Tidy up

* Link javadocs to FlowPoweredMath & GSON

* Update build.gradle.kts

.github/workflows/gradle.yml

@@ -10,10 +10,12 @@ jobs:
       with: 
         submodules: recursive
         fetch-depth: 0 # needed for versioning
-    - name: Set up Java 11
-      uses: actions/setup-java@v1
+    - name: Set up Java
+      uses: actions/setup-java@v3
       with:
-        java-version: 11
+        distribution: 'temurin'
+        java-version: 16
+        cache: 'gradle'
     - name: Build with Gradle
       run: ./gradlew clean build test
     - uses: actions/upload-artifact@v2-preview

.github/workflows/publish.yml

@@ -0,0 +1,27 @@
+name: Publish
+
+on:
+  workflow_dispatch:
+  push:
+    tags:
+      - '**'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+      with: 
+        submodules: recursive
+        fetch-depth: 0 # needed for versioning
+    - name: Set up Java
+      uses: actions/setup-java@v3
+      with:
+        distribution: 'temurin'
+        java-version: 16
+        cache: 'gradle'
+    - name: Build with Gradle
+      run: ./gradlew publish
+      env:
+        BLUECOLORED_USERNAME: ${{ secrets.BLUECOLORED_USERNAME }}
+        BLUECOLORED_PASSWORD: ${{ secrets.BLUECOLORED_PASSWORD }}

build.gradle.kts

@@ -1,4 +1,5 @@
 import java.io.IOException
+import java.util.concurrent.TimeoutException
 
 plugins {
     java
@@ -12,7 +13,11 @@ fun String.runCommand(): String = ProcessBuilder(split("\\s(?=(?:[^'\"`]*(['\"`]
     .redirectOutput(ProcessBuilder.Redirect.PIPE)
     .redirectError(ProcessBuilder.Redirect.PIPE)
     .start()
-    .apply { waitFor(60, TimeUnit.SECONDS) }
+    .apply {
+        if (!waitFor(10, TimeUnit.SECONDS)) {
+            throw TimeoutException("Failed to execute command: '" + this@runCommand + "'")
+        }
+    }
     .run {
         val error = errorStream.bufferedReader().readText().trim()
         if (error.isNotEmpty()) {
@@ -28,17 +33,20 @@ val lastVersion = lastTag.substring(1) // remove the leading 'v'
 val commits = "git rev-list --count $lastTag..HEAD".runCommand()
 println("Git hash: $gitHash" + if (clean) "" else " (dirty)")
 
-group = "de.bluecolored.bluemap.api"
+group = "de.bluecolored.bluemap"
 version = lastVersion +
         (if (commits == "0") "" else "-$commits") +
         (if (clean) "" else "-dirty")
 
 println("Version: $version")
 
-val javaTarget = 11
+val javaTarget = 16
 java {
     sourceCompatibility = JavaVersion.toVersion(javaTarget)
     targetCompatibility = JavaVersion.toVersion(javaTarget)
+
+    withSourcesJar()
+    withJavadocJar()
 }
 
 repositories {
@@ -77,8 +85,12 @@ tasks.javadoc {
     options {
         (this as? StandardJavadocDocletOptions)?.apply {
             links(
-                "https://docs.oracle.com/javase/8/docs/api/"
+                "https://docs.oracle.com/en/java/javase/16/docs/api/",
+                "https://javadoc.io/doc/com.flowpowered/flow-math/1.0.3/",
+                "https://javadoc.io/doc/com.google.code.gson/gson/2.8.0/",
             )
+            addStringOption("Xdoclint:none", "-quiet")
+            addBooleanOption("html5", true)
         }
     }
 }
@@ -96,6 +108,20 @@ tasks.processResources {
 }
 
 publishing {
+    repositories {
+        maven {
+            name = "bluecolored"
+
+            val releasesRepoUrl = "https://repo.bluecolored.de/releases"
+            val snapshotsRepoUrl = "https://repo.bluecolored.de/snapshots"
+            url = uri(if (version == lastVersion) releasesRepoUrl else snapshotsRepoUrl)
+
+            credentials {
+                username = project.findProperty("bluecoloredUsername") as String? ?: System.getenv("BLUECOLORED_USERNAME")
+                password = project.findProperty("bluecoloredPassword") as String? ?: System.getenv("BLUECOLORED_PASSWORD")
+            }
+        }
+    }
     publications {
         create<MavenPublication>("maven") {
             groupId = project.group.toString()

