Точки пересечения вертикальной прямой с прямоугольником

if (((tchk1.y <= rect1.y) and (tchk1.y >= rect2.y) and
        (tchk2.y >= rect2.y) and (tchk2.y <= rect1.y)) or
    ((tchk1.y >= rect1.y) and (tchk1.y <= rect2.y) and
        (tchk2.y <= rect2.y) and (tchk2.y >= rect1.y))) then
    begin
      cross1.y := tchk1.y;
      cross1.x := tchk1.x;
      cross2.y := tchk2.y;
      cross2.x := tchk2.x;
      cross1.existance := true;
      cross2.existance := true;
    end;

    if ((tchk1.y <= rect1.y) and (tchk1.y >= rect2.y) and
        (tchk2.y <= rect2.y)) or ((tchk1.y >= rect1.y) and
        (tchk1.y <= rect2.y) and (tchk2.y >= rect2.y)) then
    begin
      cross1.y := rect2.y;
      cross1.x := rect2.x;
      cross2.y := tchk1.y;
      cross2.x := tchk1.x;
      cross1.existance := true;
      cross2.existance := true;
    end;

    if ((tchk2.y <= rect1.y) and (tchk2.y >= rect2.y) and
        (tchk1.y >= rect1.y)) or ((tchk2.y >= rect1.y) and
        (tchk2.y <= rect2.y) and (tchk1.y <= rect1.y)) then
    begin
      cross1.y := tchk2.y;
      cross1.x := tchk2.x;
      cross2.y := rect1.y;
      cross2.x := rect1.x;
      cross1.existance := true;
      cross2.existance := true;
    end;

    if ((tchk2.y >= rect1.y) and (tchk2.y <= rect2.y) and
        (tchk1.y >= rect2.y)) or ((tchk2.y <= rect1.y) and
        (tchk2.y >= rect2.y) and (tchk1.y <= rect2.y)) then
    begin
      cross1.y := rect2.y;
      cross1.x := rect2.x;
      cross2.y := tchk2.y;
      cross2.x := tchk2.x;
      cross1.existance := true;
      cross2.existance := true;
    end;

    if ((tchk1.y <= rect1.y) and (tchk1.y >= rect2.y) and
        (tchk2.y >= rect1.y)) or ((tchk1.y >= rect1.y) and
        (tchk1.y <= rect2.y) and (tchk2.y <= rect1.y)) then
    begin
      cross1.y := rect1.y;
      cross1.x := rect1.x;
      cross2.y := tchk1.y;
      cross2.x := tchk1.x;
      cross1.existance := true;
      cross2.existance := true;
    end;

    if ((tchk1.y >= rect1.y) and (tchk2.y <= rect2.y) and (rect1.y > rect2.y))
      or ((tchk1.y >= rect2.y) and (tchk2.y <= rect1.y) and (rect1.y < rect2.y))
      or ((tchk1.y <= rect2.y) and (tchk2.y >= rect1.y) and (rect1.y > rect2.y))
      or ((tchk1.y <= rect1.y) and (tchk2.y >= rect2.y) and (rect1.y < rect2.y))
    then
    begin
      cross1.y := rect1.y;
      cross1.x := rect1.x;
      cross2.y := rect2.y;
      cross2.x := rect2.x;
      cross1.existance := true;
      cross2.existance := true;