BitmapDataExtensionsDrawQuadraticCurves(IReadWriteBitmapData, Pen, IEnumerablePointF, DrawingOptions, ParallelConfig) Method

Draws a series of quadratic Bézier curves with the specified Pen.

Definition

Namespace: KGySoft.Drawing.Shapes
Assembly: KGySoft.Drawing.Core (in KGySoft.Drawing.Core.dll) Version: 10.0.0-rc.1

public static bool DrawQuadraticCurves(
	this IReadWriteBitmapData bitmapData,
	Pen pen,
	IEnumerable<PointF> points,
	DrawingOptions? drawingOptions = null,
	ParallelConfig? parallelConfig = null
)

<ExtensionAttribute>
Public Shared Function DrawQuadraticCurves ( 
	bitmapData As IReadWriteBitmapData,
	pen As Pen,
	points As IEnumerable(Of PointF),
	Optional drawingOptions As DrawingOptions = Nothing,
	Optional parallelConfig As ParallelConfig = Nothing
) As Boolean

C++

public:
[ExtensionAttribute]
static bool DrawQuadraticCurves(
	IReadWriteBitmapData^ bitmapData, 
	Pen^ pen, 
	IEnumerable<PointF>^ points, 
	DrawingOptions^ drawingOptions = nullptr, 
	ParallelConfig^ parallelConfig = nullptr
)

[<ExtensionAttribute>]
static member DrawQuadraticCurves : 
        bitmapData : IReadWriteBitmapData * 
        pen : Pen * 
        points : IEnumerable<PointF> * 
        ?drawingOptions : DrawingOptions * 
        ?parallelConfig : ParallelConfig 
(* Defaults:
        let _drawingOptions = defaultArg drawingOptions null
        let _parallelConfig = defaultArg parallelConfig null
*)
-> bool

Parameters

bitmapData IReadWriteBitmapData: The IReadWriteBitmapData instance to draw on.
pen Pen: The Pen that determines the characteristics of the curves.
points IEnumerablePointF: The points of the curves 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: .
parallelConfig ParallelConfig (Optional): The configuration of the 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. If , then the degree of parallelization is configured automatically. This parameter is optional.
Default value: .

Return Value

Boolean
, if the operation completed successfully.
, if the operation has been canceled and the ThrowIfCanceled property of the parallelConfig parameter was .

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

In the points parameter 0 or odd number of points are expected.

When points has at least three items, the first three points define the first quadratic curve. Each additional two points define a new quadratic curve, where the last point of the previous curve is the starting point of the next curve.

This method draws quadratic Bézier curves. A quadratic Bézier curve is defined by three points: the starting point, the control point, and the end point. To draw cubic Bézier curves, you can use the DrawBeziers methods. In fact, this method transforms the quadratic curves into cubic Bézier curves internally.

This method tries to use a shortcut to draw the curves directly, which is faster than creating a Path and adding the curves to it. A shortcut is possible when the specified pen has a width between 0.25 and 1, it uses a solid Brush with an opaque color, and if drawingOptions is either , or its FastThinLines is enabled in drawingOptions, 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 curves are drawn repeatedly, creating a Path with PreferCaching enabled can provide a better performance.

Note

This method blocks the caller as it executes synchronously, though the parallelConfig parameter allows configuring the degree of parallelism, cancellation and progress reporting. Use the BeginDrawQuadraticCurves or DrawQuadraticCurvesAsync (in .NET Framework 4.0 and above) methods to perform the operation asynchronously.

If the curves are drawn by using a shortcut, then the operation cannot be canceled, it is not parallelized, and there is no progress reporting, regardless of the parallelConfig parameter.

Exceptions

ArgumentNullException	bitmapData, pen, or points is .
ArgumentException	The number of points is not zero, or an odd number.
OverflowException	The coordinates (after a possible transformation specified in drawingOptions) are outside the bounds of an int value.
OperationCanceledException	The operation has been canceled and the ThrowIfCanceled property in parallelConfig was .