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.4-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.7-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

src/main/java/de/bluecolored/bluemap/api/AssetStorage.java

@@ -0,0 +1,106 @@
+/*
+ * This file is part of BlueMap, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) Blue (Lukas Rieger) <https://bluecolored.de>
+ * Copyright (c) contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package de.bluecolored.bluemap.api;
+
+import de.bluecolored.bluemap.api.markers.POIMarker;
+import de.bluecolored.bluemap.api.markers.HtmlMarker;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.Optional;
+
+/**
+ * A storage that is able to hold any "asset"-data for a map. For example images, icons, scripts or json-files.
+ */
+@SuppressWarnings("unused")
+public interface AssetStorage {
+
+    /**
+     * Writes a new asset into this storage, overwriting any existent assets with the same name.<br>
+     * Use the returned {@link OutputStream} to write the asset-data. The asset will be added to the storage as soon as that stream
+     * gets closed!<br>
+     * <br>
+     * Example:
+     * <pre>
+     * try (OutputStream out = assetStorage.writeAsset("image.png")) {
+     *     ImageIO.write(image, "png", out);
+     * }
+     * </pre>
+     * @param name The (unique) name for this asset
+     * @return An {@link OutputStream} that should be used to write the asset and closed once!
+     * @throws IOException when the underlying storage rises an IOException
+     */
+    OutputStream writeAsset(String name) throws IOException;
+
+    /**
+     * Reads an asset from this storage.<br>
+     * Use the returned {@link InputStream} to read the asset-data.<br>
+     * <br>
+     * Example:
+     * <pre>
+     * Optional&lt;InputStream&gt; optIn = assetStorage.readAsset("image.png");
+     * if (optIn.isPresent()) {
+     *     try (InputStream in = optIn.get()) {
+     *         BufferedImage image = ImageIO.read(in);
+     *     }
+     * }
+     * </pre>
+     * @param name The name of the asset that should be read from the storage.
+     * @return An {@link Optional} with an {@link InputStream} when the asset is found, from which the asset can be read.
+     * Or an empty optional if there is no asset with this name.
+     * @throws IOException when the underlying storage rises an IOException
+     */
+    Optional<InputStream> readAsset(String name) throws IOException;
+
+    /**
+     * Checks if an asset exists in this storage without reading it.<br>
+     * This is useful if the asset has a lot of data and using {@link #readAsset(String)}
+     * just to check if the asset is present would be wasteful.
+     * @param name The name of the asset to check for
+     * @return <code>true</code> if the asset is found, <code>false</code> if not
+     * @throws IOException when the underlying storage rises an IOException
+     */
+    boolean assetExists(String name) throws IOException;
+
+    /**
+     * Returns the relative URL that can be used by the webapp to request this asset.<br>
+     * This is the url that you can e.g. use in {@link POIMarker}s or {@link HtmlMarker}s to add an icon.<br>
+     * If there is no asset with this name, then this method returns the URL that an asset with such a name <i>would</i>
+     * have if it would be added later.
+     * @param name The name of the asset
+     * @return The relative URL for an asset with the given name
+     */
+    String getAssetUrl(String name);
+
+    /**
+     * Deletes the asset with the given name from this storage, if it exists.<br>
+     * If there is no asset with this name, this method does nothing.
+     * @param name The name of the asset that should be deleted
+     * @throws IOException when the underlying storage rises an IOException
+     */
+    void deleteAsset(String name) throws IOException;
+
+}

src/main/java/de/bluecolored/bluemap/api/BlueMapAPI.java

@@ -27,7 +27,8 @@ package de.bluecolored.bluemap.api;
 import com.google.gson.Gson;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
-import de.bluecolored.bluemap.api.debug.DebugDump;
+import de.bluecolored.bluemap.api.plugin.Plugin;
+import org.jetbrains.annotations.ApiStatus;
 
 import java.io.InputStream;
 import java.io.InputStreamReader;
@@ -42,6 +43,7 @@ import java.util.function.Consumer;
  * An API to control the running instance of BlueMap.
  * <p>This API is thread-save, so you <b>can</b> use it async, off the main-server-thread, to save performance!</p>
  */
+@SuppressWarnings({"unused", "UnusedReturnValue"})
 public abstract class BlueMapAPI {
 
     @SuppressWarnings("unused")
@@ -57,6 +59,7 @@ public abstract class BlueMapAPI {
                 gitHash = element.get("git-hash").getAsString();
             } catch (Exception ex) {
                 System.err.println("Failed to load version from resources!");
+                //noinspection CallToPrintStackTrace
                 ex.printStackTrace();
             }
         }
@@ -70,35 +73,37 @@ public abstract class BlueMapAPI {
 
     private static BlueMapAPI instance;
 
-    private static final Collection<Consumer<BlueMapAPI>> onEnableConsumers = new HashSet<>(2);
-    private static final Collection<Consumer<BlueMapAPI>> onDisableConsumers = new HashSet<>(2);
+    private static final LinkedHashSet<Consumer<BlueMapAPI>> onEnableConsumers = new LinkedHashSet<>();
+    private static final LinkedHashSet<Consumer<BlueMapAPI>> onDisableConsumers = new LinkedHashSet<>();
 
