Develop Reference

How to make an image(or a rectangle) follow a Spline

I have a project that I need to make an image follow a spline.
I build the spline using Graphics.DrawCurve through an array of Points.
I'm trying to use PointAnimationUsingPath but I can't seem to get it to work. Apparently it doesn't work in C# with Windows form.
Can someone give me a light on how to do this?
Thank you All.
-----EDIT-----
Change to a WPF UserControl as recommend in comments.
Still need some help as the shape does not move exactly following the dots, below my code:
public partial class SplineBox : UserControl
{
Point[] finalPoint;
public SplineBox()
{
InitializeComponent();
}
public void MoveShape(Point[] _path)
{
// Create a NameScope for the page so that
// we can use Storyboards.
NameScope.SetNameScope(this, new NameScope());
// Create the EllipseGeometry to animate.
EllipseGeometry animatedEllipseGeometry =
new EllipseGeometry(new Point(10, 100), 15, 15);
// Register the EllipseGeometry's name with
// the page so that it can be targeted by a
// storyboard.
this.RegisterName("AnimatedEllipseGeometry", animatedEllipseGeometry);
// Create a Path element to display the geometry.
Path ellipsePath = new Path();
ellipsePath.Data = animatedEllipseGeometry;
ellipsePath.Fill = Brushes.Blue;
ellipsePath.Margin = new Thickness(15);
SplineCanvas.Children.Add(ellipsePath);
this.Content = SplineCanvas;
// Create the animation path.
PathGeometry animationPath = new PathGeometry();
PathFigure pFigure = new PathFigure();
pFigure.StartPoint = _path[0];
PolyBezierSegment pBezierSegment = new PolyBezierSegment();
for (int p = 1; p < _path.Length; p++)
{
pBezierSegment.Points.Add(_path[p]);
}
pFigure.Segments.Add(pBezierSegment);
animationPath.Figures.Add(pFigure);
// Freeze the PathGeometry for performance benefits.
animationPath.Freeze();
// Create a PointAnimationgUsingPath to move
// the EllipseGeometry along the animation path.
PointAnimationUsingPath centerPointAnimation = new PointAnimationUsingPath();
centerPointAnimation.PathGeometry = animationPath;
centerPointAnimation.Duration = TimeSpan.FromSeconds(5);
centerPointAnimation.RepeatBehavior = RepeatBehavior.Forever;
// Set the animation to target the Center property
// of the EllipseGeometry named "AnimatedEllipseGeometry".
Storyboard.SetTargetName(centerPointAnimation, "AnimatedEllipseGeometry");
Storyboard.SetTargetProperty(centerPointAnimation,
new PropertyPath(EllipseGeometry.CenterProperty));
// Create a Storyboard to contain and apply the animation.
Storyboard pathAnimationStoryboard = new Storyboard();
pathAnimationStoryboard.RepeatBehavior = RepeatBehavior.Forever;
pathAnimationStoryboard.AutoReverse = true;
pathAnimationStoryboard.Children.Add(centerPointAnimation);
// Start the Storyboard when ellipsePath is loaded.
ellipsePath.Loaded += delegate (object sender, RoutedEventArgs e)
{
// Start the storyboard.
pathAnimationStoryboard.Begin(this);
};
}
public void Paint(ScreenObject _spline)
{
List<Point> points = new List<Point>();
if (true)
{
var spline = _spline;
foreach (System.Windows.Point point in spline.SplineAnchors)
{
Point tempP = new Point((int)point.X, (int)point.Y);
points.Add(tempP);
}
finalPoint = points.ToArray();
//Pen pen = new Pen(Color.FromArgb(255, 0, 0, 255), 1);
//e.Graphics.DrawCurve(pen, finalPoint);
foreach (Point p in finalPoint)
{
// Create a red Ellipse.
Ellipse myEllipse = new Ellipse();
// Create a SolidColorBrush with a red color to fill the
// Ellipse with.
SolidColorBrush mySolidColorBrush = new SolidColorBrush();
// Describes the brush's color using RGB values.
// Each value has a range of 0-255.
mySolidColorBrush.Color = Color.FromArgb(255, 100, 255, 0);
myEllipse.Fill = mySolidColorBrush;
myEllipse.StrokeThickness = 2;
myEllipse.Stroke = Brushes.Black;
// Set the width and height of the Ellipse.
myEllipse.Width = 10;
myEllipse.Height = 10;
myEllipse.Margin = new Thickness(p.X - 5, p.Y - 5, 0, 0);
//e.Graphics.DrawRectangle(pen, new Rectangle(p.X - 5, p.Y - 5, 10, 10));
//e.Graphics.FillRectangle(Brushes.Red, new Rectangle(p.X - 5, p.Y - 5, 10, 10));
SplineCanvas.Children.Add(myEllipse);
}
}
}
}

