ZeroSeek v1.4.0 — Modular Architecture, Hybrid MMap Storage, Integrated StarLight & Hardware GPU Acceleration

ZeroSeek v1.4.0 is a milestone release delivering a modularized engine architecture, complete stabilization of the Anvil storage layer, integration of the StarLight lighting engine, natural mountain height restoration, and optional hardware GPU acceleration via the NVIDIA CUDA Driver API on Minecraft 1.21.11 (Fabric).

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What's New

1. Modular Subproject Architecture

ZeroSeek has been decoupled into four specialized, maintainable submodules:

• zeroseek-base: Core server engine containing low-level Java 22 Foreign Function & Memory (FFM) MMap I/O, native OS kernel memory hints (posix_madvise / PrefetchVirtualMemory), CPU thread affinity isolation, and the Non-Destructive TPS Governor.
• zeroseek-worldgen: Multi-threaded terrain generator with 2D Chebyshev Spatial Locking ($3 \times 3$), ChunkMap & ChunkStep interceptors, 3D biome caching, SIMD density interpolation, and memory-compact palettes.
• zeroseek-cuda: Optional GPU compute module communicating directly with nvcuda.dll / libcuda.so via Java 22 FFM downcalls for asynchronous preliminary surface noise prefetching and NVRTC runtime kernel compilation.
• zeroseek-light: High-performance deferred lighting engine embedding the StarLight lighting algorithm directly into ZeroSeek.

2. Hybrid MMap Storage Engine (Zero Corruption Guarantee)

The delta persistence subsystem (ExternalDeltaManager and RebaseWorker) has been completely removed in favor of a clean, robust hybrid storage model:

• Zero-Copy MMap Reads: Chunk reads continue to utilize ultra-fast zero-copy memory mapping via Java 22 MemorySegment and Arena.ofShared(), bypassing JVM Heap allocations.
• Vanilla Async Sector Writes: Chunk writes are delegated to vanilla Minecraft's battle-tested asynchronous StorageWorker pipeline, guaranteeing 100% Anvil sector table integrity.
• Targeted Cache Invalidation: RegionFileMixin hooks directly into sector write operations to instantly evict dirty region mappings from the bounded MmapLruCache (default 2 GB), eliminating stale cache reads without introducing thread races.

3. Integrated StarLight Lighting Engine (zeroseek-light)

• Replaced Vanilla's recursive, single-threaded LightEngine with StarLight's lock-free, bitwise SWMR (Single Writer Multi Reader) algorithm.
• Lighting propagation tasks are fully decoupled from critical chunk generation threads and processed through a non-blocking deferred queue.
• Eliminates lighting stalls during rapid world generation and high-speed player travel.

4. Hardware GPU Acceleration (zeroseek-cuda, Optional)

• Pure FFM Driver API Binding: Direct low-overhead invocation of NVIDIA CUDA Driver API without intermediate JNI or external native libraries.
• 2D Preliminary Surface Grid Prefetching: Asynchronously computes a $24 \times 24$ column grid with a $-48$ block offset on NVIDIA RTX GPUs, achieving 100% cache hit rates during Aquifer water and lava level evaluations.
• Runtime NVRTC Compilation: Dynamically compiles Minecraft density function compute kernels at server startup tailored to the host GPU architecture.

5. Micro-Architectural WorldGen Optimizations

• 3D Biome Caching (Biome3DCache & ClimateColumnCache): Thread-local spatial hash maps cache multi-octave climate samplings and climate search tree traversals, dramatically cutting redundant biome queries.
• SIMD Trilinear Density Interpolation (DensityInterpolatorSimd): Accelerates 3D density grid interpolation across chunk cell boundaries using vectorized float primitives and precomputed trigonometric lookup tables (CompactSineLUT).
• ZeroSeek Compact Hash Palette: Memory-compact palette replacement for PalettedContainer, significantly reducing memory allocations during block state storage.

