Zenthra

A high-performance, immediate-mode UI framework written in Rust. Zenthra is built from scratch with a custom GPU render pipeline, a flexible layout engine, and a widget system designed for speed and ergonomics.

Features

GPU-accelerated rendering — Rect, text, and overlay draw commands sent directly to the GPU via WGPU
Immediate-mode API — no retained widget trees, rebuild UI each frame
Flexible layout engine — Row, Column, and Wrap layouts with alignment, padding, and gap support
High-performance virtualization — LazyContainer renders only visible items, handling millions of rows smoothly
Scrollable containers — built-in scroll state, drag scrollbars, and wheel events
Text system — powered by cosmic-text with full shaping support
Input widgets — single-line Input and multi-line TextArea with cursor, selection, and scrolling
Theming — composable styling via builder methods on every widget

Quick Start

use zenthra::prelude::*;

fn main() {
    App::new()
        .title("My App")
        .size(800, 600)
        .with_ui(|ui| {
            ui.text("Hello, Zenthra!")
                .size(32.0)
                .color(Color::WHITE)
                .show();
        })
        .run();
}

Examples

cargo run --example hello
cargo run --example containers
cargo run --example text
cargo run --example edit

Widgets

Widget	Description
`container()`	Layout box with padding, bg, radius, scroll, row/column/wrap
`lazy_container()`	Virtualized container — only renders visible items
`text()`	Styled text with font size, color, alignment
`button()`	Interactive button with hover/active states
`input()`	Single-line text input
`text_area()`	Multi-line text editor

See docs/widget-guide.md for full API reference.

Architecture

See docs/architecture.md for an overview of the rendering pipeline, layout engine, and state management.

License

Apache 2.0 — see LICENSE.