Optimise BiomeManager#getFiddle

The floorMod and subtraction by 0.5 can be done before converting
to double, and the division by 1024 may be converted to a simple
multiplication. At this point, the result is exactly the same.

However, to remove the extra multiplication by 0.9, it can be
moved into the multiplication by 1/1024. This may affect
the result to one ULP, but I do not forsee that causing any problems.

src/main/java/ca/spottedleaf/moonrise/mixin/random_ticking/BiomeManagerMixin.java

@@ -0,0 +1,18 @@
+package ca.spottedleaf.moonrise.mixin.random_ticking;
+
+import net.minecraft.world.level.biome.BiomeManager;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Overwrite;
+
+@Mixin(BiomeManager.class)
+abstract class BiomeManagerMixin {
+
+    /**
+     * @reason Replace floorMod and double division to optimise the function
+     * @author Spottedleaf
+     */
+    @Overwrite
+    public static double getFiddle(final long seed) {
+        return (double)(((seed >> 24) & (1024 - 1)) - (1024/2)) * (0.9 / 1024.0);
+    }
+}

src/main/resources/moonrise.mixins.json

@@ -91,6 +91,7 @@
     "poi_lookup.AcquirePoiMixin",
     "poi_lookup.PoiManagerMixin",
     "poi_lookup.PortalForcerMixin",
+    "random_ticking.BiomeManagerMixin",
     "random_ticking.BiomeMixin",
     "random_ticking.LevelMixin",
     "random_ticking.ServerLevelMixin",