Sudoku Solver (Odin + Raylib 6)

A clean, interactive Sudoku editor and solver written in Odin using Raylib 6.

This project is both a useful tool and a learning platform for idiomatic Odin, modular design, and app structure.

Screenshots

     

  

Features

• Full 9×9 grid with clear 3×3 block borders
• Light & dark themes (toggle with Space)
• Mouse + keyboard navigation (arrows, WASD, hjkl)
• Tab / Shift+Tab jumps between 3×3 blocks
• Number entry (1–9) and clear (Backspace / Delete)
• Conflict highlighting (row, column, and 3×3 box) in red
• Lock / unlock system (Ctrl+Shift+L toggles)
  • Locked cells use bold font + outline
  • Ctrl+Shift+C clears all unlocked cells
• Backtracking solver (Alt+S); locked cells treated as givens
• Save puzzles (Ctrl+S) to puzzles/easy/<hash>.sudoku (simple text format)
• Load puzzles (Ctrl+O) — currently loads a fixed path; lists files in puzzles/easy
• Exit confirmation dialog
• Monospaced fonts (Roboto Mono)

Controls

Input	Action
Mouse click	Select cell
Arrows / WASD / hjkl	Move selection
Tab / Shift+Tab	Jump to next/previous 3×3 block
1–9	Enter number
Backspace / Delete	Clear cell
Space	Toggle light/dark theme
Ctrl+Shift+L	Toggle lock on filled cells
Ctrl+Shift+C	Clear all unlocked cells
Alt+S	Solve current board
Ctrl+S	Save puzzle
Ctrl+O	Open puzzle (path still hard-coded)
Esc, then Y/N	Quit

Building

make run      # odin run . -collection:src=src
make build    # produces ./sudoku-solver
make test     # runs logic tests

Requires a recent Odin with Raylib 6 and collection support (e.g. dev-2026-08+).

Project structure

.
├── main.odin              # entry: game.run()
├── Makefile
├── ols.json               # OLS collection: src
├── assets/
│   ├── fonts/...
│   └── screenshots/...
├── puzzles/easy/          # saved .sudoku files
└── src/
    ├── game/              # main loop
    ├── state/             # Game struct, constants, init
    ├── events/            # keyboard + mouse handlers
    ├── render/            # grid, numbers, dialogs
    ├── helpers/           # conflict check, which_block, etc.
    ├── logic/             # solver, save, load, list_puzzles
    ├── fonts/
    ├── theme/
    └── vecs/

Branches

• master — stable snapshot of what works today
• dev — active development (work only happens here)

Roadmap

1. Selectable open path / simple file picker for load
2. Dirty flag; warn on exit if unsaved
3. Undo / Redo
4. Pencil marks, more themes, export (stretch)
5. WASM / Linux polish

Project roadmap also lives on the wiki DOC.

Notes

• Coordinate convention: selected.x = row, selected.y = col
• Locked cells = puzzle givens; Ctrl+Shift+C clears the rest
• Prefer alphabetical order for struct fields and constant lists

License

Learning / personal use. Fonts are under the OFL (see assets/fonts/).