Нарисовать силовые линии электрического поля

uses graphABC;
var x1,x2,yc,x3,y3,x4,y4,x5,y5,x6,y6,x7,y7,r1,r2,r3,r4,i:integer;
    u,du:real;
begin
setwindowsize(400,400);
centerwindow;
yc:=200;
x1:=100;
x2:=300;
setpencolor(clSkyBlue);
setbrushcolor(clSkyBlue);
circle(x1,yc,15);
circle(x2,yc,15);
r1:=20;
r2:=70;
r3:=50;
r4:=60;
setpencolor(clBlack);
u:=0;
du:=pi/4;
for i:=1 to 8 do
 begin
  x3:=x1+round(r1*cos(u));
  y3:=yc-round(r1*sin(u));
  x4:=x1+round(r2*cos(u));
  y4:=yc-round(r2*sin(u));
  x5:=x1+round(r4*cos(u));
  y5:=yc-round(r4*sin(u));
  x6:=x1+round(r3*cos(u-pi/70));
  y6:=yc-round(r3*sin(u-pi/70));
  x7:=x1+round(r3*cos(u+pi/70));
  y7:=yc-round(r3*sin(u+pi/70));
  line(x3,y3,x4,y4);
  line(x5,y5,x6,y6);
  line(x5,y5,x7,y7);
  line(x6,y6,x7,y7);
  u:=u+du;
 end;
u:=0;
for i:=1 to 8 do
 begin
  x3:=x2+round(r1*cos(u));
  y3:=yc-round(r1*sin(u));
  x4:=x2+round(r2*cos(u));
  y4:=yc-round(r2*sin(u));
  line(x3,y3,x4,y4);
  x5:=x2+round(r3*cos(u));
  y5:=yc-round(r3*sin(u));
  x6:=x2+round(r4*cos(u-pi/80));
  y6:=yc-round(r4*sin(u-pi/80));
  x7:=x2+round(r4*cos(u+pi/80));
  y7:=yc-round(r4*sin(u+pi/80));
  line(x3,y3,x4,y4);
  line(x5,y5,x6,y6);
  line(x5,y5,x7,y7);
  line(x6,y6,x7,y7);
  u:=u+du;
 end;
setfontsize(12);
setfontstyle(fsBold);
textout(x1-4,yc-10,'+');
textout(x2-3,yc-10,'-');
end.