[Mainline Fix] Weather effects go through custom entities

src/main/java/cam72cam/mod/mixin/fix/rain_snow_collision/MixinWorld.java

@@ -0,0 +1,45 @@
+package cam72cam.mod.mixin.fix.rain_snow_collision;
+
+import cam72cam.mod.entity.ModdedEntity;
+import cam72cam.mod.world.ChunkPos;
+import cam72cam.mod.world.WorldEntityTracker;
+import net.minecraft.util.math.AxisAlignedBB;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.world.World;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+import java.util.Set;
+import java.util.stream.Collectors;
+
+@Mixin(World.class)
+public class MixinWorld {
+    @Inject(method = "getPrecipitationHeight", at = @At("HEAD"), cancellable = true)
+    public void checkEntityCollision(BlockPos pos, CallbackInfoReturnable<BlockPos> cir) {
+        World self = (World) (Object) this;
+        WorldEntityTracker tracker = cam72cam.mod.world.World.get(self).tracker;
+        Set<ModdedEntity> moddedEntities = tracker.queryPotentialPackedChunkPos(ChunkPos.asLong(pos))
+                                                  .stream()
+                                                  .map(tracker::queryEntities)
+                                                  .flatMap(Set::stream)
+                                                  .collect(Collectors.toSet());
+        BlockPos target = self.getChunk(pos).getPrecipitationHeight(pos);
+        if (moddedEntities != null && !moddedEntities.isEmpty()) {
+            BlockPos.MutableBlockPos mutable = new BlockPos.MutableBlockPos(target);
+            for (ModdedEntity moddedEntity : moddedEntities) {
+                AxisAlignedBB collisionBoundingBox = moddedEntity.getCollisionBoundingBox();
+                if (collisionBoundingBox == null) continue;
+
+                if (mutable.getY() < collisionBoundingBox.minY) {
+                    mutable.setY((int) collisionBoundingBox.minY);
+                }
+                while (collisionBoundingBox.intersects(new AxisAlignedBB(mutable))) {
+                    mutable.setY(mutable.getY() + 1);
+                }
+            }
+            cir.setReturnValue(mutable.toImmutable());
+        }
+    }
+}

src/main/resources/mixins.fix.universalmodcore.json

@@ -7,6 +7,7 @@
   "compatibilityLevel": "JAVA_8",
   "mixinPriority": 1301,
   "mixins": [
+    "rain_snow_collision.MixinWorld"
   ],
   "client": [
   ]