Litematica Mirror Fix

MixinChestBlock.java

package fi.dy.masa.litematica.mixin;

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 net.minecraft.block.BlockState;
import net.minecraft.block.ChestBlock;
import net.minecraft.block.enums.ChestType;
import net.minecraft.util.BlockMirror;

@Mixin({ChestBlock.class})
public class MixinChestBlock
{
    @Inject(method = "mirror", at = @At("HEAD"), cancellable = true)
    public void mirrorFixed(BlockState state, BlockMirror mirror, CallbackInfoReturnable<BlockState> c)
    {
        ChestType type = state.get(ChestBlock.CHEST_TYPE);
        if (type != ChestType.SINGLE)
        {
            // Flip chest type. (Note: It would be nice to use chestType.getOpposite)
            state = state.with(ChestBlock.CHEST_TYPE, type == ChestType.LEFT ? ChestType.RIGHT : ChestType.LEFT);
            
            // Apply rotation
            state = state.rotate(mirror.getRotation(state.get(ChestBlock.FACING)));

            c.setReturnValue(state);
            c.cancel();
        }
    }
}