Stroke.SelfIntersections-Eigenschaft
Ruft die Selbstschnittpunkte des Stroke-Objekts ab.
Namespace: Microsoft.Ink
Assembly: Microsoft.Ink (in Microsoft.Ink.dll)
Syntax
'Declaration
Public ReadOnly Property SelfIntersections As Single()
'Usage
Dim instance As Stroke
Dim value As Single()
value = instance.SelfIntersections
public float[] SelfIntersections { get; }
public:
property array<float>^ SelfIntersections {
array<float>^ get ();
}
/** @property */
public float[] get_SelfIntersections()
public function get SelfIntersections () : float[]
Eigenschaftenwert
Typ: array<System.Single[]
Ein Array von Gleitkommaindexwerten, das die Selbstschnittpunkte eines Stroke-Objekts darstellt.
Hinweise
Ein Selbstschnittpunkt ist der Punkt auf einem Strich, an dem der Strich sich selbst kreuzt.
Ein Gleitkommaindex ist ein Gleitkommawert, der eine beliebige Position zwischen zwei Punkten im Strich darstellt. Beispiele: Wenn 0,0 der erste Punkt im Strich und 1,0 der zweite Punkt im Strich ist, liegt 0,5 genau in der Mitte zwischen dem ersten und dem zweiten Punkt. Ebenso stellt ein Gleitkommaindexwert von 37,25 eine Position dar, die sich 25 Prozent entlang der Zeile zwischen den Punkten 37 und 38 des Strichs befindet.
Hinweis
Für jeden Schnittpunkt und jede Liniensegmentkombination wird ein Gleitkommaindex zurückgegeben. Wenn ein Strich über einen Schnittpunkt verfügt, dann gibt die SelfIntersections-Eigenschaft zwei Selbstschnittpunkte zurück und zwar einen für jedes Liniensegment, das an diesen Schnittpunkt grenzt.
Beispiele
In diesem C#-Beispiel werden mehrere Arten von Informationen veranschaulicht, die mit den einzelnen Stroke-Objekten aufgezeichnet werden. Das aufrufende Programm verwendet Menüelemente, um die Anzeige der Punkte, Polylinienspitzen, Bézierpunkte, Bézierspitzen und Selbstschnittmengen der einzelnen Striche zu aktivieren bzw. zu deaktivieren. Mit der InkSpaceToPixel-Methode des Renderer-Objekts werden die Punkte für die Anzeige konvertiert. Mit der LocatePoint-Methode werden die Positionen der Selbstschnittmengen interpoliert.
Microsoft.Ink.InkCollector theInkCollector;
// Event handler for the form's load event.
private void Form1_Load(object sender, System.EventArgs e)
{
// Create the InkCollector.
theInkCollector = new InkCollector(this.Handle);
// Attach an event handler for the Stroke event.
theInkCollector.Stroke += new InkCollectorStrokeEventHandler(theInkCollector_Stroke);
// Enable the InkCollector.
theInkCollector.Enabled = true;
}
// Event handler for the InkCollector's Stroke event.
private void theInkCollector_Stroke(object sender, InkCollectorStrokeEventArgs e)
{
// Force the form to repaint.
Refresh();
}
// Event handler for the Clear menu's Click event.
private void menuClear_Click(object sender, System.EventArgs e)
{
// Delete the strokes in the InkCollector.
theInkCollector.Ink.DeleteStrokes();
// Force the form to repaint.
Refresh();
}
private void menuExit_Click(object sender, System.EventArgs e)
{
this.Close();
}
// Event handler for the Click event for subitems of the Display menu.
private void menuDisplayItem_Click(object sender, System.EventArgs e)
{
// Check each subitem to see if it was clicked.
foreach (System.Windows.Forms.MenuItem menu in menuDisplay.MenuItems)
{
if (sender == menu)
{
// Toggle the menu item's checked property.
menu.Checked = !menu.Checked;
}
}
// Force the form to repaint.
this.Refresh();
}
// Event handler for the form's Paint event.
private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
{
Graphics g = e.Graphics;
// Highlight specific points or cusps of each stroke.
Strokes theStrokes = theInkCollector.Ink.Strokes;
foreach (Stroke theStroke in theStrokes)
{
// Convert the stroke's points and Bezier points from ink space to pixel coordinates.
