[vtkusers] VTK and Unicode

[Maarten Beek]

Hi David,

After copying the ushort string into a wchar_t string, ::ToNarrow() would return nonsense.

I gave the variable KWSYS_ENCODING_DEFAULT_CODEPAGE the value CP_UTF8 (defaults to CP_ACP in the vtksys CMakeLists.txt if nothing is defined) by using the add entry button in CMake.
After rebuilding VTK, this didn't solve the problem.
Would the codepage setting of the computer have to be set to CP_UTF8 at the moment of file creation for this to work? Although, this wouldn't affect my problem of getting the correct char* into the SetFileName() function. Would it?


Maarten



On Thursday, June 5, 2014 6:45:38 PM, David Gobbi <david.gobbi at gmail.com> wrote:
 


Hi Maarten,

Yes, vtksys::Encoding::ToNarrow() requires a wchart_t *.  If you like to live
dangerously, you could just use a reinterpret_cast to convert your ushort *
to a wchar_t *, but to be safe you should allocate a wchar_t string of the
right size and then copy your ushort string into it.

VTK doesn't have any cmake options related to unicode.  All file-level stuff
in VTK always uses 8-bit strings no matter what build options you choose.

  David



On Thu, Jun 5, 2014 at 4:20 PM, Maarten Beek <beekmaarten at yahoo.com> wrote:
> It's complaining about the ToNarrow() function.
> (... symbol "__declspec(dllimport) <bla-bla> __cdecl
> vtksys::Encoding::ToNarrow(<bla-bla>) referenced in function <bla-bla> )
>
> I got the VS solution from svn before my unicode changes and added the
> ToNarrow() function and everything builds fine.
> I guess if I build my app with unicode, I should do this with VTK as well
> (how? don't see such an option in cmake...).
>
>
> However the app crashes in Debug, but not in Release.
> In another app, I need to set wchar_t as a build-in type to avoid the
> unresolved external symbol error, but then an ushort* (returned by
> QString::utf16()) cannot be cast to a wchar_t*... I guess ::ToNarrow(const
> wchar_t*) needs a ::ToNarrow(const ushort*) overload?
>
> Maarten
>
>
>
> On Thursday, June 5, 2014 5:03:56 PM, David Gobbi <david.gobbi at gmail.com>
> wrote:
>
>
> Hi Maarten,
>
> I use the functions in vtksys all the time.  Not specifically the
> Encoding functions, but they shouldn't be any different.
>
> You said it reported an unresolved symbol error... what symbol
> was it complaining about?
>
>   David
>
>
> On Thu, Jun 5, 2014 at 2:56 PM, Maarten Beek <beekmaarten at yahoo.com> wrote:
>> I am linking my app with vtksys.lib.
>>
>> But your answer also tells me I can use this function in my app.
>>
>> So it must be something else... maybe the fact that my vtk is built with
>> multibyte and the app with unicode?
>> Should find a function in vtksys that is unrelated to this to test.
>>
>> Maarten
>>
>>
>> On Thursday, June 5, 2014 4:31:20 PM, David Gobbi <david.gobbi at gmail.com>
>> wrote:
>>
>>
>> An unresolved symbol just means that you have to link to the library,
>> e.g. if you have a target_link_libraries() call in your CMakeLists.txt,
>> make sure that "vtksys" is listed.
>>
>> On Thu, Jun 5, 2014 at 2:20 PM, Maarten Beek <beekmaarten at yahoo.com>
>> wrote:
>>> Hi David,
>>>
>>> Thanks for the quick reply.
>>>
>>> Sounds complicated, but I'll browse through the windows docs.
>>>
>>> In my search for a solution I also bumped into
>>> vtksys::Encoding::ToNarrow(),
>>> however this gives me an 'unresolved external symbol' link error. I have
>>> never used stuff in vtksys (and similar libs like vtkpng, vtktiff)
>>> before,
>>> so I am not really sure I am supposed to, i.e., these are just functions
>>> used by cmake and/or in just the vtk build.
>>>
>>> Maarten
>>>
>>>
>>> On Thursday, June 5, 2014 3:44:46 PM, David Gobbi <david.gobbi at gmail.com>
>>> wrote:
>>>
>>>
>>> Hi Maarten,
>>>
>>> VTK just uses C++ streams in most of its readers/writers.  On OS X,
>>> you'll find that you can use utf-8 filenames just fine.  Same for linux,
>>> for the most part at least.
>>>
>>> For Windows, you'd have to set the codepage to 65001 (utf-8).  I've
>>> done this successfully for console I/O (via SetConsoleOutputCP()),
>>> but you'll have to look through the Windows docs to see what function
>>> is needed to change the codepage used by CreateFileA.
>>>
>>> - David
>>>
>>>
>>> On Thu, Jun 5, 2014 at 1:17 PM, Maarten Beek <beekmaarten at yahoo.com>
>>> wrote:
>>>> Hi all,
>>>>
>>>> I was wondering if there is a multi-platform way of loading a file (e.g.
>>>> tif, stl) with chinese, russian characters in the file path in VTK.
>>>> How would I build VTK with Unicode characters?
>>>> Can I use a non-unicode VTK in a unicode app?
>>>>
>>>> Thanks - Maarten
>>>
>>>
>>
>>
>
>
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