计算机图形学——扫描圆

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要求：

利用中点Bresenham算法扫描转换圆心在原点, 半径为8的圆

#include <iostream>
#include "stdio.h"
#include <stdlib.h>
#include <cmath>
#include <gl/glut.h>
using namespace std;
void CirclePoint(int x,int y)
{

  glColor3f(0.0f,1.0f,0.0f);
     glPointSize(2.0f);
     glBegin(GL_POINTS);
     glVertex2i(x+80,y+80);glVertex2i(y+80,x+80);
     glVertex2i(-y+80,x+80); glVertex2i(-x+80,y+80);
     glVertex2i(-x+80,-y+80); glVertex2i(-y+80,-x+80);
     glVertex2i(y+80,-x+80); glVertex2i(x+80,-y+80);
     glEnd();
     glFlush();
}
void MidBresenhamCircle(int r)
{
 int x,y,d;
 x=0;y=r;d=1-r;
 while(x<=y){
      CirclePoint(x,y);
   if(d<0)d+=2*x+3;
   else{
   d+=2*(x-y)+5;
   y--;
   }
   x++;
 }
}

void Init(void)
{
 glClearColor(1.0f,1.0f,1.0f,0.0f);
 glMatrixMode(GL_PROJECTION);
 gluOrtho2D(0.0,200.0,0.0,150.0);
}

void Display(void)
{
 glClear(GL_COLOR_BUFFER_BIT);
    MidBresenhamCircle(8);
}
int main(int argc,char* argv[])
{
 glutInit(&argc,argv);
 glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
 glutInitWindowSize(400,300);
 glutInitWindowPosition(100,100);
 glutCreateWindow("Circle");
 Init();
 glutDisplayFunc(Display); 
 glutMainLoop();
 return 0;
}