// --------------------------------------------------------------------------------------------------------------------

// <copyright file="MirrorPadProcessor.cs" company="OxyPlot">

// Copyright (c) 2014 OxyPlot contributors

// </copyright>

// <summary>

// Provides an an ImageProcessor that performs a single-pizel mirror/clamp along the edge of an image.

// </summary>

// --------------------------------------------------------------------------------------------------------------------

#nullable enable

namespace OxyPlot.ImageSharp

{

using SixLabors.ImageSharp;

using SixLabors.ImageSharp.PixelFormats;

using SixLabors.ImageSharp.Processing.Processors;

/// <summary>

/// Performs a single-pizel mirror/clamp along the edge of the image, which is used to assist with drawing non-pixel aligned and interpolate images.

/// </summary>

internal class MirrorPadProcessor : IImageProcessor

{

private class MirrorPadImplementation<TPixel> : ImageProcessor<TPixel> where TPixel : unmanaged, IPixel<TPixel>

{

public MirrorPadImplementation(Configuration configuration, Image<TPixel> source, Rectangle sourceRectangle)

: base(configuration, source, sourceRectangle)

{

}

protected override void OnFrameApply(ImageFrame<TPixel> source)

{

source[0, 0] = source[1, 1];

source[source.Width - 1, 0] = source[source.Width - 2, 1];

source[0, source.Height - 1] = source[1, source.Height - 2];

source[source.Width - 1, source.Height - 1] = source[source.Width - 2, source.Height - 2];

for (int x = 1; x < source.Width - 1; x++)

{

source[x, 0] = source[x, 1];

source[x, source.Height - 1] = source[x, source.Height - 2];

}

for (int y = 1; y < source.Height - 1; y++)

{

source[0, y] = source[1, y];

source[source.Width - 1, y] = source[source.Width - 2, y];

}

}

}

public IImageProcessor<TPixel> CreatePixelSpecificProcessor<TPixel>(Configuration configuration, Image<TPixel> source, Rectangle sourceRectangle) where TPixel : unmanaged, IPixel<TPixel>

{

return new MirrorPadImplementation<TPixel>(configuration, source, sourceRectangle);

}

}

}