Hydraquill is a simple helper library preparing a selection of Noto fonts for use with a library like Freetype. Our list only contains the regular-weight variable-width sans-serif fonts, which results in 74MiB of raw data for full unicode coverage.

The whole package however shrinks down to only 16MiB when compressed with zstd, which is why an archive in this format will be prepared when building examples (the library includes a zstd decoder and is able to unpack it at runtime).

The library also provides a way to confirm the existence of unpacked font files and to verify their integrity using sha256 checksums.

The following dependencies must be provided through callbacks:

• zstd decoding
• sha256 hashing

The example program includes them directly, using:

• the single-file zstd decoder from the official zstd repo, found in res/zstd/files/build/single_file_libs/zstddeclib.c
• the cifra sha256 implementation, found in res/cifra/src

As hinted above, this repo uses submodules, and should be cloned like this:

git clone --recurse-submodules https://github.com/nullgemm/hydraquill.git

If you already cloned it and don't have the submodules, run this:

git submodule sync
git submodule update --init --recursive --remote

Build releases using the scripts in make/lib/release, or generate makefiles manually using those in make/lib/gen. The latter can be automated by supplying the configuration options as arguments. To build examples generate the makefiles with the scripts in make/example/gen.

Generate makefiles for the example code using the scripts in make/example/gen. They are similar to the other makefile generation scripts, and can be automated. Build and run the examples like this (you must have built a hydraquill release):

make -f makefile_example_linux
make -f makefile_example_linux run

(some underlying scripts depend on bsdtar)

The font pack is automatically generated when running the example code. Please use this approach instead of manually running the necessary scripts: it is the best way to make sure the fonts were downloaded and packed correctly. If the example program did not print any error message, you can safely use the noto.bin.zst pack found in your bin folder (the original is in res/noto).

We do not use the Noto Emoji: instead, we bundle a TTF version of Twitter's "Twemoji" set, converted from SVG by some amazing people at Mozilla. Unlike the widespread OTF rendition, which only embeds the original SVG files, Mozilla's TTF makes use of the COLR tables to provide real font outlines with color information, and is thus Freetype-compatible.

Please make sure to distribute the required license files with the font pack. They are found in res/noto/licenses (one is for Noto, the other for Twemoji).