From 7d9d18c372b06e6301c75e26688db7eaec8db16d Mon Sep 17 00:00:00 2001
From: Adrian Siekierka <kontakt@asie.pl>
Date: Tue, 7 Jun 2022 17:39:19 +0200
Subject: [PATCH] Fix inconsistent 3D print item stacking

Now prints that consist of the same set of shapes stack as they should.

Co-authored-by: Quant1um <spitfirexv22@gmail.com>
---
 .../cil/oc/common/item/data/PrintData.scala   | 28 +++++++++++++++++--
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/src/main/scala/li/cil/oc/common/item/data/PrintData.scala b/src/main/scala/li/cil/oc/common/item/data/PrintData.scala
index 35ded28d7..c162d58c0 100644
--- a/src/main/scala/li/cil/oc/common/item/data/PrintData.scala
+++ b/src/main/scala/li/cil/oc/common/item/data/PrintData.scala
@@ -1,11 +1,11 @@
 package li.cil.oc.common.item.data
 
 import java.lang.reflect.Method
-
 import li.cil.oc.Constants
 import li.cil.oc.Settings
 import li.cil.oc.api
 import li.cil.oc.common.IMC
+import li.cil.oc.common.item.data.PrintData.Shape
 import li.cil.oc.util.ExtendedAABB._
 import li.cil.oc.util.ExtendedNBT._
 import net.minecraft.item.ItemStack
@@ -82,13 +82,35 @@ class PrintData extends ItemData(Constants.BlockName.Print) {
     nbt.setBoolean("isButtonMode", isButtonMode)
     nbt.setInteger("redstoneLevel", redstoneLevel)
     nbt.setBoolean("pressurePlate", pressurePlate)
-    nbt.setNewTagList("stateOff", stateOff.map(PrintData.shapeToNBT))
-    nbt.setNewTagList("stateOn", stateOn.map(PrintData.shapeToNBT))
+    setNewShapeSet(nbt, "stateOff", stateOff)
+    setNewShapeSet(nbt, "stateOn", stateOn)
     nbt.setBoolean("isBeaconBase", isBeaconBase)
     nbt.setByte("lightLevel", lightLevel.toByte)
     nbt.setBoolean("noclipOff", noclipOff)
     nbt.setBoolean("noclipOn", noclipOn)
   }
+
+  // Shapes are stored in a set and sets do not have an order, that means NBT shape lists may be in any order.
+  // Because NBT list comparison considers order of tags in a list, and prints may have arbitrarily ordered list of shapes,
+  // the comparison fails and minecraft considers two identical prints different.
+  // One possible solution is to sort the shapes before serializing them to NBT
+  private def setNewShapeSet(nbt: NBTTagCompound, name: String, values: Iterable[Shape]) = {
+    val seq = values.toSeq.sortWith(compareShape);
+    nbt.setNewTagList(name, seq.map(PrintData.shapeToNBT))
+  }
+
+  private def compareShape(a: Shape, b: Shape): Boolean = {
+    import scala.math.Ordering.Implicits._
+    if (a.bounds.minX != b.bounds.minX) return a.bounds.minX > b.bounds.minX;
+    if (a.bounds.minY != b.bounds.minY) return a.bounds.minY > b.bounds.minY;
+    if (a.bounds.minZ != b.bounds.minZ) return a.bounds.minZ > b.bounds.minZ;
+    if (a.bounds.maxX != b.bounds.maxX) return a.bounds.maxX > b.bounds.maxX;
+    if (a.bounds.maxY != b.bounds.maxY) return a.bounds.maxY > b.bounds.maxY;
+    if (a.bounds.maxZ != b.bounds.maxZ) return a.bounds.maxZ > b.bounds.maxZ;
+    if (a.tint != b.tint) return a.tint > b.tint;
+    if (a.texture != b.texture) return a.texture > b.texture;
+    false
+  }
 }
 
 object PrintData {