Draw a circle - code review January 24 2018

DrawACircle_codereviewJan24_2018.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace DrawACircle
{
    class DrawACircle
    {
        static void Main(string[] args)
        {
        }

        /*
        problem statement: 
        You have one help function:  Set(int x, int y) which turns on a pixel at (x,y). 
        The task at hand is to come up with an algorithm and code to draw a circle on screen. 
        You can use C/C++/C#/Java or similar languages.
        */

        /// <summary>
        /// code review on 1/24/2018 based on the code written in 2012. 
        /// https://github.com/jianminchen/AlgorithmsProblems/blob/master/DrawACircle.cs
        /// Highlights of review:
        /// 1. clean up the code, define extra explanation variables:
        /// 2. remove a break statement on line 99. 
        /// 
        /// 
        /// updated on Dec 2012 
        /// since we only can show pixel on the integer, then, we do not have many options,
        /// maximum number of points on the circle is 2 * radius,
        /// Go through X anxis first, from  -radius, -radius +1, …, 0, …, radius, see if 
        /// the y value is integer or not; 
        /// We can relax the algorithm, define a variable double errorRange, so we can make
        /// it more points on circle, but less good shape;  in the algorithm, set errorRange = 0, 
        /// but make the algorithm extendable
        /// 
        /// In terms of algorithm time complexity, it is O(2n); 
        /// But if we find too less points on the circle, then we have to design the algorithm 
        /// to find the best error range to simulate  the circle.
        /// 
        /// In the last, I will start from small error range to increment the range to find best fit 
        /// </summary>
        /// <param name="xCenter"></param>
        /// <param name="yCenter"></param>
        /// <param name="radius"></param>
        public static void DrawCircle(int xCenter, int yCenter, int radius)
        {            
            if (radius < 0) 
            {
                return;
            }

            if (radius == 0)
            {
                Set(xCenter, yCenter);
            }

            // Double errorRange = 0; 
            // We may change it based on percentage, 0.1 * radius for example
            Double errorRange = 0.1 * radius;
            int n = 2;
            int lookLikeCircle = 4 + 4 * n; // we may think about at 8 point will make it look like circle, 
                                            // we have at least 4 point on integer

            int countPoint = 0;
            int tryTimeMaximum = 1000;
            int countTry = 0;

            while(true)  
            {
                for (int row = 0; row < radius; row++)
                {
                    int x1 = xCenter - row;
                    int x2 = xCenter + row;

                    Double yValue = Math.Sqrt(radius * radius - row * row);

                    if (Math.Abs(yValue - Convert.ToInt16(yValue)) < errorRange)
                    {                        
                        countPoint = countPoint + 2;
                    }
                }

                if (countPoint < lookLikeCircle)
                {
                    errorRange = errorRange * 2;
                }
                else
                {
                    for (int row = 0; row < radius; row++)
                    {
                        int left_x  = xCenter - row;
                        int right_x = xCenter + row;

                        Double yValue = Math.Sqrt(radius * radius - row * row);

                        var offset    = Convert.ToInt16(yValue);

                        int top_y    = yCenter + offset;
                        int bottom_y = yCenter - offset; 
                        
                        if (Math.Abs(yValue - offset) < errorRange)
                        {
                            Set(left_x,  top_y);
                            Set(left_x,  bottom_y);
                            Set(right_x, top_y);
                            Set(right_x, bottom_y);                            
                        }                       
                    }

                    countTry++;
                    
                    if (countTry > tryTimeMaximum)
                    {
                        break;
                    }                  
                }
            }
        }

        public static int toInt(double x)
        {
            return Convert.ToInt16(x);
        }

        public static void Set(int x, int y)
        {
        }    
    }
}