simplify survival, map and plugin code: map palette built once in a static initializer instead of a synchronized check per dither lookup, film colour as a constant, one blit for blank film and develop, shared crafting result for prepare and craft, unused photo scan state and dead null checks removed, non-italic text helper for item names, pdc getOrDefault, private map file paths, single map-init attach path, listener registration in one loop, unused image constructor removed (pptest dithers itself), comments trimmed

src/main/java/eu/mhsl/minecraft/pixelpics/Main.java

@@ -23,13 +23,15 @@ import eu.mhsl.minecraft.pixelpics.survival.JoinListener;
 import eu.mhsl.minecraft.pixelpics.survival.SurvivalRecipes;
 import eu.mhsl.minecraft.pixelpics.utils.MapColorPalette;
 import java.io.File;
+import java.io.FileInputStream;
 import java.io.InputStream;
-import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
 import org.bukkit.Bukkit;
 import org.bukkit.NamespacedKey;
+import org.bukkit.World;
+import org.bukkit.event.Listener;
 import org.bukkit.plugin.java.JavaPlugin;
 
 public final class Main extends JavaPlugin {
@@ -40,13 +42,10 @@ public final class Main extends JavaPlugin {
     private DefaultScreenRenderer screenRenderer;
     private RenderManager renderManager;
 
+    // PDC keys: photo picture id (STRING), camera/film markers (BYTE), loaded film on a camera (INTEGER)
     public final NamespacedKey pictureIdFlag = new NamespacedKey(this, "imageid");
-
-    /** Marks a {@code PLAYER_HEAD} as a camera (BYTE 1). */
     public final NamespacedKey cameraMarker = new NamespacedKey(this, "camera");
-    /** Loaded film count stored on a camera (INTEGER, 0..{@code CameraItems.MAX_FILM}). */
     public final NamespacedKey filmCountKey = new NamespacedKey(this, "filmcount");
-    /** Marks a {@code PLAYER_HEAD} as a film roll (BYTE 1). */
     public final NamespacedKey filmMarker = new NamespacedKey(this, "film");
 
     @Override
@@ -56,12 +55,11 @@ public final class Main extends JavaPlugin {
         saveDefaultConfig();
         initRenderManager();
 
-        Bukkit.getPluginManager().registerEvents(new OnMapInitialize(), this);
-        Objects.requireNonNull(Bukkit.getPluginCommand("pixelPic")).setExecutor(new PixelPicsCommand());
-
-        Bukkit.getPluginManager().registerEvents(new CameraListener(), this);
-        Bukkit.getPluginManager().registerEvents(new CraftingListener(), this);
-        Bukkit.getPluginManager().registerEvents(new JoinListener(), this);
+        Objects.requireNonNull(getCommand("pixelPic")).setExecutor(new PixelPicsCommand());
+        for (Listener listener :
+                List.of(new OnMapInitialize(), new CameraListener(), new CraftingListener(), new JoinListener())) {
+            Bukkit.getPluginManager().registerEvents(listener, this);
+        }
         SurvivalRecipes.register();
 
         initRenderer();
@@ -114,7 +112,7 @@ public final class Main extends JavaPlugin {
         // optional newer dump in the data folder (no recompile on MC updates), else the bundled copy.
         File dump = new File(getDataFolder(), "vanilla_entity_models.json");
         try (InputStream in =
-                dump.isFile() ? new java.io.FileInputStream(dump) : getResource("cem/vanilla_entity_models.json")) {
+                dump.isFile() ? new FileInputStream(dump) : getResource("cem/vanilla_entity_models.json")) {
             if (in != null) {
                 long t0 = System.nanoTime();
                 int n = cemLoader.load(in, getLogger());
@@ -125,8 +123,8 @@ public final class Main extends JavaPlugin {
         } catch (Exception e) {
             getLogger().severe("Failed to load vanilla entity models: " + e.getMessage());
         }
-        List<File> worldFolders = new ArrayList<>();
-        for (org.bukkit.World w : getServer().getWorlds()) worldFolders.add(w.getWorldFolder());
+        List<File> worldFolders =
+                getServer().getWorlds().stream().map(World::getWorldFolder).toList();
         int datapackVariants = DatapackVariants.load(cemLoader, worldFolders, getLogger());
         if (datapackVariants > 0) getLogger().info("Loaded " + datapackVariants + " datapack mob variants.");
         SkinCache skinCache = new SkinCache();
@@ -143,7 +141,7 @@ public final class Main extends JavaPlugin {
                 blockEntityBaker,
                 getLogger(),
                 renderManager.tracePool());
-        // Warm the map palette on the main thread so off-thread dithering never triggers its first init.
+        // Initialise the map palette on the main thread (MapPalette) before any off-thread dithering.
         MapColorPalette.size();
         getLogger().info("PixelPics renderer initialized with resource pack assets.");
     }
@@ -166,7 +164,6 @@ public final class Main extends JavaPlugin {
         return this.screenRenderer;
     }
 
-    /** The render queue/limiter; always available after {@code onEnable}. */
     public RenderManager getRenderManager() {
         return this.renderManager;
     }

src/main/java/eu/mhsl/minecraft/pixelpics/commands/PixelPicsCommand.java

@@ -33,7 +33,7 @@ public class PixelPicsCommand implements CommandExecutor {
         }
         if (args.length > 0) return false;
 
-        // Debug shortcut: render a photo from the player's view without needing a camera or film.
+        // Debug render without camera or film.
         if (!player.hasPermission("pixelpic.admin")) {
             player.sendActionBar(
                     Component.text("Dafür fehlt dir die Berechtigung — nutze eine Kamera.", NamedTextColor.RED));
@@ -79,12 +79,12 @@ public class PixelPicsCommand implements CommandExecutor {
 
         if (!confirm) {
             sender.sendMessage(Component.text(
-                    candidates.size() + " Aufnahme(n) könnten gelöscht werden " + "(älter als " + days
+                    candidates.size() + " Aufnahme(n) könnten gelöscht werden (älter als " + days
                             + " Tage, nicht in geladenen Itemframes/Online-Inventaren).",
                     NamedTextColor.YELLOW));
             sender.sendMessage(Component.text(
-                    "Achtung: Maps in lange ungeladenen Bereichen werden hierbei nicht "
-                            + "erkannt. Zum Löschen: /pixelPic cleanup confirm " + days,
+                    "Achtung: Maps in lange ungeladenen Bereichen werden hierbei nicht erkannt. Zum Löschen: /pixelPic cleanup confirm "
+                            + days,
                     NamedTextColor.GRAY));
             return true;
         }

src/main/java/eu/mhsl/minecraft/pixelpics/listeners/OnMapInitialize.java

@@ -8,24 +8,20 @@ import org.bukkit.event.EventHandler;
 import org.bukkit.event.Listener;
 import org.bukkit.event.server.MapInitializeEvent;
 
+/** Reattaches stored photos to their maps when the server loads them. */
 public class OnMapInitialize implements Listener {
 