Point [] ptBezierPoints = theStroke.BezierPoints;
Point [] ptStrokePoints = theStroke.GetPoints();
theInkCollector.Renderer.InkSpaceToPixel(g, ref ptBezierPoints);
theInkCollector.Renderer.InkSpaceToPixel(g, ref ptStrokePoints);
// If all points is checked, highlight the points of the stroke.
if (menuAllPoints.Checked)
{
foreach (Point pt in ptStrokePoints)
{
// draw a little diagonal line from each point
g.DrawEllipse(Pens.Magenta, pt.X-2, pt.Y-2, 4, 4);
}
}
// If polyline cusps is checked, highlight the cusps of the stroke.
if (menuPolylineCusps.Checked)
{
int[] theCusps = theStroke.PolylineCusps;
foreach (int i in theCusps)
{
// Draw a little rectangle around each polyline cusp.
g.DrawEllipse(Pens.BlueViolet, ptStrokePoints[i].X - 3, ptStrokePoints[i].Y - 3, 6, 6);
}
}
// If Bezier points is checked, highlight the Bezier points of the stroke.
if (menuBezierPoints.Checked)
{
foreach (Point pt in ptBezierPoints)
{
// Draw a little diagonal line from each Bezier point.
g.DrawEllipse(Pens.Goldenrod, pt.X-4, pt.Y-4, 8, 8);
}
}
// If Bezier cusps is checked, highlight the Bezier cusps of the stroke.
if (menuBezierCusps.Checked)
{
int [] theCusps = theStroke.BezierCusps;
foreach (int i in theCusps)
{
// Draw a little rectangle around each Bezier cusp.
g.DrawEllipse(Pens.Blue,
ptBezierPoints[i].X-5, ptBezierPoints[i].Y-5, 10, 10);
}
}
// If self intersections is checked, highlight the self intersections of the stroke.
if (menuSelfIntersections.Checked)
{
float [] theSelfIntersectionLocationsArray = theStroke.SelfIntersections;
foreach (float f in theSelfIntersectionLocationsArray)
{
Point pt = LocatePoint(theStroke, f);
theInkCollector.Renderer.InkSpaceToPixel(g, ref pt);
// Draw a little circle around each intersection.
g.DrawEllipse(Pens.Red, pt.X-7, pt.Y-7, 14, 14);
}
}
}
}
// This function returns the approximate point along
// a stroke represented by a float, as a Point.
private Point LocatePoint(Stroke theStroke, float theFIndex)
{
// Get the two nearest points to the point of interest.
Point [] ptStrokePoints = theStroke.GetPoints((int)Math.Floor(theFIndex), 2);
// Get fractional part to interpolate the distance between the points.
float theFraction = theFIndex - (float)Math.Floor(theFIndex);
int deltaX = (int)((ptStrokePoints[1].X - ptStrokePoints[0].X) * theFraction);
int deltaY = (int)((ptStrokePoints[1].Y - ptStrokePoints[0].Y) * theFraction);
// Return the interpolated point.
return new Point(ptStrokePoints[0].X + deltaX, ptStrokePoints[0].Y + deltaY);
}
In diesem Microsoft Visual Basic .NET-Beispiel werden mehrere Arten von Informationen veranschaulicht, die mit den einzelnen Stroke-Objekten aufgezeichnet werden. Das aufrufende Programm verwendet Menüelemente, um die Anzeige der Punkte, Polylinienspitzen, Bézierpunkte, Bézierspitzen und Selbstschnittmengen der einzelnen Striche zu aktivieren bzw. zu deaktivieren. Mit der InkSpaceToPixel-Methode des Renderer-Objekts werden die Punkte für die Anzeige konvertiert. Mit der LocatePoint-Methode werden die Positionen der Selbstschnittmengen interpoliert.
Dim WithEvents theInkCollector As Microsoft.Ink.InkCollector
' Event handler for the form's Load event.
Private Sub Form1_Load(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles MyBase.Load
' Create and enable the InkCollector
theInkCollector = New Microsoft.Ink.InkCollector(Me.Handle)
theInkCollector.Enabled = True
' Associate the Click event handler with subitems of the Display menu.
AddHandler menuAllPoints.Click, AddressOf menuDisplayItem_Click
AddHandler menuPolylineCusps.Click, AddressOf menuDisplayItem_Click
AddHandler menuBezierPoints.Click, AddressOf menuDisplayItem_Click
AddHandler menuBezierCusps.Click, AddressOf menuDisplayItem_Click
AddHandler menuSelfIntersections.Click, AddressOf menuDisplayItem_Click
End Sub
' Event handler for the InkCollector's Stroke event.
Private Sub theInkCollector_Stroke(ByVal sender As Object, _
ByVal e As Microsoft.Ink.InkCollectorStrokeEventArgs) Handles theInkCollector.Stroke
' Force the form to repaint.
Me.Refresh()
End Sub
' Event handler for the Clear menu's Click event.
