Compatibility

GPU Support

Backend	Platform	Status
Vulkan	Windows, Linux	✅ Supported
DirectX 12	Windows	✅ Supported
Metal	macOS	✅ Supported
WebGPU	Web (wasm)	Planned
OpenGL	All	Not supported

Crate Version Pinnings

Workspace crates use pinned version ranges. Key dependencies:

Dependency	Role
wgpu ~0.22	GPU API abstraction
winit ~0.30	Window creation and events
cosmic-text ~0.12	Text shaping (HarfBuzz)
ureq ~3.0	HTTP image loading
image ~0.25	Image decoding (PNG, JPEG, GIF, BMP, WebP)
arboard ~3.4	Clipboard access
rfd ~0.15	Native file dialogs
egui ~0.31	egui integration (driver)
bevy ~0.15	Bevy integration (driver)

Rust Version

Requires Rust 1.78 or later (for impl Trait in associated types and other recent stabilizations).

Platform-Specific Notes

Windows

• DX12 is the default backend
• System fonts in C:\Windows\Fonts\
• BGRA8 surface format

Linux

• Vulkan is the default backend
• System fonts in /usr/share/fonts/ and ~/.local/share/fonts/
• May need libx11-dev, libwayland-dev, libudev-dev for winit

macOS

• Metal is the default backend
• System fonts in /System/Library/Fonts/, /Library/Fonts/, ~/Library/Fonts/

Browser Compatibility Goals

lui aims for CSS behavior parity with web browsers, not pixel-perfect rendering. The goal is to make CSS authored for browsers work correctly in lui, not to match every browser quirk.

Feature	Goal
Box model	CSS3 parity
Flexbox	Level 1 complete
Grid	Level 1 with limitations
Selectors	Level 4 complete
Colors	sRGB with alpha, CSS Color 4
Text	Basic styling, shaping via HarfBuzz
Cascade	CSS Cascade 3 with !important and CSS-wide keywords

Known Divergences

• em/rem default to 16px when no font-size is inherited (browsers use UA defaults)
• sticky positioning degrades to relative
• z-index sorts siblings but doesn't create independent stacking contexts
• No float layout
• No baseline alignment in flex/grid
• Dashed/dotted on elliptical rounded boxes falls back to straight segments at corners