Midpoint-Circle-Drawing-Algorithm.cpp

/*
    Md. Abdul Mutalib
    B.Sc (Engg.) in CSE
    North East University Bangladesh
    Connect with me:
    Github: https://github.com/mamutalib
*/




#include <stdio.h>
#include <GL/gl.h>
#include <GL/glut.h>

#define ll long long
#define ull unsigned long long
#define ld long double
#define nl '\n'
#define fn for(int i = 0; i<n; i++)
#define ft for(int i = 0; i<t; i++)
#define wt while(t--)
#define wn while(n--)
#define fs first
#define f first
#define s second
#define pf printf
#define sc scanf

float x=0,y,x2,y2,m,i,j,p;
int dx=0,dy=0,r;


void display(void) {
    glClear (GL_COLOR_BUFFER_BIT);
    glEnd();

    glColor3f (0.0, 1.0, 0.0);
    glBegin(GL_POINTS);
    p=1-r;
    while((x<=y)){
        if(p<0){
          x=x+1;
          y=y;
            printf("%0.2f %0.2f\n",x,y);
            p=p+(2*x)+1;
            }


            else{
            x=x+1;
            y=y-1;
            printf("%0.2f %0.2f\n",x,y);
            p=p+(2*x)+1-(2*y);
            }
            glVertex3f (((x/100)), ((y/100)), 0.0);
            glVertex3f (((y/100)), ((x/100)), 0.0);
            glVertex3f ((-(x/100)), (-(y/100)), 0.0);
            glVertex3f ((-(x/100)), ((y/100)), 0.0);
            glVertex3f (((x/100)), (-(y/100)), 0.0);
            glVertex3f (((y/100)), (-(x/100)), 0.0);
            glVertex3f ((-(y/100)), (-(x/100)), 0.0);
            glVertex3f ((-(y/100)), ((x/100)), 0.0);
        }
    glEnd();

    glFlush ();
}

void init (void) {
    glClearColor (0.0, 0.0, 0.0, 0.0);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
}

int main(int argc, char** argv){

    printf("Enter radius: ");
    scanf("%d",&r);
    y=r;


    glutInit(&argc, argv);
    glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
    glutInitWindowSize (500, 500);
    glutInitWindowPosition (100, 100);
    glutCreateWindow ("Midpoint Circle Drawing Algorithm");
    init ();
    glutDisplayFunc(display);
    glutMainLoop();
    return 0;
}