gi-gtk-declarative VS nanovg

Have a look at https://reflex-frp.org/, or https://owickstrom.github.io/gi-gtk-declarative/, they are an interesting and different way of working with UI in a non imperative way.

There's also gi-gtk-declarative.

What are the main differences to and advantages over gi-gtk-declarative?

Indeed I don't have to publicize it, but sometimes I want to help others who are stuck when an upstream author is unresponsive. The question I asked yesterday was specifically in response to creating a workaround for gi-gtk-declarative @ https://github.com/owickstrom/gi-gtk-declarative

Yeah, if you are interested enough to check out my PR at gi-gtk-declarative (https://github.com/owickstrom/gi-gtk-declarative/pull/90), then you will see how much I bent over backwards to avoid laying the foundations for an ormolu/fourmolu-like situation. Although, given that the project appears to be the only maintained declarative gui library in Haskell, I think the single-point-of-failure needs to be addressed.

I use nanovg for my projects and it works surprisingly well for its size. It integration is pretty simple .... if you know a little bit of OpenGL, otherwise there is a slight learning curve.

The "engine" is built on top of amazing https://www.lwjgl.org/ and https://github.com/bkaradzic/bgfx/, and UI system is baked by https://github.com/memononen/nanovg and https://github.com/facebook/yoga

NanoVG is the closest thing I came across when I had a similar quesiton: https://github.com/memononen/NanoVG

unfortunately it doesn't seem like it's getting steady updates now unlike the last time I checked. But I imagine it's pretty mature at this point. There also seem to be ports in Metal/DX11 if you didn't want to be stuck in OpenGL.

Also there's NanoVG if you really want a vector api in C, but don't need anti-aliased clipping.

Getting sufficient antialiasing quality for 2D graphics is difficult on GPUs. https://github.com/memononen/nanovg accomplishes this with GL2/GLES2 level hardware for most of the stuff one would want to render as part of a GUI. My project https://github.com/styluslabs/nanovgXC supports rendering arbitrary paths with exact coverage antialiasing, but requires GLES3.1 or GL4 level hardware for reasonable performance.

> to learn the 'nuts and bolts' of rendering

These nuts and bolts are very different between CPU and GPU. CPU-based libraries are painting pixels in bitmaps in system memory. Most GPU-based libraries are uploading indexed triangle meshes, and rendering them with weird shaders.

Worse, there're no good open source implementations of GPU-based ones. Microsoft ships an implementation as a part of OS (Direct2D) but it's not open source. Linux simply doesn't have an equivalent.

At least for initial versions, consider C interop with this https://github.com/memononen/nanovg It cuts a few corners (no cleartype for text, CPU overhead for repeated rendering of same static paths) but it's still good overall, simple, and easy to use.

> My only concern with C# is the cross compatibility

Works well on Linux, Windows and OSX, including ARM CPUs. Not sure about Android and iOS, never tested.

My largest concern with C# would be performance. Technically the language allows to code in any style, but most guides and examples are using OO-heavy one.

In fact, if using a modern graphics pipeline with shaders, you will actually have to learn how to draw a single rectangle to your screen, and then use that knowledge to draw (anti-aliased) lines, rectangles, arcs, circles, ellipses, etc. too. For instance, have a look at https://www.cairographics.org/ https://github.com/vurtun/nuklear https://github.com/memononen/nanovg and https://github.com/nical/lyon. There are probably also tutorials on how to draw vectorized graphics using OpenGL, Vulkan, etc.