cotis-wgpu 0.1.0-alpha

Desktop wgpu renderer backend for Cotis
Documentation

cotis-wgpu

cotis-wgpu is the desktop wgpu renderer backend for Cotis. It implements Cotis's renderer traits on top of wgpu, winit, and glyphon, and can be used as a drop-in alternative to other Cotis backends such as cotis-raylib.

Status: Early 0.1.0-alpha release. APIs are still evolving alongside the core Cotis crates.

This repository contains the renderer backend only. A full desktop application also needs core Cotis crates, a layout engine, and a pipe from the ecosystem below.

Architecture

Each frame flows through five stages. This crate owns the renderer stage:

flowchart LR
    UI[UI_closure] --> LayoutMgr[CotisLayoutManager]
    LayoutMgr --> LayoutOut[RenderCommandOutput]
    LayoutOut --> Pipe[cotis-pipes]
    Pipe --> Renderer[CotisWgpuRenderer]
  1. A layout manager prepares for the frame.
  2. UI code builds the element tree through the configurator API.
  3. The layout manager produces layout output items.
  4. A pipe transforms those items into renderer commands.
  5. CotisWgpuRenderer draws the command stream through wgpu.

Installation

Add the renderer and required core crates to your Cargo.toml:

cotis-wgpu = "0.1.0-alpha"
cotis = "0.1.0-alpha"
cotis-defaults = "0.1.0-alpha"
cotis-utils = "0.1.0-alpha"
cotis-layout = "0.1.0-alpha"
cotis-pipes = "0.1.0-alpha"

Quick start

Clone this repository and run the shipped example:

git clone https://github.com/igna-778/cotis-wgpu
cd cotis-wgpu
cargo run --example basic_example -p cotis-wgpu

The example opens a resizable window, lays out UI with cotis-layout and cotis-pipes, and renders rectangles, borders, and text through wgpu.

Typical app wiring

use cotis::cotis_app::CotisApp;
use cotis_layout::preamble::CotisLayoutManager;
use cotis_pipes::cotis_layout_pipes::CotisLayoutToRenderListPipeForGenerics;
use cotis_utils::math::Dimensions;
use cotis_wgpu::prelude::*;

let renderer = CotisWgpuRenderer::auto_start();
let manager = CotisLayoutManager::new(Dimensions::new(1000.0, 800.0));
let mut app = CotisApp::new(renderer, manager, CotisLayoutToRenderListPipeForGenerics);

while !app.render().window_should_close() {
    app.compute_frame(|root| {
        // Build your UI tree here.
    });
}

Swap cotis-wgpu for cotis-raylib or another backend without changing layout or UI code.

Ecosystem

Cotis is split across several repositories. This repo provides the wgpu renderer; sibling repos provide core traits, layout, and pipes.

Repository Role
cotis Core traits and CotisApp orchestration
cotis-layout Flexbox-style layout engine (CotisLayoutManager)
cotis-pipes Layout output to render commands (CotisLayoutToRenderListPipeForGenerics)
cotis-wgpu (this repo) Desktop renderer (wgpu + winit + glyphon)
cotis-raylib Desktop renderer (raylib)
cotis-renderer-template Scaffold for authoring a custom render backend
cotis-cli Plugin host for installable build and run routines

Pick a renderer backend and swap it without changing layout or UI code. Use cotis-renderer-template to implement a new backend.

Features

Feature Effect
complex-color Enables ColorLayer types from cotis-defaults; gradients are not rendered (solid/layered fallback only)

Known limitations

  • Gradients — complex-color is supported, but gradient layers fall back to solid or layered colors.
  • Images — Image commands render as colored placeholder rectangles (no texture sampling yet).
  • Alpha blending — limited support; see crate rustdoc for details.

Documentation