     @EventHandler
     public void onMapInitialize(MapInitializeEvent event) {
         int mapId = event.getMap().getId();
-
-        // Fast path: use the cached dithered indices (no re-quantization).
         byte[] indices = MapManager.readIndices(mapId);
-        if (indices != null) {
-            MapManager.attachView(event.getMap(), new ImageMapRenderer(indices));
-            return;
+        if (indices == null) {
+            // No index cache (yet): dither the stored PNG once and cache the result.
+            BufferedImage image = MapManager.readImage(mapId);
+            if (image == null) return;
+            indices = MapImageDither.dither(image);
+            MapManager.saveIndices(indices, mapId);
         }
-
-        // Fallback/migration: dither from the stored PNG once, then cache for next time.
-        BufferedImage image = MapManager.readImage(mapId);
-        if (image == null) return;
-        indices = MapImageDither.dither(image);
-        MapManager.saveIndices(indices, mapId);
         MapManager.attachView(event.getMap(), new ImageMapRenderer(indices));
     }
 }

src/main/java/eu/mhsl/minecraft/pixelpics/survival/CameraItems.java

@@ -17,42 +17,34 @@ import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.ItemMeta;
 import org.bukkit.inventory.meta.SkullMeta;
 import org.bukkit.inventory.meta.components.EquippableComponent;
-import org.bukkit.persistence.PersistentDataContainer;
 import org.bukkit.persistence.PersistentDataType;
 
 /**
- * Factory and identity helpers for the survival items: the camera and the film roll are custom-skinned
- * {@code PLAYER_HEAD}s (the texture renders client-side without a resource pack), the photo is the
- * existing {@code FILLED_MAP}. Identity is carried by PDC markers (robust against renames), and the
- * camera's loaded film count lives in PDC as well.
+ * Camera and film roll are custom-skinned {@code PLAYER_HEAD}s (the skin needs no client resource pack), the photo is
+ * a {@code FILLED_MAP}. Identity is carried by PDC markers, so renaming does not matter.
  */
 public final class CameraItems {
 
-    /** Maximum film rolls a camera can hold; one roll yields one photo. */
     public static final int MAX_FILM = 8;
 
     private static final int CAMERA_MODEL_DATA = 1001;
     private static final int FILM_MODEL_DATA = 1002;
 
-    static final String CAMERA_TEXTURE_B64 =
+    private static final String CAMERA_TEXTURE_B64 =
             "eyJ0ZXh0dXJlcyI6eyJTS0lOIjp7InVybCI6Imh0dHA6Ly90ZXh0dXJlcy5taW5lY3JhZnQubmV0L3RleHR1cmUvZDlkMmNiZjAyZDMwOGI2MDY1YTZmZThjNjU3MWI2MzU2NjMzZjQxOTJlOGVjNzEyMTNjNzcwNzgwZTNkZTRlMiJ9fX0=";
-    static final String FILM_TEXTURE_B64 =
+    private static final String FILM_TEXTURE_B64 =
             "eyJ0ZXh0dXJlcyI6eyJTS0lOIjp7InVybCI6Imh0dHA6Ly90ZXh0dXJlcy5taW5lY3JhZnQubmV0L3RleHR1cmUvMTVkMGY0OGJlNzNkYmIwZDJjYjE1NTRjMmUzODZiNWNjM2FiMjFhNGRjYWU4ZmYzOGI3NzRhZDNkMDFkMGE1OSJ9fX0=";
 
     private CameraItems() {}
 
-    // --- factories ---
-
-    /** A camera holding {@code filmCount} (clamped to 0..{@link #MAX_FILM}) loaded film rolls. */
     public static ItemStack createCamera(int filmCount) {
         int count = Math.clamp(filmCount, 0, MAX_FILM);
         ItemStack item = new ItemStack(Material.PLAYER_HEAD);
         SkullMeta meta = (SkullMeta) item.getItemMeta();
         applyHead(meta, "pixelpics:camera", CAMERA_TEXTURE_B64);
-        meta.displayName(Component.text("Kamera", NamedTextColor.WHITE).decoration(TextDecoration.ITALIC, false));
+        meta.displayName(plain("Kamera", NamedTextColor.WHITE));
         meta.setCustomModelData(CAMERA_MODEL_DATA);
-        // A camera carries per-item state (loaded film count), so it must not stack — otherwise loading
-        // or shooting a stacked camera would duplicate or desync the whole stack.
+        // The camera carries per-item state (film count): a stack would duplicate or desync on loading/shooting.
         meta.setMaxStackSize(1);
         meta.getPersistentDataContainer().set(Main.getInstance().cameraMarker, PersistentDataType.BYTE, (byte) 1);
         meta.getPersistentDataContainer().set(Main.getInstance().filmCountKey, PersistentDataType.INTEGER, count);
@@ -62,40 +54,35 @@ public final class CameraItems {
         return item;
     }
 
-    /** A single film roll. */
     public static ItemStack createFilm() {
         ItemStack item = new ItemStack(Material.PLAYER_HEAD);
         SkullMeta meta = (SkullMeta) item.getItemMeta();
         applyHead(meta, "pixelpics:film", FILM_TEXTURE_B64);
-        meta.displayName(Component.text("Filmrolle", NamedTextColor.WHITE).decoration(TextDecoration.ITALIC, false));
+        meta.displayName(plain("Filmrolle", NamedTextColor.WHITE));
         meta.setCustomModelData(FILM_MODEL_DATA);
-        // Lore leads with "Filmrolle" so the recipe book search finds it by name (see applyCameraLore).
-        meta.lore(List.of(Component.text("Filmrolle – lädt eine Kamera auf.", NamedTextColor.GRAY)
-                .decoration(TextDecoration.ITALIC, false)));
+        // Leads with "Filmrolle" for the recipe book search (see applyCameraLore).
+        meta.lore(List.of(plain("Filmrolle – lädt eine Kamera auf.", NamedTextColor.GRAY)));
         meta.getPersistentDataContainer().set(Main.getInstance().filmMarker, PersistentDataType.BYTE, (byte) 1);
         makeUnwearable(meta);
         item.setItemMeta(meta);
         return item;
     }
 
-    /** Display name applied to a developed photo map (white, like a normally renamed item). */
     public static Component photoDisplayName() {
-        return Component.text("Foto", NamedTextColor.WHITE).decoration(TextDecoration.ITALIC, false);
+        return plain("Foto", NamedTextColor.WHITE);
     }
 
-    /** Returns a copy of {@code camera} with its film count set to {@code newCount} and lore refreshed. */
+    /** A copy of {@code camera} with the given film count; stays component-equal to {@code createCamera(count)}. */
     public static ItemStack withFilmCount(ItemStack camera, int newCount) {
         int count = Math.clamp(newCount, 0, MAX_FILM);
         ItemStack copy = camera.clone();
-        SkullMeta meta = (SkullMeta) copy.getItemMeta();
+        ItemMeta meta = copy.getItemMeta();
         meta.getPersistentDataContainer().set(Main.getInstance().filmCountKey, PersistentDataType.INTEGER, count);
         applyCameraLore(meta, count);
         copy.setItemMeta(meta);
         return copy;
     }
 
-    // --- identity ---
-
     public static boolean isCamera(ItemStack item) {
         return hasMarker(item, Main.getInstance().cameraMarker);
     }
@@ -104,50 +91,46 @@ public final class CameraItems {
         return hasMarker(item, Main.getInstance().filmMarker);
     }
 
-    /** A photo is a filled map carrying our picture id. */
     public static boolean isPhoto(ItemStack item) {
-        if (item == null || item.getType() != Material.FILLED_MAP || !item.hasItemMeta()) return false;
-        return item.getItemMeta()
-                .getPersistentDataContainer()
-                .has(Main.getInstance().pictureIdFlag, PersistentDataType.STRING);
+        return item != null
+                && item.getType() == Material.FILLED_MAP
+                && item.hasItemMeta()
+                && item.getItemMeta()
+                        .getPersistentDataContainer()
+                        .has(Main.getInstance().pictureIdFlag, PersistentDataType.STRING);
     }
 
