Practical C Programming

How to do it...

The following are the steps for drawing a circle:

1. Initialize GLUT, define the size of a top-level window, and create it. Also, set the initial position of the window for displaying our circle.
2. Define a callback function that is auto-invoked after creating the window.
3. In the callback function, color buffers are cleared and the color for displaying the circle is set.
4. The statements for drawing a circle are grouped within a pair of glBegin and glEnd functions along with the GL_LINE_LOOP keyword.
5. Use a for loop to draw small lines from 0 to 360 to give the shape of a circle.

The program for drawing a circle is as follows:

//opengldrawshapes2.c#include <GL/glut.h> #include<math.h> #define pi 3.142857 void drawshapes() {  glClearColor(0.0f, ...