pie

{$loadlib pumbaa.dll}

var
  s: TStringArray;

procedure TPAControlPie(var TPA: TPointArray; kind: TControlKind; center: TPoint; RMin, RMax, AStart, AEnd: Extended);
var
  h, i, t: Integer;
  a, r: Extended;
begin
  h := High(TPA);
  t := 0;
  case kind of
    ckFilter:
    for i := 0 to h do
    begin
      r := Sqrt((TPA[i].X * TPA[i].X) + (TPA[i].Y * TPA[i].Y));
      if ((r < RMin) or (r > RMax)) then
      begin
        a := ArcTan2((TPA[i].Y - center.Y), (TPA[i].X - center.X));
        if ((a >= AStart) or (a <= AEnd)) then
        begin
          TPA[t] := TPA[i];
          t := (t + 1);
        end;
      end;
    end;
    ckExtract:
    for i := 0 to h do
    begin
      r := Sqrt((TPA[i].X * TPA[i].X) + (TPA[i].Y * TPA[i].Y));
      if ((r >= RMin) and (r <= RMax)) then
      begin
        a := ArcTan2((TPA[i].Y - center.Y), (TPA[i].X - center.X));
        if ((a >= AStart) and (a <= AEnd)) then
        begin
          TPA[t] := TPA[i];
          t := (t + 1);
        end;
      end;
    end;
  end;
  SetLength(TPA, t);
end;

var
  TPA: TPointArray;

begin
  TPA := [Point(0, 0), Point(2, 2), Point(2, 3), Point(5, 10)];
  TPAControlPie(TPA, ckExtract, Point(0, 0), 2.5, 3, Pi / 8, 7 * Pi / 8);
  WriteLn(pp_ToStr(TPA));
end.