-    /** Loaded film on a camera, or 0 if the item is not a camera. */
+    /** Loaded film on a camera, 0 for any other item. */
     public static int getFilmCount(ItemStack item) {
         if (!isCamera(item)) return 0;
-        Integer v = item.getItemMeta()
+        return item.getItemMeta()
                 .getPersistentDataContainer()
-                .get(Main.getInstance().filmCountKey, PersistentDataType.INTEGER);
-        return v == null ? 0 : v;
+                .getOrDefault(Main.getInstance().filmCountKey, PersistentDataType.INTEGER, 0);
     }
 
-    // --- internals ---
-
     private static boolean hasMarker(ItemStack item, NamespacedKey key) {
-        if (item == null || item.getType() != Material.PLAYER_HEAD || !item.hasItemMeta()) return false;
-        PersistentDataContainer pdc = item.getItemMeta().getPersistentDataContainer();
-        return pdc.has(key, PersistentDataType.BYTE);
+        return item != null
+                && item.getType() == Material.PLAYER_HEAD
+                && item.hasItemMeta()
+                && item.getItemMeta().getPersistentDataContainer().has(key, PersistentDataType.BYTE);
+    }
+
+    private static Component plain(String text, NamedTextColor color) {
+        return Component.text(text, color).decoration(TextDecoration.ITALIC, false);
     }
 
     private static void applyCameraLore(ItemMeta meta, int count) {
-        // The first line carries the word "Kamera" so the recipe book search (which indexes the result
-        // item's lore, not its custom display name — every item here is a PLAYER_HEAD named "Spielerkopf"
-        // by default) can find it when the player types "kamera".
+        // The recipe book search indexes the result's lore, not its custom name (every item here is a
+        // PLAYER_HEAD), so the first line carries the word "Kamera".
         meta.lore(List.of(
-                Component.text("Kamera für Sofortbildfotos", NamedTextColor.GRAY)
-                        .decoration(TextDecoration.ITALIC, false),
-                Component.text(
-                                "Film: " + count + " / " + MAX_FILM,
-                                count > 0 ? NamedTextColor.YELLOW : NamedTextColor.RED)
-                        .decoration(TextDecoration.ITALIC, false),
-                Component.text("Rechtsklick: Foto aufnehmen", NamedTextColor.DARK_GRAY)
-                        .decoration(TextDecoration.ITALIC, false)));
+                plain("Kamera für Sofortbildfotos", NamedTextColor.GRAY),
+                plain("Film: " + count + " / " + MAX_FILM, count > 0 ? NamedTextColor.YELLOW : NamedTextColor.RED),
+                plain("Rechtsklick: Foto aufnehmen", NamedTextColor.DARK_GRAY)));
     }
 
     /**
-     * Overrides the {@code PLAYER_HEAD}'s default head-equippable component so the item cannot be worn:
-     * the slot is moved to {@code SADDLE} (no player slot accepts it, so the helmet slot rejects it —
-     * blocking right-click, shift-click and dispenser equipping) and right-click swap is disabled.
+     * Overrides the head's equippable component: no player slot accepts {@code SADDLE}, which blocks right-click,
+     * shift-click and dispenser equipping; swapping is disabled as well.
      */
     private static void makeUnwearable(ItemMeta meta) {
         EquippableComponent eq = meta.getEquippable();
@@ -157,7 +140,6 @@ public final class CameraItems {
     }
 
     private static void applyHead(SkullMeta meta, String seed, String textureB64) {
-        if (textureB64 == null || textureB64.isBlank()) return;
         UUID synthetic = UUID.nameUUIDFromBytes(seed.getBytes(StandardCharsets.UTF_8));
         PlayerProfile profile = Bukkit.createProfileExact(synthetic, null);
         profile.setProperty(new ProfileProperty("textures", textureB64));

src/main/java/eu/mhsl/minecraft/pixelpics/survival/CameraListener.java

@@ -15,9 +15,8 @@ import org.bukkit.inventory.EquipmentSlot;
 import org.bukkit.inventory.ItemStack;
 
 /**
- * Takes a photo when a player right-clicks while holding a camera. Consumes one loaded film per shot;
- * with no film loaded it gives a short fail feedback. Guards against the well-known double-fire of
- * {@link PlayerInteractEvent} (off-hand fire + air/block) via a hand filter and a per-player cooldown.
+ * Right-click with a camera takes a photo and uses one film. {@link PlayerInteractEvent} can fire twice per click
+ * (off hand, air + block), hence the hand filter and the per-player cooldown.
  */
 public class CameraListener implements Listener {
 
@@ -33,25 +32,19 @@ public class CameraListener implements Listener {
         ItemStack inHand = event.getItem();
         if (!CameraItems.isCamera(inHand)) return;
 
+        event.setCancelled(true);
         Player player = event.getPlayer();
         long now = System.currentTimeMillis();
-        if (now - lastUse.getOrDefault(player.getUniqueId(), 0L) < COOLDOWN_MILLIS) {
-            event.setCancelled(true);
-            return;
-        }
+        if (now - lastUse.getOrDefault(player.getUniqueId(), 0L) < COOLDOWN_MILLIS) return;
         lastUse.put(player.getUniqueId(), now);
 
-        event.setCancelled(true);
-
         int film = CameraItems.getFilmCount(inHand);
         if (film <= 0) {
-            // Dry "empty shutter" click — no film loaded.
             player.playSound(player.getLocation(), Sound.BLOCK_DISPENSER_FAIL, 1f, 1.2f);
             player.sendActionBar(Component.text("Kein Film geladen!", NamedTextColor.RED));
             return;
         }
 
-        // Only charge film if the shot was actually accepted (renderer ready, not queue-rejected).
         if (PhotoService.takePhoto(player)) {
             player.getInventory().setItemInMainHand(CameraItems.withFilmCount(inHand, film - 1));
         }

src/main/java/eu/mhsl/minecraft/pixelpics/survival/CraftingListener.java

@@ -21,12 +21,10 @@ import org.bukkit.inventory.meta.MapMeta;
 import org.bukkit.persistence.PersistentDataType;
 
 /**
- * Drives the two dynamic recipes whose inputs carry variable NBT: <em>load film</em>
- * (camera + film → camera+1) and <em>copy photo</em> (photo + film → 2 photos sharing the same map).
- * {@link PrepareItemCraftEvent} computes the result preview and validates the loose
- * {@code MaterialChoice} matches; {@link CraftItemEvent} performs the consumption/doubling manually
- * (the vanilla machinery cannot, given the variable-NBT ingredients) and blocks shift-click and any
- * attempt to leak our custom items into other recipes.
+ * Load film (camera + film -> camera with one more film) and copy photo (photo + film -> a second photo on the same
+ * map) have variable-NBT inputs, so the result is computed here: {@link PrepareItemCraftEvent} shows it and rejects
+ * loose {@code MaterialChoice} matches, {@link CraftItemEvent} performs the craft by hand. Shift-click is refused, and
+ * our items never feed any other recipe.
  */
 public class CraftingListener implements Listener {
 
@@ -36,30 +34,16 @@ public class CraftingListener implements Listener {
         NONE
     }
 
-    /** Scanned crafting grid: the relevant items and whether any of our marked items are present. */
-    private record Scan(Kind kind, ItemStack camera, ItemStack film, ItemStack photo, boolean hasOurItems) {}
+    private record Scan(Kind kind, ItemStack camera, ItemStack photo, boolean hasOurItems) {}
 
