The geometry of a shape is represented by the NGeometry class an instance of which can be obtained from the Geometry property of each shape. The geometry is responsible for the appearance (fill, stroke, shadow and arrowheads) of a shape and for generating an NGraphicsPath for the shape. The current path can be obtained from the Path property of the geometry.

The NGeometry object is a collection for objects that derive from the base NGeometryCommand class. In this way the path represented by the geometry is defined by a sequence of geometry commands. There are two distinct types of geometry commands - plotter commands and draw box commands. that are discussed in the next section.

You can hide the fill, the stroke, the shadow and/or the arrowheads of each figure in a shape geometry by setting the respective Show... properties to false. All geometry commands that start (NMoveTo) or draw a new figure (NDrawRectangle, NDrawEllipse, NDrawPath etc.) have these properties.

If ShowFill is true, the area surrounded by the geometry will be filled with the filling specified by the Fill property. The FillRule property specifies the algorithm used to define whether a point is inside the geometry or not. By default it is set to EvenOdd.

If ShowStroke is true, the geometry outline will be stroked with the Stroke property.

If ShowShadow is true, the area surrounded by the geometry will drop the shadow specified by the Shadow property.

If ShowArrowheads is true, the geometry will display the arrowheads specified by the BeginArrowhead and EndArrowhead properties at the first and last geometry points respectively.

For example, to hide the fill of a figure started with NMoveTo, you can use the following piece of code:

NMoveTo moveTo = new NMoveTo();
moveTo.ShowFill = false;
shape.Geometry.AddRelative(moveTo);

Any graphics path created by the NGeometry object can have round corners, which is controlled by the CornerRounding property.

The code fragment below demonstrates how to create a shape with yellow color fill, blue 3 DIPs (Device Independent Pixels) wide stroke and red text:

// Create a rectangle shape
NShapeFactory basicShapeFactory = new NBasicShapeFactory();
NShape shape = basicShapeFactory.CreateShape((int)ENBasicShape.Rectangle);

// Set geometry fill and stroke
shape.Geometry.Fill = new NColorFill(NColor.Yellow);
shape.Geometry.Stroke = new NStroke(3, NColor.Blue);

// Set text and text fill
shape.Text = "My Shape";
shape.TextBlock.Fill = new NColorFill(NColor.Red);

// Position the page and add it to the active page
shape.SetPinPoint(new NPoint(200, 200));
drawingView.ActivePage.Items.Add(shape);

As mentioned there are two distinct types of geometry commands - plotter commands and draw box commands.

Plotter Commands

Plotter commands are intended to be placed in a sequence and define the path of a shape via primitive drawing commands such as move to, line to, arc to etc that resemble the commands of a plotter machine. All plotter commands derive from the NPlotterCommand class. Each plotter command has X and Y properties that define the location of the command. Depending on the plotter command, it may have additional properties that control the curve plotted by the command. Plotter commands are summarized by the following table:

The following example demonstrates how to draw a rectangle using plotter commands:

NShape shape = new NShape();
shape.Init2DShape();
shape.Geometry.Add(new NMoveTo(0, 0));
shape.Geometry.Add(new NLineTo("Width", 0));
shape.Geometry.Add(new NLineTo("Width", "Height"));
shape.Geometry.Add(new NLineTo(0, "Height"));
shape.Geometry.CloseLastFigure = true;

Draw Box Commands

Draw box commands are intended to create entire path figures or paths. All drawing box commands derive from the NDrawBoxCommand class. Each drawing box command has a "drawing box", which is specified by the Left, Top, Right and Bottom properties of the drawing box command. The draw box command "draws" a figure or path inside this drawing box. The NDrawBoxCommand command also has a ClosePrevFigure property, which indicates whether the previous figure in the path needs to be closed. Draw box commands are summarized by the following table:

The following example draws an ellipse using draw box commands:

NShape shape = new NShape();
shape.Init2DShape();
shape.Geometry.Add(new NDrawEllipse(0, 0, "Width", "Height"));

Drawing Commands with Relative Coordinates

When the geometry command Relative property is true, the X and Y properties of plotter commands and the Left, Top, Right, Bottom properties of draw box commands, as well as other properties that define command "locations" are in shape "relative" coordinates. This helps you create scalable geometries that are defined as "factors" from the shape Width and Height. Although this can also be achieved via expressions (for example Width*0.5, Height*0.3), using relative coordinates is more memory efficient and fast to calculate.

To add commands as relative to a geometry you can use the AddRelative method of the geometry or the Rel...To methods like RelMoveTo, RelLineTo, RelCubicBezierTo, etc. These methods will automatically set the Relative property of the passed geometry command to true.

 The previous two examples can be rewritten with relative commands as follows:

// Draw rectangle using relative plotter commands to fill the shape Width/Height box
NShape rect = new NShape();
rect.Init2DShape();
rect.Geometry.RelMoveTo(0, 0);
rect.Geometry.RelLineTo(1, 0);
rect.Geometry.RelLineTo(1, 1);
rect.Geometry.RelLineTo(0, 1);
rect.Geometry.CloseLastFigure = true;

// Draw ellipse using relative draw box commands to fill the shape Width/Height box
NShape ellipse = new NShape();
ellipse.Init2DShape();
ellipse.Geometry.AddRelative(new NDrawEllipse(0, 0, 1, 1));