[vtkusers] Using fontconfig with vtkTextMapper/vtkTextProperty?

[Elvis Stansvik]

2016-10-20 16:41 GMT+02:00 David Lonie <david.lonie at kitware.com>:
> Correct -- Set ForceCompiledFonts off on vtkFreeTypeTools, and set the name
> of the font using vtkTextProperty::SetFontFamilyAsString.
>
> As you discovered, this requires the RenderingFreeTypeFontConfig module to
> be enabled and linked to the final application. There is an example usage in
> Rendering/FreeTypeFontConfig/Testing/Cxx/TestSystemFontRendering.cxx if you
> get stuck.
>
> Let us know if you have further issues, AFAIK this functionality is not
> widely used.

Yep, it now seems to work. E.g. I can now do:

    textProperty->SetFontSize(10);
    textProperty->SetFontFamilyAsString("Noto Sans");

However, one thing puzzles me: The font is much smaller than what I
would have expected. I set it to 10 points here, but the result is
much smaller (see attached screenshot).

My goal is to use
QFontDatabase::systemFont(QFontDatabase::GeneralFont) to get the
system font through Qt, and use its values for .fontSize() and
.family() when constructing my vtkTextProperty, to make the font in
VTK match my system font.

Any idea why the text is rendered so small? The vtkTextProperty is set
on a vtkTextMapper which in turn is set on a vtkActor2D.

Thanks in advance,
Elvis

>
> HTH,
> Dave
>
> On Thu, Oct 20, 2016 at 9:34 AM, Elvis Stansvik
> <elvis.stansvik at orexplore.com> wrote:
>>
>> 2016-10-20 14:49 GMT+02:00 Elvis Stansvik <elvis.stansvik at orexplore.com>:
>> > 2016-10-20 14:48 GMT+02:00 Elvis Stansvik
>> > <elvis.stansvik at orexplore.com>:
>> >> 2016-10-20 14:06 GMT+02:00 Elvis Stansvik
>> >> <elvis.stansvik at orexplore.com>:
>> >>> Hi,
>> >>>
>> >>> How can I load a system font through fontconfig and use it with
>> >>> vtkTextMapper/vtkTextProperty?
>> >>>
>> >>> I've called vtkFreeTypeTools::GetInstance()->ForceCompiledFontsOff(),
>> >>> but I can't find any API on vtkTextProperty to set a font family to
>> >>> use for a fontconfig-based search.
>> >>
>> >> Am I supposed to pass the fontconfig family name (e.g. "Noto Sans") to
>> >> vtkTextProperty::SetFontFamilyAsString(..) ? I tried it but it didn't
>> >> seem to have any effect.
>> >>
>> >> In fact, I just had a look at the build log for the Debian package I
>> >> built of 7.1.0.rc1, and it's not mentioning "FontConfig" at all (see
>> >> attached log). Does that mean my build doesn't have fontconfig
>> >
>> > Sorry, forgot the attachment, here it is in case it's too big to be
>> > attached:
>> >
>> >
>> > https://dl.dropboxusercontent.com/u/22350696/vtk7_7.1.0~rc1-0ubuntu1_amd64.build.bz2
>> >
>> > Elvis
>>
>> Sorry for the noise. Just adding
>> -DModule_vtkRenderingFreeTypeFontConfig=ON to my build and
>> libfontconfig1-dev to the build dependencies, and I get
>>
>>     --  * vtkRenderingFreeTypeFontConfig, requested by
>> Module_vtkRenderingFreeTypeFontConfig.
>>
>> in the VTK CMake output. Building now and will report back how it went.
>>
>> Still interested in if vtkTextProperty::SetFontFamilyAsString(..) is
>> the right API to set the fontconfig family name.
>>
>> Elvis
>>
>> >
>> >> support? Must I enable the FreeTypeFontConfig module explicitly? (not
>> >> enough that fontconfig is found on the system?).
>> >>
>> >> Elvis
>> >>
>> >>>
>> >>> Elvis
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