Use PistonStructureResolver in PistonCalculator

Numbering now comes directly from the vanilla resolver instead of a
custom breadth-first search, so the order matches the real move order
(including backtracking through slime/honey chains). The display of
more than 12 blocks is removed; a blocked piston is shown in red.

Refs: #158

BauSystem/BauSystem_Main/src/de/steamwar/bausystem/features/util/PistonCalculator.java

@@ -23,15 +23,17 @@ import de.steamwar.bausystem.BauSystem;
 import de.steamwar.bausystem.Permission;
 import de.steamwar.entity.*;
 import de.steamwar.linkage.Linked;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.Direction;
+import net.minecraft.world.level.block.piston.PistonStructureResolver;
 import org.bukkit.Bukkit;
 import org.bukkit.Location;
 import org.bukkit.Material;
 import org.bukkit.block.Block;
 import org.bukkit.block.BlockFace;
-import org.bukkit.block.PistonMoveReaction;
-import org.bukkit.block.TileState;
 import org.bukkit.block.data.BlockData;
 import org.bukkit.block.data.type.Piston;
+import org.bukkit.craftbukkit.CraftWorld;
 import org.bukkit.entity.Display;
 import org.bukkit.entity.Player;
 import org.bukkit.entity.TextDisplay;
@@ -170,7 +172,7 @@ public class PistonCalculator implements Listener {
         private boolean pulling = false;
         private List<Location> movedBlocks = new ArrayList<>();
         private List<Location> brokenBlocks = new ArrayList<>();
-        private Set<Location> immovableBlocks = new HashSet<>();
+        private boolean blocked = false;
 
         public PistOrder(Block piston) {
             this.piston = piston;
@@ -179,7 +181,7 @@ public class PistonCalculator implements Listener {
         public void calculate() {
             movedBlocks.clear();
             brokenBlocks.clear();
-            immovableBlocks.clear();
+            blocked = false;
 
             if (piston.isEmpty()) {
                 Bukkit.getScheduler().runTaskLater(BauSystem.getInstance(), () -> {
@@ -199,7 +201,7 @@ public class PistonCalculator implements Listener {
 
             pulling = piston.getType() == Material.STICKY_PISTON && (piston.getRelative(pistonData.getFacing()).getType() == Material.AIR || pistonData.isExtended());
 
-            calculate(piston, pistonData.getFacing(), (pulling ? pistonData.getFacing().getOppositeFace() : pistonData.getFacing()));
+            resolve(pistonData.getFacing());
 
             Collections.reverse(movedBlocks);
             Collections.reverse(brokenBlocks);
@@ -207,86 +209,23 @@ public class PistonCalculator implements Listener {
             visualize();
         }
 
-        private void calculate(Block origin, BlockFace facing, BlockFace direction) {
+        private void resolve(BlockFace facing) {
-            Block calcOrigin = origin;
+            PistonStructureResolver resolver = new PistonStructureResolver(
-            if (facing != direction) calcOrigin = origin.getRelative(facing, 3);
+                    ((CraftWorld) piston.getWorld()).getHandle(),
-
+                    new BlockPos(piston.getX(), piston.getY(), piston.getZ()),
-            List<Block> toCalc = new LinkedList<>();
+                    Direction.valueOf(facing.name()),
-            calcDirection(origin, null, calcOrigin, facing != direction ? origin.getRelative(facing) : null, facing, direction, toCalc);
+                    !pulling
-
+            );
-            while (!toCalc.isEmpty()) {
+            if (!resolver.resolve()) {
-                Block current = toCalc.remove(0);
+                blocked = true;
-                if (!movedBlocks.contains(current.getLocation())) {
+                return;
-                    movedBlocks.add(current.getLocation());
-                }
-
-                Material type = current.getType();
-                if (type != Material.SLIME_BLOCK && type != Material.HONEY_BLOCK) continue;
-                Material oppositeType = type == Material.SLIME_BLOCK ? Material.HONEY_BLOCK : Material.SLIME_BLOCK;
-
-                for (BlockFace face : FACES) {
-                    Block block = current.getRelative(face);
-                    if (block.getType().isAir()) continue;
-                    if (isImmovable(block) || block.getPistonMoveReaction() == PistonMoveReaction.BREAK) continue;
-                    if (face != direction || face == direction.getOppositeFace()) {
-                        switch (block.getType()) {
-                            case BLACK_GLAZED_TERRACOTTA:
-                            case GRAY_GLAZED_TERRACOTTA:
-                            case BLUE_GLAZED_TERRACOTTA:
-                            case BROWN_GLAZED_TERRACOTTA:
-                            case CYAN_GLAZED_TERRACOTTA:
-                            case GREEN_GLAZED_TERRACOTTA:
-                            case LIGHT_BLUE_GLAZED_TERRACOTTA:
-                            case LIGHT_GRAY_GLAZED_TERRACOTTA:
-                            case LIME_GLAZED_TERRACOTTA:
-                            case MAGENTA_GLAZED_TERRACOTTA:
-                            case ORANGE_GLAZED_TERRACOTTA:
-                            case PINK_GLAZED_TERRACOTTA:
-                            case PURPLE_GLAZED_TERRACOTTA:
-                            case RED_GLAZED_TERRACOTTA:
-                            case WHITE_GLAZED_TERRACOTTA:
-                            case YELLOW_GLAZED_TERRACOTTA:
-                                continue;
-                            default:
-                                break;
-                        }
-                    }
-                    if (block.getType() != oppositeType) {
-                        if (!movedBlocks.contains(block.getLocation())) toCalc.add(block);
-                        calcDirection(null, origin, block, null, facing, direction, toCalc);
-                    }
-                }
             }
-
+            resolver.getToPush().forEach(pos -> movedBlocks.add(toLocation(pos)));
-            movedBlocks.remove(origin.getLocation());
+            resolver.getToDestroy().forEach(pos -> brokenBlocks.add(toLocation(pos)));
-            if (facing != direction) movedBlocks.remove(origin.getRelative(facing, 1).getLocation());
-            if (pulling) immovableBlocks.remove(origin.getRelative(facing).getLocation());
         }
 