     @EventHandler
     public void onPrepare(PrepareItemCraftEvent event) {
         CraftingInventory inv = event.getInventory();
         Scan scan = scan(inv.getMatrix());
-
-        switch (scan.kind()) {
-            case LOAD -> {
-                int count = CameraItems.getFilmCount(scan.camera());
-                inv.setResult(
-                        count >= CameraItems.MAX_FILM
-                                ? null
-                                : single(CameraItems.withFilmCount(scan.camera(), count + 1)));
-            }
-            case COPY -> inv.setResult(buildPhotoCopy(scan.photo()));
-            case NONE -> {
-                // Block our loose MaterialChoice recipes from matching garbage, and stop our items
-                // from being consumed by any unrelated (vanilla) recipe.
-                if (isDynamicRecipe(event.getRecipe()) || scan.hasOurItems()) {
-                    inv.setResult(null);
-                }
-            }
+        if (scan.kind() != Kind.NONE) {
+            inv.setResult(result(scan));
+        } else if (isDynamicRecipe(event.getRecipe()) || scan.hasOurItems()) {
+            inv.setResult(null);
         }
     }
 
@@ -67,50 +51,36 @@ public class CraftingListener implements Listener {
     public void onCraft(CraftItemEvent event) {
         CraftingInventory inv = event.getInventory();
         Scan scan = scan(inv.getMatrix());
-
         if (scan.kind() == Kind.NONE) {
-            // Defensive: never let our items be consumed by another recipe.
             if (scan.hasOurItems()) event.setCancelled(true);
             return;
         }
 
         event.setCancelled(true);
         Player player = (Player) event.getWhoClicked();
-
         if (event.isShiftClick()) {
             player.sendActionBar(Component.text("Bitte einzeln herstellen.", NamedTextColor.YELLOW));
             return;
         }
 
-        ItemStack result;
+        ItemStack result = result(scan);
+        if (result == null) return;
         ItemStack[] matrix = inv.getMatrix();
-        if (scan.kind() == Kind.LOAD) {
-            int count = CameraItems.getFilmCount(scan.camera());
-            if (count >= CameraItems.MAX_FILM) return;
-            result = single(CameraItems.withFilmCount(scan.camera(), count + 1));
-            consumeFirst(matrix, CameraItems::isCamera);
-            consumeFirst(matrix, CameraItems::isFilm);
-        } else { // COPY
-            result = buildPhotoCopy(scan.photo());
-            if (result == null) return;
-            consumeFirst(matrix, CameraItems::isFilm); // original photo stays
-        }
+        if (scan.kind() == Kind.LOAD) consumeFirst(matrix, CameraItems::isCamera);
+        consumeFirst(matrix, CameraItems::isFilm); // a copied photo keeps its original
 
-        // Apply on the next tick so the click settles before we mutate the grid and hand over the item.
-        ItemStack finalResult = result;
+        // Next tick, so the click settles before the grid changes and the item is handed over.
         Bukkit.getScheduler().runTask(Main.getInstance(), () -> {
             inv.setMatrix(matrix);
-            give(player, finalResult);
+            give(player, result);
             player.playSound(player.getLocation(), Sound.UI_TOAST_IN, 0.7f, 1.4f);
             player.updateInventory();
         });
     }
 
-    // --- helpers ---
-
     private static Scan scan(ItemStack[] matrix) {
         int cameras = 0, films = 0, photos = 0, others = 0;
-        ItemStack camera = null, film = null, photo = null;
+        ItemStack camera = null, photo = null;
         for (ItemStack it : matrix) {
             if (it == null || it.getType().isAir()) continue;
             if (CameraItems.isCamera(it)) {
@@ -118,67 +88,64 @@ public class CraftingListener implements Listener {
                 camera = it;
             } else if (CameraItems.isFilm(it)) {
                 films++;
-                film = it;
             } else if (CameraItems.isPhoto(it)) {
                 photos++;
                 photo = it;
             } else others++;
         }
-        boolean ours = cameras + films + photos > 0;
         Kind kind = Kind.NONE;
-        if (others == 0) {
-            if (cameras == 1 && films == 1 && photos == 0) kind = Kind.LOAD;
-            else if (photos == 1 && films == 1 && cameras == 0) kind = Kind.COPY;
+        if (others == 0 && films == 1) {
+            if (cameras == 1 && photos == 0) kind = Kind.LOAD;
+            else if (photos == 1 && cameras == 0) kind = Kind.COPY;
         }
-        return new Scan(kind, camera, film, photo, ours);
+        return new Scan(kind, camera, photo, cameras + films + photos > 0);
+    }
+
+    /** The crafted item, or null when the camera is full or the photo has no map. */
+    private static ItemStack result(Scan scan) {
+        if (scan.kind() == Kind.COPY) return photoCopy(scan.photo());
+        int count = CameraItems.getFilmCount(scan.camera());
+        if (count >= CameraItems.MAX_FILM) return null;
+        ItemStack camera = CameraItems.withFilmCount(scan.camera(), count + 1);
+        camera.setAmount(1); // the grid may hold an old camera stack
+        return camera;
     }
 
     private static boolean isDynamicRecipe(Recipe recipe) {
-        if (!(recipe instanceof Keyed keyed)) return false;
-        NamespacedKey key = keyed.getKey();
-        return SurvivalRecipes.LOAD.equals(key) || SurvivalRecipes.COPY.equals(key);
+        return recipe instanceof Keyed keyed
+                && (SurvivalRecipes.LOAD.equals(keyed.getKey()) || SurvivalRecipes.COPY.equals(keyed.getKey()));
     }
 
-    /** A second photo referencing the same {@link org.bukkit.map.MapView} and picture id as {@code photo}. */
-    private static ItemStack buildPhotoCopy(ItemStack photo) {
+    private static ItemStack photoCopy(ItemStack photo) {
         MapMeta src = (MapMeta) photo.getItemMeta();
         if (!src.hasMapView() || src.getMapView() == null) return null;
         ItemStack copy = new ItemStack(Material.FILLED_MAP);
         MapMeta dst = (MapMeta) copy.getItemMeta();
         dst.setMapView(src.getMapView());
-        String pid = src.getPersistentDataContainer().get(Main.getInstance().pictureIdFlag, PersistentDataType.STRING);
-        if (pid != null) {
-            dst.getPersistentDataContainer().set(Main.getInstance().pictureIdFlag, PersistentDataType.STRING, pid);
-        }
+        NamespacedKey key = Main.getInstance().pictureIdFlag;
+        dst.getPersistentDataContainer()
+                .set(
+                        key,
+                        PersistentDataType.STRING,
+                        src.getPersistentDataContainer().get(key, PersistentDataType.STRING));
         dst.displayName(CameraItems.photoDisplayName());
         copy.setItemMeta(dst);
         return copy;
     }
 
