_oldVisToUse.Child = prevVisual;
needsMouseReSync = true;
}
Point ptOnVisual = TextureCoordsToVisualCoords(isectInfo.PointHit, _hiddenVisual);
newOffsetX = mousePos.X - ptOnVisual.X;
newOffsetY = mousePos.Y - ptOnVisual.Y;
}
else
{
// because we didn't interesect with anything, we need to move the hidden visual off
// screen so that it can no longer be interacted with
newOffsetX = ActualWidth + 1;
newOffsetY = ActualHeight + 1;
}
// compute the scale needed
double newScale;
if (scaleHiddenVisual)
{
newScale = Math.Max(Viewport3D.RenderSize.Width,
Viewport3D.RenderSize.Height);
}
else
{
newScale = 1.0;
}
// do the actual positioning
needsMouseReSync |= PositionHiddenVisual(newOffsetX, newOffsetY, newScale, mousePos);
return needsMouseReSync;
}
/// <summary>
/// Finds the point in edges that is closest ot the mouse position. Updates closestIntersectionInfo
/// with the results of this calculation
/// </summary>
/// <param name="mousePos">The mouse position</param>
/// <param name="edges">The edges to test against</param>
/// <param name="imv3DHit">The model that has the visual on it with capture</param>
private void FindClosestIntersection(Point mousePos, List<HitTestEdge> edges, InteractiveVisual3D imv3DHit)
{
double closestDistance = Double.MaxValue;
Point closestIntersection = new Point(); // the uv of the closest intersection
// Find the closest point to the mouse position
for (int i=0; i<edges.Count; i++)
{
Vector v1 = mousePos - edges[i]._p1Transformed;
Vector v2 = edges[i]._p2Transformed - edges[i]._p1Transformed;
Point currClosest;
double distance;
// calculate the distance from the mouse position to this edge
// The closest distance can be computed by projecting v1 on to v2. If the
// projectiong occurs between _p1Transformed and _p2Transformed, then this is the
// closest point. Otherwise, depending on which side it lies, it is either _p1Transformed
// or _p2Transformed.
//
// The projection equation is given as: (v1 DOT v2) / (v2 DOT v2) * v2.
// v2 DOT v2 will always be positive. Thus, if v1 DOT v2 is negative, we know the projection
// will occur before _p1Transformed (and so it is the closest point). If (v1 DOT v2) is greater
// than (v2 DOT v2), then we have gone passed _p2Transformed and so it is the closest point.
// Otherwise the projection gives us this value.
//
double denom = v2 * v2;
if (denom == 0)
{
currClosest = edges[i]._p1Transformed;
distance = v1.Length;
}
else
{
double numer = v2 * v1;
if (numer < 0)
{
currClosest = edges[i]._p1Transformed;
}
else
{
if (numer > denom)
{
currClosest = edges[i]._p2Transformed;
}
else
{
currClosest = edges[i]._p1Transformed + (numer / denom) * v2;
}
}
distance = (mousePos - currClosest).Length;
}
// see if we found a new closest distance
if (distance < closestDistance)
{
closestDistance = distance;
if (denom != 0)
{
closestIntersection = ((currClosest - edges[i]._p1Transformed).Length / Math.Sqrt(denom) *
(edges[i]._uv2 - edges[i]._uv1)) + edges[i]._uv1;
}
else
{
closestIntersection = edges[i]._uv1;
}
}
}
if (closestDistance != Double.MaxValue)
{
UIElement uiElemWCapture = (UIElement)Mouse.Captured;
UIElement uiElemOnMesh = imv3DHit.InternalVisual;
Rect contBounds = VisualTreeHelper.GetDescendantBounds(uiElemWCapture);
Point ptOnVisual = TextureCoordsToVisualCoords(closestIntersection, uiElemOnMesh);
Point ptRelToCapture = uiElemOnMesh.TransformToDescendant(uiElemWCapture).Transform(ptOnVisual);
// we want to "ring" around the outside so things like buttons are not pressed
// this code here does that - the +BUFFER_SIZE and -BUFFER_SIZE are to give a bit of a
// buffer for any numerical issues
if (ptRelToCapture.X <= contBounds.Left + 1) ptRelToCapture.X -= BUFFER_SIZE;
if (ptRelToCapture.Y <= contBounds.Top + 1) ptRelToCapture.Y -= BUFFER_SIZE;
if (ptRelToCapture.X >= contBounds.Right - 1) ptRelToCapture.X += BUFFER_SIZE;
if (ptRelToCapture.Y >= contBounds.Bottom - 1) ptRelToCapture.Y += BUFFER_SIZE;
