Fan with Regulator

#include
#include
#include
#include
#include
#define pi 3.142857
#define ROUND(a) (int)(a+0.5)
void pie(int sa,int ea,int xc,int yc,int r)
{ double a1,a2;int x,y;
a1=(pi*sa)/180;
x=xc+r*cos(a1);
y=yc+r*sin(a1);
line(xc,yc,x,y);
a2=-(pi*ea)/180;
x=xc+r*cos(a2);
y=yc+r*sin(a2);
line(xc,yc,x,y);
}



void runfan(int d)
{ int i=0,sa=0,ea=1;

while(!kbhit())
{delay(d);
cleardevice();
circle(100,100,50);
line(90,150,90,250);
line(110,150,110,250);
line(40,250,40,300);
line(160,250,160,300);
line(40,300,160,300);
line(40,250,160, 250);
outtextxy(45,275,"0");
outtextxy(75,275,"1");
outtextxy(105,275,"2");
outtextxy(135,275,"3");

pie(sa,ea,100,100,50);
pie(sa+150,ea+150,100,100,50);
pie(sa+300,ea+300,100,100,50);

i++;
sa=sa-10;ea=ea+10;
}
}

void main()
{int d=0,cho;

int gd,gm;
detectgraph(&gd,&gm);
initgraph(&gd,&gm,"..\\bgi");
runfan(0);
do{

printf("\n enter speed of regulator");
scanf("%d",&d);
switch(d)
{case 0: runfan(d);
break;
case 1:
runfan(70);break;
case 2: runfan(50);break;
case 3: runfan(20);break;
}
printf("\n press 1 to continue");
scanf("%d",&cho);
}while(cho==1);


getch();
}