-    /** Forces a crafting result to a single item — one craft yields exactly one camera, never a stack. */
-    private static ItemStack single(ItemStack item) {
-        item.setAmount(1);
-        return item;
-    }
-
     private static void consumeFirst(ItemStack[] matrix, Predicate<ItemStack> pred) {
         for (int i = 0; i < matrix.length; i++) {
             ItemStack it = matrix[i];
-            if (it != null && !it.getType().isAir() && pred.test(it)) {
-                int amt = it.getAmount();
-                if (amt <= 1) matrix[i] = null;
-                else {
-                    it.setAmount(amt - 1);
-                    matrix[i] = it;
-                }
+            if (it != null && pred.test(it)) {
+                if (it.getAmount() <= 1) matrix[i] = null;
+                else it.setAmount(it.getAmount() - 1);
                 return;
             }
         }
     }
 
     private static void give(Player player, ItemStack item) {
-        ItemStack cursor = player.getItemOnCursor();
-        if (cursor.getType().isAir()) {
+        if (player.getItemOnCursor().getType().isAir()) {
             player.setItemOnCursor(item);
         } else {
             player.getInventory().addItem(item).values().forEach(left -> player.getWorld()

src/main/java/eu/mhsl/minecraft/pixelpics/survival/PhotoService.java

@@ -9,7 +9,6 @@ import eu.mhsl.minecraft.pixelpics.utils.ImageMapRenderer;
 import eu.mhsl.minecraft.pixelpics.utils.MapImageDither;
 import eu.mhsl.minecraft.pixelpics.utils.MapManager;
 import java.awt.image.BufferedImage;
-import java.util.Objects;
 import java.util.UUID;
 import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.format.NamedTextColor;
@@ -23,26 +22,18 @@ import org.bukkit.inventory.ItemStack;
 import org.bukkit.inventory.meta.MapMeta;
 import org.bukkit.map.MapView;
 import org.bukkit.persistence.PersistentDataType;
-import org.bukkit.util.Vector;
 
 /**
- * Renders a photo of a player's current view and delivers it as a developing {@code FILLED_MAP},
- * with a shutter sound + flash particles on capture and a chime when the picture finishes developing.
- * Heavy work is funneled through {@link RenderManager} (per-player single slot, global concurrency
- * limit + queue, bounded low-priority CPU). Shared by the camera item (survival) and the
- * {@code /pixelPic} debug command. Film accounting is the caller's responsibility.
+ * Photographs a player's view into a {@code FILLED_MAP} that develops once the render (throttled by
+ * {@link RenderManager}) is done. Used by the camera and {@code /pixelPic}; film is the caller's business.
  */
 public final class PhotoService {
 
-    /** Render result carried back to the main thread: PNG source + dithered map indices. */
     private record RenderOutput(BufferedImage image, byte[] indices) {}
 
     private PhotoService() {}
 
-    /**
-     * Captures and delivers a photo. Returns {@code false} (with action-bar feedback) if the renderer
-     * is unavailable or the request is rejected by the queue — callers should not charge film then.
-     */
+    /** False (with action-bar feedback) when no photo was taken: no renderer, or rejected by the queue. */
     public static boolean takePhoto(Player player) {
         Main plugin = Main.getInstance();
         DefaultScreenRenderer renderer = plugin.getScreenRenderer();
@@ -66,18 +57,17 @@ public final class PhotoService {
 
         boolean dispatched = false;
         try {
-            Resolution resolution = new Resolution(128, 128);
+            // The world snapshot is taken now, on the main thread; tracing happens later off-thread.
+            RenderJob job = renderer.prepare(
+                    player.getEyeLocation(), new Resolution(MapImageDither.SIZE, MapImageDither.SIZE), user);
 
-            // Capture the world snapshot on the main thread (the moment of the shot).
-            RenderJob job = renderer.prepare(player.getEyeLocation(), resolution, user);
-
-            // Hand the map over immediately, showing blank "film"; it develops once the render is ready.
+            // The map is handed over right away and shows blank film until the picture develops.
             ImageMapRenderer mapRenderer = new ImageMapRenderer();
             MapView mapView = Bukkit.createMap(player.getWorld());
             int id = mapView.getId();
             MapManager.attachView(mapView, mapRenderer);
 
-            ItemStack map = new ItemStack(Material.FILLED_MAP, 1);
+            ItemStack map = new ItemStack(Material.FILLED_MAP);
             MapMeta meta = (MapMeta) map.getItemMeta();
             meta.getPersistentDataContainer()
                     .set(
@@ -88,12 +78,8 @@ public final class PhotoService {
             meta.displayName(CameraItems.photoDisplayName());
             map.setItemMeta(meta);
             player.getInventory().addItem(map);
-
-            // Feedback is sound + particles only; no action-bar text on a normal shot.
             playShutter(player);
 
-            // Trace + dither off-thread (queued), then develop on the main thread. The cancel token is
-            // tripped by the watchdog on timeout; we bail out before the (now pointless) dithering.
             manager.dispatch(
                     user,
                     cancelled -> {
@@ -102,7 +88,7 @@ public final class PhotoService {
                         return new RenderOutput(image, MapImageDither.dither(image));
                     },
                     out -> {
-                        MapManager.saveImage(Objects.requireNonNull(out).image(), id);
+                        MapManager.saveImage(out.image(), id);
                         MapManager.saveIndices(out.indices(), id);
                         mapRenderer.develop(out.indices());
                         player.playSound(player.getLocation(), Sound.BLOCK_AMETHYST_BLOCK_CHIME, 0.8f, 1.2f);
@@ -110,7 +96,6 @@ public final class PhotoService {
                     () -> player.sendActionBar(Component.text("Rendern fehlgeschlagen.", NamedTextColor.RED)));
             dispatched = true;
         } finally {
-            // prepare()/map setup threw before handing off — free the reserved slot.
             if (!dispatched) manager.release(user);
         }
 
@@ -120,8 +105,7 @@ public final class PhotoService {
     private static void playShutter(Player player) {
         player.playSound(player.getLocation(), Sound.BLOCK_VAULT_OPEN_SHUTTER, 1f, 1.4f);
         Location eye = player.getEyeLocation();
-        Vector forward = eye.getDirection().normalize().multiply(1.0);
-        Location flash = eye.clone().add(forward);
+        Location flash = eye.clone().add(eye.getDirection());
         player.getWorld().spawnParticle(Particle.END_ROD, flash, 12, 0.2, 0.2, 0.2, 0.01);
         player.getWorld().spawnParticle(Particle.FIREWORK, flash, 6, 0.1, 0.1, 0.1, 0.02);
     }

src/main/java/eu/mhsl/minecraft/pixelpics/survival/SurvivalRecipes.java

@@ -1,8 +1,8 @@
 package eu.mhsl.minecraft.pixelpics.survival;
 
 import eu.mhsl.minecraft.pixelpics.Main;
-import java.util.ArrayList;
 import java.util.List;
+import java.util.stream.IntStream;
 import org.bukkit.Bukkit;
 import org.bukkit.Material;
 import org.bukkit.NamespacedKey;
@@ -12,10 +12,8 @@ import org.bukkit.inventory.ShapedRecipe;
 import org.bukkit.inventory.ShapelessRecipe;
 
 /**
- * Registers the four survival recipes and makes them discoverable in the recipe book. Camera and
- * film have fixed results; load-film and copy-photo use {@code MaterialChoice} ingredients (their
- * inputs carry variable NBT) and their real results are computed dynamically in {@link CraftingListener}
- * — the registered result here is only the book/preview icon.
+ * The four survival recipes. Load film and copy photo only register a recipe book icon as result; the real result
+ * is computed in {@link CraftingListener}.
  */
 public final class SurvivalRecipes {
 
@@ -37,7 +35,6 @@ public final class SurvivalRecipes {
     public static void register() {
         unregister();
 
