Fatal error during graphic initialization

Hello all,

If you find errors below, give feedback, if it helps also.

Philippe

It's true, there is about 7 subjects in this forum about this message :

[OS Context]
Platform : Win7 / 64bit
OCC6.5.1 Debug
VS2008=vc9
target : win32

[Situation]
I've worked for more than ten years with OCC, I know this message quite well, usually it's easy to get rid of it, but recently I couldn't figure why I could not open 3dView anymore in my App (VS2008) ...
It didn't worked anymore even for OCC sample, even with batch files (*.bat) that does the work for env. var.

Usually the answer in this forum is Look at "CSF_GraphicShr" environment variable, it is not set properly.
A lot of people says in this forum it does not solve their problem, it's just because this simple assomption is not 100% true.
It's a starting point but not the solution.
Some beginners will go away probably just because of one line in OCC code.
You have to understand precisely what is happening. takes hours !

I personnaly don't use env. variables,, it's a unix approach, not always easy to check or not fast to configure.
You can use OSD_Environment
OSD_Environment anEnvironmentVariable(aKeyName);
anEnvironmentVariable.SetValue(aKeyName);
anEnvironmentVariable.Build();

I would prefer an xml SetOccConfiguration("occ_config.xml") but it's another discussion

[My end solution was :]

Change "d:\OpenCASCADE6.5.1\ros\src\OSD\OSD_SharedLibrary.cxx"

Standard_Boolean OSD_SharedLibrary :: DlOpen ( const OSD_LoadMode Mode ) {

// ( myHandle = ( HINSTANCE )LoadLibraryEx ( myName, NULL, LOAD_WITH_ALTERED_SEARCH_PATH) ) == NULL
// replaced by
( myHandle = ( HINSTANCE ) ::LoadLibrary (myName) ) == NULL

Recompile OCC entirely and it will probably work

LOAD_WITH_ALTERED_SEARCH_PATH);

[First Analysis :]
In fact CSF_GraphicShr is not really mandatory. You can delete it. It will take dllName="TKOpenGl.dll" by default
If you look code, OCC will try to Load Dll TKOpenGl.dll with this call ::LoadLibraryEx (dllName, NULL, LOAD_WITH_ALTERED_SEARCH_PATH);

[CODE]

*********************** **********************

void Graphic3d_WNTGraphicDevice::SetGraphicDriver ()
{
Standard_CString TheShr = getenv("CSF_GraphicShr");
if ( ! TheShr || ( strlen( TheShr ) == 0 ) )
TheShr = "TKOpenGl.dll";

MySharedLibrary.SetName ( TheShr );
Result = MySharedLibrary.DlOpen (OSD_RTLD_LAZY);

etc ...
}

Standard_Boolean OSD_SharedLibrary :: DlOpen ( const OSD_LoadMode Mode ) {
::LoadLibraryEx (myName, NULL, LOAD_WITH_ALTERED_SEARCH_PATH);
lastDLLError = GetLastError ();
} // end OSD_SharedLibrary :: DlOpen

*********************** CODE> **********************

*********************** CODE> **********************
void 3dViewerWnd::CreateIndependentViewer(V3d_TypeOfView aDefaultTypeOfView)
{
// if this not working dont go further
if (!ForceMyLoadTKOpenGL())
return;

if (myGraphicDevice.IsNull())
myGraphicDevice = new Graphic3d_WNTGraphicDevice(); // call SetGraphicDriver
}

init 3dViewerWnd::ForceMyLoadTKOpenGL()
{
Standard_Address pHandle = NULL;
if ( ( pHandle ) == NULL &&
( pHandle = ( HINSTANCE ) ::LoadLibrary (MyT("TKOpenGl.dll")) ) == NULL
) {
// CString aString;
// MyTools::GetLastWin32Error(aString);
//::MessageBox(aString);
return 0;
}
return 1;

}
*********************** CODE> **********************

[SEARCH FOR TYPICAL PROBLEMS]
So you have to find why this dll Load fails.

Sources of problem can be
Mixing x64 with win32 compilation or
Release with Debug dll or
Multi-Threaded Dll with Single Threaded Dll or
Your Os can't find your Library.
Mixing OCC versions without knowing it (6.5.1 with 6.2.0)
You installed another software that use OCC and this software puts OCC dll in System32 (bad luck)
SetDllDirectory is called somewhere (your code or even not) and will redirect badly LoadLibraryEx call

Look all OCC Dll path in the Debug Window when they are being loaded by the sytem.
Search in your computer ALL "TKOpenGL.dll" and you could find some surprise.

Use Depends http://www.dependencywalker.com/ and Drag and Drop "TKernel.dll", "TKOpenGl.dll" then your exe inside it.

After, understand this notes :

[Windows documentation:]
Dynamic-Link Library Search Order
Note that the standard search strategy and the alternate search strategy specified by LoadLibraryEx with LOAD_WITH_ALTERED_SEARCH_PATH differ in just one way:
The standard search begins in the calling application's directory, and the *** alternate search begins in the directory *** of the executable module that LoadLibraryEx is loading.
If a module changes the standard search order by calling the LoadLibraryEx function with LOAD_WITH_ALTERED_SEARCH_PATH, the system searches the directory the specified module was loaded from instead of the directory of the calling process. The system searches these locations in this order:

The package dependency graph of the process. This is specified in the section of the application's package manifest. Dependencies are searched in the order they appear in the manifest.
The directory the specified module was loaded from.
The System directory (%SystemRoot%\system32).

LoadLibraryEx:
If lpFileName specifies a relative path, the entire relative path is appended to every token in the DLL search path.
To load a module from a relative path without searching any other path, use GetFullPathName to get a nonrelative path and call LoadLibraryEx with the nonrelative path.
If the module is being loaded as a datafile and the relative path starts with .\ or ..\, the relative path is treated as an absolute path.
If lpFileName specifies an absolute path and dwFlags is set to LOAD_WITH_ALTERED_SEARCH_PATH, LoadLibraryEx uses the altered search path. *** LOAD_WITH_ALTERED_SEARCH_PATH does not work with relative paths. ***
Alternate Search Order for Desktop Applications

The standard search order used by the system can be changed by calling the LoadLibraryEx function with LOAD_WITH_ALTERED_SEARCH_PATH. The standard search order can also be changed by calling the SetDllDirectory function.

So what you can try first :
call
::LoadLibrary ("TKernel.dll") Doest it work ?
yes : continue, no : check your "Path" env Variable and get error code and message associate with it

call
::LoadLibrary ("TKOpenGl.dll") Doest it work ?
yes : your CSF_GraphicShr is not set properly or check there is no OCC dll in your App Directory. No : continue or call this before new Graphic3d_WNTGraphicDevice();

call
::LoadLibrary ("D:\\OpenCASCADE6.5.1\\ros\\win32\\vc9\\bind\\TKOpenGl.dll") Doest it work with your full path ?
yes : check your "Path" env Variable and check there is no OCC dll in your App Directory. You could think one Dll is used and in fact it's another one
no : check the full path between "", then clean and recompile OCC Project entirely and check before the platform, the lib and include path, "VCVER" env Var, "OS_TYPE" env var. (vc9, win32 for ex)

If like me it does not work after all that awful work :
1°) workaround is call ::LoadLibrary("TKOpenGl.dll") before OCC call to "new Graphic3d_WNTGraphicDevice(); "
or
2°) change OCC code in OSD_SharedLibrary :: DlOpen () then recompile OCC

Hope this approach will helps.
If I find the solution without changing OCC code, I will post it.

Philippe