     /**
      * Getter for the {@link RenderManager}.
      * @return the {@link RenderManager}
      */
-    @DebugDump
     public abstract RenderManager getRenderManager();
 
     /**
      * Getter for the {@link WebApp}.
      * @return the {@link WebApp}
      */
-    @DebugDump
     public abstract WebApp getWebApp();
 
+    /**
+     * Getter for the {@link Plugin}
+     * @return the {@link Plugin}
+     */
+    public abstract Plugin getPlugin();
+
     /**
      * Getter for all {@link BlueMapMap}s loaded by BlueMap.
      * @return an unmodifiable collection of all loaded {@link BlueMapMap}s
      */
-    @DebugDump
     public abstract Collection<BlueMapMap> getMaps();
 
     /**
      * Getter for all {@link BlueMapWorld}s loaded by BlueMap.
      * @return an unmodifiable collection of all loaded {@link BlueMapWorld}s
      */
-    @DebugDump
     public abstract Collection<BlueMapWorld> getWorlds();
 
     /**
@@ -129,14 +134,12 @@ public abstract class BlueMapAPI {
      * Getter for the installed BlueMap version
      * @return the version-string
      */
-    @DebugDump
     public abstract String getBlueMapVersion();
 
     /**
      * Getter for the installed BlueMapAPI version
      * @return the version-string
      */
-    @DebugDump
     public String getAPIVersion() {
         return VERSION;
     }
@@ -155,6 +158,7 @@ public abstract class BlueMapAPI {
      * <p><b>The {@link Consumer} can be called multiple times if BlueMap disables and enables again, e.g. if BlueMap gets reloaded!</b></p>
      * <p><i>(Note: The consumer will likely be called asynchronously, <b>not</b> on the server-thread!)</i></p>
      * <p>Remember to unregister the consumer when you no longer need it using {@link #unregisterListener(Consumer)}.</p>
+     * <p>The {@link Consumer}s are guaranteed to be called in the order they were registered in.</p>
      * @param consumer the {@link Consumer}
      */
     public static synchronized void onEnable(Consumer<BlueMapAPI> consumer) {
@@ -168,6 +172,7 @@ public abstract class BlueMapAPI {
      * <p><b>The {@link Consumer} can be called multiple times if BlueMap disables and enables again, e.g. if BlueMap gets reloaded!</b></p>
      * <p><i>(Note: The consumer will likely be called asynchronously, <b>not</b> on the server-thread!)</i></p>
      * <p>Remember to unregister the consumer when you no longer need it using {@link #unregisterListener(Consumer)}.</p>
+     * <p>The {@link Consumer}s are guaranteed to be called in the order they were registered in.</p>
      * @param consumer the {@link Consumer}
      */
     public static synchronized void onDisable(Consumer<BlueMapAPI> consumer) {
@@ -189,39 +194,33 @@ public abstract class BlueMapAPI {
      * @return <code>true</code> if the instance has been registered, <code>false</code> if there already was an instance registered
      * @throws ExecutionException if a listener threw an exception during the registration
      */
-    protected static synchronized boolean registerInstance(BlueMapAPI instance) throws ExecutionException {
+    @ApiStatus.Internal
+    protected static synchronized boolean registerInstance(BlueMapAPI instance) throws Exception {
         if (BlueMapAPI.instance != null) return false;
 
         BlueMapAPI.instance = instance;
 
-        List<Throwable> thrownExceptions = new ArrayList<>(0);
+        List<Exception> thrownExceptions = new ArrayList<>(0);
 
         for (Consumer<BlueMapAPI> listener : BlueMapAPI.onEnableConsumers) {
             try {
                 listener.accept(BlueMapAPI.instance);
-            } catch (Throwable ex) {
+            } catch (Exception ex) {
                 thrownExceptions.add(ex);
             }
         }
 
-        if (!thrownExceptions.isEmpty()) {
-            ExecutionException ex = new ExecutionException(thrownExceptions.get(0));
-            for (int i = 1; i < thrownExceptions.size(); i++) {
-                ex.addSuppressed(thrownExceptions.get(i));
-            }
-            throw ex;
-        }
-
-        return true;
+        return throwAsOne(thrownExceptions);
     }
 
