Stroke.BezierCusps Property
Gets an array that contains the indices of the cusps of the Bezier approximation of the Stroke object.
Namespace: Microsoft.Ink
Assembly: Microsoft.Ink (in microsoft.ink.dll)
Syntax
'Declaration
Public ReadOnly Property BezierCusps As Integer()
'Usage
Dim instance As Stroke
Dim value As Integer()
value = instance.BezierCusps
public int[] BezierCusps { get; }
public:
property array<int>^ BezierCusps {
array<int>^ get ();
}
/** @property */
public int[] get_BezierCusps ()
public function get BezierCusps () : int[]
Not applicable.
Property Value
An Array of the indices of the points that are the cusps of the Bezier approximation of the Stroke object.
Remarks
The array returned by the BezierCusps property is a subset of the array returned by the BezierPoints property. Each index in the BezierCusps property corresponds to a point in the array returned by the BezierPoints property that is a cusp of the Bezier control points for the stroke.
A cusp is a point on the stroke where the direction of writing changes in a discontinuous fashion. For example, if the stroke represents the capital letter "L", this property returns three cusps: two corresponding to the first and last control points on the stroke and the third representing the corner of the "L".
The location of a Bezier cusp can be determined by using the cusp as an index into the array returned by the BezierPoints property.
Example
This C# example demonstrates several kinds of information that is recorded with each Stroke object. The calling program uses menu items to toggle the display of each stroke's points, polyline cusps, Bezier points, Bezier cusps, and self-intersections. The Renderer object's InkSpaceToPixel method is used to convert the points for display. The LocatePoint method is used to interpolate the locations of the self-intersections.
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);
}
This Microsoft® Visual Basic® .NET example demonstrates several kinds of information that is recorded with each Stroke object. The calling program uses menu items to toggle the display of each stroke's points, polyline cusps, Bezier points, Bezier cusps, and self-intersections. The Renderer object's InkSpaceToPixel method is used to convert the points for display. The LocatePoint method is used to interpolate the locations of the self-intersections.
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
Platforms
Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.
Version Information
.NET Framework
Supported in: 3.0
See Also
Reference
Stroke Class
Stroke Members
Microsoft.Ink Namespace
Stroke.BezierPoints