harfbuzz/README.mingw.md

Most HarfBuzz developers do so on Linux or macOS. However, HarfBuzz is a cross-platform library and it is important to ensure that it works on Windows as well. In particular, we use this workflow to develop and test the HarfBuzz Uniscribe shaper and DirectWrite shaper and font backend, all from Linux or macOS.

This document provides instructions for cross-compiling HarfBuzz on Linux or macOS, for Windows, using the MinGW toolchain, and running tests and utilties under Wine.

We then discuss using native Windows Uniscribe or DirectWrite DLLs, which allows you to test HarfBuzz's shaping against the Microsoft shaping engines instead of those provided by Wine.

This document assumes that you are familiar with building HarfBuzz on Linux or macOS.

You can build for 32bit or 64bit Windows. If your intention is to use a native Uniscribe usp10.dll from Windows 7 or before, you would need to build for 32bit. If you want to use a native DirectWrite DLL from Windows 10 or later, you would need to build for 64bit.

We suggest you read to the end of this document before starting, as it provides a few different ways to build and test HarfBuzz for Windows.

1. Install Wine.

• Fedora: dnf install wine.
• Ubuntu, 32bit: apt install wine wine32.
• Ubuntu, 64bit: apt install wine wine64.
• Mac: brew install wine-stable.

Note that to run Wine on Apple silicon systems, you need the Apple Rosetta translator. Follow the instructions you got from brew. This should do it:

• softwareupdate --install-rosetta --agree-to-license

2. Install the mingw-w64 cross-compiler.

• Fedora, 32bit: dnf install mingw32-gcc-c++
• Fedora, 64bit: dnf install mingw64-gcc-c++
• Ubuntu, 32bit: apt install g++-mingw-w64-i686
• Ubuntu, 64bit: apt install g++-mingw-w64-x86-64
• Mac: brew install mingw-w64

3. Install dependencies.

First, make sure you do not have the mingw32 harfbuzz package, as that will override our own build with older meson:

• Fedora, 32bit: dnf remove mingw32-harfbuzz
• Fedora, 64bit: dnf remove mingw64-harfbuzz

Then install the actual dependencies:

• Fedora, 32bit: dnf install mingw32-glib2 mingw32-cairo mingw32-freetype
• Fedora, 64bit: dnf install mingw64-glib2 mingw64-cairo mingw64-freetype

If you cannot find these packages for your distribution, or you are on macOS, you can skip to the next step, as meson will automatically download and build the dependencies for you.

4. If you are familiar with meson, you can use the cross-compile files we provide to find your way around. But we do not recommend this way. Read until the end of this section before deciding which one to use.

• 32bit: meson --cross-file=.ci/win32-cross-file.txt build-win -Dglib-enabled -Dcairo=enabled -Dgdi=enabled -Ddirectwrite=enabled
• 64bit: meson --cross-file=.ci/win64-cross-file.txt build-win -Dglib-enabled -Dcairo=enabled -Dgdi=enabled -Ddirectwrite=enabled

In which case, you will proceed to run ninja as usual to build:

• ninja -C build-win

Or you can simply invoke the scripts we provide for our Continuous Integration system, to configure and build HarfBuzz for you. This is the easiest way to build HarfBuzz for Windows and how we build our Windows binaries:

• 32bit: ./.ci/build-win.sh 32 && ln -s build-win32 build-win
• 64bit: ./.ci/build-win.sh 64 && ln -s build-win64 build-win

This might take a while, since, if you do not have the dependencies installed, meson will download and build them for you.

5. If everything succeeds, you should have the hb-shape.exe, hb-view.exe, hb-subset.exe, and hb-info.exe executables in build-win/util.

6. Configure your wine to find system mingw libraries. While there, set it also to find the built HarfBuzz DLLs:

• Fedora, 32bit: export WINEPATH="$HOME/harfbuzz/build-win/src;/usr/i686-w64-mingw32/sys-root/mingw/bin"
• Fedora, 64bit: export WINEPATH="$HOME/harfbuzz/build-win/src;/usr/x86_64-w64-mingw32/sys-root/mingw/bin"
• Other systems: export WINEPATH="$HOME/harfbuzz/build-win/src"

Adjust for the path where you have built HarfBuzz. You might want to add this to your .bashrc or .zshrc file.

Alternatively, can skip this step if commands are run through the meson devenv command, which we will introduce in the next step. I personally find it more convenient to set the WINEPATH variable, as it allows me to run the executables directly from the shell.