     /**
      * Used by BlueMap to unregister the API and call the listeners properly.
      * @param instance the {@link BlueMapAPI} instance
-     * @return <code>true</code> if the instance was unregistered, <code>false</code> if there was no or an other instance registered
+     * @return <code>true</code> if the instance was unregistered, <code>false</code> if there was no or another instance registered
      * @throws ExecutionException if a listener threw an exception during the un-registration
      */
-    protected static synchronized boolean unregisterInstance(BlueMapAPI instance) throws ExecutionException {
+    @ApiStatus.Internal
+    protected static synchronized boolean unregisterInstance(BlueMapAPI instance) throws Exception {
         if (BlueMapAPI.instance != instance) return false;
 
         List<Exception> thrownExceptions = new ArrayList<>(0);
@@ -236,8 +235,12 @@ public abstract class BlueMapAPI {
 
         BlueMapAPI.instance = null;
 
+        return throwAsOne(thrownExceptions);
+    }
+
+    private static boolean throwAsOne(List<Exception> thrownExceptions) throws Exception {
         if (!thrownExceptions.isEmpty()) {
-            ExecutionException ex = new ExecutionException(thrownExceptions.get(0));
+            Exception ex = thrownExceptions.get(0);
             for (int i = 1; i < thrownExceptions.size(); i++) {
                 ex.addSuppressed(thrownExceptions.get(i));
             }

src/main/java/de/bluecolored/bluemap/api/BlueMapMap.java

@@ -27,8 +27,8 @@ package de.bluecolored.bluemap.api;
 import com.flowpowered.math.vector.Vector2i;
 import com.flowpowered.math.vector.Vector3d;
 import com.flowpowered.math.vector.Vector3i;
-import de.bluecolored.bluemap.api.debug.DebugDump;
 import de.bluecolored.bluemap.api.markers.MarkerSet;
+import org.jetbrains.annotations.ApiStatus;
 
 import java.util.Map;
 import java.util.function.Predicate;
@@ -37,42 +37,46 @@ import java.util.function.Predicate;
  * This class represents a map that is rendered by BlueMap of a specific world ({@link BlueMapWorld}).
  * Each map belongs to a map configured in BlueMap's configuration file (in the <code>maps: []</code> list).
  */
+@SuppressWarnings("unused")
 public interface BlueMapMap {
 
     /**
      * Returns this maps id, this is equal to the id configured in bluemap's config for this map.
      * @return the id of this map
      */
-    @DebugDump
     String getId();
 
     /**
      * Returns this maps display-name, this is equal to the name configured in bluemap's config for this map.
      * @return the name of this map
      */
-    @DebugDump
     String getName();
 
     /**
      * Getter for the {@link BlueMapWorld} of this map.
      * @return the {@link BlueMapWorld} of this map
      */
-    @DebugDump
     BlueMapWorld getWorld();
 
+    /**
+     * Getter for this map's {@link AssetStorage}. <br>
+     * Each map has its own storage for assets. Assets that are stored here will be available to every webapp that
+     * is displaying this map. E.g. these assets are also available in server-networks.
+     * @return the {@link AssetStorage} of this map
+     */
+    AssetStorage getAssetStorage();
+
     /**
      * Getter for a (modifiable) {@link Map} of {@link MarkerSet}s with the key being the {@link MarkerSet}'s id.
      * Changing this map will change the {@link MarkerSet}s and markers displayed on the web-app for this map.
      * @return a {@link Map} of {@link MarkerSet}s.
      */
-    @DebugDump
     Map<String, MarkerSet> getMarkerSets();
 
     /**
      * Getter for the size of all tiles on this map in blocks.
      * @return the tile-size in blocks
      */
-    @DebugDump
     Vector2i getTileSize();
 
     /**
@@ -80,7 +84,6 @@ public interface BlueMapMap {
      * E.g. an offset of (2|-1) would mean that the tile (0|0) has block (2|0|-1) at it's min-corner.
      * @return the tile-offset in blocks
      */
-    @DebugDump
     Vector2i getTileOffset();
 
     /**
@@ -90,6 +93,7 @@ public interface BlueMapMap {
      * <p>Any previously set filters will get overwritten with the new one. You can get the current filter using {@link #getTileFilter()} and combine them if you wish.</p>
      * @param filter The filter that will be used from now on.
      */
+    @ApiStatus.Experimental
     void setTileFilter(Predicate<Vector2i> filter);
 
     /**
@@ -106,8 +110,9 @@ public interface BlueMapMap {
     boolean isFrozen();
 
     /**
-     * Returns the currently set TileFilter. The default TileFilter is equivalent to <code>t -> true</code>.
+     * Returns the currently set TileFilter. The default TileFilter is equivalent to <code>t -&gt; true</code>.
      */
+    @ApiStatus.Experimental
     Predicate<Vector2i> getTileFilter();
 
     /**

src/main/java/de/bluecolored/bluemap/api/BlueMapWorld.java

@@ -24,8 +24,6 @@
  */
 package de.bluecolored.bluemap.api;
 
