以下是Bresenham的直线生成算法和整圆生成算法，已调试过，没有任何问题。

Bresenham直线生成算法
#include "stdio.h"
#include "graphics.h"
Bresenham_line(x0,y0,x1,y1,color)
int x0,y0,x1,y1,color;
{
int x,y,dx,dy, i; float k,e;
dx=x1-x0;dy=y1-y0;
k=(dy*1.0)/dx; e=-0.5; x=x0; y=y0;
for (x=x0; x<=x1; x++)
{
putpixel(x,y,color);
e=e+k;
if(e>=0)
{ y++;e=e-1;}
}
}
int main()
{
int x0,y0,x1,y1,c;
int driver=DETECT,mode=0;
initgraph(&driver,&mode,"c:\\tc");
setbkcolor(BLUE);
setcolor(YELLOW);
printf("input x0,y0,x1,y1,c");
scanf("%d%d%d%d%d",&x0,&y0,&x1,&y1,&c);
Bresenham_line(x0,y0,x1,y1,c);
getch();
closegraph();
}
当取e=2*dy-dx时，可以消除浮点和除法运算
#include "stdio.h"
#include "graphics.h"
Bresenham_line(x0,y0,x1,y1,color)
int x0,y0,x1,y1,color;
{
int x,y,dx,dy, i,e; float k;
dx=x1-x0;dy=y1-y0;
k=(dy*1.0)/dx; e=2*dy-dx; x=x0; y=y0;
for (x=x0; x<=x1; x++)
{
putpixel(x,y,color);
e=e+2*dy;
if(e>=0)
{ y++;e=e-2*dx;}
}
}
int main()
{
int x0,y0,x1,y1,c;
int driver=DETECT,mode=0;
initgraph(&driver,&mode,"c:\\tc");
setbkcolor(BLUE);
setcolor(YELLOW);
printf("input x0,y0,x1,y1,c");
scanf("%d%d%d%d%d",&x0,&y0,&x1,&y1,&c);
Bresenham_line(x0,y0,x1,y1,c);
getch();
closegraph();
}
Bresenham整圆生成算法
#include "stdio.h"
#include "graphics.h"
void circlePoints(int x0,int y0,int x,int y,int color) {
putpixel(x+x0,y+y0,color);
putpixel(x+x0,-y+y0,color);
putpixel(y+x0,x+y0,color);
putpixel(y+x0,-x+y0,color);
putpixel(-x+x0,-y+y0,color);
putpixel(-x+x0,y+y0,color);
putpixel(-y+x0,-x+y0,color);
putpixel(-y+x0,x+y0,color);
}
Bresenhamcircle (int x0,int y0,int r)
{
int x,y,d,color=15;
d=3-2*r;
x=0;y=r; /*从(0，r)开始画圆*/?
circlePoints(x0,y0,x,y,color);
while(x<y)
{
if(d<0){d=d+4*x+6;x++;}
else{d= d+4*(x-y)+10;x++;y--;}
circlePoints(x0,y0,x,y,color);
}
}
main()
{
int r,x0,y0;
int driver=DETECT,mode=0;
initgraph(&driver,&mode,"c:\\tc");
setbkcolor(BLUE);
setcolor(YELLOW);
printf("input x0,y0,r\n");
scanf("%d%d%d",&x0,&y0,&r);
Bresenhamcircle(x0,y0,r);
getch();
closegraph();
}。