docs-desktop/dotnet-desktop-guide/framework/wpf/graphics-multimedia/geometry-overview.md

---
title: "Geometry Overview"
ms.date: "03/30/2017"
dev_langs: 
  - "csharp"
  - "vb"
helpviewer_keywords: 
  - "geometry classes [WPF]"
  - "graphics [WPF], geometry classes"
ms.assetid: 9fba8934-98b7-4af6-82f6-f4ef887f963a
---
# Geometry Overview
This overview describes how to use the [!INCLUDE[TLA#tla_winclient](../../../includes/tlasharptla-winclient-md.md)] <xref:System.Windows.Media.Geometry> classes to describe shapes. This topic also contrasts the differences between <xref:System.Windows.Media.Geometry> objects and <xref:System.Windows.Shapes.Shape> elements.  

<a name="wcpsdk_graphics_geometry_introduction"></a>
## What Is a Geometry?  
 The <xref:System.Windows.Media.Geometry> class and the classes which derive from it, such as <xref:System.Windows.Media.EllipseGeometry>, <xref:System.Windows.Media.PathGeometry>, and <xref:System.Windows.Media.CombinedGeometry>, enable you to describe the geometry of a 2D shape. These geometric descriptions have many uses, such defining a shape to paint to the screen or defining hit-test and clip regions. You can even use a geometry to define an animation path.  
  
 <xref:System.Windows.Media.Geometry> objects can be simple, such as rectangles and circles, or composite, created from two or more geometry objects.  More complex geometries can be created by using the <xref:System.Windows.Media.PathGeometry> and <xref:System.Windows.Media.StreamGeometry> classes, which enable you to describe arcs and curves.  
  
 Because a <xref:System.Windows.Media.Geometry> is a type of <xref:System.Windows.Freezable>, <xref:System.Windows.Media.Geometry> objects provide several special features: they can be declared as [resources](/dotnet/desktop-wpf/fundamentals/xaml-resources-define), shared among multiple objects, made read-only to improve performance, cloned, and made thread-safe. For more information about the different features provided by <xref:System.Windows.Freezable> objects, see the [Freezable Objects Overview](../advanced/freezable-objects-overview.md).  
  
<a name="wcpsdk_graphics_geometry_geometryandshapes"></a>
## Geometries vs. Shapes  
 The <xref:System.Windows.Media.Geometry> and <xref:System.Windows.Shapes.Shape> classes seem similar in that they both describe 2D shapes (compare <xref:System.Windows.Media.EllipseGeometry> and <xref:System.Windows.Shapes.Ellipse> for example), but there are important differences.  
  
 For one, the <xref:System.Windows.Media.Geometry> class inherits from the <xref:System.Windows.Freezable> class while the <xref:System.Windows.Shapes.Shape> class inherits from <xref:System.Windows.FrameworkElement>. Because they are elements, <xref:System.Windows.Shapes.Shape> objects can render themselves and participate in the layout system, while <xref:System.Windows.Media.Geometry> objects cannot.  
  
 Although <xref:System.Windows.Shapes.Shape> objects are more readily usable than <xref:System.Windows.Media.Geometry> objects, <xref:System.Windows.Media.Geometry> objects are more versatile. While a <xref:System.Windows.Shapes.Shape> object is used to render 2D graphics, a <xref:System.Windows.Media.Geometry> object can be used to define the geometric region for 2D graphics, define a region for clipping, or define a region for hit testing, for example.  
  
### The Path Shape  
 One <xref:System.Windows.Shapes.Shape>, the <xref:System.Windows.Shapes.Path> class, actually uses a <xref:System.Windows.Media.Geometry> to describe its contents. By setting the <xref:System.Windows.Shapes.Path.Data%2A> property of the <xref:System.Windows.Shapes.Path> with a <xref:System.Windows.Media.Geometry> and setting its <xref:System.Windows.Shapes.Shape.Fill%2A> and <xref:System.Windows.Shapes.Shape.Stroke%2A> properties, you can render a <xref:System.Windows.Media.Geometry>.  
  
