www.pudn.com > IntroductionTo3DGameEngineDesign.rar > DXUtil.cs
//-----------------------------------------------------------------------------
// File: DXUtil.cs
//
// Desc: Shortcut macros and functions for using DX objects
//
// Copyright (c) 2001-2002 Microsoft Corporation. All rights reserved
//-----------------------------------------------------------------------------
using System;
using System.IO;
using System.Runtime.InteropServices;
public enum TIMER
{
RESET,
START,
STOP,
ADVANCE,
GETABSOLUTETIME,
GETAPPTIME,
GETELAPSEDTIME
};
public class DXUtil
{
#region Timer Internal Stuff
[System.Security.SuppressUnmanagedCodeSecurity] // We won't use this maliciously
[DllImport("kernel32")]
private static extern bool QueryPerformanceFrequency(ref long PerformanceFrequency);
[System.Security.SuppressUnmanagedCodeSecurity] // We won't use this maliciously
[DllImport("kernel32")]
private static extern bool QueryPerformanceCounter(ref long PerformanceCount);
[System.Security.SuppressUnmanagedCodeSecurity] // We won't use this maliciously
[DllImport("winmm.dll")]
public static extern int timeGetTime();
private static bool m_bTimerInitialized = false;
private static bool m_bUsingQPF = false;
private static bool m_bTimerStopped = true;
private static long m_llQPFTicksPerSec = 0;
private static long m_llStopTime = 0;
private static long m_llLastElapsedTime = 0;
private static long m_llBaseTime = 0;
private static double m_fLastElapsedTime = 0.0;
private static double m_fBaseTime = 0.0;
private static double m_fStopTime = 0.0;
#endregion
// Constants for SDK Path registry keys
private const string g_sSDKPath = "Software\\Microsoft\\DirectX SDK";
private const string g_sSDKKey = "DX9SDK Samples Path";
private DXUtil() { /* Private Constructor */ }
//-----------------------------------------------------------------------------
// Name: DXUtil.GetDXSDKMediaPath()
// Desc: Returns the DirectX SDK media path
//-----------------------------------------------------------------------------
public static string GetDXSDKMediaPath()
{
Microsoft.Win32.RegistryKey rKey = Microsoft.Win32.Registry.LocalMachine.OpenSubKey(g_sSDKPath);
string sReg = null;
if (rKey != null)
{
sReg = (string)rKey.GetValue(g_sSDKKey);
rKey.Close();
}
if (sReg != null)
sReg += @"\Media\";
else
return null;
return sReg;
}
//-----------------------------------------------------------------------------
// Name: DXUtil.Timer()
// Desc: Performs timer opertations. Use the following commands:
// TIMER.RESET - to reset the timer
// TIMER.START - to start the timer
// TIMER.STOP - to stop (or pause) the timer
// TIMER.ADVANCE - to advance the timer by 0.001 seconds
// TIMER.GETABSOLUTETIME - to get the absolute system time
// TIMER.GETAPPTIME - to get the current time
// TIMER.GETELAPSEDTIME - to get the time that elapsed between
// TIMER_GETELAPSEDTIME calls
//-----------------------------------------------------------------------------
public static float Timer(TIMER command)
{
if( !m_bTimerInitialized )
{
m_bTimerInitialized = true;
// Use QueryPerformanceFrequency() to get frequency of timer. If QPF is
// not supported, we will timeGetTime() which returns milliseconds.
