Сортировка при удалении невидимых частей - C#

// построчное сканирование с использованием z-буфера
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Threading;
 
namespace lab2
{
    public partial class main : Form
    {
        public Graphics Grafica;
        public Figure[] Figure;
        public Color[] RGB;
        public Random Random;
        public int Count;
 
        public double ZBuffer;
        public Color FrameBuffer;
 
        public main()
        {
            InitializeComponent();
 
            Grafica = this.CreateGraphics();
            Random = new Random(unchecked((int)DateTime.Now.Ticks));
            Count = Random.Next(3, 10);
            Figure = new Figure[Count];
            RGB = new Color[10];
            RGB[0] = Color.Aqua;
            RGB[1] = Color.Red;
            RGB[2] = Color.Orange;
            RGB[3] = Color.Yellow;
            RGB[4] = Color.Green;
            RGB[5] = Color.BlueViolet;
            RGB[6] = Color.CornflowerBlue;
            RGB[7] = Color.Chocolate;
            RGB[8] = Color.LemonChiffon;
            RGB[9] = Color.PeachPuff;
            
        }
 
        private void button1_Click(object sender, EventArgs e)
        {
            //Генерация полигонов
            Grafica.Clear(this.BackColor);
            for (int i = 0; i < Count; i++)
            {
                Figure[i] = new Figure();
                Figure[i].count_vertex = 3;
                Figure[i].Point = new Point3D[Figure[i].count_vertex];
                Figure[i].color = RGB[i];
                //Генерация точек полигона
                for (int j = 0; j < 3; j++)
                {
                    Figure[i].Point[j] = new Point3D();
                    Figure[i].Point[j].x = Random.Next(-150, 150);
                    Figure[i].Point[j].y = Random.Next(-150, 150);
                    Figure[i].Point[j].z = Random.Next(-500, 500);
                }
                //Определение коэффициентов уравнения плоскости по методу Ньюэла
                Figure[i].A = Figure[i].Point[0].y * (Figure[i].Point[1].z - Figure[i].Point[2].z) + Figure[i].Point[1].y * (Figure[i].Point[2].z - Figure[i].Point[0].z) + Figure[i].Point[2].y * (Figure[i].Point[0].z - Figure[i].Point[1].z);
                Figure[i].B = Figure[i].Point[0].z * (Figure[i].Point[1].x - Figure[i].Point[2].x) + Figure[i].Point[1].z * (Figure[i].Point[2].x - Figure[i].Point[0].x) + Figure[i].Point[2].z * (Figure[i].Point[0].x - Figure[i].Point[1].x);
                Figure[i].C = Figure[i].Point[0].x * (Figure[i].Point[1].y - Figure[i].Point[2].y) + Figure[i].Point[1].x * (Figure[i].Point[2].y - Figure[i].Point[0].y) + Figure[i].Point[2].x * (Figure[i].Point[0].y - Figure[i].Point[1].y);
                Figure[i].D = -(Figure[i].Point[0].x * (Figure[i].Point[1].y * Figure[i].Point[2].z - Figure[i].Point[2].y * Figure[i].Point[1].z) + Figure[i].Point[1].x * (Figure[i].Point[2].y * Figure[i].Point[0].z - Figure[i].Point[0].y * Figure[i].Point[2].z) + Figure[i].Point[2].x * (Figure[i].Point[0].y * Figure[i].Point[1].z - Figure[i].Point[1].y * Figure[i].Point[0].z));
                Figure[i].Sort();
            }
            //Отрисовка полигонов
            float cx = this.Width / 2, cy = this.Height / 2;
            for (int i = 0; i < Count; i++)
            {
                Pen pen = new Pen(Figure[i].color, 2);
                Grafica.DrawLine(pen, (float)Figure[i].Point[0].x + cx, (float)Figure[i].Point[0].y + cy, (float)Figure[i].Point[1].x + cx, (float)Figure[i].Point[1].y + cy);
                Grafica.DrawLine(pen, (float)Figure[i].Point[0].x + cx, (float)Figure[i].Point[0].y + cy, (float)Figure[i].Point[2].x + cx, (float)Figure[i].Point[2].y + cy);
                Grafica.DrawLine(pen, (float)Figure[i].Point[2].x + cx, (float)Figure[i].Point[2].y + cy, (float)Figure[i].Point[1].x + cx, (float)Figure[i].Point[1].y + cy);
            }
        }
 
