eu4rs

eu4rs is an experimental open-source game engine reimplementation ("source port") for Europa Universalis IV.

Goals

• Performance: High-performance rendering using wgpu (Vulkan/Metal/DX12).
• Compatibility: Load and play using original game assets (data-driven design).
• Portability: Native support for Windows and Linux.
• Safety: Built in Rust for memory safety and concurrency.

Project Structure

This project is organized as a Cargo Workspace containing:

• eu4viz: The main visualizer application for viewing and interacting with EU4 maps.
• eu4data: A library containing strong types and logic for EU4 game objects.
• eu4txt: A library (crate) providing a custom parser/tokenizer for the EU4 text format (Windows-1252 encoded). See docs/file_formats.md.

Installation

Ensure you have Rust installed.

git clone <repository-url>
cd eu4rs
cargo build --release

Usage

Launch the Interactive Map (GUI) - Recommended default

cargo run

Controls

• Zoom: Scroll Wheel (Up/Down)
• Pan: Middle Mouse Button (Hold & Drag)
• Inspect: Left Click on a province to view details
• Toggle Map Mode: Press Tab to cycle through map modes (Province, Political, Trade Goods, Religion, Culture).

Render map to an image file (Headless)

cargo run -- snapshot --output province_map.png --mode province
cargo run -- snapshot --output political_map.png --mode political
cargo run -- snapshot --output tradegoods_map.png --mode trade-goods
cargo run -- snapshot --output religion_map.png --mode religion
cargo run -- snapshot --output culture_map.png --mode culture

Parse and pretty-print files (verifies parsing logic)

cargo run -p eu4viz -- --pretty-print --eu4-path "path/to/specific/file.txt"

features

• Custom Parser: Handles EU4's specific text format, including comments (#), whitespace-separated tokens, and key=value structures.
• Encoding Support: Automatically handles WINDOWS_1252 encoding common in Paradox files.
• Tolerant Parsing: Designed to handle quirks in game files (mostly).
• CI/CD: Automated GitHub Actions pipeline for building, testing, and linting (fmt, clippy).
• Statistics: The Filescanner provides quick statistics on your installation.
• Interactive Map: A hardware-accelerated (Vulkan/wgpu) map viewer that renders the game's provinces.bmp with correct aspect ratio and windowing.
• Political Map Mode: Visualizes country ownership with borders and filling based on game data.
• Headless Rendering: Ability to render the map to an image file without opening a window (--snapshot), suitable for automated testing in CI.
• Data Expansion: Parses and visualizes complex game data including Religion, Culture, and Trade Goods.
• Serde Support: eu4txt implements serde::Deserializer, allowing direct mapping of game files to Rust structs (in eu4data).

Documentation

• System Architecture: Overview of crate structure, rendering pipeline, and data flow.
• File Formats: Details on the EU4 text format, encoding, and syntax.
• Data Coverage: How we track Parse/Visualize/Simulate progress across game data.
• Supported Fields: Auto-generated matrix of every known EU4 data field.

License

Apache-2.0