Draw spline(smooth path) with SkiaSharp lib on Xamarin.Forms?

问题

I'm making app with using Xamarin forms.

I want to draw a smooth path (spline) with SKPath, but I am unable to find a simple way to achieve this.

Skiasharp does not support it currently unless I make path smoothly myself.

Thanks.

回答1:

SkiaSharp supports cubic Bezier curves. So, what you can do, is divide the spline into segments (points determine segment endpoints), and draw each segment using a cubic Bezier curve. To do this, you need to introduce two control points between each point in your spline curve. These points need to be selected so that the curves in neighboring segments connect smoothly.

I just did an implementation of this. The public static SKPath CreateSpline(params SKPoint[] Points) method generates a path that you can use to draw a spline between points. You can view the implementation here:

https://github.com/PeterWaher/IoTGateway/blob/master/Script/Waher.Script.Graphs/Functions/Plots/Plot2DCurve.cs

Example:

回答2:

I am not sure exactly what you are asking, but there are two areas for smoothing:

Anti-aliasing using SKPaint.IsAntialias:

var paint = new SKPaint {
    IsAntialias = true
};
canvas.DrawPath (path, paint);

Path Curves:

If you need the curves in the path, such as round corners, you will need to use the various curve methods. These include, but are not limited to, SKPath.ArcTo() and 'SKPath.CubicTo():

var path = new SKPath();
path.MoveTo(10, 10);
path.ArcTo(SKRect.Create(10, 10, 30, 30), 0, 45);

Path docs: https://developer.xamarin.com/api/type/SkiaSharp.SKPath/

来源：https://stackoverflow.com/questions/41802311/draw-splinesmooth-path-with-skiasharp-lib-on-xamarin-forms

标签

Xamarin

xamarin.forms

skiasharp