Click here to Skip to main content
15,921,837 members
Please Sign up or sign in to vote.
4.33/5 (2 votes)
See more:
Hello, Thank you for read my question. I'm appreciated with your concern.

I'm trying to drawing a text based circle without drawing header file or external class.
but include only "math.h" or any equivalent header/class like has "pi" value or "cosine/sine" function stuffs.

My goal is make a text based circle like next.


I need a circle curve equation code for C based programming language.
I tried to make a curve with using **"y=Cos(pi*x)"** but unfortunately it's not a plane circle curve.

Hence I'd like to know the circle curve equation example code in C based programming language.

Thank you!

try playing with : X*X + Y*Y = const
which is the simple circle equation; naturally for any 0 < X < sqrt(const) you'll have 2 Y solutions, positive and negative, which is what you want
Share this answer
What you probably mean is a parameterized circle equation: Let variable t run from 0 to 2*PI in small increments and then calculate:
double x, y;
x = cos (t) * r;
y = sin (t) * r;

This will give you a set of coordinated for a circle around the origin with radius r.

If you want to print the circle in the way you showed in your question then consider that the space taken up by each print character is different in x and y direction. Hence you have to compensate this by applying a correction factor in the x or y calculation. Otherwise the circle will appear as an ellipse on your chart.
Share this answer
Maciej Los 5-Aug-13 15:35pm    
nv3 5-Aug-13 18:24pm    
Thank you!
If i understand you well, you need to create 2 dimension array of chars (filled with 0 - zero), then to replace some chars with other (1 - one) to imitate a circle... The size of array should be calculated based on r (radius).

Have a look here:[^], here:[^] and here:[^]

Simple replace SetPixel/DrawPixel function with your own to replace char in a 2D-array of chars ;)
Share this answer
CPallini 5-Aug-13 9:36am    
Maciej Los 5-Aug-13 15:34pm    
Thank you, Carlo ;)
class Program
   const int N = 20;
   static void Main()
     char [, ] circle = new char[2*N+1, 2*N+1];
     double phi, dphi = 0.5 / N;

     phi = 0.0;

     for (int y = 0; y < 2*N+1; y++)
       for (int x = 0; x < 2*N+1; x++)
         circle[y, x] = '0';

     while (phi <= 2*Math.PI)
       int x = (int) Math.Round( N + N * Math.Cos(phi));
       int y = (int)Math.Round(N + N * Math.Sin(phi));
       circle[y, x] = '1';
       phi += dphi;

     for (int y = 0; y < 2*N+1; y++)
       for (int x = 0; x < 2*N+1; x++)
         Console.Write(circle[y, x]);
Share this answer
Maciej Los 5-Aug-13 8:20am    
Good job, Carlo!
This is what i was trying to explain in few word ;)
CPallini 5-Aug-13 9:36am    
Thank you, I followed your recipe. :-)
Maciej Los 5-Aug-13 15:34pm    
Naz_Firdouse 5-Aug-13 9:05am    
CPallini 5-Aug-13 9:36am    
Thank you.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

CodeProject, 20 Bay Street, 11th Floor Toronto, Ontario, Canada M5J 2N8 +1 (416) 849-8900