Bresenham's Line and Circle Algorithms - source code

Bresenham's Line and Circle Algorithms

This code implements Bresenham algorithm for drawing cricle.This technique can be appied to draw anything (not only circle). I use mingw32 and openGL library.

كود:

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#include <windows.h>
#include <GL/glut.h>
#include <stdio.h>
#include <math.h>

void init(void){
    glClearColor(1.0,1.0,0.0,0.0);
    glMatrixMode(GL_PROJECTION);
    gluOrtho2D(0.0,200.0,0.0,150.0);
}
void setPixel(GLint x,GLint y)
{
    glBegin(GL_POINTS);
        glVertex2i(x,y);
    glEnd();
}
void Circle(){
       
        int xCenter=100,yCenter=100,r=50;
        int x=0,y=r;
        int d=3-(2*r);
        glClear(GL_COLOR_BUFFER_BIT);
    glColor3f(1,0,0.5); 
    while(x<=y){

                setPixel(xCenter+x,yCenter+y);
                setPixel(xCenter+y,yCenter+x);
                setPixel(xCenter-x,yCenter+y);
                setPixel(xCenter+y,yCenter-x);
                setPixel(xCenter-x,yCenter-y);
                setPixel(xCenter-y,yCenter-x);
                setPixel(xCenter+x,yCenter-y);
                setPixel(xCenter-y,yCenter+x);

                if (d<0)
                        d += (4*x)+6;
                else
                {
                        d += (4*(x-y))+10;
                        y -= 1;
                }
                x++;

        }

        glFlush();

}

int main(int argc,char **argv){
    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);
    glutInitWindowPosition(0,0);
    glutInitWindowSize(500,500);
    glutCreateWindow("Bresenham Circle");
    init();
    glutDisplayFunc(Circle);
    glutMainLoop();
    return 0;
}

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