-import de.bluecolored.bluemap.api.debug.DebugDump;
-
 import java.nio.file.Path;
 import java.util.Collection;
 
@@ -38,21 +36,21 @@ public interface BlueMapWorld {
      * Getter for the id of this world.
      * @return the id of this world
      */
-    @DebugDump
     String getId();
 
     /**
-     * Getter for the {@link Path} of this world's save-files (folder). This matches the folder configured in bluemap's config for this map ( <code>world:</code> ).
+     * Getter for the {@link Path} of this world's save-files.<br>
+     * (To be exact: the parent-folder of the regions-folder used for rendering)
      * @return the save-folder of this world.
+     * @deprecated Getting the save-folder of a world is no longer supported. As it is not guaranteed that every world has a save-folder.
      */
-    @DebugDump
+    @Deprecated
     Path getSaveFolder();
 
     /**
      * Getter for all {@link BlueMapMap}s for this world
      * @return an unmodifiable {@link Collection} of all {@link BlueMapMap}s for this world
      */
-    @DebugDump
     Collection<BlueMapMap> getMaps();
 
 }

src/main/java/de/bluecolored/bluemap/api/ContentTypeRegistry.java

@@ -0,0 +1,121 @@
+/*
+ * This file is part of BlueMap, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) Blue (Lukas Rieger) <https://bluecolored.de>
+ * Copyright (c) contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package de.bluecolored.bluemap.api;
+
+import java.nio.file.Path;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * This Content-Type registry is used by the internal webserver to get the content-type of an asset.<br>
+ * The most commonly used file-suffixes and their content-types are registered by default, but you can use the static
+ * methods of this class to add more, if you need them.<br>
+ * <b>Note:</b> that any additionally added types won't work if the user uses an external webserver to serve their map-files.
+ */
+public class ContentTypeRegistry {
+
+    private static final String DEFAULT_CONTENT_TYPE = "application/octet-stream";
+    private static final Map<String, String> SUFFIX_MAP = new HashMap<>();
+
+    static {
+        register("txt", "text/plain");
+        register("css", "text/css");
+        register("csv", "text/csv");
+        register("htm", "text/html");
+        register("html", "text/html");
+        register("js", "text/javascript");
+        register("xml", "text/xml");
+
+        register("png", "image/png");
+        register("jpg", "image/jpeg");
+        register("jpeg", "image/jpeg");
+        register("gif", "image/gif");
+        register("webp", "image/webp");
+        register("tif", "image/tiff");
+        register("tiff", "image/tiff");
+        register("svg", "image/svg+xml");
+
+        register("json", "application/json");
+
+        register("mp3", "audio/mpeg");
+        register("oga", "audio/ogg");
+        register("wav", "audio/wav");
+        register("weba", "audio/webm");
+
+        register("mp4", "video/mp4");
+        register("mpeg", "video/mpeg");
+        register("webm", "video/webm");
+
+        register("ttf", "font/ttf");
+        register("woff", "font/woff");
+        register("woff2", "font/woff2");
+    }
+
+    /**
+     * Derives the content-type (mime) string using a path denoting a file
+     * @param path The path pointing at the file
+     * @return The derived content-type string
+     */
+    public static String fromPath(Path path) {
+        return fromFileName(path.getFileName().toString());
+    }
+
+    /**
+     * Derives the content-type (mime) string from the name of a file
+     * @param fileName The name of the file
+     * @return The derived content-type string
+     */
+    public static String fromFileName(String fileName) {
+        int i = fileName.lastIndexOf('.');
+        if (i < 0) return DEFAULT_CONTENT_TYPE;
+
+        int s = fileName.lastIndexOf('/');
+        if (i < s) return DEFAULT_CONTENT_TYPE;
+
+        String suffix = fileName.substring(i + 1);
+        return fromFileSuffix(suffix);
+    }
+
+    /**
+     * Searches and returns the content-type for the provided file-suffix.
+     * @param suffix The type-suffix of a file-name
+     * @return The content-type string
+     */
+    public static String fromFileSuffix(String suffix) {
+        String contentType = SUFFIX_MAP.get(suffix);
+        if (contentType != null) return contentType;
+        return DEFAULT_CONTENT_TYPE;
+    }
+
+    /**
+     * Registers a new file-suffix =&gt; content-type mapping to this registry.
+     * @param fileSuffix The type-suffix of a file-name
+     * @param contentType The content-type string
+     */
+    public static void register(String fileSuffix, String contentType) {
+        SUFFIX_MAP.put(fileSuffix, contentType);
+    }
+
+}

src/main/java/de/bluecolored/bluemap/api/RenderManager.java

@@ -25,14 +25,13 @@
 package de.bluecolored.bluemap.api;
 
 import com.flowpowered.math.vector.Vector2i;
-import de.bluecolored.bluemap.api.debug.DebugDump;
 
