Slant

An educational phone game from the IDEMS game studio, based on Slant (also known as Gokigen Naname) from Simon Tatham's Portable Puzzle Collection.

Draw a diagonal line in every square so that each numbered point touches exactly that many lines, without the lines forming a closed loop.

• Swipe diagonally across a square to draw its line; tap a line to remove it. Connected lines share a colour.
• Thinking mode for hypotheses: lines are drawn dotted and still count towards the solution; keep or discard them all at once. Solid lines are protected while thinking.
• Sizes 4×4 to 10×10 (or custom up to 15×15), Easy and Hard.
• An interactive tutorial on first launch (and from the ? button).
• Puzzles are generated on the device; the generator is an exact port of the original, so a game ID such as 8x8dh#123456789012345 gives the same puzzle as the original collection.

Built with Angular and Capacitor (Android, and iOS later).

Getting started

The shared engine and shell come from the games-common-core submodule, so clone with:

git clone --recurse-submodules https://github.com/IDEMSInternational/slant.git
cd slant
npm install

(If you already cloned without it: git submodule update --init.) Run npm install here only, never inside games-common-core.

npm start              # dev server at http://localhost:4200
npm test               # unit tests, including 680 puzzles checked against the original
npm run build          # production web build
npm run apk            # Android debug APK -> Slant.apk

npm run apk needs JDK 21 (JAVA_HOME) and the Android SDK (ANDROID_HOME, or android/local.properties with sdk.dir=...).

To use a newer version of the shared code:

git submodule update --remote games-common-core
npm test -- --watch=false
git commit -am "Update games-common-core"

Layout

src/games/slant/            the game: no Angular except board/
  generator/                puzzle generation (random maze, then clues)
  solver/                   deduction solver (Easy and Hard techniques)
  state, moves, input, ...  rules and touch handling
  tutorial.ts               the interactive tutorial's steps
  board/                    the Angular board component (SVG) and line colours
  testing/                  reference puzzles recorded from the original
src/app/                    wires the game into the shared shell
games-common-core/          shared engine and shell (submodule)
tools/c-reference/          builds the original C generator to record
                            reference puzzles (needs gcc and a checkout
                            of the original collection next to this one)
android/                    Capacitor's Android project

Licence

MIT. Parts are ports of Simon Tatham's Portable Puzzle Collection; see LICENSE.