        private void button2_Click(object sender, EventArgs e)
        {
            int m1;
            float cx = this.Width / 2, cy = this.Height / 2;
            for (int y = -150; y < 150; y++)
            {
                for (int x = -150; x < 150; x++)
                {
                    FrameBuffer = Color.Black;
                    ZBuffer = -100500000000;
                    for (int i = 0; i < Count; i++)
                    {
                        if (x >= (y - Figure[i].b1) / Figure[i].k1)
                        {
                            if ((Figure[i].znak2 == true && y < Figure[i].k2 * x + Figure[i].b2) || (Figure[i].znak2 == false && y > Figure[i].k2 * x + Figure[i].b2))
                            {
                               if ((Figure[i].znak3 == true && y < Figure[i].k3 * x + Figure[i].b3) || (Figure[i].znak3 == false && y > Figure[i].k3 * x + Figure[i].b3))
                                {
                                    //вычисляем глубину каждого пиксела. по уравнению плоскости
                                    int z = (int)((-Figure[i].D - Figure[i].A * x - Figure[i].B * y) / Figure[i].C);
                                    if (ZBuffer < z)
                                    {
                                        ZBuffer = z;
                                        FrameBuffer = Figure[i].color;
                                    }
                               }
                            }
                        }
                    }
                    Pen pen = new Pen(FrameBuffer, 2);
                    Grafica.DrawEllipse(pen, x + cx, y + cy, 1, 1);
                    Grafica.DrawRectangle(pen, x + cx, 160 + cy, 1, 10);
                }
            }
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
 
namespace lab2
{
    //Точка в пространсве
    public class Point3D
    {
        public double x, y, z;
    }

    public class Figure
    {
        public int count_vertex;   //число вершин
        public Color color; //цвет
        public Point3D[] Point = new Point3D[3];//массив вершин
        public double A, B, C, D;
        public double k1, b1, k2, b2, k3, b3;
        public bool znak2,znak3;

        public void Sort()
        {
            Point3D MaxPoint = this.Point[0], MinPoint = Point[0];
            int MaxIndex = 0, MinIndex = 0;
            for (int i = 1; i < 3; i++)
            {
                if (Point[i].y > MaxPoint.y)
                {
                    MaxPoint = Point[i];
                    MaxIndex = i;
                }
 
                if (Point[i].y < MinPoint.y)
                {
                    MinPoint = Point[i];
                    MinIndex = i;
                }
            }
            int MidIndex = 3 - MaxIndex - MinIndex;
            Point3D MidPoint = Point[MidIndex];
 
            double k = (MaxPoint.y - MinPoint.y) / (MaxPoint.x - MinPoint.x); //угловой коэффициент
            double b = MaxPoint.y - k * MaxPoint.x; //свободный член
            double tx_sr = (MidPoint.y - b) / k;
 
            if (tx_sr > MidPoint.x)
            {
                Point[0] = MaxPoint;
                Point[1] = MidPoint;
                Point[2] = MinPoint;
            }
            else
            {
                Point[0] = MaxPoint;
                Point[1] = MinPoint;
                Point[2] = MidPoint;
            }
 
            k1 = (Point[0].y - Point[1].y) / (Point[0].x - Point[1].x);
            b1 = Point[1].y - k1*Point[1].x;
            k2 = (Point[0].y - Point[2].y) / (Point[0].x - Point[2].x);
            b2 = Point[0].y - k2*Point[0].x;
            k3 = (Point[1].y - Point[2].y) / (Point[1].x - Point[2].x);
            b3 = Point[1].y - k3 * Point[1].x;
            if (Point[1].y < k2 * Point[1].x + b2) znak2 = true; else znak2 = false;
            if (Point[0].y < k3 * Point[0].x + b3) znak3 = true; else znak3 = false;
 
        }
    }
}