Pulsar

A high-performance lighting engine mod for Minecraft 1.12.2, built on Starlight's BFS propagation algorithm.

Warning

This mod is a personal hobby project and is currently in the early stages of development. As no precise benchmarks or tests have been carried out, we cannot guarantee its effectiveness. It may also corrupt your world, so we do not recommend using it unless you fully understand what it does. We accept no responsibility for any damage caused by its use.

Overview

Pulsar replaces Minecraft’s default lighting engine with a modern BFS-based implementation derived from Starlight. It is intended for use with CleanroomLoader.

Bringing the power of Starlight to 1.12.2.

What It Does

• Replaces vanilla's slow, iterative light propagation with Starlight-equivalent BFS
• Uses SWMR (Single Writer Multi Reader) nibble arrays for thread-safe concurrent lighting
• Runs light computation on dedicated worker threads with time-budgeted drain loops
• Writes results back to vanilla blockLight/skyLight nibbles — fully transparent to other mods

What It Doesn't Do

• No RGB / colored lighting (scalar only — same visual output as vanilla)
• No custom rendering pipeline — works through vanilla Chunk.getLightFor(), so renderers like Celeritas read correct values automatically

Incompatibilities

Pulsar fully replaces the vanilla lighting engine, so it conflicts with any mod that touches the same area.

Not compatible

• Phosphor (Forge) — mixes into the same methods; will not work alongside Pulsar.
• Alfheim — Phosphor-derived, conflicts for the same reason.
• Other lighting engine replacements — any mod that overrides Chunk.checkLight, recheckGaps, or enqueueRelightChecks will likely conflict.
• The Aether II — bundles Phosphor and therefore conflicts. Use The Aether II: Phosphor Not Included (a fork with Phosphor stripped) instead.

Not recommended

• OptiFine — its ASM-level Chunk modifications can interfere with Pulsar's mixins. If you want rendering speed, consider Celeritas instead.
• CubicChunks — extended world heights are not supported.

Requirements

• CleanroomLoader >= 0.5.x

Credits

• Claude — During development, Claude's ideas came to our rescue on numerous occasions.
• Starlight by Spottedleaf — the architecture and core algorithms (BFS propagation, SWMR nibble arrays, deferred lighting) are derived from Starlight's design.
• SuperNova by mitchej123 — a Starlight-inspired RGB colored lighting engine for 1.7.10. Pulsar is a scalar-only port of SuperNova's Starlight-derived BFS engine, with all RGB / color features removed. The majority of Pulsar's light engine, mixin targets and chunk-send strategy were rewritten with reference to SuperNova's implementation.
• Hodgepodge by GTNHdev — several of its optimizations are embedded in Pulsar, rewritten with reference to Hodgepodge's implementation.
• Alfheim by Desoroxxx — referenced when implementing Pulsar's BFS queue dedup layer (currently deprecated).
• GTNHLib by GTNHdev — code from several of SuperNova's dependencies has been rewritten for 1.12.2 and embedded into Pulsar.
• CleanroomModTemplate by CleanroomMC — Pulsar uses CleanroomMC's developer-friendly modern 1.12.2 modding template.

License

LGPL-3.0)