<a name="commonproperties"></a>
## Common Properties That Take a Geometry  
 The preceding sections mentioned that Geometry objects can be used with other objects for a variety of purposes, such as drawing shapes, animating, and clipping. The following table lists several classes that have properties that take a <xref:System.Windows.Media.Geometry> object.  
  
|Type|Property|  
|----------|--------------|  
|<xref:System.Windows.Media.Animation.DoubleAnimationUsingPath>|<xref:System.Windows.Media.Animation.DoubleAnimationUsingPath.PathGeometry%2A>|  
|<xref:System.Windows.Media.DrawingGroup>|<xref:System.Windows.Media.DrawingGroup.ClipGeometry%2A>|  
|<xref:System.Windows.Media.GeometryDrawing>|<xref:System.Windows.Media.GeometryDrawing.Geometry%2A>|  
|<xref:System.Windows.Shapes.Path>|<xref:System.Windows.Shapes.Path.Data%2A>|  
|<xref:System.Windows.UIElement>|<xref:System.Windows.UIElement.Clip%2A>|  
  
<a name="wcpsdk_graphics_geometry_geometrytypes"></a>
## Simple Geometry Types  
 The base class for all geometries is the abstract class <xref:System.Windows.Media.Geometry>.  The classes which derive from the <xref:System.Windows.Media.Geometry> class can be roughly grouped into three categories: simple geometries, path geometries, and composite geometries.  
  
 Simple geometry classes include <xref:System.Windows.Media.LineGeometry>, <xref:System.Windows.Media.RectangleGeometry>, and <xref:System.Windows.Media.EllipseGeometry> and are used to create basic geometric shapes, such as lines, rectangles, and circles.  
  
- A <xref:System.Windows.Media.LineGeometry> is defined by specifying the start point of the line and the end point.  
  
- A <xref:System.Windows.Media.RectangleGeometry> is defined with a <xref:System.Windows.Rect> structure which specifies its relative position and its height and width. You can create a rounded rectangle by setting the <xref:System.Windows.Media.RectangleGeometry.RadiusX%2A> and <xref:System.Windows.Media.RectangleGeometry.RadiusY%2A> properties.  
  
- An <xref:System.Windows.Media.EllipseGeometry> is defined by a center point, an x-radius and a y-radius.  The following examples show how to create simple geometries for rendering and for clipping.  
  
 These same shapes, as well as more complex shapes, can be created using a <xref:System.Windows.Media.PathGeometry> or by combining geometry objects together, but these classes provide a simpler means for producing these basic geometric shapes.  
  
 The following example shows how to create and render a <xref:System.Windows.Media.LineGeometry>.  As noted previously, a <xref:System.Windows.Media.Geometry> object is unable to draw itself, so the example uses a <xref:System.Windows.Shapes.Path> shape to render the line.  Because a line has no area, setting the <xref:System.Windows.Shapes.Shape.Fill%2A> property of the <xref:System.Windows.Shapes.Path> would have no effect; instead, only the <xref:System.Windows.Shapes.Shape.Stroke%2A> and <xref:System.Windows.Shapes.Shape.StrokeThickness%2A> properties are specified. The following illustration shows the output from the example.  
  
 ![A LineGeometry](./media/graphicsmm-line.gif "graphicsmm_line")  
A LineGeometry drawn from (10,20) to (100,130)  
  
 [!code-xaml[GeometryOverviewSamples_snip#GraphicsMMLineGeometryExample](~/samples/snippets/csharp/VS_Snippets_Wpf/GeometryOverviewSamples_snip/CS/GeometryExamples.xaml#graphicsmmlinegeometryexample)]  
  
 [!code-csharp[GeometryOverviewSamples_procedural_snip#GraphicsMMLineGeometryExample](~/samples/snippets/csharp/VS_Snippets_Wpf/GeometryOverviewSamples_procedural_snip/CSharp/GeometryExamples.cs#graphicsmmlinegeometryexample)]
 [!code-vb[GeometryOverviewSamples_procedural_snip#GraphicsMMLineGeometryExample](~/samples/snippets/visualbasic/VS_Snippets_Wpf/GeometryOverviewSamples_procedural_snip/visualbasic/geometryexamples.vb#graphicsmmlinegeometryexample)]  
  
 The next example shows how to create and render an <xref:System.Windows.Media.EllipseGeometry>.  The examples sets the <xref:System.Windows.Media.EllipseGeometry.Center%2A> of the <xref:System.Windows.Media.EllipseGeometry> is set to the point `50,50` and the x-radius and the y-radius are both set to `50`, which creates a circle with a diameter of 100.  The interior of the ellipse is painted by assigning a value to the Path element's Fill property, in this case <xref:System.Windows.Media.Brushes.Gold%2A>. The following illustration shows the output from the example.  
  