long qwTicksPerSec = 0;
m_bUsingQPF = QueryPerformanceFrequency( ref qwTicksPerSec );
if( m_bUsingQPF )
m_llQPFTicksPerSec = qwTicksPerSec; // in msec
}
if( m_bUsingQPF )
{
double fTime;
double fElapsedTime;
long qwTime = 0;
// Get either the current time or the stop time, depending
// on whether we're stopped and what command was sent
if( m_llStopTime != 0 && command != TIMER.START && command != TIMER.GETABSOLUTETIME)
qwTime = m_llStopTime;
else
QueryPerformanceCounter( ref qwTime );
// Return the elapsed time
if( command == TIMER.GETELAPSEDTIME )
{
fElapsedTime = (double) ( qwTime - m_llLastElapsedTime ) / (double) m_llQPFTicksPerSec;
m_llLastElapsedTime = qwTime;
return (float)fElapsedTime;
}
// Return the current time
if( command == TIMER.GETAPPTIME )
{
double fAppTime = (double) ( qwTime - m_llBaseTime ) / (double) m_llQPFTicksPerSec;
return (float)fAppTime;
}
// Reset the timer
if( command == TIMER.RESET )
{
m_llBaseTime = qwTime;
m_llLastElapsedTime = qwTime;
m_llStopTime = 0;
m_bTimerStopped = false;
return 0.0f;
}
// Start the timer
if( command == TIMER.START )
{
if( m_bTimerStopped )
m_llBaseTime += qwTime - m_llStopTime;
m_llStopTime = 0;
m_llLastElapsedTime = qwTime;
m_bTimerStopped = false;
return 0.0f;
}
// Stop the timer
if( command == TIMER.STOP )
{
m_llStopTime = qwTime;
m_llLastElapsedTime = qwTime;
m_bTimerStopped = true;
return 0.0f;
}
// Advance the timer by millisecond
if( command == TIMER.ADVANCE )
{
m_llStopTime += m_llQPFTicksPerSec/1000;
return 0.0f;
}
if( command == TIMER.GETABSOLUTETIME )
{
fTime = qwTime / (double) m_llQPFTicksPerSec;
return (float)fTime;
}
return -1.0f; // Invalid command specified
}
else
{
// Get the time using timeGetTime()
double fTime;
double fElapsedTime;
// Get either the current time or the stop time, depending
// on whether we're stopped and what command was sent
if( m_fStopTime != 0.0 && command != TIMER.START && command != TIMER.GETABSOLUTETIME)
fTime = m_fStopTime;
else
fTime = timeGetTime();
// Return the elapsed time
if( command == TIMER.GETELAPSEDTIME )
{
fElapsedTime = (double) (fTime - m_fLastElapsedTime);
m_fLastElapsedTime = fTime;
return (float) fElapsedTime;
}
// Return the current time
if( command == TIMER.GETAPPTIME )
{
return (float) (fTime - m_fBaseTime);
}
// Reset the timer
if( command == TIMER.RESET )
{
m_fBaseTime = fTime;
m_fLastElapsedTime = fTime;
m_fStopTime = 0;
m_bTimerStopped = false;
return 0.0f;
}
// Start the timer
if( command == TIMER.START )
{
if( m_bTimerStopped )
m_fBaseTime += fTime - m_fStopTime;
m_fStopTime = 0.0f;
m_fLastElapsedTime = fTime;
m_bTimerStopped = false;
return 0.0f;
}
// Stop the timer
if( command == TIMER.STOP )
{
m_fStopTime = fTime;
m_fLastElapsedTime = fTime;
m_bTimerStopped = true;
return 0.0f;
}
// Advance the timer by 1/10th second
if( command == TIMER.ADVANCE )
{
m_fStopTime += 0.1f;
return 0.0f;
}
if( command == TIMER.GETABSOLUTETIME )
{
return (float) fTime;
}
return -1.0f; // Invalid command specified
}
}
//-----------------------------------------------------------------------------
// Name: DXUtil.FindMediaFile()
// Desc: Returns a valid path to a DXSDK media file
//-----------------------------------------------------------------------------
public static string FindMediaFile( string sPath, string sFilename )
{
// First try to load the file in the full path
if (sPath != null)
{
if (File.Exists(AppendDirSep(sPath) + sFilename))
return AppendDirSep(sPath) + sFilename;
}
// if not try to find the filename in the current folder.
if (File.Exists(sFilename))
return AppendDirSep(Directory.GetCurrentDirectory()) + sFilename;
// last, check if the file exists in the media directory
if (File.Exists(AppendDirSep(GetDXSDKMediaPath()) + sFilename))
return AppendDirSep(GetDXSDKMediaPath()) + sFilename;
throw new FileNotFoundException("Could not find this file.", sFilename);
}
//-----------------------------------------------------------------------------
// Name: DXUtil.AppendDirSep()
// Desc: Returns a valid string with a directory separator at the end.
//-----------------------------------------------------------------------------
private static string AppendDirSep(string sFile)
{
if (!sFile.EndsWith(@"\"))
return sFile + @"\";
return sFile;
}
}