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;
}
