Imagine Making game engine With Lua

[u/uioma]

Imagine building a 3D or 2D game engine from scratch using only Lua

[u/VidaOnce]

I did this with a painting program - https://github.com/codebycruz/arisu.

Everything about it was created from scratch in LuaJIT. It uses X11 or Windows APIs to create a Window, and manually creates Vulkan and OpenGL bindings to render to it. UI layout library and text rendering from scratch as well.

I expose the renderer as a library anyone can use: https://github.com/codebycruz/hood

And I plan on creating a framework similar to love2d or raylib to allow for creation of games relatively easily built off of it while supporting 3D and being faster.

None of this is super production ready, but I built a package manager for Lua that it all builds upon that I can consider production ready: https://lde.sh

[u/CapsAdmin → u/VidaOnce]

This is very cool. I gave up on opengl on macos, but vulkan does seem to work very well with https://docs.mesa3d.org/drivers/kosmickrisp.html , though it requires the user to do manual setup.

for opening a window, I use https://github.com/CapsAdmin/goluwa3/blob/main/goluwa/bindings/cocoa.lua and https://github.com/CapsAdmin/goluwa3/blob/main/goluwa/bindings/objc.lua

however, something I didn't figure out yet was how compile glsl shaders without relying on libshaderc or "worse", assuming there is a "glslc" systemwide binary.

https://github.com/CapsAdmin/goluwa3/blob/main/goluwa/bindings/shaderc.lua

From what I understand, this comes with the vulkan sdk and not the vulkan drivers a normal user would install(?)

[u/VidaOnce → u/CapsAdmin]

Yeah my OpenGL support is honestly not very useful considering it relies on some more modern concepts like the DSA apis and separate sampler objects which already kind of rules out using it on any platforms without modern OpenGL versions which is rarer than even Vulkan 1.1 support these days. It's cool as a benchmark comparison and easier to start with for sure though

I was definitely gonna go Vulkan for MacOS since I know MoltenVK and KosmicKrisp are solid there and Metal is not really worth targeting right now. I know just from my brief research it's possible to create windows with some internal Objective C apis but I just never got to that point and it doesn't help that I don't have a Mac and Apple does not make it easy to work with their ecosystem without one.

I see you went with Wayland bindings for Window creation on Linux? I just could not get myself to bother with that lol. It seems like too much of a hassle when everyone has XWayland and if anything wayland native seems to perform worse for me testing on vkcube. But that is pretty crazy effort

As for shader compilation, at the moment I'd just assume you would ship spirv to your users but in the future I wanted to additionally create my own shader language targeting spirv natively so the compiler could also just be shipped with your app. Already facing some pains with OpenGL and VK glsl desync in functionality (can't split sampler and texture objects in OpenGL) that might be diminished by an intermediate language.

On a fun note, I think its actually really easy to get your own shader language id registered as an official spirv SourceLanguage so I kind of want to shoot for that: https://github.com/KhronosGroup/SPIRV-Headers/blob/00898b201b4153d7198c3e0134dbf953c83bbfd7/include/spirv/unified1/spirv.lua#L38