-import java.io.IOException;
 import java.util.Collection;
 
 /**
  * The {@link RenderManager} is used to schedule tile-renders and process them on a number of different threads.
  */
+@SuppressWarnings("unused")
 public interface RenderManager {
 
     /**
@@ -67,29 +66,25 @@ public interface RenderManager {
      * An update-task will be scheduled right after the purge, to get the map up-to-date again.
      * @param map the map to be purged
      * @return true if a new task has been scheduled, false if not (usually because there is already an update-task for this map scheduled)
-     * @throws IOException if an IOException occurs while trying to create the task.
      */
-    boolean scheduleMapPurgeTask(BlueMapMap map) throws IOException;
+    boolean scheduleMapPurgeTask(BlueMapMap map);
 
     /**
      * Getter for the current size of the render-queue.
      * @return the current size of the render-queue
      */
-    @DebugDump
     int renderQueueSize();
 
     /**
      * Getter for the current count of render threads.
      * @return the count of render threads
      */
-    @DebugDump
     int renderThreadCount();
 
     /**
      * Whether this {@link RenderManager} is currently running or stopped.
      * @return <code>true</code> if this renderer is running
      */
-    @DebugDump
     boolean isRunning();
 
     /**

src/main/java/de/bluecolored/bluemap/api/WebApp.java

@@ -24,24 +24,22 @@
  */
 package de.bluecolored.bluemap.api;
 
-import de.bluecolored.bluemap.api.debug.DebugDump;
-import de.bluecolored.bluemap.api.markers.Marker;
-import de.bluecolored.bluemap.api.markers.POIMarker;
-import com.flowpowered.math.vector.Vector2i;
+import org.jetbrains.annotations.ApiStatus;
 
 import java.awt.image.BufferedImage;
 import java.io.IOException;
 import java.nio.file.Path;
 import java.util.Map;
 import java.util.UUID;
+import java.util.function.Consumer;
 
+@SuppressWarnings("unused")
 public interface WebApp {
 
     /**
      * Getter for the configured web-root folder
      * @return The {@link Path} of the web-root folder
      */
-    @DebugDump
     Path getWebRoot();
 
     /**
@@ -49,6 +47,7 @@ public interface WebApp {
      * @param player the UUID of the player
      * @param visible true if the player-marker should be visible, false if it should be hidden
      */
+    @ApiStatus.Experimental
     void setPlayerVisibility(UUID player, boolean visible);
 
     /**
@@ -56,34 +55,59 @@ public interface WebApp {
      * @see #setPlayerVisibility(UUID, boolean)
      * @param player the UUID of the player
      */
+    @ApiStatus.Experimental
     boolean getPlayerVisibility(UUID player);
 
     /**
-     * Creates an image-file with the given {@link BufferedImage} somewhere in the web-root, so it can be used in the web-app (e.g. for {@link Marker}-icons).
-     *
-     * <p>The given <code>path</code> is used as file-name and (separated with '/') optional folders to organize the image-files.
-     * Do NOT include the file-ending! (e.g. <code>"someFolder/somePOIIcon"</code> will result in a file "somePOIIcon.png" in a folder "someFolder").</p>
-     * <p>If the image file with the given path already exists, it will be replaced.</p>
-     *
-     * @param image the image to create
-     * @param path the path/name of this image, the separator-char is '/'
-     * @return the relative address of the image in the web-app,
-     * which can be used as it is e.g. in the {@link POIMarker#setIcon(String, Vector2i)} method
-     * @throws IOException If an {@link IOException} is thrown while writing the image
+     * Registers a css-style so the webapp loads it.<br>
+     * This method should only be used inside the {@link Consumer} that got registered <i>(before bluemap loaded,
+     * pre server-start!)</i> to {@link BlueMapAPI#onEnable(Consumer)}.<br>
+     * Invoking this method at any other time is not supported.<br>
+     * Style-registrations are <b>not persistent</b>, register your style each time bluemap enables!<br>
+     * <br>
+     * Example:
+     * <pre>
+     * BlueMapAPI.onEnable(api -&gt; {
+     *    api.getWebApp().registerStyle("js/my-custom-style.css");
+     * });
+     * </pre>
+     * @param url The (relative) URL that links to the style.css file. The {@link #getWebRoot()}-method can be used to
+     *            create the custom file in the correct location and make it available to the web-app.
      */
+    void registerStyle(String url);
+
+    /**
+     * Registers a js-script so the webapp loads it.<br>
+     * This method should only be used inside the {@link Consumer} that got registered <i>(before bluemap loaded,
+     * pre server-start!)</i> to {@link BlueMapAPI#onEnable(Consumer)}.<br>
+     * Invoking this method at any other time is not supported.<br>
+     * Script-registrations are <b>not persistent</b>, register your script each time bluemap enables!<br>
+     * <br>
+     * Example:
+     * <pre>
+     * BlueMapAPI.onEnable(api -&gt; {
+     *    api.getWebApp().registerScript("js/my-custom-script.js");
+     * });
+     * </pre>
+     * @param url The (relative) URL that links to the script.js file. The {@link #getWebRoot()}-method can be used to
+     *            create the custom file in the correct location and make it available to the web-app.
+     */
+    void registerScript(String url);
+
+    // ------
+
+    /**
+     * @deprecated You should use the {@link #getWebRoot()} method to create the image-files you need, or store map/marker
+     * specific images in the map's storage (See: {@link BlueMapMap#getAssetStorage()})!
+     */
+    @Deprecated(forRemoval = true)
     String createImage(BufferedImage image, String path) throws IOException;
 
