//Kaynak : UDDF - Unoffical Delphi Developers FAQ
{
A High Resolution timer for Most Win95 Systems
From: John_Mertus@brown.edu (John_Mertus)
File Name: HRTimer.PAS V1.00
Created: Apr 17 1997, 06:40 on the ThinkPAd by John Mertus
Revision #6: Oct 12 1997, 10:56 on the Gateway by John Mertus
Var
HRT : THRTimer
HRT := THRTimer.Create;
HRT.StartTimer; Resets the timer to zero
HRT.ReadTimer; Returns the elapsed time in milliseconds
since the time start
HRT.Free;
Edit history
Version 1.00 Initial release
}
{------------------Unit HRTimer---------------------John Mertus April 97---}
Unit HRTimer;
{--------------------Interface-------------------------------}
interface
Uses Windows;
Type
THRTimer = Class(TObject)
Constructor Create;
Function StartTimer : Boolean;
Function ReadTimer : Double;
private
StartTime : Double;
ClockRate : Double;
public
Exists : Boolean;
End;
{------------------------Implementation---------------------------------}
implementation
{------------------Create-------------------------John Mertus----Mar 97-}
Constructor THRTimer.Create;
{ This reads the windows HR time and stores it for later use. }
{ }
{*************************************************************************}
Var
QW : TLargeInteger;
BEGIN
Inherited Create;
Exists := QueryPerformanceFrequency(QW);
ClockRate := QW.QuadPart;
END;
{------------------StartTimer---------------------John Mertus----Mar 97-}
Function THRTimer.StartTimer : Boolean;
{ This reads the windows HR time and stores it for later use. }
{ }
{*************************************************************************}
Var
QW : TLargeInteger;
BEGIN
Result := QueryPerformanceCounter(QW);
StartTime := QW.QuadPart;
END;
{-------------------ReadTimer---------------------John Mertus----Mar 97---}
Function THRTimer.ReadTimer : Double;
{ This reads the windows HR time and stores it for later use. }
{ }
{*************************************************************************}
Var
ET : TLargeInteger;
BEGIN
QueryPerformanceCounter(ET);
Result := 1000.0*(ET.QuadPart - StartTime)/ClockRate;
END;
end.