ManipulateStampXYZ.cs

using System;
using System.Drawing;
using System.IO;

namespace XYZmanipulator
{
    class Program
    {
        static void Main()
        {
            using StreamWriter sw = new(@"C:\Users\delta\Desktop\scanFormat2.txt");
            string line;
            int idx = 0;
            float radius = 25;
            PointF center = new(42, 50);
            RectangleF rectangleOuter = new(32, 40, 20, 20);
            RectangleF rectangleInner = new(36, 44, 12, 12);
            StreamReader file = new(@"C:\Users\delta\Desktop\scan.txt");
            while ((line = file.ReadLine()) != null)
            {
                idx++;
                string[] vs = line.Split('\t');
                float X = float.Parse(vs[0]);
                float Y = float.Parse(vs[1]);
                float Z = float.Parse(vs[2]);
                string lineF = string.Format("{0}\t{1}\t{2}",
                    Math.Round(X,2),
                    Math.Round(Y,2),
                    Math.Round(Z-7,2));
                PointF pointF = new(X, Y);
                double distance = Math.Sqrt(Math.Pow(X - center.X, 2) + Math.Pow(Y - center.Y, 2));
                if (idx % 25 == 0)
                {
                    if (distance > radius)
                        sw.WriteLine(lineF);
                    else if (rectangleOuter.Contains(pointF) && !rectangleInner.Contains(pointF))
                        sw.WriteLine(lineF);
                }
                else if (idx % 500 == 0)
                    sw.WriteLine(lineF);
            }
            file.Close();
        }
    }
}