Bresenham画圆算法

R (xc,yc)

X (0,0)

要求：1. 圆心的坐标、半径和圆周颜色都要求可以随机输入；

#include\"graphics.h\" #include\"stdio.h\"

void cc(int radius,int centerx,int centery,int color) {

int x=0; int y=radius;

int delta = 2*(1-radius); int direction; while(y>=0){

putpixel(centerx+x,centery+y,3); putpixel(centerx-x,centery+y,3); putpixel(centerx+x,centery-y,3); putpixel(centerx-x,centery-y,3); if(delta<0){

if(2*(delta+y)-1<0){ direction = 1; } else{

direction = 2; } }

else if(delta > 0){

if(2*(delta+y)-1<=0){ direction = 2;

} else{

direction = 3; } } else{

direction = 2; }

switch(direction ){ case 1: x++;

delta += (2*x+1); break; case 2: x++; y--;

delta += 2*(x-y+1); break; case 3: y--;

delta += (-2*y+1); break; }

} }

main() {

int i,gdriver,gmode; gdriver=DETECT;

initgraph(&gdriver,&gmode,\"\"); cc(80,100,100,4); getch(); closegraph(); }