Matching Unity and Inky topic

ink_dart is checked against inkle's C# runtime, so a story plays the same here as in Unity, Inky or inklecate: the same seed and choices give the same text, tags, choices, errors and save files.

Numbers

ink's numbers follow C#, not Dart or JavaScript:

• Integers are 32-bit and wrap around on overflow.
• Floats are 32-bit and print the way .NET does: 7 / 3.0 prints 2.3333333, very small or large values use E notation (1E-05), and infinity prints Infinity.
• A float result stays a float even when it's whole (1.5 * 2 is 3.0, saved as 3.0).

inkjs, the JavaScript port, uses 64-bit doubles and turns whole results into integers, so a story can print different numbers there than in Unity. ink_dart sides with Unity.

Randomness

RANDOM, LIST_RANDOM and shuffles use .NET's seeded System.Random, as the C# runtime does, so the same storySeed gives the same rolls and shuffles as a Unity build. Set story.state.storySeed to fix the seed, for example in tests.

One difference

The C# runtime prints floats in the device's language settings (2,5 in some locales). ink_dart always prints the invariant form (2.5).

How it's checked

Every release plays 176 stories (inkjs's test corpus, inkjs's integration story, and cases written for the port) and compares each line, tag, choice, error and save with what the C# runtime recorded. Each story is also replayed through a save and load at every choice, and saves made by inkjs are loaded too. A fuzzer plays thousands of random runs in both runtimes and compares them.

Classes

Story

A Story is the core class that represents a complete Ink narrative, and manages the evaluation and state of it.