dxutil.cpp

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//-----------------------------------------------------------------------------
// File: DXUtil.cpp
//
// Desc: Shortcut macros and functions for using DX objects
//
//
// Copyright (c) 1997-2000 Microsoft Corporation. All rights reserved
//-----------------------------------------------------------------------------
#define STRICT
#include <windows.h>
#include <mmsystem.h>
#include <tchar.h>
#include <stdio.h> 
#include <stdarg.h>
#include "DXUtil.h"




//-----------------------------------------------------------------------------
// Name: DXUtil_GetDXSDKMediaPath()
// Desc: Returns the DirectX SDK media path
//-----------------------------------------------------------------------------
const TCHAR* DXUtil_GetDXSDKMediaPath()
{
    static TCHAR strNull[2] = _T("");
    static TCHAR strPath[MAX_PATH];
    DWORD dwType;
    DWORD dwSize = MAX_PATH;
    HKEY  hKey;

    // Open the appropriate registry key
    LONG lResult = RegOpenKeyEx( HKEY_LOCAL_MACHINE,
                                _T("Software\\Microsoft\\DirectX"),
                                0, KEY_READ, &hKey );
    if( ERROR_SUCCESS != lResult )
        return strNull;

    lResult = RegQueryValueEx( hKey, _T("DX8SDK Samples Path"), NULL,
                              &dwType, (BYTE*)strPath, &dwSize );
    RegCloseKey( hKey );

    if( ERROR_SUCCESS != lResult )
        return strNull;

    _tcscat( strPath, _T("\\Media\\") );

    return strPath;
}




//-----------------------------------------------------------------------------
// Name: DXUtil_FindMediaFile()
// Desc: Returns a valid path to a DXSDK media file
//-----------------------------------------------------------------------------
HRESULT DXUtil_FindMediaFile( TCHAR* strPath, TCHAR* strFilename )
{
    HANDLE file;

    if( NULL==strFilename || NULL==strPath )
        return E_INVALIDARG;

    // Check if the file exists in the current directory
    _tcscpy( strPath, strFilename );

    file = CreateFile( strPath, GENERIC_READ, FILE_SHARE_READ, NULL, 
                       OPEN_EXISTING, 0, NULL );
    if( INVALID_HANDLE_VALUE != file )
    {
        CloseHandle( file );
        return S_OK;
    }
    
    // Check if the file exists in the current directory
    _stprintf( strPath, _T("%s%s"), DXUtil_GetDXSDKMediaPath(), strFilename );

    file = CreateFile( strPath, GENERIC_READ, FILE_SHARE_READ, NULL, 
                       OPEN_EXISTING, 0, NULL );
    if( INVALID_HANDLE_VALUE != file )
    {
        CloseHandle( file );
        return S_OK;
    }

    // On failure, just return the file as the path
    _tcscpy( strPath, strFilename );
    return E_FAIL;
}




//-----------------------------------------------------------------------------
// Name: DXUtil_ReadStringRegKey()
// Desc: Helper function to read a registry key string
//-----------------------------------------------------------------------------
HRESULT DXUtil_ReadStringRegKey( HKEY hKey, TCHAR* strRegName, TCHAR* strValue, 
                                 DWORD dwLength, TCHAR* strDefault )
{
    DWORD dwType;

    if( ERROR_SUCCESS != RegQueryValueEx( hKey, strRegName, 0, &dwType, 
                                          (BYTE*)strValue, &dwLength ) )
    {
        _tcscpy( strValue, strDefault );
    }

    return S_OK;
}




//-----------------------------------------------------------------------------
// Name: DXUtil_WriteStringRegKey()
// Desc: Helper function to write a registry key string
//-----------------------------------------------------------------------------
HRESULT DXUtil_WriteStringRegKey( HKEY hKey, TCHAR* strRegName,
                                  TCHAR* strValue )
{
    if( ERROR_SUCCESS != RegSetValueEx( hKey, strRegName, 0, REG_SZ, 
                                        (BYTE*)strValue, 
                                        (_tcslen(strValue)+1)*sizeof(TCHAR) ) )
        return E_FAIL;

    return S_OK;
}




//-----------------------------------------------------------------------------
// Name: DXUtil_ReadIntRegKey()
// Desc: Helper function to read a registry key int
//-----------------------------------------------------------------------------
HRESULT DXUtil_ReadIntRegKey( HKEY hKey, TCHAR* strRegName, DWORD* pdwValue, 
                              DWORD dwDefault )
{
    DWORD dwType;
    DWORD dwLength = sizeof(DWORD);

    if( ERROR_SUCCESS != RegQueryValueEx( hKey, strRegName, 0, &dwType, 
                                          (BYTE*)pdwValue, &dwLength ) )
    {
        *pdwValue = dwDefault;
    }