Stack polygons on top of each other, join by diagonal lines

I want to do a perfectly simple thing. I want to draw two quadrilateral polygons, which have the top and bottom lines as parallel diagonals. I also want to draw these polygons stacked on top of each other.
However, after I draw the two polygons, there is a tiny but visible gap between them. It looks like this:
Here's the code that I use (I'm with Silverlight, which means WriteableBitmap):
var bmp = new System.Windows.Media.Imaging.WriteableBitmap((int)this.displayImage.Width, (int)this.displayImage.Height);
var polygon = new System.Windows.Shapes.Polygon()
{
StrokeThickness = 0,
Fill = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Colors.Black),
Points = new System.Windows.Media.PointCollection()
{
new System.Windows.Point(10, 10),
new System.Windows.Point(100, 40),
new System.Windows.Point(100, 130),
new System.Windows.Point(10, 100)
}
};
var polygon2 = new System.Windows.Shapes.Polygon()
{
StrokeThickness = 0,
Fill = new System.Windows.Media.SolidColorBrush(System.Windows.Media.Colors.Black),
Points = new System.Windows.Media.PointCollection()
{
new System.Windows.Point(10, 100),
new System.Windows.Point(100, 130),
new System.Windows.Point(100, 220),
new System.Windows.Point(10, 190)
}
};
bmp.Render(polygon, null);
bmp.Invalidate();
bmp.Render(polygon2, null);
bmp.Invalidate();
displayImage.Source = bmp;
Here displayImage is an Image control on the main grid.
What do I do to get rid of this gap?
P.S. If possible, I'd like solutions that do not use the WriteableBitmapEx library, as I don't want to drag an entire library into my project for such a small task. Also, if possible, I'd like to leave the polygons' size and coordinates the same.

Draw and fill polygon with 4 vertices (positions in 2D) via sharpdx API

I have 4 float points (positions in 2D) and I want to draw and fill a polygon (with vertices at those 4 positions) in 2D.
How can I do that with sharpdx?

I have found how to draw and fill a polygon. I have used drawGeometry and fillGeometry methods of RenderTarget object.
I wont mention how to initialize the directx
PathGeometry geo1;
GeometrySink sink1;
FactoryD2D factory = new FactoryD2D();
var dpi = factory.DesktopDpi;
RenderTarget renderTarget;
renderTarget = new RenderTarget(factory, backBuffer, new RenderTargetProperties()
{
DpiX = dpi.Width,
DpiY = dpi.Height,
MinLevel = SharpDX.Direct2D1.FeatureLevel.Level_DEFAULT,
PixelFormat = new SharpDX.Direct2D1.PixelFormat(Format.Unknown, AlphaMode.Ignore),
Type = RenderTargetType.Hardware,
Usage = RenderTargetUsage.None
});
// and after all initialization
pta[0] = new SharpDX.Vector2(pts[4].X, pts[4].Y);
pta[1] = new SharpDX.Vector2(pts[5].X, pts[5].Y);
pta[2] = new SharpDX.Vector2(pts[6].X, pts[6].Y);
pta[3] = new SharpDX.Vector2(pts[7].X, pts[7].Y);
geo1 = new PathGeometry(factory);
sink1 = geo1.Open();
sink1.BeginFigure(pta[0], new FigureBegin());
sink1.AddLines(new SharpDX.Vector2[] { pta[1], pta[2], pta[3] });
sink1.EndFigure(new FigureEnd());
sink1.Close();
Color penColor = Color.Black;
SolidColorBrush penBrush = new SolidColorBrush(g, new SharpDX.Color(penColor.R, penColor.G, penColor.B));
Color color = AddColor(pt, zmin, zmax);
SolidColorBrush aBrush = new SolidColorBrush(g, new SharpDX.Color(color.R, color.G, color.B));
renderTarget.DrawGeometry(geo1, penBrush);
renderTarget.FillGeometry(geo1, aBrush);
geo1.Dispose();
sink1.Dispose();
You can add other geos and sinks in order to add more shapes on to it
Hope this help to somebody who is lost and trying to find an answer desperately like me

