fix(chunkloader): support trapdoor ceilings and creeper-specific spawning on simulated platforms

src/main/java/dev/marcospaulo/canalhandia/ChunkLoaders.java

@@ -465,7 +465,7 @@ final class ChunkLoaders {
         int baseZ = loader.chunkZ() << 4;
         ThreadLocalRandom rnd = ThreadLocalRandom.current();
 
-        for (int i = 0; i < 2; i++) {
+        for (int i = 0; i < 4; i++) {
             int rx = baseX + rnd.nextInt(16);
             int rz = baseZ + rnd.nextInt(16);
             int topY = Math.max(w.getMinHeight() + 2, Math.min(w.getMaxHeight() - 2, loader.y() + rnd.nextInt(-24, 25)));
@@ -474,15 +474,30 @@ final class ChunkLoaders {
             Block space = w.getBlockAt(rx, topY, rz);
             Block spaceAbove = w.getBlockAt(rx, topY + 1, rz);
 
-            if (!ground.getType().isSolid() || !space.getType().isAir() || !spaceAbove.getType().isAir()) {
+            if (!ground.getType().isSolid() || ground.isLiquid() || ground.getType() == Material.LAVA || ground.getType() == Material.WATER) {
                 continue;
             }
-            if (ground.isLiquid() || ground.getType() == Material.LAVA || ground.getType() == Material.WATER) {
+            if (!space.getType().isAir()) {
+                continue;
+            }
+
+            boolean isAirAbove = spaceAbove.getType().isAir();
+            boolean isTrapdoorAbove = isTrapdoor(spaceAbove.getType());
+            if (!isAirAbove && !isTrapdoorAbove) {
                 continue;
             }
 
             int light = space.getLightLevel();
-            EntityType toSpawn = pickEntityType(w, space, light);
+            EntityType toSpawn;
+            if (isTrapdoorAbove) {
+                if (light > 0) {
+                    continue;
+                }
+                toSpawn = EntityType.CREEPER;
+            } else {
+                toSpawn = pickEntityType(w, space, light);
+            }
+
             if (toSpawn == null) {
                 continue;
             }
@@ -497,6 +512,11 @@ final class ChunkLoaders {
         }
     }
 
+    static boolean isTrapdoor(Material mat) {
+        if (mat == null) return false;
+        return mat.name().endsWith("_TRAPDOOR");
+    }
+
     static EntityType pickEntityType(World w, Block space, int light) {
         boolean isSlime = false;
         try {

src/test/java/dev/marcospaulo/canalhandia/ChunkLoaderTest.java

@@ -212,6 +212,16 @@ class ChunkLoaderTest {
         assertTrue(loader.timeLeft().contains("h"));
     }
 
+    @Test
+    void recognizesTrapdoorsCorrectly() {
+        assertTrue(ChunkLoaders.isTrapdoor(org.bukkit.Material.OAK_TRAPDOOR));
+        assertTrue(ChunkLoaders.isTrapdoor(org.bukkit.Material.IRON_TRAPDOOR));
+        assertTrue(ChunkLoaders.isTrapdoor(org.bukkit.Material.SPRUCE_TRAPDOOR));
+        assertFalse(ChunkLoaders.isTrapdoor(org.bukkit.Material.AIR));
+        assertFalse(ChunkLoaders.isTrapdoor(org.bukkit.Material.STONE));
+        assertFalse(ChunkLoaders.isTrapdoor(null));
+    }
+
     @Test
     void simulationSafelyNoopsWithNullPlugin() {
         loaders.startSimulation();