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Bug Fixes & Critical Stability

1. Elimination of Region File Corruption

• Issue: In prior builds (v1.2.0–v1.3.0), the asynchronous RebaseWorker thread merged .raw delta files back into .mca files concurrently with active game writes. Under high write concurrency, this caused sector allocation table collisions and region file corruption.
• Fix: Complete removal of delta layer files and background rebase threads. Writes now flow through vanilla storage workers, while reads utilize the fast MMap path with strict sector invalidation.

2. Restoration of Natural Mountain Heights (Removal of NoiseHeightCuller)

• Issue: An experimental height-culling optimization (NoiseHeightCuller) prematurely skipped noise evaluations above Y=264, causing artificial flat plateaus on high mountain peaks (Jagged Peaks, Frozen Peaks, Stony Peaks).
• Fix: Completely excised NoiseHeightCuller. Mountain peaks now generate authentically up to the full vanilla build ceiling (Y=320) with natural slopes and cliffs. Terrain generation speed is maintained through SIMD interpolation and GPU prefetching instead of destructive culling.

3. Elimination of Lighting Thread Stalls

• Issue: Vanilla lighting calculations during concurrent chunk generation frequently blocked worker threads waiting for neighbor chunk light propagation.
• Fix: Integration of the lock-free StarLight engine resolves neighbor lighting dependencies asynchronously without thread contention.

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⚠️ Compatibility & Incompatibilities

Because ZeroSeek deeply modifies low-level Minecraft server subsystems (Region I/O, WorldGen chunk scheduling, Noise evaluation, and Lighting), running other mods that modify the same systems will cause startup crashes or fatal conflicts.

❌ Incompatible Mods (Do NOT install alongside ZeroSeek)

• C2ME (Concurrent Chunk Management Engine): Hard conflict. Both mods replace chunk task scheduling, ChunkStep hooks, and region I/O. Will cause startup crashes and deadlocks.
• StarLight / ScalableLux: Hard conflict. ZeroSeek v1.4.0 already integrates StarLight inside zeroseek-light. Adding external StarLight or ScalableLux will cause duplicate Mixin injection crashes on LevelLightEngine and ThreadedLevelLightEngine.
• Noisium: Hard conflict. Both mods hook into the same density function and noise evaluation pipelines.
• Krypton: May cause packet race conditions with async chunk serialization.

✅ Fully Compatible & Recommended Mods

• Performance: FerriteCore, ModernFix, MemoryLeakFix, FastSuite.
• Gameplay & Entities: Lithium (compatible with entity and AI optimizations; ZeroSeek handles chunk I/O and worldgen).
• Client Visuals: Sodium, Iris, Nvidium, Voxy (ZeroSeek is strictly server-side).
• WorldGen Datapacks: Terralith, Biomes O' Plenty, Nullscape.
• Dynmap / Map Viewers: BlueMap, Dynmap, Pl3xMap.

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Configuration Changes (config/zeroseek.json)

New configuration options available in v1.4.0:

• cudaAccelerationEnabled (default: false): Enables NVIDIA GPU acceleration via CUDA Driver API. Requires an NVIDIA RTX GPU and modern NVIDIA display drivers.
• cudaPrefetchEnabled (default: true): Asynchronous 2D grid prefetching for surface noise.
• cudaPrefetchRadius (default: 5): Chunk radius for GPU prefetch dispatch.
• biomeOptimizationEnabled (default: true): Enables 3D biome caching and climate column acceleration.

Legacy delta settings (rebaseIntervalSeconds, rebaseBatchSize, deltaStoragePath) have been deprecated and removed.

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Target Platform & Requirements

• Minecraft: 1.21.11 (Official Mojang Mappings)
• Fabric Loader: 0.18.2+
• Fabric API: 0.139.4+1.21.11
• Java Toolchain: Java 22 (release = 22 required for FFM API)
• Operating System: Windows (x64) and Linux (x64)
• Side: Dedicated Server (Server-side only)
• Output Jar: zeroseek-1.4.0.jar