Digraph DS

Digraph DS is a graph editor and analysis tool for Nintendo DS. Draw and move vertices with the stylus, connect them with directed or undirected edges, and explore the results on the second screen. Projects can be saved to SD or a flashcart filesystem.

This is the continuation of Digraph Explorer 0.5.10, built with Rust, Bevy ECS, and BlocksDS through devy. This repository contains the application; devy provides the runtime and hardware services.

What you can do

• Edit graphs, pan and zoom, or generate complete and random graphs.
• Explore paths, connectivity, cuts, matchings, DAG transformations, and game positions such as P/N and Sprague–Grundy values.
• Compare the original graph with an analysis result and apply supported transformations when you want to keep them.
• Save named projects, reopen them from the graph menu, and change the theme.

Build the ROM

You need Rust, a nightly toolchain with rust-src, Python 3, Wonderful Toolchain, and BlocksDS.

git clone https://github.com/Vjarkjan/digraph-ds.git
cd digraph-ds
rustup toolchain install nightly --component rust-src --component clippy
bash scripts/nds.sh rom

The ROM is written to output/digraph-ds.nds. Open it in a DS emulator or copy it to your homebrew loader. Cargo fetches the pinned devy revision; you do not need a separate engine checkout.

The build defaults to /opt/wonderful and /opt/wonderful/thirdparty/blocksds/core. Set WONDERFUL_TOOLCHAIN and BLOCKSDS if your installation is elsewhere. NDS_TOOLCHAIN selects another Rust nightly, and DIGRAPH_ARM7 can select a different compatible ARM7 binary.

Controls

The bottom screen is the editor. Select a tool from the menu, then use the stylus to place, select, or drag vertices. For edges, choose the edge tool and tap the two endpoints. The upper screen shows the graph or the current result.

Button	Action
A / B	Open vertex / edge tools
Y / X	Open algorithms / components
Down	Open or close the menu
Left / Right	Move through menu items
A in a menu or dialog	Confirm
B in a menu or dialog	Close
Start / Select	Zoom in / out
L with the menu closed	Apply the current supported transformation
Up outside a dialog	Clear the graph

The GRAPH tab contains graph generation, view switching, statistics, SAVE AS..., and OPEN SAVED.... Algorithms that need a source or target use the vertices selected with SET SOURCE and SET TARGET.

Saved projects

Storage is initialized on the first save or load. The app tries sd:/graph/analysis/, then fat:/graph/analysis/. Your loader must provide SD access or a working DLDI filesystem. Editing and analysis also work without writable storage.

Named projects use .dgxp files and a graphs.dgxi index. The quick save/load actions use current.dgxp. Project names accept up to 12 ASCII letters, digits, hyphens, or underscores. Keep the index with the project files when backing up the library.

Development

cargo test --locked
cargo run --locked
cargo clippy --locked --all-targets -- -D warnings
bash scripts/nds.sh clippy

On a computer, cargo run initializes the editor and checks the starter graph without opening a window. The graphical application runs in the DS ROM.

See the code guide, restrictions, and validation record for the module layout and tested behavior. The application grew from the local Digraph work on kts-nds; its extraction is recorded in Doc/origin.md.