#include <stdio.h>
#include <graphics.h>
#include <math.h>
#include <dos.h>
#include <conio.h>

int driver=DETECT, mode, blad;
double ax, ay, X, Xmin=0, Xmax=20, Ymin=0, Ymax=20;
int r=30,kat,xx,yy;
struct arccoordstype arcinfo;

void rys_kolo(int x, int y, int kat) {
moveto(0,getmaxy());
xx=ax*(Xmax-Xmin);
yy=ay*(Ymax-0.75*Xmax);
lineto(xx,yy);
circle(x,y,r);
arc(x,y,0,kat,r);
getarccoords(&arcinfo);
line(arcinfo.xend,arcinfo.yend,x,y);
}  //koniec 'rys_kolo'

void main(void) {

initgraph(&driver,&mode,"d:\\programy\\borlandc\\bgi\\");
if ((blad=graphresult())!=grOk) {
printf(grapherrormsg(blad));
printf("\n\nWci˜nij dowolny klawisz...");
getch();
}
ax=(getmaxx()/(Xmax-Xmin));
ay=(getmaxy()/(Xmax-Xmin));
moveto(0,getmaxy());
xx=ax*(Xmax-Xmin);
yy=ay*(Ymax-0.75*Xmax);
lineto(xx,yy);
kat=0;
delay(2000);

float DX=0.008;
for (X=Xmax-1;X>=Xmin+1;X-=DX) {
DX+=0.0008;
kat+=(180/M_PI)*((DX*getmaxx())/(Xmax*r*cos(40*M_PI/180)));
cleardevice();
xx=ax*(X-Xmin);
yy=ay*(Ymax-((0.75*X)+1.45));
rys_kolo(xx,yy,kat);
delay(8);
}  //koniec for


getch();
closegraph();
}  //koniec main