gtk3/win32/README_FEATURES_MSVC.md

Preameble

This file attempts to give further info about how to enable features that are not available in the Visual Studio project files shipped with the source release archive, i.e. beyond building GTK with the GDK Win32 backend, with or without the Broadway GDK backend.

The following also apply to Visual Studio builds done with Meson in terms of getting the required dependencies for the optional features.

Notes on enabling EGL (ANGLE/D3D support) for Windows/Visual Studio builds

There is now support in the GL context creation code for Windows in GDK for creating and using EGL (OpenGL ES 3) contexts, which can be used instead of the existing OpenGL (Desktop) support, especially when the graphics drivers do not support OpenGL adequately.

This support is not enabled by default in the project files. In order to do so, please do the following:

• Obtain or compile a build of recent version of ANGLE. The one that comes with QT 5.10.x is sufficiently recent, but not the one that comes with QT-5.6.x. Note that Visual Studio 2013 or later is required for building ANGLE from QT-5.10.x, but the Visual Studio 2013-built ANGLE DLLs does work without problems with GTK+ built with Visual Studio 2008~2013.
  You may need to obtain D3Dcompiler_[47|43|42].dll if it does not come with the system (which is part of the DirectX runtimes). Visual Studio 2015 or later can use ANGLE from QT 5.11.x or later, or from Google's GIT repos, which may require later version of Visual Studio to build. Its headers and .lib needs to be set to be found by the compiler and linker respectively before building libepoxy.

• Build libepoxy with EGL support, which has to be enabled explicitly on Windows builds. Pass in -Degl=yes when building libepoxy using Meson. Build and install, making sure the headers and .lib can be located by the compiler and linker respectively.

• Either:

  • Open the vsX/gtk+.sln, and open the project properties in the gdk3-win32 project. Under "C/C++", add GDK_WIN32_ENABLE_EGL in the Preprocessor Definitions to the existing definitions in there for the configuration that is being built. Then build the solution.

• Or:

  • Run in a Visual Studio command prompt: Go to $(srcroot)\win32, and run nmake /f generate-msvc.mak regenerate-gdk-vsproj USE_EGL=1. To undo that, run that command without USE_EGL=1. Python 3.x must be present in your %PATH% or passed in via PYTHON=<path_to_python_interpreter>. This will update all gdk3-win32 projects (i.e. VS2008~2022).

• To force the use of the EGL code, set the envvar GDK_GL=(...,)gles, where (...,) are the other GDK_GL options desired.

Enabling the font tweaking features and the font features demo

The font tweaking features in the GTK DLL is enabled automatically if the Pango 1.44.0 and HarfBuzz 2.2.0 (or later) headers and libraries (and hence DLLs) are found during compile time. Check in gtkfontchooserwidget.c that the #pragma comment(lib, "harfbuzz") line to ensure that you have your HarfBuzz .lib file named as such, which is the default .lib name for HarfBuzz builds.

Alternatively, they can be manually enabled by running nmake /f generate-msvc.mak regenerate-gtk-vsproj FONT_FEATURES_USE_PANGOFT2=1 meaning that PangoFT2 must be present, which depends on HarfBuzz, FontConfig and FreeType. You will then need to ensure the gtk-3 projects have the correct .lib's of PangoFT2, HarfBuzz and FreeType in the Additional Libraries entry under the linker settings, as they assume the most common names are used there.

Please note that the font features demo is not built into gtk3-demo by default. To do that, run in a Visual Studio command prompt:

• Go to $(srcroot)\win32, and run nmake /f generate-msvc.mak regenerate-demos-h-win32 FONT_FEATURES_DEMO=1. To undo that, run that command without FONT_FEATURES_DEMO=1. Python 3.x must be present in your %PATH% or passed in via PYTHON=<path_to_python_interpreter>.

• If you are building the font features demo with the older PangoFT2-style (i.e. pre-Pango-1.44.x and pre-HarfBuzz-2.2.0) support, pass in FONT_FEATURES_USE_PANGOFT2=1 in addition to FONT_FEATURES_DEMO=1 in the NMake command line. The gtk3-demo project files will also be updated with the appropriate dependent libraries linked in-please check that the project settings contain the correct .lib file names for your system, as they assume the most common names are used there.

Building the translations

Building translations is supported via Meson builds or via the Visual Studio projects, both of which require a working msgfmt.exe (from gettext-tools, a part of gettext) in the %PATH%, or for the Visual Studio projects, passed into the arguments in InstallBuildsBase in gtk3-build-defines.[props|vsprops] with MSGFMT=<path_to_msgfmt.exe>. For the Visual Studio projects, for this to work one needs to also supply a INSTALL_TRANSLATIONS=1 (without the quotes) argument to the same InstallBuildsBase in the afore-mentioned property sheet. Using msgfmt.exe from Cygwin or MSYS2 is supported as well.