 ![An EllipseGeometry](./media/graphicsmm-ellipse.gif "graphicsmm_ellipse")  
An EllipseGeometry drawn at (50,50)  
  
 [!code-xaml[GeometryOverviewSamples_snip#GraphicsMMEllipseGeometryExample](~/samples/snippets/csharp/VS_Snippets_Wpf/GeometryOverviewSamples_snip/CS/GeometryExamples.xaml#graphicsmmellipsegeometryexample)]  
  
 [!code-csharp[GeometryOverviewSamples_procedural_snip#GraphicsMMEllipseGeometryExample](~/samples/snippets/csharp/VS_Snippets_Wpf/GeometryOverviewSamples_procedural_snip/CSharp/GeometryExamples.cs#graphicsmmellipsegeometryexample)]
 [!code-vb[GeometryOverviewSamples_procedural_snip#GraphicsMMEllipseGeometryExample](~/samples/snippets/visualbasic/VS_Snippets_Wpf/GeometryOverviewSamples_procedural_snip/visualbasic/geometryexamples.vb#graphicsmmellipsegeometryexample)]  
  
 The following example shows how to create and render a <xref:System.Windows.Media.RectangleGeometry>.  The position and the dimensions of the rectangle are defined by a <xref:System.Windows.Rect> structure. The position is `50,50` and the height and width are both `25`, which creates a square. The following illustration shows the output from the example.  
  
 ![A RectangleGeometry](./media/graphicsmm-rectangle.gif "graphicsmm_rectangle")  
A RectangleGeometry drawn at 50,50  
  
 [!code-xaml[GeometryOverviewSamples_snip#GraphicsMMRectangleGeometryExample](~/samples/snippets/csharp/VS_Snippets_Wpf/GeometryOverviewSamples_snip/CS/GeometryExamples.xaml#graphicsmmrectanglegeometryexample)]  
  
 [!code-csharp[GeometryOverviewSamples_procedural_snip#GraphicsMMRectangleGeometryExample](~/samples/snippets/csharp/VS_Snippets_Wpf/GeometryOverviewSamples_procedural_snip/CSharp/GeometryExamples.cs#graphicsmmrectanglegeometryexample)]
 [!code-vb[GeometryOverviewSamples_procedural_snip#GraphicsMMRectangleGeometryExample](~/samples/snippets/visualbasic/VS_Snippets_Wpf/GeometryOverviewSamples_procedural_snip/visualbasic/geometryexamples.vb#graphicsmmrectanglegeometryexample)]  
  
 The following example shows how to use an <xref:System.Windows.Media.EllipseGeometry> as the clip region for an image.  An <xref:System.Windows.Controls.Image> object is defined with a <xref:System.Windows.FrameworkElement.Width%2A> of 200 and a <xref:System.Windows.FrameworkElement.Height%2A> of 150.  An <xref:System.Windows.Media.EllipseGeometry> with a <xref:System.Windows.Media.EllipseGeometry.RadiusX%2A> value of 100, a <xref:System.Windows.Media.EllipseGeometry.RadiusY%2A> value of 75, and a <xref:System.Windows.Media.EllipseGeometry.Center%2A> value of 100,75 is set to the <xref:System.Windows.UIElement.Clip%2A> property of the image.  Only the part of the image that is within the area of the ellipse will be displayed. The following illustration shows the output from the example.  
  
 ![An Image with and without clipping](./media/graphicsmm-clipexample.png "graphicsmm_clipexample")  
An EllipseGeometry used to clip an Image control  
  
 [!code-xaml[GeometryOverviewSamples_snip#GraphicsMMImageClipGeometryExample](~/samples/snippets/csharp/VS_Snippets_Wpf/GeometryOverviewSamples_snip/CS/GeometryExamples.xaml#graphicsmmimageclipgeometryexample)]  
  
 [!code-csharp[GeometryOverviewSamples_procedural_snip#GraphicsMMImageClipGeometryExample](~/samples/snippets/csharp/VS_Snippets_Wpf/GeometryOverviewSamples_procedural_snip/CSharp/GeometryExamples.cs#graphicsmmimageclipgeometryexample)]
 [!code-vb[GeometryOverviewSamples_procedural_snip#GraphicsMMImageClipGeometryExample](~/samples/snippets/visualbasic/VS_Snippets_Wpf/GeometryOverviewSamples_procedural_snip/visualbasic/geometryexamples.vb#graphicsmmimageclipgeometryexample)]  
  
<a name="wcpsdk_graphics_geometry_pathgeometry"></a>
## Path Geometries  
 The <xref:System.Windows.Media.PathGeometry> class and its lightweight equivalent, the <xref:System.Windows.Media.StreamGeometry> class, provide the means to describe multiple complex figures composed of arcs, curves, and lines.  
  