-        private void calcDirection(Block origin, Block blockOrigin, Block calcOrigin, Block ignore, BlockFace facing, BlockFace direction, List<Block> toCalc) {
+        private Location toLocation(BlockPos pos) {
-            for (int i = 1; i < 24; i++) {
+            return new Location(piston.getWorld(), pos.getX(), pos.getY(), pos.getZ());
-                Block block = calcOrigin.getRelative(direction, i);
-                if (block.equals(ignore)) return;
-                if (block.getPistonMoveReaction() == PistonMoveReaction.BREAK) {
-                    if (!brokenBlocks.contains(block.getLocation())) {
-                        brokenBlocks.add(block.getLocation());
-                    }
-                    return;
-                }
-                if (isImmovable(block)) {
-                    immovableBlocks.add(block.getLocation());
-                    return;
-                }
-                if (block.getType().isAir()) return;
-                if (facing == direction && block.equals(blockOrigin)) {
-                    immovableBlocks.add(block.getLocation());
-                    return;
-                }
-                if (facing != direction && (block.equals(origin) || block.getRelative(facing.getOppositeFace()).equals(origin))) {
-                    return;
-                }
-                if (!movedBlocks.contains(block.getLocation())) toCalc.add(block);
-            }
         }
 
         private void visualize() {
@@ -321,21 +260,11 @@ public class PistonCalculator implements Listener {
                 textDisplay.setBrightness(new Display.Brightness(15, 15));
             }
 
-            for (Location location : immovableBlocks) {
-                CWireframe wireframe = new CWireframe(server);
-                wireframe.setPos1(location);
-                wireframe.setPos2(location);
-                wireframe.setWidth(1 / 32f);
-                wireframe.setBlock(Material.RED_CONCRETE.createBlockData());
-            }
-
             CWireframe wireframe = new CWireframe(server);
             wireframe.setPos1(piston.getLocation());
             wireframe.setPos2(piston.getLocation());
-            if (!immovableBlocks.isEmpty()) {
+            if (blocked) {
                 wireframe.setBlock(Material.RED_CONCRETE.createBlockData());
-            } else if (movedBlocks.size() > 12) {
-                wireframe.setBlock(Material.YELLOW_CONCRETE.createBlockData());
             } else {
                 wireframe.setBlock(Material.LIME_CONCRETE.createBlockData());
             }
@@ -348,7 +277,11 @@ public class PistonCalculator implements Listener {
             } else {
                 text.append("§ePush\n");
             }
-            text.append("§f").append(movedBlocks.size()).append(" §eBlocks");
+            if (blocked) {
+                text.append("§cBlocked");
+            } else {
+                text.append("§f").append(movedBlocks.size()).append(" §eBlocks");
+            }
             textDisplay.setText(text.toString());
             textDisplay.setBillboard(Display.Billboard.CENTER);
             textDisplay.setAlignment(TextDisplay.TextAlignment.CENTER);
@@ -358,26 +291,4 @@ public class PistonCalculator implements Listener {
             textDisplay.setBrightness(new Display.Brightness(15, 15));
         }
     }
-
-    private boolean isImmovable(Block block) {
-        if (block.isEmpty() || block.isLiquid()) {
-            return false;
-        }
-        BlockData blockData = block.getBlockData();
-        if (blockData instanceof Piston) {
-            return ((Piston) blockData).isExtended();
-        }
-        if (block.getState() instanceof TileState) {
-            return true;
-        }
-        PistonMoveReaction reaction = block.getPistonMoveReaction();
-        if (reaction == PistonMoveReaction.IGNORE) return true;
-        if (reaction == PistonMoveReaction.BLOCK) return true;
-        switch (block.getType()) {
-            case OBSIDIAN:
-                return true;
-            default:
-                return false;
-        }
-    }
 }