femtovg VS stb

Femtovg (https://github.com/femtovg/femtovg) which uses OpenGL to render

Congrats! I don't want to diminish the accomplishment, but have you seen femtovg? It seems like it's probably well-aligned with your needs.

I'm currently using femtovg for vector graphics in my games, and I would like to get into bevy by porting one of my game prototypes using it to bevy.

I use femtovg It's a simple vector graphics engine having all the important features you probably want from a 2D rendering engine: simple shapes, images, text

https://github.com/femtovg/femtovg/pull/5

Before Power10 was done, IBM actually asked us Raptor users about proposals for useful machine code instructions to add to it. I replied that I’d like to have hardware UTF-8 de-/encoding but they wanted a more detailed proposal and I never got around to write it. I’m not even sure that this would be worthwhile, but I see UTF-8 de-/encoding everywhere in the code I write and would like it to approach memory read/write speeds.

I was very disappointed to learn that they had gone more proprietary with Power10 so I would not have been able to use those instructions anyway. What a pity!

In my actual code, I'm using a library called femtovg that is a Rust port of a C library for 2D rendering. But In the blog post I kept the example simple to keep it relevant for people who might want to use Web Workers + WASM for other things; didn't want to get hung up on femtovg for someone who had never heard of it. As you say, if you all you need to do is basic 2D manipulations of a canvas that are supported by the native API, then you likely don't need WASM.

You guys should also check out the femtovg project, a 2D rendering API that sixty fps relies on.

https://github.com/femtovg/femtovg

It's a decent starting point for trying to build your own toolkit.

I have recently added a wgpu backend but for now it lives in my fork https://github.com/adamnemecek/femtovg

run the demo with `cargo run --example wgpu_demo --release`.

Also join the femtovg discord https://discord.gg/V69VdVu

I'm involved with the femtovg project. We are definitely looking for contributors. Join the discord channel.

It's not a GUI framework but I'm involved with this project called femtovg, it's a Rust nanovg port. I've recently added a wgpu backend. Run the demo with cargo run --example wgpu_demo --release. Some people have been using it for their own UIs, e.g. tuix. I think that you should consider rolling your own GUI toolkit, it's not that bad and you'll appreciate the control.

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.