BitmapDataExtensionsBeginDrawPolygon(IReadWriteBitmapData, Color32, IEnumerablePoint, DrawingOptions, AsyncConfig) Method

Begins to draw a one-pixel wide polygon with the specified color asynchronously.

Definition

Namespace: KGySoft.Drawing.Shapes
Assembly: KGySoft.Drawing.Core (in KGySoft.Drawing.Core.dll) Version: 9.1.1
C#
public static IAsyncResult BeginDrawPolygon(
	this IReadWriteBitmapData bitmapData,
	Color32 color,
	IEnumerable<Point> points,
	DrawingOptions? drawingOptions = null,
	AsyncConfig? asyncConfig = null
)

Parameters

bitmapData  IReadWriteBitmapData
The IReadWriteBitmapData instance to draw on.
color  Color32
The color of the polygon to draw.
points  IEnumerablePoint
The vertices of the polygon to draw.
drawingOptions  DrawingOptions  (Optional)
A DrawingOptions instance that specifies the drawing options to use. If , then the default options are used. This parameter is optional.
Default value: .
asyncConfig  AsyncConfig  (Optional)
The configuration of the asynchronous operation such as parallelization, cancellation, reporting progress, etc. When Progress is set in this parameter, then this library always passes a DrawingOperation instance to the generic methods of the IAsyncProgress interface. This parameter is optional.
Default value: .

Return Value

IAsyncResult
An IAsyncResult that represents the asynchronous operation, which could still be pending.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IReadWriteBitmapData. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).

Remarks

Every pair of two consecutive points specifies a side of the polygon. In addition, if the last point and the first point do not coincide, they specify the last side of the polygon.

This method tries to use a shortcut to draw the polygon directly, which is faster than creating a Path and adding the points to it. A shortcut is possible when drawingOptions is and the specified color is opaque, or when FastThinLines is enabled in drawingOptions, and it specifies that no anti-aliasing and no alpha blending is required, the transformation is the identity matrix, and neither Quantizer nor Ditherer is specified.

When no shortcut can be used and the same polygon is drawn repeatedly, creating a Path with PreferCaching enabled can provide a better performance.

In .NET Framework 4.0 and above you can use also the DrawPolygonAsync methods.

To finish the operation and to get the exception that occurred during the operation you have to call the EndDrawPolygon method.

This method is not a blocking call even if the MaxDegreeOfParallelism property of the asyncConfig parameter is 1.

If the polygon is drawn by using a shortcut, then the operation is executed synchronously, it cannot be canceled, it is not parallelized, and there is no progress reporting, regardless of the asyncConfig parameter.

Exceptions

ArgumentNullExceptionbitmapData or points is .
OverflowExceptionA Path is created internally and the width or height of Path.Bounds overflows.

See Also