-        // Camera
         ShapedRecipe camera = new ShapedRecipe(CAMERA, CameraItems.createCamera(0));
         camera.shape("IDI", "GLG", "IRI");
         camera.setIngredient('I', Material.IRON_INGOT);
@@ -47,35 +44,29 @@ public final class SurvivalRecipes {
         camera.setIngredient('R', Material.REDSTONE);
         Bukkit.addRecipe(camera, false);
 
-        // Film roll
         ShapedRecipe film = new ShapedRecipe(FILM, CameraItems.createFilm());
         film.shape(" P ", "PIP", " P ");
         film.setIngredient('P', Material.PAPER);
         film.setIngredient('I', Material.INK_SAC);
         Bukkit.addRecipe(film, false);
 
-        // Load film: camera + film. Use ExactChoice so the recipe book renders the real camera/film
-        // textures instead of generic player heads. The camera choice enumerates every loadable fill
-        // level (0..MAX_FILM-1) so a partly loaded camera still matches; the actual result is still
-        // validated and computed dynamically in CraftingListener.
-        List<ItemStack> loadableCameras = new ArrayList<>();
-        for (int i = 0; i < CameraItems.MAX_FILM; i++) {
-            loadableCameras.add(CameraItems.createCamera(i));
-        }
+        // ExactChoice so the recipe book shows the real head textures; every loadable fill level is listed
+        // because a used camera must still match.
+        List<ItemStack> loadableCameras = IntStream.range(0, CameraItems.MAX_FILM)
+                .mapToObj(CameraItems::createCamera)
+                .toList();
         ShapelessRecipe load = new ShapelessRecipe(LOAD, CameraItems.createCamera(1));
         load.addIngredient(RecipeChoice.exactChoice(loadableCameras));
         load.addIngredient(RecipeChoice.exactChoice(CameraItems.createFilm()));
         Bukkit.addRecipe(load, false);
 
-        // Copy photo: photo + film. The photo carries a variable map id (cannot be enumerated), so it
-        // stays a MaterialChoice (a filled-map icon, not a player head); the film uses ExactChoice so
-        // its real texture shows in the book.
+        // The photo's map id cannot be enumerated, so it stays a MaterialChoice.
         ShapelessRecipe copy = new ShapelessRecipe(COPY, new ItemStack(Material.FILLED_MAP));
         copy.addIngredient(new RecipeChoice.MaterialChoice(Material.FILLED_MAP));
         copy.addIngredient(RecipeChoice.exactChoice(CameraItems.createFilm()));
         Bukkit.addRecipe(copy, false);
 
-        // Cover /reload while players are online; fresh joins are handled by JoinListener.
+        // Players already online after a reload; later joins are handled by JoinListener.
         Bukkit.getOnlinePlayers().forEach(p -> p.discoverRecipes(allKeys()));
     }
 

src/main/java/eu/mhsl/minecraft/pixelpics/utils/ImageMapRenderer.java

@@ -1,6 +1,5 @@
 package eu.mhsl.minecraft.pixelpics.utils;
 
-import java.awt.image.BufferedImage;
 import org.bukkit.entity.Player;
 import org.bukkit.map.MapCanvas;
 import org.bukkit.map.MapRenderer;
@@ -8,41 +7,31 @@ import org.bukkit.map.MapView;
 import org.jetbrains.annotations.NotNull;
 
 /**
- * Draws precomputed map palette indices onto the canvas. Supports a Polaroid-style "developing"
- * animation: the picture dissolves in over {@link #DEVELOP_MILLIS} once the render is ready, like an
- * old instant camera. Persisted maps are drawn instantly without animation.
- *
- * <p>{@code render()} is invoked by Bukkit each tick for viewing players, which drives the animation;
- * progress is based on wall-clock time so it is correct even if the player looks away and back.
+ * Draws precomputed map palette indices. A fresh photo shows blank film until {@link #develop} and then dissolves in
+ * over {@link #DEVELOP_MILLIS} like an instant camera picture; persisted maps are drawn at once. Bukkit calls
+ * {@code render} every tick for viewing players; progress follows the wall clock, so looking away does not stall it.
  */
+@SuppressWarnings("deprecation") // MapCanvas.setPixel(int, int, byte)
 public class ImageMapRenderer extends MapRenderer {
 
     public static final int MAP_SIZE = MapImageDither.SIZE;
     private static final long DEVELOP_MILLIS = 3000;
+    private static final byte FILM = MapColorPalette.mapIndex(MapColorPalette.nearestPos(206, 202, 190));
 
-    private static byte filmIndex = 0;
-    private static boolean filmResolved = false;
-
-    private volatile byte[] indices; // MAP_SIZE*MAP_SIZE, null while still rendering
+    private volatile byte[] indices; // null while still rendering
     private final boolean animate;
-    private volatile long developStart = 0; // 0 until indices are available
+    private volatile long developStart;
     private boolean finished = false;
     private boolean blankDrawn = false;
 
-    /** Persisted/instant map: draw the full picture immediately, no animation. */
+    /** A persisted picture, drawn without animation. */
     public ImageMapRenderer(byte[] indices) {
         this.indices = indices;
         this.animate = false;
     }
 
-    /** Fresh capture from a rendered image: dithers immediately, then develops. */
-    public ImageMapRenderer(BufferedImage image) {
-        this(MapImageDither.dither(image));
-    }
-
-    /** Pending capture: shows blank film until {@link #develop} supplies the picture. */
+    /** A pending capture. */
     public ImageMapRenderer() {
-        this.indices = null;
         this.animate = true;
     }
 
@@ -50,58 +39,39 @@ public class ImageMapRenderer extends MapRenderer {
         return indices;
     }
 
-    /** Supplies the finished picture and starts the developing animation. */
     public void develop(byte[] indices) {
-        this.indices = indices;
         this.developStart = System.currentTimeMillis();
-        this.finished = false;
+        this.indices = indices;
     }
 
     @Override
     public void render(@NotNull MapView map, @NotNull MapCanvas canvas, @NotNull Player player) {
         if (finished) return;
         byte[] data = this.indices;
-
-        // Still rendering: show a blank "film" once.
         if (data == null) {
             if (!blankDrawn) {
-                fill(canvas, film());
+                blit(canvas, null, 0);
                 blankDrawn = true;
             }
             return;
         }
-
-        if (!animate) {
-            blit(canvas, data, 1.0);
-            finished = true;
-            return;
-        }
-
-        double progress = (System.currentTimeMillis() - developStart) / (double) DEVELOP_MILLIS;
+        double progress = animate ? (System.currentTimeMillis() - developStart) / (double) DEVELOP_MILLIS : 1.0;
         blit(canvas, data, progress);
         if (progress >= 1.0) finished = true;
     }
 
-    /** Draws revealed pixels at the given progress; unrevealed pixels stay film-colored. */
-    private void blit(MapCanvas canvas, byte[] data, double progress) {
-        byte film = film();
+    /** Draws the pixels revealed at {@code progress}; the rest (all of them without data) stay film-coloured. */
+    private static void blit(MapCanvas canvas, byte[] data, double progress) {
         for (int y = 0; y < MAP_SIZE; y++) {
             for (int x = 0; x < MAP_SIZE; x++) {
-                byte value = (progress >= 1.0 || revealThreshold(x, y) <= progress) ? data[y * MAP_SIZE + x] : film;
-                canvas.setPixel(x, y, value);
+                boolean revealed = data != null && (progress >= 1.0 || revealThreshold(x, y) <= progress);
+                canvas.setPixel(x, y, revealed ? data[y * MAP_SIZE + x] : FILM);
             }
         }
     }
 
