How to know whether the font is TrueTypeFont or not

function IsTrueTypeFont(FontName : string):boolean;
const
  PITCH_MASK: byte = $0F;
var
  TxMet: TTextMetric;
  TempCanvas : TCanvas;
  PitchTest : byte;
begin
  TempCanvas:=TCanvas.Create;
  TempCanvas.Handle:=CreateCompatibleDC(0) ;
  TempCanvas.Font.Name:=FontName;
  GetTextMetrics(TempCanvas.Handle, TxMet) ;
  PitchTest:=TxMet.tmPitchAndFamily and PITCH_MASK;
  Result:=(PitchTest and TMPF_TRUETYPE) <> 0;
  TempCanvas.free;
end;