Зачем тут Round и Integer?

[Alex Lulin]

• function TmsCircle.ContainsPt(const aPoint: TPointF): Boolean;
• var
• l_StartRectPoint, l_FinishRectPoint : TPointF;
• l_x0, l_y0, l_a, l_b : Integer;
• l_Rect : TRectF;
• begin
• l_Rect := DrawBounds;
• Result := l_Rect.Contains(aPoint);
• l_StartRectPoint := l_Rect.TopLeft;
• l_FinishRectPoint := l_Rect.BottomRight;
• l_x0 := Round(l_StartRectPoint.X + l_FinishRectPoint.X) div 2;
• l_y0 := Round(l_StartRectPoint.Y + l_FinishRectPoint.Y) div 2;
• l_a := Round(l_FinishRectPoint.X - l_StartRectPoint.X) div 2;
• l_b := Round(l_FinishRectPoint.Y - l_StartRectPoint.Y) div 2;
• Result := Sqr((aPoint.X - l_x0)/l_a)+
• Sqr((aPoint.Y - l_y0)/l_b) <= 1.0;
• end;

[Ihor Bielykh]

формула расчета такая