Light Dust

Major Performance Overhauls

I was working to improve performance on my next mod mob detection when I figured that I would take my time looking over and optimizing my older code. Heres what has changed.

TLDR; It is much more optimized. Please use this version hence the version numbering.

• GC Micro-stutters: Completely overhauled the volumetric scanning system (BFS) used for ambient dust generation. The mod now recycles memory internally using static ArrayDeque and HashSet structures rather than creating thousands of temporary objects every few ticks.
  
  • ~90% reduction in memory allocation churn, which should eliminate major GC induced lag spikes.
    
    
• Primitive Maps via FastUtil: Purged standard Java ConcurrentHashMap caches in favor of FastUtil's Long2IntOpenHashMap and Long2ObjectOpenHashMap. This stops Java from constantly boxing primitive long coordinates into bloated Long objects, should save massive amounts of hidden memory churn.
  
  
• Distance Based Simulation LOD: Added a Level of Detail (LOD) check to the particle tick loop. Dust particles further than 16 blocks away from the player now skip expensive wind, lighting, and thermal math.
  
  
• Temporal Interleaving: * Maximized the mod's custom tickOffset staggering system. Instead of all 1,200 particles calculating their environment on the exact same frame, the mod splits the workload, forcing only 5% of active particles to calculate heavy environmental physics per frame.
  
  
• Optimized Mod Compatibility Layer: Replaced Java Reflection with native JVM MethodHandles for Curios and Accessories integration. Additionally, adjusted the slot scanning routine to check for handheld lights every 5 ticks instead of every single tick.
  
  • ~60% faster compatibility layer execution, saves up to 80% of CPU cycles previously spent on inventory polling.
    
    
• Config Caching: Particle properties (such as gravity, bounce forces, and wind deflection rules) are now cached locally as primitive values the moment a dust particle is spawned. This prevents thousands of active particles from concurrently invoking Forge's synchronized config map lookups every single frame.
  
  • ~85% drop in config related thread stalls, should massively improve FPS when theres a lot of particles on screen.
    
    
• Blockstate Checks for Thermal Drafts: Block searches for heat sources (Lava, Magma, Fire) have been changed to poll every 20 ticks (1 second) instead of 10. The physical force applied to the particles has been scaled to compensate for the delay, you will notice it a little bit but I doubt people are looking that closely to see.
  
  • 50% fewer getBlockState() chunk lookups.
    
    
• Thermal Draft Physics: Turned off physics, and player interactions when dust is affected by therumal updraft.
  
  • Should significantly reduce FPS drops when above or near lava pools or large amounts of heat sources.
    
    

Old vs New

Note: Data represents estimated (not experimental) performance scaling in a dense underground cave environment in many different environments using an RTX 3090 with default settings.

Bug Fixes

• Critical Lava Pool Lag Fix: Fixed a severe flaw where ambient dust would continuously spawn inside lava pools (because of the high light level) and fail to despawn instantly. Fluid collision checks now run instantly every tick, and the volumetric spawner strictly ignores fluid blocks, fixing a massive FPS drain in the Nether and deep caves.