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.
• Book-screen foundation with server-authoritative naming, binding, and explicit link activation.
• Ponder dependency and isolated destination-preview level boundary.
• Server-provided destination snapshots rendered as rotating Ponder scenes.
• Book Stand floating names synchronized from the stored book stack.
• Open the stored book screen from a Book Stand with server-validated linking.
• 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 0.1.4 moves Linking Book binding and travel behind a book screen. The client requests an action, while the server revalidates the held book and owns all changes to its destination and custom name. Descriptive Book Age references now carry a display name alongside their stable UUID, with backward-compatible decoding for existing UUID-only data.

Version 0.1.5 ensures the book interaction listener opens screens only for the logical-client event. This avoids calling the render system from the integrated server thread when a book is used in singleplayer.

Version 0.1.6 gives the Linking Book screen an open-book layout inspired by the legacy interface. The destination preview occupies the left page, the book name and destination details occupy the right page, and the preview itself is the link action; the separate Link and Done buttons have been removed.

Version 0.1.7 suppresses Minecraft's default full-screen menu blur for the Linking Book screen. The open-book texture supplies the GUI background while the world remains sharp behind it.

Version 0.1.8 renders all Linking Book destination details in the same dark ink color as the book name for consistent contrast against the parchment.

Version 0.1.9 synchronizes the Book Stand's stored stack to clients and renders its display name as a camera-facing label above the book.

Version 0.1.10 corrects the nameplate transform and matches Minecraft's normal plus see-through text passes so angled stand geometry cannot hide the label.

Version 0.1.11 opens the stored book interface when a Book Stand is used with an empty hand. Linking Books travel through the preview panel, and the server revalidates the stand position, interaction distance, stored item, and target.

Version 0.1.12 replaces the Linking Book screen's convenience text draws with explicit no-shadow rendering for clearer dark ink on the parchment texture.

Version 0.1.13 requests a bounded, server-validated 9-by-7-by-9 block snapshot from the held book or nearby Book Stand and renders it as a clipped, rotating Ponder world section on the Linking Book's left page.

Version 0.1.14 expands the destination snapshot to 9-by-7-by-17 blocks along the Z axis, rescales the rotating scene to expose that depth, and colors the panel background with the destination biome's sky color.

Version 0.1.15 adds three dedicated-server GameTests covering Linking Book component serialization, successful safe travel with restored orientation, and rejection of fully blocked destinations. The test suite uses a minimal bundled structure template and runs with ./gradlew runGameTestServer.

Version 0.1.16 makes destination previews sample a centered 17-by-7-by-17 volume. The Ponder scene uses a scale that keeps its full horizontal diagonal inside the panel, so the complete snapshot remains available during its orbit.

The preview code is separated behind a renderer interface and uses an isolated Ponder level populated from server-authoritative destination snapshots.

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.