-    @SuppressWarnings("deprecation")
-    private void fill(MapCanvas canvas, byte value) {
-        for (int y = 0; y < MAP_SIZE; y++) {
-            for (int x = 0; x < MAP_SIZE; x++) canvas.setPixel(x, y, value);
-        }
-    }
-
-    /** Per-pixel reveal time in [0,1]: mostly noise plus a gentle top-to-bottom sweep for an organic develop. */
-    private double revealThreshold(int x, int y) {
+    /** Per-pixel reveal time in [0,1): mostly noise plus a gentle top-to-bottom sweep. */
+    private static double revealThreshold(int x, int y) {
         int h = (x * 374761393 + y * 668265263);
         h = (h ^ (h >>> 13)) * 1274126177;
         double noise = ((h >>> 8) & 0xFFFF) / 65535.0;
@@ -109,16 +79,8 @@ public class ImageMapRenderer extends MapRenderer {
         return Math.min(0.999, noise * 0.7 + sweep * 0.3);
     }
 
-    /** The blank-film map colour a photo shows while it is still being rendered. */
+    /** The blank-film colour of a photo that is still rendering. */
     public static byte filmColor() {
-        return film();
-    }
-
-    private static byte film() {
-        if (!filmResolved) {
-            filmIndex = MapColorPalette.mapIndex(MapColorPalette.nearestPos(206, 202, 190));
-            filmResolved = true;
-        }
-        return filmIndex;
+        return FILM;
     }
 }

src/main/java/eu/mhsl/minecraft/pixelpics/utils/MapColorPalette.java

@@ -2,84 +2,63 @@ package eu.mhsl.minecraft.pixelpics.utils;
 
 import eu.mhsl.minecraft.pixelpics.render.util.ColorUtil;
 import java.awt.Color;
-import java.util.ArrayList;
-import java.util.List;
+import java.util.Arrays;
 import org.bukkit.map.MapPalette;
 
 /**
- * The set of usable Minecraft map colors, with nearest-color matching in CIELAB (perceptual) space.
- * Built once from {@link MapPalette}. Matching in Lab rather than RGB keeps hues correct (greens stay
- * green instead of collapsing to gray).
+ * The opaque Minecraft map colours with nearest-colour matching in CIELAB (in RGB, greens collapse to grey). Built
+ * from {@link MapPalette} on class initialisation, which {@code Main} triggers on the main thread.
  */
 public final class MapColorPalette {
 
-    private static volatile boolean initialized = false;
-    private static byte[] indices;
-    private static int[] rgb;
-    private static double[][] lab;
-    private static int[] argbByIndex; // all 256 map colour bytes → ARGB (transparent slots alpha 0)
+    private static final byte[] INDICES;
+    private static final double[][] LAB;
+    private static final int[] ARGB_BY_INDEX = new int[256]; // raw map colour byte -> ARGB, transparent = 0
+
+    static {
+        byte[] indices = new byte[256];
+        double[][] lab = new double[256][];
+        int n = 0;
+        for (int i = 0; i < 256; i++) {
+            Color c = color((byte) i);
+            if (c == null || c.getAlpha() < 255) continue;
+            ARGB_BY_INDEX[i] = 0xFF000000 | (c.getRGB() & 0xFFFFFF);
+            indices[n] = (byte) i;
+            lab[n++] = rgbToLab(c.getRed(), c.getGreen(), c.getBlue());
+        }
+        INDICES = Arrays.copyOf(indices, n);
+        LAB = Arrays.copyOf(lab, n);
+    }
 
     private MapColorPalette() {}
 
-    // MapPalette.getColor(byte) is deprecated for removal with no replacement for enumerating the
-    // index->colour palette; suppress until the API offers an alternative.
+    // MapPalette.getColor is deprecated for removal without a replacement for enumerating the palette; it throws
+    // past the last colour.
     @SuppressWarnings("removal")
-    private static synchronized void ensure() {
-        if (initialized) return;
-        List<Byte> idx = new ArrayList<>();
-        List<Integer> rgbs = new ArrayList<>();
-        List<double[]> labs = new ArrayList<>();
-        for (int i = 0; i < 256; i++) {
-            Color c;
-            try {
-                c = MapPalette.getColor((byte) i);
-            } catch (Throwable t) {
-                continue;
-            }
-            if (c.getAlpha() < 255) continue; // skip transparent slots
-            idx.add((byte) i);
-            rgbs.add((c.getRed() << 16) | (c.getGreen() << 8) | c.getBlue());
-            labs.add(rgbToLab(c.getRed(), c.getGreen(), c.getBlue()));
+    private static Color color(byte index) {
+        try {
+            return MapPalette.getColor(index);
+        } catch (Throwable t) {
+            return null;
         }
-        indices = new byte[idx.size()];
-        rgb = new int[idx.size()];
-        lab = new double[idx.size()][];
-        for (int i = 0; i < idx.size(); i++) {
-            indices[i] = idx.get(i);
-            rgb[i] = rgbs.get(i);
-            lab[i] = labs.get(i);
-        }
-        argbByIndex = new int[256];
-        for (int i = 0; i < 256; i++) {
-            try {
-                Color c = MapPalette.getColor((byte) i);
-                argbByIndex[i] = c.getAlpha() < 255 ? 0 : (0xFF << 24) | (c.getRGB() & 0xFFFFFF);
-            } catch (Throwable t) {
-                argbByIndex[i] = 0;
-            }
-        }
-        initialized = true;
     }
 
     /** ARGB of a raw map colour byte as the client draws it; transparent slots are 0. */
     public static int argb(byte mapColor) {
-        ensure();
-        return argbByIndex[mapColor & 0xFF];
+        return ARGB_BY_INDEX[mapColor & 0xFF];
     }
 
     public static int size() {
-        ensure();
-        return indices.length;
+        return INDICES.length;
     }
 
-    /** Index into the internal arrays of the perceptually nearest palette color. */
+    /** Position of the perceptually nearest palette colour. */
     public static int nearestPos(int r, int g, int b) {
-        ensure();
         double[] target = rgbToLab(r, g, b);
         double best = Double.MAX_VALUE;
         int bestPos = 0;
-        for (int i = 0; i < lab.length; i++) {
-            double[] l = lab[i];
+        for (int i = 0; i < LAB.length; i++) {
+            double[] l = LAB[i];
             double dl = target[0] - l[0], da = target[1] - l[1], db = target[2] - l[2];
             double d = dl * dl + da * da + db * db;
             if (d < best) {
@@ -90,18 +69,13 @@ public final class MapColorPalette {
         return bestPos;
     }
 
-    /** CIELAB of the palette color at {@code pos} (do not modify). */
+    /** CIELAB of the palette colour at {@code pos} (do not modify). */
     public static double[] lab(int pos) {
-        ensure();
-        return lab[pos];
+        return LAB[pos];
     }
 
     public static byte mapIndex(int pos) {
-        return indices[pos];
-    }
-
-    public static int mapRgb(int pos) {
-        return rgb[pos];
+        return INDICES[pos];
     }
 
     public static double[] rgbToLab(int r, int g, int b) {

src/main/java/eu/mhsl/minecraft/pixelpics/utils/MapImageDither.java

@@ -3,38 +3,26 @@ package eu.mhsl.minecraft.pixelpics.utils;
 import java.awt.image.BufferedImage;
 