Unable to Remove Child in WPF

I have a uniform grid that has rectangles dynamically added to it. I want to remove a particular rectangle, but I am getting the following error when trying to pass it to the Remove method:
Cannot convert from 'System.Drawing.Rectangle' to 'System.Windows.UIElement'
My code is:
Rectangle swatch = (Rectangle)ug_Thumbnails.FindName("s_" + _instance);
ug_Thumbnails.Children.Remove(swatch);
I tried casting, and got an error saying that you couldn't do it.
EDIT: Per request, here's the code to create the rectangle:
System.Windows.Shapes.Rectangle swatch = new System.Windows.Shapes.Rectangle();
swatch.Width = 50;
swatch.Height = 50;
swatch.Margin = new Thickness(0, 5, 5, 0);
swatch.StrokeThickness = 1;
swatch.Stroke = System.Windows.Media.Brushes.Gray;
swatch.Name = "s_" + name.ToString();
double groupsize = 100 / colors.Count();
DrawingBrush blackBrush = new DrawingBrush();
DrawingGroup checkersDrawingGroup = new DrawingGroup();
List<SolidColorBrush> brushes = colors;
double location = 0;
for (int i = 0; i < colors.Count(); i++)
{
GeometryDrawing drawing = new GeometryDrawing(brushes[i], null,
new RectangleGeometry(new Rect(location, 0, groupsize, groupsize)));
checkersDrawingGroup.Children.Add(drawing);
location += groupsize;
}
blackBrush.Drawing = checkersDrawingGroup;
swatch.Fill = blackBrush;
swatch.MouseUp += new MouseButtonEventHandler(loadSwatchResources);
ug_Thumbnails.Children.Add(swatch);

You need to use the Rectangle in System.Windows.Shapes when trying to reference a rectangle in WPF. This is specifically for rectangles in WPF and as such is a bit different than the System.Drawing rectangle class. You should be able to cast to this version of rectangle since it derives from FrameworkElement. See http://msdn.microsoft.com/en-us/library/system.windows.shapes.rectangle(v=vs.110).aspx for more info.

How to create dashline C# graph

I'm trying to add a dashline for a graph but it keeps coming out as a solid line. How can I fix that?
static public NPlot.Bitmap.PlotSurface2D getDashlineGraph(int itemID, int width, int height)
{
NPlot.Bitmap.PlotSurface2D plot = new NPlot.Bitmap.PlotSurface2D(width, height);
plot.BackColor = Color.WhiteSmoke;
plot.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
LinePlot TotaldashLine = new LinePlot(straightline, timer);
float[] pattern = { 5.0f, 10.0f };
TotaldashLine.Pen = new Pen(Color.Green,0.5f);
TotaldashLine.Pen.DashPattern = pattern;
plot.Add(TotaldashLine, NPlot.PlotSurface2D.XAxisPosition.Bottom, NPlot.PlotSurface2D.YAxisPosition.Right, 100);
Grid oGrid = new Grid();
oGrid.HorizontalGridType = Grid.GridType.Coarse;
oGrid.VerticalGridType = Grid.GridType.Coarse;
plot.Add(oGrid);
plot.Refresh();
return plot;
}

You need to specify that you want your Pen to draw dashed using Pen.DashStyle:
TotaldashLine.Pen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dash;
Once you have done that, you can additionally customize the lengths of dashes and gaps using the Pen.DashPattern as you have.