 At the heart of a <xref:System.Windows.Media.PathGeometry> is a collection of <xref:System.Windows.Media.PathFigure> objects, so named because each figure describes a discrete shape in the <xref:System.Windows.Media.PathGeometry>. Each <xref:System.Windows.Media.PathFigure> is itself comprised of one or more <xref:System.Windows.Media.PathSegment> objects, each of which describes a segment of the figure.  
  
 There are many types of segments.  
  
|Segment Type|Description|Example|  
|------------------|-----------------|-------------|  
|<xref:System.Windows.Media.ArcSegment>|Creates an elliptical arc between two points.|[Create an Elliptical Arc](how-to-create-an-elliptical-arc.md).|  
|<xref:System.Windows.Media.BezierSegment>|Creates a cubic Bezier curve between two points.|[Create a Cubic Bezier Curve](how-to-create-a-cubic-bezier-curve.md).|  
|<xref:System.Windows.Media.LineSegment>|Creates a line between two points.|[Create a LineSegment in a PathGeometry](how-to-create-a-linesegment-in-a-pathgeometry.md)|  
|<xref:System.Windows.Media.PolyBezierSegment>|Creates a series of cubic Bezier curves.|See the <xref:System.Windows.Media.PolyBezierSegment> type page.|  
|<xref:System.Windows.Media.PolyLineSegment>|Creates a series of lines.|See the <xref:System.Windows.Media.PolyLineSegment> type page.|  
|<xref:System.Windows.Media.PolyQuadraticBezierSegment>|Creates a series of quadratic Bezier curves.|See the <xref:System.Windows.Media.PolyQuadraticBezierSegment> page.|  
|<xref:System.Windows.Media.QuadraticBezierSegment>|Creates a quadratic Bezier curve.|[Create a Quadratic Bezier Curve](how-to-create-a-quadratic-bezier-curve.md).|  
  
 The segments within a <xref:System.Windows.Media.PathFigure> are combined into a single geometric shape with the end point of each segment being the start point of the next segment. The <xref:System.Windows.Media.PathFigure.StartPoint%2A> property of a <xref:System.Windows.Media.PathFigure> specifies the point from which the first segment is drawn. Each subsequent segment starts at the end point of the previous segment. For example, a vertical line from `10,50` to `10,150` can be defined by setting the <xref:System.Windows.Media.PathFigure.StartPoint%2A> property to `10,50` and creating a <xref:System.Windows.Media.LineSegment> with a <xref:System.Windows.Media.LineSegment.Point%2A> property setting of `10,150`.  
  
 The following example creates a simple <xref:System.Windows.Media.PathGeometry> comprised of a single <xref:System.Windows.Media.PathFigure> with a <xref:System.Windows.Media.LineSegment> and displays it using a <xref:System.Windows.Shapes.Path> element. The <xref:System.Windows.Media.PathFigure> object's <xref:System.Windows.Media.PathFigure.StartPoint%2A> is set to `10,20` and a <xref:System.Windows.Media.LineSegment> is defined with an end point of `100,130`. The following illustration shows the <xref:System.Windows.Media.PathGeometry> created by this example.  
  