     /**
-     * Lists all images that are available. This includes all images previously created with the {@link #createImage(BufferedImage, String)}
-     * function, but might include more.
-     * @return A map of available images where:
-     * <ul>
-     * <li>the <b>key</b> is the image path how it would be used in the "path" parameter of the {@link #createImage(BufferedImage, String)} method</li>
-     * <li>and the <b>value</b> is the relative address of the image. The same ones that are returned from the {@link #createImage(BufferedImage, String)} method</li>
-     * </ul>
-     * @throws IOException If an {@link IOException} is thrown while reading the images
+     * @deprecated You should use the {@link #getWebRoot()} method to find the image-files you need, or read map/marker
+     * specific images from the map's storage (See: {@link BlueMapMap#getAssetStorage()})!
      */
-    @DebugDump
+    @Deprecated(forRemoval = true)
     Map<String, String> availableImages() throws IOException;
 
 }

src/main/java/de/bluecolored/bluemap/api/debug/DebugDump.java

@@ -30,8 +30,7 @@ import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
 /**
- * Marks a class, field or method to be included in detail in a possible state-dump.
- * E.g. triggered by <code>/bluemap debug dump</code>
+ * @deprecated not implemented, unused
  */
 @Retention(RetentionPolicy.RUNTIME)
 @Target({
@@ -39,6 +38,7 @@ import java.lang.annotation.Target;
         ElementType.FIELD,
         ElementType.TYPE
 })
+@Deprecated(forRemoval = true)
 public @interface DebugDump {
 
     String value() default "";

src/main/java/de/bluecolored/bluemap/api/gson/MarkerGson.java

@@ -49,8 +49,9 @@ public final class MarkerGson {
             .setLenient()
             .create();
 
-    /* This class can not be instantiated. */
-    private MarkerGson() {}
+    private MarkerGson() {
+        throw new UnsupportedOperationException("Utility class");
+    }
 
     public static GsonBuilder addAdapters(GsonBuilder builder) {
         return builder
@@ -235,8 +236,8 @@ public final class MarkerGson {
             }
 
             out.beginObject();
-            out.name("x"); out.value(value.getX());
-            out.name(useZ ? "z" : "y"); out.value(value.getY());
+            out.name("x"); writeRounded(out, value.getX());
+            out.name(useZ ? "z" : "y"); writeRounded(out, value.getY());
             out.endObject();
         }
 
@@ -262,6 +263,13 @@ public final class MarkerGson {
             return new Vector2d(x, y);
         }
 
+        private void writeRounded(JsonWriter json, double value) throws IOException {
+            // rounding and remove ".0" to save string space
+            double d = Math.round(value * 10000d) / 10000d;
+            if (d == (long) d) json.value((long) d);
+            else json.value(d);
+        }
+
     }
 
     static class Vector3dAdapter extends TypeAdapter<Vector3d> {
@@ -274,9 +282,9 @@ public final class MarkerGson {
             }
 
             out.beginObject();
-            out.name("x"); out.value(value.getX());
-            out.name("y"); out.value(value.getY());
-            out.name("z"); out.value(value.getZ());
+            out.name("x"); writeRounded(out, value.getX());
+            out.name("y"); writeRounded(out, value.getY());
+            out.name("z"); writeRounded(out, value.getZ());
             out.endObject();
         }
 
@@ -302,6 +310,13 @@ public final class MarkerGson {
             return new Vector3d(x, y, z);
         }
 
