Kynareth/src/Managers/ImageManager.Magik.cs

using System.Text;
using Exsersewo.Common.Utilities;
using ImageMagick;

namespace Kynareth.Managers;

public static partial class ImageManager
{
	readonly static Encoding s_defaultEncoding = Encoding.Unicode;
	const double c_defaultFontSize = 20;

	public static async Task<(MemoryStream data, string contentType)> GetLiquidRescaledImageAsync(string image)
	{
		var imageStream = await HttpWebClient.GetStreamAsync(new Uri(image)).ConfigureAwait(false);
		
		using var magikImage = new MagickImageCollection(imageStream);

		Parallel.ForEach(magikImage, LiquidResizeFrame);

		MemoryStream stream = new();

		magikImage.Write(stream);

		stream.Position = 0;

		magikImage.Dispose();

		string cType = "image/png";

		if (magikImage.Count > 1) cType = "image/gif";

		return (stream, cType);
	}

	static void LiquidResizeFrame(IMagickImage<byte> frame)
	{
		int originalWidth = frame.Width;
		int originalHeight = frame.Height;

		frame.Resize(800, 600);

		frame.LiquidRescale(new MagickGeometry
		{
			X = 1,
			Width = Convert.ToInt32(frame.Width * 0.5),
			Height = Convert.ToInt32(frame.Height * 0.5)
		});

		frame.LiquidRescale(new MagickGeometry
		{
			X = 2,
			Width = Convert.ToInt32(frame.Width * 1.5),
			Height = Convert.ToInt32(frame.Height * 1.5)
		});

		frame.Resize(originalWidth, originalHeight);
	}
}