 ![A LineGeometry](./media/graphicsmm-line.gif "graphicsmm_line")  
A PathGeometry that contains a single LineSegment  
  
 [!code-xaml[GeometryOverviewSamples_snip#GraphicsMMPathGeometryLineExample](~/samples/snippets/csharp/VS_Snippets_Wpf/GeometryOverviewSamples_snip/CS/GeometryExamples.xaml#graphicsmmpathgeometrylineexample)]  
  
 [!code-csharp[GeometryOverviewSamples_procedural_snip#GraphicsMMPathGeometryLineExample](~/samples/snippets/csharp/VS_Snippets_Wpf/GeometryOverviewSamples_procedural_snip/CSharp/GeometryExamples.cs#graphicsmmpathgeometrylineexample)]
 [!code-vb[GeometryOverviewSamples_procedural_snip#GraphicsMMPathGeometryLineExample](~/samples/snippets/visualbasic/VS_Snippets_Wpf/GeometryOverviewSamples_procedural_snip/visualbasic/geometryexamples.vb#graphicsmmpathgeometrylineexample)]  
  
 It is worth contrasting this example with the preceding <xref:System.Windows.Media.LineGeometry> example.  The syntax used for a <xref:System.Windows.Media.PathGeometry> is much more verbose than that used for a simple <xref:System.Windows.Media.LineGeometry>, and it may make more sense to use the <xref:System.Windows.Media.LineGeometry> class in this case, but the verbose syntax of the <xref:System.Windows.Media.PathGeometry> allows for extremely intricate and complex geometric regions.  
  
 More complex geometries can be created by using a combination of <xref:System.Windows.Media.PathSegment> objects.  
  
 The next example uses a <xref:System.Windows.Media.BezierSegment>, a <xref:System.Windows.Media.LineSegment>, and an <xref:System.Windows.Media.ArcSegment> to create shape. The example first creates a cubic Bezier curve is by defining four points: a start point, which is the end point of the previous segment, an end point (<xref:System.Windows.Media.BezierSegment.Point3%2A>), and two control points (<xref:System.Windows.Media.BezierSegment.Point1%2A> and <xref:System.Windows.Media.BezierSegment.Point2%2A>).  The two control points of a cubic Bezier curve behave like magnets, attracting portions of what would otherwise be a straight line towards themselves, producing a curve. The first control point, <xref:System.Windows.Media.BezierSegment.Point1%2A>, affects the beginning portion of the curve; the second control point, <xref:System.Windows.Media.BezierSegment.Point2%2A>, affects the ending portion of the curve.  
  
 The example then adds a <xref:System.Windows.Media.LineSegment>, which is drawn between the end point of the preceding <xref:System.Windows.Media.BezierSegment> that preceded it to the point specified by its <xref:System.Windows.Media.LineSegment> property.  
  
 The example then adds an <xref:System.Windows.Media.ArcSegment>, which is drawn from the end point of the preceding <xref:System.Windows.Media.LineSegment> to the point specified by its <xref:System.Windows.Media.ArcSegment.Point%2A> property. The example also specifies the arc's x- and y-radius (<xref:System.Windows.Media.ArcSegment.Size%2A>), a rotation angle (<xref:System.Windows.Media.ArcSegment.RotationAngle%2A>), a flag indicating how large the angle of the resulting arc should be (<xref:System.Windows.Media.ArcSegment.IsLargeArc%2A>), and a value indicating in which direction the arc is drawn (<xref:System.Windows.Media.ArcSegment.SweepDirection%2A>). The following illustration shows the shape created by this example.  
  
 ![A PathGeometry](./media/graphicsmm-path2.gif "graphicsmm_path2")  
A PathGeometry  
  
 [!code-xaml[GeometryOverviewSamples_snip#GraphicsMMPathGeometryComplexExample](~/samples/snippets/csharp/VS_Snippets_Wpf/GeometryOverviewSamples_snip/CS/GeometryExamples.xaml#graphicsmmpathgeometrycomplexexample)]  
  
 [!code-csharp[GeometryOverviewSamples_procedural_snip#GraphicsMMPathGeometryComplexExample](~/samples/snippets/csharp/VS_Snippets_Wpf/GeometryOverviewSamples_procedural_snip/CSharp/GeometryExamples.cs#graphicsmmpathgeometrycomplexexample)]
 [!code-vb[GeometryOverviewSamples_procedural_snip#GraphicsMMPathGeometryComplexExample](~/samples/snippets/visualbasic/VS_Snippets_Wpf/GeometryOverviewSamples_procedural_snip/visualbasic/geometryexamples.vb#graphicsmmpathgeometrycomplexexample)]  
  
 Even more complex geometries can be created by using multiple <xref:System.Windows.Media.PathFigure> objects within a <xref:System.Windows.Media.PathGeometry>.  
  
