rivencraft/docs/PORTING.md

Porting plan

Mystcraft Legacy contains more than 700 Java source files and targets Minecraft 1.12.2. The Minecraft world-generation, dimension, registry, networking, and rendering APIs have all changed substantially since that release. The port is split into independently testable milestones.

Milestones

1. Bootstrap — NeoForge 1.21.1 build, mod metadata, item registration, and CI. Complete.
2. Books and linking — descriptive/linking book data components, lectern-like interaction, safe teleportation, and return links. In progress.
3. Ages — dimension definitions backed by data packs, deterministic seeds, lifecycle management, and persistence.
4. Writing system — pages, symbols, notebooks, desks, and book assembly.
5. Age grammar — translate symbol combinations into modern biome, noise, dimension-type, and worldgen configuration.
6. Instability — deterministic validation and effects with server-safe behavior.
7. Structures and polish — libraries, crystals, portals, recipes, models, sounds, advancements, compatibility, and migration tests.

Provenance rules

• New code uses the net.dnorberg.rivencraft package.
• Adapted Mystcraft code must retain its upstream copyright notice and be tracked in this document or a nearby source comment.
• Do not copy generated, binary, or third-party dependency content from the legacy repository.
• Preserve LGPL-3.0-or-later compatibility for the complete distributed mod.

First vertical slice

The first functional target is: create a Descriptive Book, bind it to one server-managed Age definition, travel to that Age, and use a Linking Book to return. This exercises persistence, networking, dimensions, and safety before the symbol grammar is introduced.

Milestone 2 progress

• Persistent, network-synchronized link-target data component.
• Linking Book binding with dimension, block position, yaw, and pitch.
• Server-authoritative cross-dimension travel with world-border, collision, fluid, and floor checks.
• Nearby landing search and clear failure messages.
• Descriptive Book identity and Age reference components.
• Return-link creation as part of Descriptive Book travel.
• Lectern-to-Book-Stand conversion, displayed book, activation, removal, persistence, and drops.
• Automated in-game tests for binding, persistence, and travel.

The temporary shapeless Linking Book recipe makes the linking subsystem easy to test. It can move into the writing/bookbinder progression when that system is implemented.

Age references use UUIDs rather than dimension keys. Milestone 3 will own the mapping from that stable identity to server data and a runtime dimension. This keeps saved books valid if an Age is migrated or regenerated.

Vanilla lecterns accept extensible item tags when inserting books, but their block entity still validates only vanilla writable and written books. To avoid an invalid lectern state, inserting a Rivencraft book converts the lectern into a visually compatible Rivencraft Book Stand. Removing the book converts it back.

Mystcraft Legacy did not impose an item cooldown when linking. Rivencraft's initial cooldown used Minecraft's item-type cooldown system, which delayed all Linking Book stacks at once. Version 0.1.3 removes that cooldown to match the legacy behavior.

Version policy

Versions follow x.y.z:

• x: major release point.
• y: number of completed milestones.
• z: iteration within the active milestone, including bug-fix releases.

Starting work on a milestone increments z. Completing it increments y and resets z to zero. The first milestone-2 slice is therefore 0.1.1, and milestone 2 completion will be 0.2.0.

Milestone 1 acceptance record

• The project builds on a Java 21 JDK with ./gradlew build.
• Mod identity and dependencies are declared in generated NeoForge metadata.
• Registrations are isolated by registry type and use deferred registration.
• The Descriptive Book loads with a model, name, tooltip, and creative tab.
• CI builds every pushed commit and pull request.