harfbuzz VS stb

For C/C++ projects that use meson as the build system, there is an excellent way to manage dependencies:

https://mesonbuild.com/Wrapdb-projects.html

https://mesonbuild.com/Wrap-dependency-system-manual.html

meson will download and build the libraries automatically and give you a variable which you pass as a regular dependency into the built target:

https://github.com/qemu/qemu/tree/005ad32358f12fe9313a4a0191...

https://github.com/harfbuzz/harfbuzz/tree/main/subprojects

https://github.com/harfbuzz/harfbuzz/blob/37457412b3212463c5...

Or, if you're using proper operating systems, they're managed by the usual package manager, just like everything else.

If you sympathize with the travails of people working on text rendering in applications, please consider supporting (among other projects):

1. The LibreOffice project (libreoffice.org), the free office application suite. This is where the rubber hits the road and developers deal with the extreme complexities of everything regarding text - shaping, styling, multi-object interaction, multi-language, you name it. And - they/we absolutely need donations to manage a project with > 200 million users: https://www.libreoffice.org/donate

2. harfbuzz (https://harfbuzz.github.io), and specifically Behdad Esfahood the main contributor. Although, TBH, I've not quite figured out whether you can donate to that or to him. At least star the project on GitHub I guess.

As for text, it depends very heavily on what exactly you need. Simple ASCII text and bitmap fonts? Just do it yourself or get a .bdf parser. Simple Latin/Cyrillic-like writing with ok-looking vector fonts (ttfs)? stb_truetype has all you need. Font hinting, subpixel rendering? You use freetype. More complex writing like Arabic? You will have to do shaping as well, say with HarfBuzz. Need right-to-left or unidirectional text? Hypenation? Go for platform APIs if you can (DirectWrite om Windows, CoreText on Mac).

Gold standard? Even though serious bugs are not fixed [1] because "the code is too fragile to touch at this point"? Looks like Android uses HarfBuzz, if so it can't be that bad.

[1] https://github.com/harfbuzz/harfbuzz/issues/2814

The linked libraries are not even close to solving limited subsets of problems solved by FreeType or HarfBuzz. No test is needed if they do not even have a working implementation of particular requisites: Do they work on heterogeneous layouts, directions, languages, locales, scripts, symbols and composites, extensions, variations, legacy, missing, partial or corrupted instructions, standards interpretations, platforms, output devices, nonstandard point structures and grids?

They do not. What they solve is almost a toy problem compared to the size, scope and breadth of these libraries.

Just because some project is implemented in Rust does not make it comparable never mind superior by default.

There is a world out there and it is not homogeneous format and standards-compliant Latin fonts in English LTR text in linear disposition with some generic rectangular subpixel rendering on a regular rectangular grid.

I warmly welcome you to browse closed issues of FreeType [1] and also the closed issues of HarfBuzz [2]. If you feel inspired please do also look into mailing lists and discussion pages related to the development, building, tracking and patching of packages of these projects in any of the numerous places it is used.

The only argument Rust people have is in relation WASM but if you insist in targeting WASM why not fork FreeType, strip it to the strict subset of features your application needs and target it?

Why do it in the first place? Why reinvent the wheel?

As such I will restate my view: I see no gain in using any of these subpar libraries.

[1] https://gitlab.freedesktop.org/freetype/freetype/-/issues/?s...

[2] https://github.com/harfbuzz/harfbuzz/issues?q=is%3Aclosed

Have you considered not using an engine at all, in favor of libraries? There are many amazing libraries I've used for game development - all in C/C++ - that you can piece together:

* General: [stb](https://github.com/nothings/stb)

Great to see more accessible references on font internals. I have dabbled on this a bit last year and managed to have a parser and render the points of a glyph's contour (I stopped before Bezier and shape filling stuff). I still have not considered hinting, so it's nice that it's covered. What helped me was an article from the Handmade Network [1] and the source of stb_truetype [2] (also used in Dear ImGUI).

[1] https://handmade.network/forums/articles/t/7330-implementing....

[2] https://github.com/nothings/stb/blob/master/stb_truetype.h

So I read through the materials on mesh shaders and work graphs and looked at sample code. These won't really work (see below). As I implied previously, it's best to research/discuss these sort of matters with professional graphics programmers who have experience actually using the technologies under consideration.

So for the sake of future web searchers who discover this thread: there are only two proven ways to efficiently draw thousands of unique textures of different sizes with a single draw call that are actually used by experienced graphics programmers in production code as of 2023.

Proven method #1: Pack these thousands of textures into a texture atlas.

Proven method #2: Use bindless resources, which is still fairly bleeding edge, and will require fallback to atlases if targeting the PC instead of only high end console (Xbox Series S|X...).

Mesh shaders by themselves won't work: These have similar texture access limitations to the old geometry/tessellation stage they improve upon. A limited, fixed number of textures still must be bound before each draw call (say, 16 or 32 textures, not 1000s), unless bindless resources are used. So mesh shaders must be used with an atlas or with bindless resources.

Work graphs by themselves won't work: This feature is bleeding edge shader model 6.8 whereas bindless resources are SM 6.6. (Xbox Series X|S might top out at SM 6.7, I can't find an authoritative answer.) It looks like work graphs might only work well on nVidia GPUs and won't work well on Intel GPUs anytime soon (but, again, I'm not knowledgeable enough to say this authoritatively). Furthermore, this feature may have a hard dependency on using bindless to begin with. That is, I can't tell if one is allowed to execute a work graph that binds and unbinds individual texture resources. And if one could do such a thing, it would certainly be slower than using bindless. The cost of bindless is paid "up front" when the textures are uploaded.

Some programmers use Texture2DArray/GL_TEXTURE_2D_ARRAY as an alternative to atlases but two limitations are (1) the max array length (e.g. GL_MAX_ARRAY_TEXTURE_LAYERS) might only be 256 (e.g. for OpenGL 3.0), (2) all textures must be the same size.

Finally, for the sake of any web searcher who lands on this thread in the years to come, to pack an atlas well a good packing algorithm is needed. It's harder to pack triangles than rectangles but triangles use atlas memory more efficiently and a good triangle packing will outperform the fancy new bindless rendering. Some open source starting points for packing:

https://github.com/nothings/stb/blob/master/stb_rect_pack.h

https://github.com/ands/trianglepacker

The STB headers are mostly built like that: https://github.com/nothings/stb

You could also add an optional 'convenience API' over the lower-level flexible-but-inconvenient core API, as long as core library can be compiled on its own.

In essence it's just a way to decouple the actually important library code from runtime environment details which might be better implemented outside the C/C++ stdlib.

It's already as simple as the stdlib IO functions not being asynchrononous while many operating systems provide more modern alternatives. For a specific type of library (such an image decoder) it's often better to delegate such details to the library user instead of circumventing the stdlib and talking directly to OS APIs.

My stuff for instance:

https://github.com/floooh/sokol

...inspired by:

https://github.com/nothings/stb

But it's not so much about the build system, but requiring a separate C/C++ compiler toolchain (Rust needs this, Zig currently does not - unless the proposal is implemented).

STB Libraries: https://github.com/nothings/stb

stb_ds is also very popular.