 The following example creates a <xref:System.Windows.Media.PathGeometry> with two <xref:System.Windows.Media.PathFigure> objects, each of which contains multiple <xref:System.Windows.Media.PathSegment> objects.  The <xref:System.Windows.Media.PathFigure> from the above example and a <xref:System.Windows.Media.PathFigure> with a <xref:System.Windows.Media.PolyLineSegment> and a <xref:System.Windows.Media.QuadraticBezierSegment> are used.  A <xref:System.Windows.Media.PolyLineSegment> is defined with an array of points and the <xref:System.Windows.Media.QuadraticBezierSegment> is defined with a control point and an end point. The following illustration shows the shape created by this example.  
  
 ![A PathGeometry](./media/graphicsmm-path.gif "graphicsmm_path")  
A PathGeometry with multiple figures  
  
 [!code-xaml[GeometryOverviewSamples_snip#GraphicsMMPathGeometryComplexMultiExample](~/samples/snippets/csharp/VS_Snippets_Wpf/GeometryOverviewSamples_snip/CS/GeometryExamples.xaml#graphicsmmpathgeometrycomplexmultiexample)]  
  
 [!code-csharp[GeometryOverviewSamples_procedural_snip#GraphicsMMPathGeometryComplexMultiExample](~/samples/snippets/csharp/VS_Snippets_Wpf/GeometryOverviewSamples_procedural_snip/CSharp/GeometryExamples.cs#graphicsmmpathgeometrycomplexmultiexample)]
 [!code-vb[GeometryOverviewSamples_procedural_snip#GraphicsMMPathGeometryComplexMultiExample](~/samples/snippets/visualbasic/VS_Snippets_Wpf/GeometryOverviewSamples_procedural_snip/visualbasic/geometryexamples.vb#graphicsmmpathgeometrycomplexmultiexample)]  
  
### StreamGeometry  
 Like the <xref:System.Windows.Media.PathGeometry> class, a <xref:System.Windows.Media.StreamGeometry> defines a complex geometric shape that may contain curves, arcs, and lines. Unlike a <xref:System.Windows.Media.PathGeometry>, the contents of a  <xref:System.Windows.Media.StreamGeometry> do not support data binding, animation, or modification. Use a <xref:System.Windows.Media.StreamGeometry> when you need to describe a complex geometry but do not want the overhead of supporting data binding, animation, or modification. Because of its efficiency, the <xref:System.Windows.Media.StreamGeometry> class is a good choice for describing adorners.  
  
 For an example, see [Create a Shape Using a StreamGeometry](how-to-create-a-shape-using-a-streamgeometry.md).  
  
### Path Markup Syntax  
 The <xref:System.Windows.Media.PathGeometry> and <xref:System.Windows.Media.StreamGeometry> types support a [!INCLUDE[TLA#tla_xaml](../../../includes/tlasharptla-xaml-md.md)] attribute syntax using a special series of move and draw commands. For more information, see [Path Markup Syntax](path-markup-syntax.md).  
  
<a name="wcpsdk_graphics_geometry_introduction2"></a>
## Composite Geometries  
 Composite geometry objects can be created using a <xref:System.Windows.Media.GeometryGroup>, a <xref:System.Windows.Media.CombinedGeometry>, or by calling the static <xref:System.Windows.Media.Geometry> method <xref:System.Windows.Media.Geometry.Combine%2A>.  
  
- The <xref:System.Windows.Media.CombinedGeometry> object and the <xref:System.Windows.Media.Geometry.Combine%2A> method performs a Boolean operation to combine the area defined by two geometries. <xref:System.Windows.Media.Geometry> objects that have no area are discarded. Only two <xref:System.Windows.Media.Geometry> objects can be combined (although these two geometries may also be composite geometries).  
  
- The <xref:System.Windows.Media.GeometryGroup> class creates an amalgamation of the <xref:System.Windows.Media.Geometry> objects it contains without combining their area. Any number of <xref:System.Windows.Media.Geometry> objects can be added to a <xref:System.Windows.Media.GeometryGroup>. For an example, see [Create a Composite Shape](how-to-create-a-composite-shape.md).  
  
 Because they do not perform a combine operation, using <xref:System.Windows.Media.GeometryGroup> objects provides performance benefits over using <xref:System.Windows.Media.CombinedGeometry> objects or the <xref:System.Windows.Media.Geometry.Combine%2A> method.  
  
