public static SKShader ToSkiaShader(IGradientBrush gradientBrush, IShape shape)
{
SKShaderTileMode tileMode = gradientBrush.SpreadMethod switch
{
GradientSpreadMethod.Pad => SKShaderTileMode.Clamp,
GradientSpreadMethod.Reflect => SKShaderTileMode.Mirror,
GradientSpreadMethod.Repeat => SKShaderTileMode.Repeat,
_ => throw new InvalidOperationException($"Unknown GradientSpreadmethod value {gradientBrush.SpreadMethod}")
};
List <SKColor> skiaColors = new List <SKColor>();
List <float> skiaColorPositions = new List <float>();
foreach (IGradientStop gradientStop in gradientBrush.GradientStops)
{
skiaColors.Add(ToSkiaColor(gradientStop.Color));
skiaColorPositions.Add((float)gradientStop.Offset);
}
if (gradientBrush is ILinearGradientBrush linearGradientBrush)
{
SKPoint skiaStartPoint = new SKPoint(
(float)(shape.Left + linearGradientBrush.StartPoint.X * shape.Width),
(float)(shape.Top + linearGradientBrush.StartPoint.Y * shape.Height));
SKPoint skiaEndPoint = new SKPoint(
(float)(shape.Left + linearGradientBrush.EndPoint.X * shape.Width),
(float)(shape.Top + linearGradientBrush.EndPoint.Y * shape.Height));
return(SKShader.CreateLinearGradient(skiaStartPoint, skiaEndPoint, skiaColors.ToArray(), skiaColorPositions.ToArray(), tileMode));
}
else if (gradientBrush is IRadialGradientBrush radialGradientBrush)
{
SKPoint skiaCenterPoint = new SKPoint(
(float)(shape.Left + radialGradientBrush.Center.X * shape.Width),
(float)(shape.Top + radialGradientBrush.Center.Y * shape.Height));
float radius = (float)(radialGradientBrush.RadiusX * shape.Width);
return(SKShader.CreateRadialGradient(skiaCenterPoint, radius, skiaColors.ToArray(), skiaColorPositions.ToArray(), tileMode));
}
else
{
throw new InvalidOperationException($"GradientBrush type {gradientBrush.GetType()} is unknown");
}
}
internal static IGradientBrush ConvertSolidColorBrushToGradient(IGradientBrush gradientBrush, ISolidColorBrush solidColorBrush)
{
switch (gradientBrush)
{
case IRadialGradientBrush oldRadial:
return(new ImmutableRadialGradientBrush(
CreateStopsFromSolidColorBrush(solidColorBrush, oldRadial.GradientStops), solidColorBrush.Opacity,
oldRadial.SpreadMethod, oldRadial.Center, oldRadial.GradientOrigin, oldRadial.Radius));
case IConicGradientBrush oldConic:
return(new ImmutableConicGradientBrush(
CreateStopsFromSolidColorBrush(solidColorBrush, oldConic.GradientStops), solidColorBrush.Opacity,
oldConic.SpreadMethod, oldConic.Center, oldConic.Angle));
case ILinearGradientBrush oldLinear:
return(new ImmutableLinearGradientBrush(
CreateStopsFromSolidColorBrush(solidColorBrush, oldLinear.GradientStops), solidColorBrush.Opacity,
oldLinear.SpreadMethod, oldLinear.StartPoint, oldLinear.EndPoint));
default:
throw new NotSupportedException($"Gradient of type {gradientBrush?.GetType()} is not supported");
}