7. Run the hb-shape executable under Wine:

• wine build-win/util/hb-shape.exe perf/fonts/Roboto-Regular.ttf Test

Or using `meson devenv to do the same:

• meson devenv -C build-win util/hb-shape.exe $PWD/perf/fonts/Roboto-Regular.ttf Test

You probably will get lots of Wine warnings, but if all works fine, you should see:

[gid57=0+1123|gid74=1+1086|gid88=2+1057|gid89=3+670]

You can make Wine less verbose, without hiding all errors, by setting:

• export WINEDEBUG=fixme-all,warn-all,err-plugplay,err-seh,err-rpc,err-ntoskrnl,err-winediag,err-systray,err-hid

Add this to your .bashrc or .zshrc file as well.

Next, let's try some non-Latin text. Unfortunately, the command-line parsing of our cross-compiled glib is not quite Unicode-aware, at least when run under Wine. So you will need to find some other way to feed Unicode text to the shaper. There are three different ways you can try:

• echo حرف | wine build-win/util/hb-shape.exe perf/fonts/Amiri-Regular.ttf
• wine build-win/util/hb-shape.exe perf/fonts/Amiri-Regular.ttf -u 062D,0631,0641
• wine build-win/util/hb-shape.exe perf/fonts/Amiri-Regular.ttf --text-file harf.txt

To get the Unicode codepoints for a string, you can use the hb-unicode-decode utility:

$ test/shape/hb-unicode-decode حرف
U+062D,U+0631,U+0641

8. Next, let's try the hb-view utility. By default, hb-view outputs ANSI text, which Wine will not display correctly. You can use the -o option to redirect the output to a file, or just redirect the output using the shell, which will produce a PNG file.

• wine build-win/util/hb-view.exe perf/fonts/Roboto-Regular.ttf Test > test.png

7. As noted, if your Linux has binfmt_misc enabled, you can run the executables directly. If not, you can modify the cross-file to use the exe_wrapper option as specified before.

• build-win/util/hb-shape.exe perf/fonts/Roboto-Regular.ttf Test

If that does not work, you can use the wine command as shown above.

10. You can try running the test suite. If on Linux with binfmt_misc enabled, you can run the tests directly:

• ninja -C build-win test

For other situations, use meson devenv:

• meson devenv -C build-win ninja test

This might take a couple of minutes to run. Running under Wine is expensive, so be patient.

If all goes well, tests should run. If all is well, you should probably see about 400 tests pass, some skipped, but none failing.

11. In the above testing situation, the directwrite test will be disabled automatically upon detection of running under Wine. The reason the directwrite test would otherwise fails is that we are running against the Wine-provided DirectWrite DLL, which is an incomplete reimplementation of the DirectWrite API by Wine, and not the real thing.

If you want to test the Uniscribe or DirectWrite shapers against the real Uniscribe / DirectWrite, you can follow the instructions below.

11. Old Uniscribe: Assuming a 32bit build for now.

Bring a 32bit version of usp10.dll for yourself from C:\Windows\SysWOW64\usp10.dll of your 64bit Windows installation, or C:\Windows\System32\usp10.dll for 32bit Windows installation.

You want one from Windows 7 or earlier. One that is not just a proxy for TextShaping.dll. Rule of thumb, your usp10.dll should have a size more than 500kb.

Put the file in ~/.wine/drive_c/windows/syswow64/ so wine can find it.

You can now tell wine to use the native usp10.dll:

• export WINEDLLOVERRIDES="usp10=n"
• wine build-win/util/hb-shape.exe perf/fonts/Roboto-Regular.ttf Test --shaper=uniscribe

12. DirectWrite and new Uniscribe: You can use the same method to test the DirectWrite shaper against the native DirectWrite DLL. Try with a 64bit build this time.

Bring TextShaping.dll, DWrite.dll, and usp10.dll from your 64bit Windows installation (C:\Windows\System32) to ~/.wine/drive_c/windows/system32/.

You want the ones from Windows 10 or later. You might have some luck downloading them from the internet, but be careful with the source. I had success with the DLLs from https://dllme.com, but I cannot vouch for the site.

You can now tell wine to use the native DirectWrite:

• export WINEDLLOVERRIDES="textshaping,dwrite,usp10=n"
• wine build-win/util/hb-shape.exe perf/fonts/Roboto-Regular.ttf Test --shaper=directwrite

If all works well, you should be able to rerun the tests and see all pass this time.

13. For some old instructions on how to test HarfBuzz's native Indic shaper against Uniscribe, see: https://github.com/harfbuzz/harfbuzz/issues/3671

14. That's it! If you made it this far, you are now able to develop and test HarfBuzz on Windows, from Linux or macOS. Enjoy!