Как убрать рыбий глаз в RayCast

У меня код C#. Сделана система левый край -1 правый 1 верх -1 низ 1. Вот код

using System;
namespace RayCast2D
{
    partial class Render
    {
        static public Vector cameraPoint = new Vector(0, 0);
        static public double cameraR = 0;
        public const int lines = 100;
        static public void Render3D()
        {
            for(double x = -lines;x < lines;x++)
            {
                for(double z = 0.1;z < 8;z += 0.025)
                {
                    double angle = cameraR + x * 48 / lines;
                    Vector vector = new Vector(cameraPoint.x + MathApp.Sin(angle) * z, cameraPoint.y + MathApp.Cos(angle) * z);
                    ColorRGB color = Game.ObjRender(vector, z);
                    if(((int)(vector.x * 2) + (int)(vector.y * 2)) % 2 == 0)
                    {
                        Rect(x / lines * 2, 1 / z, 2.0 / lines, 0.1 / Math.Pow(z, 2), (int)(255 / Math.Max(z, 1)), 0, 0);
                    }
                    if(color.r != -1)
                    {
                        Rect(x / lines * 2, 0, 2.0 / lines, 2 / z, (byte)(color.r * 255), (byte)(color.g * 255), (byte)(color.b * 255));
                        z = double.MaxValue;
                    }
                }
            }
        }
    }
}

using System;
namespace RayCast2D
{
    struct Vector
    {
        public double x, y;
        public Vector(double _x, double _y)
        {
            x = _x;
            y = _y;
        }
        public bool HitBox(in Vector a, in Vector b)
        {
            if(x > Math.Min(a.x, b.x) && x < Math.Max(a.x, b.x))
                if(y > Math.Min(a.y, b.y) && y < Math.Max(a.y, b.y))
                    return true;
            return false;
        }
    }
    struct ColorRGB
    {
        public double r, g, b;
        public ColorRGB(double _r, double _g, double _b)
        {
            r = _r;
            g = _g;
            b = _b;
        }
        public ColorRGB(double _r, double _g, double _b, double z)
        {
            r = _r / z;
            g = _g / z;
            b = _b / z;
        }
    }
    class MathApp
    {
        static public double Sin(double a)
        {
            return Math.Sin(a * Math.PI / 180);
        }
        static public double Cos(double a)
        {
            return Math.Cos(a * Math.PI / 180);
        }
        static public double Dist(double x, double y, double x2, double y2)
        {
            return Math.Sqrt(Math.Pow(x2 - x, 2) + Math.Pow(y2 - y, 2));
        }
    }
}

using System;
namespace RayCast2D
{
    class Game
    {
        static public void Draw()
        {
            Render.Render3D();
        }
        static public ColorRGB ObjRender(Vector vector, double z)
        {
            if(vector.HitBox(new Vector(-5, -5), new Vector(5, -4)))
                return new ColorRGB(1, 1, 1, z);
            return new ColorRGB(-1, -1, -1);
        }
    }
}

Помогите пожалуйста как решить проблему.