Add BlockConnections compactor

pom.xml

@@ -7,7 +7,7 @@
     <groupId>com.viaversion</groupId>
     <artifactId>mappingsgenerator</artifactId>
     <name>MappingsGenerator</name>
-    <version>3.2.0</version>
+    <version>3.2.1</version>
 
     <url>https://github.com/ViaVersion/Mappings</url>
     <inceptionYear>2020</inceptionYear>

src/main/java/com/viaversion/mappingsgenerator/extra/BlockConnections.java

@@ -0,0 +1,135 @@
+/*
+ * This file is part of ViaVersion Mappings - https://github.com/ViaVersion/Mappings
+ * Copyright (C) 2023 Nassim Jahnke
+ * Copyright (C) 2023 ViaVersion and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.viaversion.mappingsgenerator.extra;
+
+import com.github.steveice10.opennbt.tag.builtin.ByteArrayTag;
+import com.github.steveice10.opennbt.tag.builtin.CompoundTag;
+import com.github.steveice10.opennbt.tag.builtin.IntArrayTag;
+import com.github.steveice10.opennbt.tag.builtin.ListTag;
+import com.github.steveice10.opennbt.tag.builtin.ShortTag;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.viaversion.mappingsgenerator.MappingsLoader;
+import com.viaversion.mappingsgenerator.MappingsOptimizer;
+import it.unimi.dsi.fastutil.ints.IntArrayList;
+import it.unimi.dsi.fastutil.ints.IntList;
+import it.unimi.dsi.fastutil.objects.Object2IntMap;
+import it.unimi.dsi.fastutil.objects.Object2IntOpenHashMap;
+import java.util.List;
+import java.util.Map;
+
+public final class BlockConnections {
+
+    private static final List<String> HORIZONTAL_BLOCK_FACES = List.of("north", "south", "east", "west");
+    private static final List<String> CONNECTION_TYPES = List.of("fence", "netherFence", "pane", "cobbleWall", "redstone", "allFalseIfStairPre1_12");
+
+    public static void main(final String[] args) throws Exception {
+        final JsonArray blockstates = MappingsLoader.load("mapping-1.13.json").getAsJsonArray("blockstates");
+        final Object2IntMap<String> statesMap = new Object2IntOpenHashMap<>();
+        statesMap.defaultReturnValue(-1);
+        for (int id = 0; id < blockstates.size(); id++) {
+            statesMap.put(blockstates.get(id).getAsString(), id);
+        }
+
+        final JsonObject object = MappingsLoader.load("extra/blockConnections.json");
+        final CompoundTag tag = new CompoundTag();
+        ListTag list = new ListTag();
+        tag.put("data", list);
+        for (final Map.Entry<String, JsonElement> entry : object.entrySet()) {
+            final CompoundTag blockTag = new CompoundTag();
+            final int blockStateId = statesMap.getInt(entry.getKey());
+            if (blockStateId != -1) {
+                blockTag.put("id", new ShortTag((short) blockStateId));
+            } else {
+                // Used for fences, so the json file doesn't need to contain every single block state
+                final int[] ids = statesMap.object2IntEntrySet().stream().filter(e -> {
+                    final int propertiesIndex = e.getKey().indexOf('[');
+                    if (propertiesIndex == -1) {
+                        return false;
+                    }
+
+                    return e.getKey().substring(0, propertiesIndex).equals(entry.getKey());
+                }).mapToInt(Object2IntMap.Entry::getIntValue).toArray();
+
+                if (ids.length == 0) {
+                    throw new IllegalArgumentException("Invalid block state " + entry.getKey());
+                }
+
+                blockTag.put("ids", new IntArrayTag(ids));
+            }
+
+            list.add(blockTag);
+
+            final JsonObject blockObject = entry.getValue().getAsJsonObject();
+            for (final Map.Entry<String, JsonElement> blockEntry : blockObject.entrySet()) {
+                final byte connectionTypeId = connectionTypeToId(blockEntry.getKey());
+                final JsonObject valuesObject = blockEntry.getValue().getAsJsonObject();
+                if (valuesObject.size() != 4) {
+                    throw new IllegalArgumentException("Invalid block connection " + blockEntry.getKey());
+                }
+
+                final IntList faces = new IntArrayList(4);
+                for (final Map.Entry<String, JsonElement> faceEntry : valuesObject.entrySet()) {
+                    if (faceEntry.getValue().getAsBoolean()) {
+                        final byte faceId = blockFaceToId(faceEntry.getKey());
+                        faces.add(faceId);
+                    }
+                }
+
+                if (faces.isEmpty()) {
+                    throw new IllegalArgumentException("Invalid block connection (empty faces) " + blockEntry.getKey());
+                }
+
+                final byte[] facesArray = new byte[faces.size()];
+                for (int i = 0; i < facesArray.length; i++) {
+                    facesArray[i] = (byte) faces.getInt(i);
+                }
+                blockTag.put(Integer.toString(connectionTypeId), new ByteArrayTag(facesArray));
+            }
+
+            if (blockTag.size() == 1) {
+                throw new IllegalArgumentException("Invalid block state (blockTag only contains id tag?) " + entry.getKey());
+            }
+
+            // Before 1.12, stairs did not connect to fences
+            if (entry.getKey().contains("stairs[")) {
+                blockTag.put(Integer.toString(connectionTypeToId("allFalseIfStairPre1_12")), new ByteArrayTag());
+            }
+        }
+
+        MappingsOptimizer.write(tag, MappingsOptimizer.OUTPUT_DIR.resolve("extra/blockConnections.nbt"));
+    }
+
+    private static byte connectionTypeToId(final String type) {
+        final byte id = (byte) CONNECTION_TYPES.indexOf(type);
+        if (id == -1) {
+            throw new IllegalArgumentException("Invalid connection type " + type);
+        }
+        return id;
+    }
+
+    private static byte blockFaceToId(final String type) {
+        final byte id = (byte) HORIZONTAL_BLOCK_FACES.indexOf(type);
+        if (id == -1) {
+            throw new IllegalArgumentException("Invalid block face " + type);
+        }
+        return id;
+    }
+}