 /**
- * Quantizes a rendered image to Minecraft map color indices. The result is a {@code 128*128} byte
- * array of palette indices, ready to blit onto a {@link org.bukkit.map.MapCanvas}.
- *
- * <p>Uses dampened Floyd–Steinberg error diffusion in CIELAB space with <em>constrained</em>
- * candidates: a pixel may only take a palette color that is nearly as close to its original color
- * as the best match. Colors the map palette cannot represent well (e.g. light sky blue, sunset
- * tones) would otherwise be approximated by mixing far-apart colors, producing a harsh,
- * high-contrast checkerboard; the constraint keeps the dither between neighbouring colors only,
- * so flat areas stay calm while gradients still blend.
- *
- * <p>This is the expensive step; computing it once and caching the byte array lets map re-rendering
- * after a restart be a cheap copy instead of a full re-quantization.
+ * Quantizes an image to {@code SIZE*SIZE} map colour indices: dampened Floyd–Steinberg in CIELAB with
+ * <em>constrained</em> candidates, i.e. a pixel may only take a colour nearly as close to its original as the best
+ * match. Colours the palette represents badly (light sky blue, sunset tones) would otherwise be mixed from far-apart
+ * colours into a harsh checkerboard; this way flat areas stay calm while gradients still blend. Expensive, hence the
+ * on-disk index cache in {@link MapManager}.
  */
 public final class MapImageDither {
 
     public static final int SIZE = 128;
 
-    /** Fraction of quantization error diffused. */
+    /** Fraction of the quantization error that is diffused. */
     private static final double DITHER_STRENGTH = 0.6;
 
-    /**
-     * A candidate is allowed when its Lab distance to the original pixel is at most
-     * {@code best * CANDIDATE_RATIO + CANDIDATE_SLACK}, where {@code best} is the distance of the
-     * nearest palette color.
-     */
+    // A candidate may be at most best * CANDIDATE_RATIO + CANDIDATE_SLACK (Lab distance) from the original pixel.
     private static final double CANDIDATE_RATIO = 1.1;
-
     private static final double CANDIDATE_SLACK = 1.5;
 
     private MapImageDither() {}
 
-    /** Returns a {@code SIZE*SIZE} array of map palette indices (row-major, y*SIZE + x). */
+    /** Row-major ({@code y*SIZE + x}) map colour indices. */
     public static byte[] dither(BufferedImage image) {
         int w = Math.min(SIZE, image.getWidth());
         int h = Math.min(SIZE, image.getHeight());

src/main/java/eu/mhsl/minecraft/pixelpics/utils/MapManager.java

@@ -20,9 +20,8 @@ import org.bukkit.inventory.meta.MapMeta;
 import org.bukkit.map.MapView;
 
 /**
- * Persists rendered images (PNG, source of truth) and their dithered map-color indices (cache) to
- * disk, (re)attaches the renderer to a {@link MapView}, and supports orphan cleanup. State is
- * filesystem-backed so screenshots survive a restart.
+ * Photo storage in {@code images/}: the PNG is the source of truth, {@code .mcmap} caches its dithered map indices.
+ * Also (re)attaches renderers to map views and finds orphans for cleanup.
  */
 public class MapManager {
 
@@ -42,12 +41,12 @@ public class MapManager {
         mapView.setTrackingPosition(false);
     }
 
-    public static File getImagePath(int mapId) {
-        return new File(imageFolder(), String.format("mapId_%d.png", mapId));
+    private static File getImagePath(int mapId) {
+        return new File(imageFolder(), "mapId_" + mapId + ".png");
     }
 
-    public static File getIndexPath(int mapId) {
-        return new File(imageFolder(), String.format("mapId_%d.mcmap", mapId));
+    private static File getIndexPath(int mapId) {
+        return new File(imageFolder(), "mapId_" + mapId + ".mcmap");
     }
 
     private static boolean ensureFolder() {
@@ -77,7 +76,7 @@ public class MapManager {
         }
     }
 
-    /** Reads the cached dithered indices, or {@code null} if absent/invalid. */
+    /** The cached indices, or {@code null} if absent or invalid. */
     public static byte[] readIndices(int id) {
         File path = getIndexPath(id);
         if (!path.isFile()) return null;
@@ -89,7 +88,7 @@ public class MapManager {
         }
     }
 
-    /** Reads the stored image, or {@code null} if it does not exist or cannot be read. */
+    /** The stored image, or {@code null} if absent or unreadable. */
     public static BufferedImage readImage(int id) {
         File path = getImagePath(id);
         if (!path.isFile()) return null;
@@ -105,16 +104,12 @@ public class MapManager {
         return getIndexPath(id).isFile() || getImagePath(id).isFile();
     }
 
-    // --- Cleanup support ---
-
-    /** A map id stored on disk together with the newest of its files' last-modified time. */
+    /** A stored map id with the newest last-modified time of its files. */
     public record StoredMap(int id, long lastModified) {}
 
-    /** All map ids that have files on disk. */
     public static Set<StoredMap> listStored() {
         Set<StoredMap> result = new HashSet<>();
-        File folder = imageFolder();
-        File[] files = folder.listFiles();
+        File[] files = imageFolder().listFiles();
         if (files == null) return result;
         Set<Integer> seen = new HashSet<>();
         for (File f : files) {
@@ -132,7 +127,7 @@ public class MapManager {
         return f.isFile() ? f.lastModified() : 0L;
     }
 
-    /** Map ids referenced by currently-loaded item frames and online players (inventory + ender chest). */
+    /** Map ids held by online players (inventory, ender chest, cursor) and loaded item frames. */
     public static Set<Integer> collectInUseMapIds() {
         Set<Integer> inUse = new HashSet<>();
         for (Player p : Bukkit.getOnlinePlayers()) {
@@ -149,18 +144,20 @@ public class MapManager {
     }
 
     private static void addFromContents(Set<Integer> set, ItemStack[] contents) {
-        if (contents == null) return;
         for (ItemStack item : contents) addFromItem(set, item);
     }
 
     private static void addFromItem(Set<Integer> set, ItemStack item) {
-        if (item == null || item.getType() != Material.FILLED_MAP || !item.hasItemMeta()) return;
-        if (item.getItemMeta() instanceof MapMeta meta && meta.hasMapView() && meta.getMapView() != null) {
+        if (item != null
+                && item.getType() == Material.FILLED_MAP
+                && item.getItemMeta() instanceof MapMeta meta
+                && meta.hasMapView()
+                && meta.getMapView() != null) {
             set.add(meta.getMapView().getId());
         }
     }
 
-    /** Deletes both files for a map id. Returns true if anything was deleted. */
+    /** Deletes both files of a map id; true if anything was deleted. */
     public static boolean delete(int id) {
         boolean deleted = false;
         File png = getImagePath(id);

tools/edgecase-plugin/pptest/PPTest.java

@@ -2071,7 +2071,7 @@ public class PPTest extends JavaPlugin {
         g.fillRect(48, 56, 32, 12);
         g.dispose();
         org.bukkit.map.MapView v = Bukkit.createMap(w);
-        eu.mhsl.minecraft.pixelpics.utils.MapManager.attachView(v, new eu.mhsl.minecraft.pixelpics.utils.ImageMapRenderer(img));
+        eu.mhsl.minecraft.pixelpics.utils.MapManager.attachView(v, new eu.mhsl.minecraft.pixelpics.utils.ImageMapRenderer(eu.mhsl.minecraft.pixelpics.utils.MapImageDither.dither(img)));
         return synthMap = mapItem(v);
     }