Learn Rust & egui — Schematic and PCB Design Review System

Interactive engineering course for learning Rust and egui by building a 2D CAD Schematic and PCB Design Review System, verified continuously with unit tests (cargo test) and mutation testing (cargo-mutants).

Live Course on GitHub Pages

• Course Index

Foundation: Project Setup & Immediate-Mode Core (0001–0002)

• Lesson 0001: Bootstrapping Your Rust & eframe Project (apps/0001-project-setup-and-eframe-boot)
• Lesson 0002: The Immediate-Mode Loop & Mutable State (&mut) (apps/0002-the-immediate-mode-loop)

Act I: The 2D CAD Canvas & Viewport (0003–0006)

• Lesson 0003: Custom 2D Canvas & Drawing Primitives with Painter (apps/0003-custom-2d-canvas-and-painter)
• Lesson 0004: World-to-Screen Transforms, Drag Panning & Cursor-Centred Zoom (apps/0004-world-to-screen-transforms-pan-and-zoom)
• Lesson 0005: Modelling PCB Layers, Traces & Deterministic Z-Ordering (apps/0005-modeling-layers-traces-and-footprints)
• Lesson 0006: Spatial Hit-Testing, Selection State & Net Cross-Probing (apps/0006-hit-testing-and-net-cross-probing)

Act II: Schematic Views, Layout & egui_kittest (0007–0010)

• Lesson 0007: Schematic Symbols, Text Rendering & Headless UI Verification (egui_kittest) (apps/0007-schematic-symbols-and-text-rendering)
• Lesson 0008: Split Viewports (egui::Scene) & Schematic-to-PCB Cross-Probing (apps/0008-split-viewports-and-egui-scene)
• Lesson 0009: Searchable Netlist & Virtualised BOM Inspector (apps/0009-searchable-netlist-and-bom-inspector)
• Lesson 0010: Keyboard Shortcuts (F, M, Esc) & Point-to-Point CAD Ruler (apps/0010-keyboard-shortcuts-and-point-to-point-ruler)

Act III: Design Review Workflows (0011–0014)

• Lesson 0011: Review Pins, HashMap Entry API & Floating Callout Windows (apps/0011-review-pins-and-sticky-note-callouts)
• Lesson 0012: Review Status Triage, Severity Filtering & Sign-Off Rules (apps/0012-review-status-workflow-and-popups)
• Lesson 0013: DRC Clearance Violation Halos, Bounding-Box Reduction & Minimap Clamping (apps/0013-drc-violation-overlay-and-minimap)
• Lesson 0014: Custom egui::Widget Layer Swatches, Struct Lifetimes ('a) & Harness::new_ui_state (apps/0014-custom-layer-swatch-widget-and-design-tokens)

Act IV: Engine-First Architecture & Persistence (0015–0018)

• Lesson 0015: Multi-Crate Workspace — Separating pcb-doc (L1) from pcb-reviewer (L6) (apps/0015-multi-crate-workspace-doc-vs-ui-egui)
• Lesson 0016: Loading & Saving Board & Review Session Files (serde, serde_json & thiserror) (apps/0016-loading-board-and-review-files-serde)
• Lesson 0017: Copy-on-Write Document Snapshots with Arc & Arc::make_mut (apps/0017-copy-on-write-arc-document-snapshots)
• Lesson 0018: Undo/Redo History (VecDeque) & Continuous Slider Drag Coalescing (apps/0018-undo-redo-history-and-slider-coalescing)

Act V: Command Engine, Performance & Polish (0019–0022)

• Lesson 0019: The Command Pattern (CommandSpec), Command Palette & panic_hunt Fuzzing (apps/0019-the-command-pattern-and-command-palette)
• Lesson 0020: Spatial Viewport Culling (Rect::intersects) & Frame-Time Budgets (apps/0020-viewport-culling-and-cached-tessellation)
• Lesson 0021: Non-Blocking Background File Import (mpsc) & Progress UI (apps/0021-non-blocking-file-import-and-progress-ui)
• Lesson 0022: Offscreen Snapshot Parity (gpu_lock), Quality Scorecards & WebAssembly (wasm32) (apps/0022-headless-snapshot-testing-and-wasm-build)

Act VI: Real-World KiCad Parsing (nom) & Embedded SQL (Turso) (0023–0026)

• Lesson 0023: S-Expression Tokenizer & AST with nom (L0 Standalone Crate) (apps/0023-sexpr-tokenizer-and-ast-with-nom)
• Lesson 0024: Lowering KiCad .kicad_pcb S-Expressions into BoardModel & Corpus Oracles (apps/0024-parsing-kicad-pcb-and-sch-into-domain-model)
• Lesson 0025: Embedded SQL Review Store with Turso (turso_parser & Async tokio Bridge) (apps/0025-embedded-sql-review-store-with-turso)
• Lesson 0026: Local-First Replica Sync, Atomic SQL Transactions & Tamper-Evident Audit Trails (apps/0026-local-first-review-sync-and-audit-trail)

Act VII: Agentic Hardware Review & Model Context Protocol (rmcp) (0027–0030)

• Lesson 0027: LLM-Native Spatial & Electrical Queries (schemars JSON Schema) (apps/0027-llm-native-spatial-and-electrical-queries)
• Lesson 0028: Headless MCP Server (rmcp), Resources, Tools, Prompts & Mock Duplex Client (apps/0028-headless-mcp-server-rmcp-and-mock-client)
• Lesson 0029: Bridged MCP Control Channel, Bearer Auth & Cropped Live GUI Snapshots (apps/0029-bridged-mcp-control-channel-and-live-gui-snapshots)
• Lesson 0030: Embedded egui MCP Inspector Workbench, Agent Playbooks & Act VII Scorecard (apps/0030-egui-mcp-inspector-workbench-and-agent-playbooks)

Reference & Cheat Sheets

• Glossary of Rust & egui Terms
• Immediate-Mode GUI Cheat Sheet
• Testing & Mutation Coverage Cheat Sheet

Running the Companion Rust Applications

Each lesson has a runnable companion Cargo crate in ./apps/<NNNN-lesson-slug>/:

# Run Lesson 0006's interactive PCB Reviewer desktop app
cargo run --manifest-path ./apps/0006-hit-testing-and-net-cross-probing/Cargo.toml

# Run unit tests and mutation testing
cargo test --manifest-path ./apps/0006-hit-testing-and-net-cross-probing/Cargo.toml
cargo mutants -d ./apps/0006-hit-testing-and-net-cross-probing

Building the Course Pages from Markdown (build.py)

All course pages (index.md, lessons/*.md, and reference/*.md) are authored in Markdown and compiled to standalone HTML via build.py:

# Compile all Markdown pages in-place and run link, frontmatter, and equal-word-count quiz checks
.venv/bin/python build.py --check

# Or build a standalone bundle into _site/ (used by GitHub Pages CI)
.venv/bin/python build.py --out-dir _site --check

License

Licensed under the Apache License, Version 2.0.

Disclaimer

This is not an official Google product.