Cupola/Program.cs

using ComputeSharp;
using static Cupola.Program;

namespace Cupola
{
    internal partial class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Image Dir?");
            string? fileLoc = Console.ReadLine();

            if (fileLoc == null)
                throw new ArgumentException("input should not be NULL");

            string[] files = Directory.GetFiles(fileLoc);

            ReadWriteTexture2D<Bgra32, float4>[] images = new ReadWriteTexture2D<Bgra32, Float4>[files.Length];

            for (int i = 0; i < files.Length; i++)
            {
                Console.WriteLine(files[i]);
                images[i] = GraphicsDevice.GetDefault().LoadReadWriteTexture2D<Bgra32, float4>(files[i]);
            }

            Console.WriteLine("Output: ");

            string? name = Console.ReadLine();

            if (name == null)
                throw new Exception("UwU");

            Console.WriteLine("mode?");
            Console.WriteLine();
            ConsoleKey key = Console.ReadKey().Key;

            if (key == ConsoleKey.P)
            {
                ReadWriteTexture2D<Bgra32, Float4> brightest = images[0];
                ReadWriteTexture2D<Bgra32, Float4> output = images[0];

                for (int i = 1; i < images.Length; i++)
                {
                    Console.WriteLine(i.ToString());

                    ReadWriteTexture2D<Bgra32, Float4> temp = images[i];

                    GraphicsDevice.GetDefault().For
                    (
                        temp.Width,
                        temp.Height,
                        new Brightest(brightest, temp)
                    );

                    GraphicsDevice.GetDefault().For
                    (
                        temp.Width,
                        temp.Height,
                        new Average(temp, output)
                    );

                    GraphicsDevice.GetDefault().For
                    (
                        temp.Width,
                        temp.Height,
                        new Average(temp, brightest)
                    );

                    output = temp;
                }

                output.Save(name + ".jpg");
            }
            else
            {
                ReadWriteTexture2D<Bgra32, Float4> i1 = images[0];
                ReadWriteTexture2D<Bgra32, Float4> i2 = images[1];

                GraphicsDevice.GetDefault().For
                (
                    i1.Width,
                    i1.Height,
                    new Average(i1, i2)
                );

                i1.Save(name + ".jpg");
            }
        }

        [AutoConstructor]
        public readonly partial struct Brightest : IComputeShader
        {
            public readonly IReadWriteNormalizedTexture2D<float4> input1;
            public readonly IReadWriteNormalizedTexture2D<float4> input2;

            // Other captured resources or values here...

            public void Execute()
            {
                float3 i1 = input1[ThreadIds.XY].RGB;
                float3 i2 = input2[ThreadIds.XY].RGB;

                float i1Intensity = i1.X * i1.Y * i1.Z;
                float i2Intensity = i2.X * i2.Y * i2.Z;

                if (i1Intensity > i2Intensity)
                {
                    input1[ThreadIds.XY].RGB = i1;
                }
                else
                {
                    input1[ThreadIds.XY].RGB = i2;
                }
            }
        }

        [AutoConstructor]
        public readonly partial struct Average : IComputeShader
        {
            public readonly IReadWriteNormalizedTexture2D<float4> input1;
            public readonly IReadWriteNormalizedTexture2D<float4> input2;

            // Other captured resources or values here...

            public void Execute()
            {
                float3 i1 = input1[ThreadIds.XY].RGB;
                float3 i2 = input2[ThreadIds.XY].RGB;

                float3 o1 = 0;

                o1.X = (i1.X + i2.X) / 2;
                o1.Y = (i1.Y + i2.Y) / 2;
                o1.Z = (i1.Z + i2.Z) / 2;

                input1[ThreadIds.XY].RGB = o1;
            }
        }
    }
}