EntityScaling ignores meta.rounding_unit, hardcodes rounding from modifier value

[rumrunner0]

EntityScaling ignores meta.rounding_unit config, hardcodes rounding from modifier value.

Summary

EntityScaling.apply() computes its own rounding unit from modifier.value * 0.25F instead of reading meta.rounding_unit from the config. This causes entity attribute modifiers to be rounded to arbitrary increments that don't match the user-configured rounding unit. ItemScaling correctly reads the config value via getRoundingUnit(), so loot scaling rounds properly while entity scaling does not.

Affected code

EntityScaling.java, lines 81-83:

var modifierValue = modifier.randomizedValue(level);
var roundingUnit = modifier.value * 0.25F;  // BUG: hardcoded, ignores config
modifierValue = (float) MathHelper.round(modifierValue, roundingUnit);

Reproduction

Config:

{
  "meta": {
    "rounding_unit": 0.5
  },
  "difficulty_types": [
    {
      "name": "wilds",
      "entities": [
        {
          "entity_matches": { "attitude": "ANY", "type": "" },
          "attributes": [
            {
              "attribute": "minecraft:generic.max_health",
              "operation": "MULTIPLY_BASE",
              "randomness": 0.0,
              "value": 0.15,
              "offset": 2.0
            }
          ]
        }
      ]
    }
  ]
}

Expected: Zombie (20 base HP) gets modifier value 2.0 + (0.15 * 1) = 2.15, rounded to nearest 0.5 = 2.0 or 2.5, resulting in 20 * 3.0 = 60.0 or 20 * 3.5 = 70.0 HP.

Actual: Rounding unit is computed as 0.15 * 0.25 = 0.0375. Modifier value 2.15 rounds to 57 * 0.0375 = 2.1375. Zombie gets 20 * 3.1375 = 62.75 HP.

The bug is more visible with non-zero offset, but also affects any modifier where value * 0.25 doesn't align with the configured rounding_unit. For example, with value: 0.3 and randomness: 0.05 at level 1, the rounding unit becomes 0.075 instead of the configured 0.5, producing values like 18.39 HP on mobs that should show clean half-point increments.

Additionally, when modifier.value is 0.0 (e.g., a flat offset-only modifier), the rounding unit becomes 0.0. In MathHelper.round(), this computes 1.0 / 0.0 = Infinity, then Math.round(value * Infinity) = Long.MAX_VALUE, then Long.MAX_VALUE / Infinity = 0.0. The modifier is silently zeroed out instead of being applied.

Suggested fix

Option A: Extract a shared RoundingHelper class that reads meta.rounding_unit from config. Both EntityScaling and ItemScaling use it instead of each having their own implementation.

// RoundingHelper.java (new file in net.dungeon_difficulty.logic)
package net.dungeon_difficulty.logic;

import net.dungeon_difficulty.DungeonDifficulty;
import org.jetbrains.annotations.Nullable;

public class RoundingHelper {
    @Nullable
    public static Double getRoundingUnit() {
        var config = DungeonDifficulty.config.value;
        if (config.meta != null && config.meta.rounding_unit != null) {
            return config.meta.rounding_unit;
        }
        return null;
    }
}

// EntityScaling.java, replace lines 81-83:
var modifierValue = modifier.randomizedValue(level);
var roundingUnit = RoundingHelper.getRoundingUnit();
if (roundingUnit != null) {
    modifierValue = (float) MathHelper.round(modifierValue, roundingUnit);
}

// ItemScaling.java, replace private getRoundingUnit() and its call sites:
var roundingUnit = RoundingHelper.getRoundingUnit();
if (roundingUnit != null) {
    value = MathHelper.round(value, roundingUnit);
}

Option B (more flexible, preferable): Introduce a separate config parameter for entity scaling rounding (e.g., meta.entity_rounding_unit), then wire it in EntityScaling the same way ItemScaling currently reads meta.rounding_unit. This would allow independent control over rounding precision for entity stats vs. item stats. RoundingHelper could expose two methods (getEntityRoundingUnit() and getItemRoundingUnit()) in this case.

Thank you!