Massive performance issue in net.vit.jurassicreborn.common.util.EntityColorTint

[pycoda]

using jurassic-reborn 1.20.1, forge version 47.4.16, java 17.0.8

there is a serious performance issue in net.vit.jurassicreborn.common.util.EntityColorTint.

the method isEntityInList(Entity) is called during entity rendering and performs a linear scan over a class list using Class.isAssignableFrom every call, with no caching.

this runs per-entity, per-frame, on the render thread.

symptoms:

• spawning as few as 10 vanilla sheep drops fps from ~60 to ~30 when looking at them
• spark profiler shows EntityColorTint.isEntityInList taking ~50–60% of total render time (https://spark.lucko.me/XrbBdL3Mxn)
• issue reproduces even with only vanilla entities (no dinosaurs required, tested on sheep, chicken and cows)

problematic code:

public static boolean isEntityInList(Entity test){
    for(Class<? extends Entity> entity : entityClasses){
        if(entity.isAssignableFrom(test.getClass())){
            return true;
        }
    }
    return false;
}

why this is bad:

• called repeatedly for the same entity classes

• cost scales with entities × frames × class list size

proposed fix (tested):
cache results per entity class and invalidate cache when the list changes

private static final Map<Class<? extends Entity>, Boolean> CLASS_CACHE = new HashMap<>();

...

public static boolean isEntityInList(Entity test) {
    Class<? extends Entity> clazz = test.getClass();

    Boolean cached = CLASS_CACHE.get(clazz);
    if (cached != null) return cached;

    boolean result = false;
    for (Class<? extends Entity> entity : entityClasses) {
        if (entity.isAssignableFrom(clazz)) {
            result = true;
            break;
        }
    }

    CLASS_CACHE.put(clazz, result);
    return result;
}

also clear the cache in:

• addEntityClassToList
• removeEntityClassFromList

result after patch:

• fps drop completely eliminated
• same scene stays at ~60 fps

this is not a forge issue, gpu issue, or entity count issue

(images show before and after results, MASSIVE ~75% decrease in render thread)

fixed ver:
EntityColorTint.java