Private Sub menuClear_Click(ByVal sender As Object, _
ByVal e As System.EventArgs) Handles menuClear.Click
' Delete the strokes in the InkCollector.
theInkCollector.Ink.DeleteStrokes()
' Force the form to repaint.
Me.Refresh()
End Sub
' Event handler for the Click event for subitems of the Display menu.
Private Sub menuDisplayItem_Click(ByVal sender As Object, _
ByVal e As System.EventArgs)
' Check each subitem to see if it was clicked.
For Each menu As System.Windows.Forms.MenuItem In menuDisplay.MenuItems
If (sender Is menu) Then
' Toggle the menu item's checked property.
menu.Checked = Not menu.Checked
End If
Next
' Force the form to repaint.
Me.Refresh()
End Sub
' Event handler for the form's Paint event.
Private Sub Form1_Paint(ByVal sender As Object, _
ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint
Dim g As Graphics = e.Graphics
' Highlight specific points or cusps of each stroke.
Dim theStrokes As Microsoft.Ink.Strokes = theInkCollector.Ink.Strokes
For Each theStroke As Microsoft.Ink.Stroke In theStrokes
' Convert the stroke's points and Bezier points from ink space to pixel coordinates.
Dim ptBezierPoints() As Point = theStroke.BezierPoints
Dim ptStrokePoints() As Point = theStroke.GetPoints()
theInkCollector.Renderer.InkSpaceToPixel(g, ptBezierPoints)
theInkCollector.Renderer.InkSpaceToPixel(g, ptStrokePoints)
' If all points is checked, highlight the points of the stroke.
If (menuAllPoints.Checked) Then
For Each pt As Point In ptStrokePoints
' draw a little diagonal line from each point
g.DrawEllipse(Pens.Magenta, pt.X - 2, pt.Y - 2, 4, 4)
Next
End If
' If polyline cusps is checked, highlight the cusps of the stroke.
If (menuPolylineCusps.Checked) Then
Dim theCusps() As Integer = theStroke.PolylineCusps
For Each i As Integer In theCusps
' Draw a little rectangle around each polyline cusp.
g.DrawEllipse(Pens.BlueViolet, ptStrokePoints(i).X - 3, ptStrokePoints(i).Y - 3, 6, 6)
Next
End If
' If Bezier points is checked, highlight the Bezier points of the stroke.
If (menuBezierPoints.Checked) Then
For Each pt As Point In ptBezierPoints
' Draw a little diagonal line from each Bezier point.
g.DrawEllipse(Pens.Goldenrod, pt.X - 4, pt.Y - 4, 8, 8)
Next
End If
' If Bezier cusps is checked, highlight the Bezier cusps of the stroke.
If (menuBezierCusps.Checked) Then
Dim theCusps() As Integer = theStroke.BezierCusps
For Each i As Integer In theCusps
' Draw a little rectangle around each Bezier cusp.
g.DrawEllipse(Pens.Blue, ptBezierPoints(i).X - 5, ptBezierPoints(i).Y - 5, 10, 10)
Next
End If
' If self intersections is checked, highlight the self intersections of the stroke.
If (menuSelfIntersections.Checked) Then
Dim theSelfIntersectionLocationsArray() As Single = theStroke.SelfIntersections
For Each f As Single In theSelfIntersectionLocationsArray
Dim pt As Point = LocatePoint(theStroke, f)
theInkCollector.Renderer.InkSpaceToPixel(g, pt)
' Draw a little circle around each intersection.
g.DrawEllipse(Pens.Red, pt.X - 7, pt.Y - 7, 14, 14)
Next
End If
Next
End Sub
' This function returns the approximate point along
' a stroke represented by a float, as a Point.
Private Function LocatePoint(ByVal theStroke As Microsoft.Ink.Stroke, _
ByVal theFIndex As Single) As Point
' Get the two nearest points to the point of interest.
Dim ptStrokePoints() As Point = theStroke.GetPoints(Math.Floor(theFIndex), 2)
' Get fractional part to interpolate the distance between the points.
Dim theFraction As Single = theFIndex - Math.Floor(theFIndex)
Dim deltaX As Integer = (ptStrokePoints(1).X - ptStrokePoints(0).X) * theFraction
Dim deltaY As Integer = (ptStrokePoints(1).Y - ptStrokePoints(0).Y) * theFraction
' Return the interpolated point.
LocatePoint = New Point(ptStrokePoints(0).X + deltaX, ptStrokePoints(0).Y + deltaY)
End Function
Plattformen
Windows Vista
.NET Framework und .NET Compact Framework unterstützen nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen für .NET Framework.
Versionsinformationen
.NET Framework
Unterstützt in: 3.0