<a name="combindgeometriessection"></a>
## Combined Geometries  
 The preceding section mentioned the <xref:System.Windows.Media.CombinedGeometry> object and the <xref:System.Windows.Media.Geometry.Combine%2A> method combine the area defined by the geometries they contain. The <xref:System.Windows.Media.GeometryCombineMode> enumeration specifies how the geometries are combined. The possible values for the <xref:System.Windows.Media.CombinedGeometry.GeometryCombineMode%2A> property are: <xref:System.Windows.Media.GeometryCombineMode.Union>, <xref:System.Windows.Media.GeometryCombineMode.Intersect>, <xref:System.Windows.Media.GeometryCombineMode.Exclude>, and <xref:System.Windows.Media.GeometryCombineMode.Xor>.  
  
 In the following example, a <xref:System.Windows.Media.CombinedGeometry> is defined with a combine mode of Union.  Both <xref:System.Windows.Media.CombinedGeometry.Geometry1%2A> and the <xref:System.Windows.Media.CombinedGeometry.Geometry2%2A> are defined as circles of the same radius, but with centers offset by 50.  
  
 [!code-xaml[GeometrySample#23](~/samples/snippets/csharp/VS_Snippets_Wpf/GeometrySample/CS/combininggeometriesexample.xaml#23)]  
  
 ![Results of the Union combine mode](./media/mil-task-combined-geometry-union.PNG "mil_task_combined_geometry_union")  
  
 In the following example, a <xref:System.Windows.Media.CombinedGeometry> is defined with a combine mode of <xref:System.Windows.Media.GeometryCombineMode.Xor>.  Both <xref:System.Windows.Media.CombinedGeometry.Geometry1%2A> and the <xref:System.Windows.Media.CombinedGeometry.Geometry2%2A> are defined as circles of the same radius, but with centers offset by 50.  
  
 [!code-xaml[GeometrySample#24](~/samples/snippets/csharp/VS_Snippets_Wpf/GeometrySample/CS/combininggeometriesexample.xaml#24)]  
  
 ![Results of the Xor combine mode](./media/mil-task-combined-geometry-xor.PNG "mil_task_combined_geometry_xor")  
  
 For additional examples, see [Create a Composite Shape](how-to-create-a-composite-shape.md) and [Create a Combined Geometry](how-to-create-a-combined-geometry.md).  
  
<a name="freezable_features"></a>
## Freezable Features  
 Because it inherits from the <xref:System.Windows.Freezable> class, the <xref:System.Windows.Media.Geometry> class  provide several special features: <xref:System.Windows.Media.Geometry> objects can be declared as [XAML Resources](/dotnet/desktop-wpf/fundamentals/xaml-resources-define), shared among multiple objects, made read-only to improve performance, cloned, and made thread-safe. For more information about the different features provided by <xref:System.Windows.Freezable> objects, see the [Freezable Objects Overview](../advanced/freezable-objects-overview.md).  
  
<a name="othergeometryfeatures"></a>
## Other Geometry Features  
 The <xref:System.Windows.Media.Geometry> class also provides useful utility methods, such as the following:  
  
- <xref:System.Windows.Media.Geometry.GetArea%2A> - Gets the area of the <xref:System.Windows.Media.Geometry>.  
  
- <xref:System.Windows.Media.Geometry.FillContains%2A> - Determines whether the Geometry contains another <xref:System.Windows.Media.Geometry>.  
  
- <xref:System.Windows.Media.Geometry.StrokeContains%2A> - Determines whether the stroke of a <xref:System.Windows.Media.Geometry> contains a specified point.  
  
 See the <xref:System.Windows.Media.Geometry> class for a complete listing of its methods.  
  
## See also

- <xref:System.Windows.Media.Geometry>
- <xref:System.Windows.Media.PathGeometry>
- <xref:System.Windows.Shapes.Path>
- <xref:System.Windows.Media.GeometryDrawing>
- [2D Graphics and Imaging](../advanced/optimizing-performance-2d-graphics-and-imaging.md)
- [Path Markup Syntax](path-markup-syntax.md)
- [How-to Topics](geometries-how-to-topics.md)
- [Animation Overview](animation-overview.md)
- [Shapes and Basic Drawing in WPF Overview](shapes-and-basic-drawing-in-wpf-overview.md)
- [Drawing Objects Overview](drawing-objects-overview.md)