    return S_OK;
}




//-----------------------------------------------------------------------------
// Name: DXUtil_WriteIntRegKey()
// Desc: Helper function to write a registry key int
//-----------------------------------------------------------------------------
HRESULT DXUtil_WriteIntRegKey( HKEY hKey, TCHAR* strRegName, DWORD dwValue )
{
    if( ERROR_SUCCESS != RegSetValueEx( hKey, strRegName, 0, REG_DWORD, 
                                        (BYTE*)&dwValue, sizeof(DWORD) ) )
        return E_FAIL;

    return S_OK;
}




//-----------------------------------------------------------------------------
// Name: DXUtil_ReadBoolRegKey()
// Desc: Helper function to read a registry key BOOL
//-----------------------------------------------------------------------------
HRESULT DXUtil_ReadBoolRegKey( HKEY hKey, TCHAR* strRegName, BOOL* pbValue, 
                              BOOL bDefault )
{
    DWORD dwType;
    DWORD dwLength = sizeof(BOOL);

    if( ERROR_SUCCESS != RegQueryValueEx( hKey, strRegName, 0, &dwType, 
                                          (BYTE*)pbValue, &dwLength ) )
    {
        *pbValue = bDefault;
    }

    return S_OK;
}




//-----------------------------------------------------------------------------
// Name: DXUtil_WriteBoolRegKey()
// Desc: Helper function to write a registry key BOOL
//-----------------------------------------------------------------------------
HRESULT DXUtil_WriteBoolRegKey( HKEY hKey, TCHAR* strRegName, BOOL bValue )
{
    if( ERROR_SUCCESS != RegSetValueEx( hKey, strRegName, 0, REG_DWORD, 
                                        (BYTE*)&bValue, sizeof(BOOL) ) )
        return E_FAIL;

    return S_OK;
}




//-----------------------------------------------------------------------------
// Name: DXUtil_ReadGuidRegKey()
// Desc: Helper function to read a registry key guid
//-----------------------------------------------------------------------------
HRESULT DXUtil_ReadGuidRegKey( HKEY hKey, TCHAR* strRegName, GUID* pGuidValue, 
                               GUID& guidDefault )
{
    DWORD dwType;
    DWORD dwLength = sizeof(GUID);

    if( ERROR_SUCCESS != RegQueryValueEx( hKey, strRegName, 0, &dwType, 
                                          (LPBYTE) pGuidValue, &dwLength ) )
    {
        *pGuidValue = guidDefault;
    }

    return S_OK;
}




//-----------------------------------------------------------------------------
// Name: DXUtil_WriteGuidRegKey()
// Desc: Helper function to write a registry key guid
//-----------------------------------------------------------------------------
HRESULT DXUtil_WriteGuidRegKey( HKEY hKey, TCHAR* strRegName, GUID guidValue )
{
    if( ERROR_SUCCESS != RegSetValueEx( hKey, strRegName, 0, REG_BINARY, 
                                        (BYTE*)&guidValue, sizeof(GUID) ) )
        return E_FAIL;

    return S_OK;
}




//-----------------------------------------------------------------------------
// 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 0.1 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
//-----------------------------------------------------------------------------
FLOAT __stdcall DXUtil_Timer( TIMER_COMMAND command )
{
    static BOOL     m_bTimerInitialized = FALSE;
    static BOOL     m_bUsingQPF         = FALSE;
    static LONGLONG m_llQPFTicksPerSec  = 0;

    // Initialize the timer
    if( FALSE == m_bTimerInitialized )
    {
        m_bTimerInitialized = TRUE;

        // Use QueryPerformanceFrequency() to get frequency of timer.  If QPF is
        // not supported, we will timeGetTime() which returns milliseconds.
        LARGE_INTEGER qwTicksPerSec;
        m_bUsingQPF = QueryPerformanceFrequency( &qwTicksPerSec );
        if( m_bUsingQPF )
            m_llQPFTicksPerSec = qwTicksPerSec.QuadPart;
    }

    if( m_bUsingQPF )
    {
        static LONGLONG m_llStopTime        = 0;
        static LONGLONG m_llLastElapsedTime = 0;
        static LONGLONG m_llBaseTime        = 0;
        double fTime;
        double fElapsedTime;
        LARGE_INTEGER qwTime;
        
        // 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.QuadPart = m_llStopTime;
        else
            QueryPerformanceCounter( &qwTime );

        // Return the elapsed time
        if( command == TIMER_GETELAPSEDTIME )
        {
            fElapsedTime = (double) ( qwTime.QuadPart - m_llLastElapsedTime ) / (double) m_llQPFTicksPerSec;
            m_llLastElapsedTime = qwTime.QuadPart;
            return (FLOAT) fElapsedTime;
        }
    
        // Return the current time
        if( command == TIMER_GETAPPTIME )
        {
            double fAppTime = (double) ( qwTime.QuadPart - m_llBaseTime ) / (double) m_llQPFTicksPerSec;
            return (FLOAT) fAppTime;
        }