Point finalVisualPoint = uiElemWCapture.TransformToAncestor(uiElemOnMesh).Transform(ptRelToCapture);
_closestIntersectInfo = new ClosestIntersectionInfo(VisualCoordsToTextureCoords(finalVisualPoint, uiElemOnMesh),
imv3DHit.InternalVisual,
imv3DHit);
}
}
/// <summary>
/// Constructs the InteractiveViewport3D
/// </summary>
public Interactive3DDecorator()
: base()
{
// keep everything within our bounds so that the hidden visuals are only
// accessable over the Viewport3D
ClipToBounds = true;
// the offset of the hidden visual and the transform associated with it
_offsetX = _offsetY = 0.0;
_scale = 1;
// set up the hidden visual transforms
_hiddenVisTranslate = new TranslateTransform(_offsetX, _offsetY);
_hiddenVisScale = new ScaleTransform(_scale, _scale);
_hiddenVisTransform = new TransformGroup();
_hiddenVisTransform.Children.Add(_hiddenVisScale);
_hiddenVisTransform.Children.Add(_hiddenVisTranslate);
// the layer that contains our moving visual
_hiddenVisual = new Decorator();
_hiddenVisual.Opacity = 0.0;
_hiddenVisual.RenderTransform = _hiddenVisTransform;
// where we store the previous hidden visual so that it can be in the tree
// after it is removed so any state (i.e. mouse over) can be updated.
_oldHiddenVisual = new Decorator();
_oldHiddenVisual.Opacity = 0.0;
// the keyboard focus visual
_oldKeyboardFocusVisual = new Decorator();
_oldKeyboardFocusVisual.Opacity = 0.0;
// add all of the hidden visuals
PostViewportChildren.Add(_oldHiddenVisual);
PostViewportChildren.Add(_oldKeyboardFocusVisual);
PostViewportChildren.Add(_hiddenVisual);
// initialize other member variables to null
_closestIntersectInfo = null;
_lastValidClosestIntersectInfo = null;
AllowDrop = true;
}
/// <summary>
/// The HTResult function simply takes the intersection closest to the origin and
/// and stores the intersection info for that closest intersection point.
/// </summary>
/// <param name="rawresult"></param>
/// <returns></returns>
private HitTestResultBehavior HTResult(System.Windows.Media.HitTestResult rawresult)
{
RayHitTestResult rayResult = rawresult as RayHitTestResult;
HitTestResultBehavior hitTestResultBehavior = HitTestResultBehavior.Continue;
// since we're hit testing a viewport3D we should be getting the ray hit test result back
if (rayResult != null) {
_closestIntersectInfo = GetIntersectionInfo(rayResult);
hitTestResultBehavior = HitTestResultBehavior.Stop;
}
return hitTestResultBehavior;
}
/// <summary>
/// Arranges the hidden visuals so that interactivity is achieved.
/// </summary>
/// <param name="mouseposition">The location of the mouse</param>
/// <returns>Whether a mouse resynch is necessary</returns>
private bool ArrangeHiddenVisual(Point mouseposition, bool scaleHiddenVisual)
{
bool needMouseResync = false;
// get the underlying viewport3D we're enhancing
Viewport3D viewport3D = Viewport3D;
// if the viewport3D exists - perform a hit test operation on the underlying visuals
if (viewport3D != null) {
// set up the hit test parameters
PointHitTestParameters pointparams = new PointHitTestParameters(mouseposition);
_closestIntersectInfo = null;
_mouseCaptureInHiddenVisual = _hiddenVisual.IsMouseCaptureWithin;
// first hit test - this one attempts to hit a visible mesh if possible
VisualTreeHelper.HitTest(viewport3D, InteractiveMV3DFilter, HTResult, pointparams);
// perform capture positioning if we didn't hit anything and something has capture
if (_closestIntersectInfo == null &&
_mouseCaptureInHiddenVisual &&
_lastValidClosestIntersectInfo != null) {
HandleMouseCaptureButOffMesh(_lastValidClosestIntersectInfo.InteractiveModelVisual3DHit,
mouseposition);
}
else if (_closestIntersectInfo != null) {
// save it for if we walk off the mesh and something has capture
_lastValidClosestIntersectInfo = _closestIntersectInfo;
}
// update the location if we have positioning information
needMouseResync = UpdateHiddenVisual(_closestIntersectInfo,
mouseposition,
scaleHiddenVisual);
}
return needMouseResync;
}