+        private void writeRounded(JsonWriter json, double value) throws IOException {
+            // rounding and remove ".0" to save string space
+            double d = Math.round(value * 10000d) / 10000d;
+            if (d == (long) d) json.value((long) d);
+            else json.value(d);
+        }
+
     }
 
     static class Vector2iAdapter extends TypeAdapter<Vector2i> {

src/main/java/de/bluecolored/bluemap/api/markers/DetailMarker.java

@@ -0,0 +1,74 @@
+/*
+ * This file is part of BlueMap, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) Blue (Lukas Rieger) <https://bluecolored.de>
+ * Copyright (c) contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package de.bluecolored.bluemap.api.markers;
+
+/**
+ * @see POIMarker
+ * @see ShapeMarker
+ * @see ExtrudeMarker
+ * @see LineMarker
+ */
+public interface DetailMarker {
+
+    /**
+     * Getter for the detail of this marker. The label can include html-tags.
+     * @return the detail of this {@link Marker}
+     */
+    String getDetail();
+
+    /**
+     * Sets the detail of this {@link Marker}. The detail can include html-tags.<br>
+     * This is the text that will be displayed on the popup when you click on this marker.
+     * <p>
+     * 	<b>Important:</b><br>
+     * 	Html-tags in the label will not be escaped, so you can use them to style the {@link Marker}-detail.<br>
+     * 	Make sure you escape all html-tags from possible user inputs to prevent possible
+     * 	<a href="https://en.wikipedia.org/wiki/Cross-site_scripting">XSS-Attacks</a> on the web-client!
+     * </p>
+     *
+     * @param detail the new detail for this {@link ObjectMarker}
+     */
+    void setDetail(String detail);
+
+    interface Builder<B> {
+
+        /**
+         * Sets the detail of the {@link Marker}. The detail can include html-tags.<br>
+         * This is the text that will be displayed on the popup when you click on the marker.
+         * <p>
+         * 	<b>Important:</b><br>
+         * 	Html-tags in the label will not be escaped, so you can use them to style the {@link Marker}-detail.<br>
+         * 	Make sure you escape all html-tags from possible user inputs to prevent possible
+         * 	<a href="https://en.wikipedia.org/wiki/Cross-site_scripting">XSS-Attacks</a> on the web-client!
+         * </p>
+         *
+         * @param detail the new detail for the {@link Marker}
+         * @return this builder for chaining
+         */
+        B detail(String detail);
+
+    }
+
+}

src/main/java/de/bluecolored/bluemap/api/markers/DistanceRangedMarker.java

@@ -25,9 +25,14 @@
 package de.bluecolored.bluemap.api.markers;
 
 import com.flowpowered.math.vector.Vector3d;
-import de.bluecolored.bluemap.api.debug.DebugDump;
 
-@DebugDump
+/**
+ * @see HtmlMarker
+ * @see POIMarker
+ * @see ShapeMarker
+ * @see ExtrudeMarker
+ * @see LineMarker
+ */
 public abstract class DistanceRangedMarker extends Marker {
 
     private double minDistance, maxDistance;

src/main/java/de/bluecolored/bluemap/api/markers/ElementMarker.java

@@ -0,0 +1,137 @@
+/*
+ * This file is part of BlueMap, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) Blue (Lukas Rieger) <https://bluecolored.de>
+ * Copyright (c) contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package de.bluecolored.bluemap.api.markers;
+
+import com.flowpowered.math.vector.Vector2i;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.regex.Pattern;
+
+/**
+ * @see HtmlMarker
+ * @see POIMarker
+ */
+public interface ElementMarker {
+
+    Pattern STYLE_CLASS_PATTERN = Pattern.compile("-?[_a-zA-Z]+[_a-zA-Z0-9-]*");
+
+    /**
+     * Getter for the position (in pixels) where the element is anchored to the map.
+     * @return the anchor-position in pixels
+     */
+    Vector2i getAnchor();
+
+    /**
+     * Sets the position (in pixels) where the element is anchored to the map.
+     * @param anchor the anchor-position in pixels
+     */
+    void setAnchor(Vector2i anchor);
+
+    /**
+     * Sets the position (in pixels) where the element is anchored to the map.
+     * @param x the anchor-x-position in pixels
+     * @param y the anchor-y-position in pixels
+     */
+    default void setAnchor(int x, int y) {
+        setAnchor(new Vector2i(x, y));
+    }
+
+    /**
+     * Getter for an (unmodifiable) collection of CSS-classed that the element of this marker will have.
+     * @return the style-classes of this element-marker
+     */
+    Collection<String> getStyleClasses();
+
+    /**
+     * Sets the CSS-classes that the element of this marker will have.<br>
+     * All classes must match <code>-?[_a-zA-Z]+[_a-zA-Z0-9-]*</code><br>
+     * Any existing classes on this marker will be removed.
+     * @param styleClasses the style-classes this element-marker will have
+     */
+    default void setStyleClasses(String... styleClasses) {
+        this.setStyleClasses(Arrays.asList(styleClasses));
+    }
+
+    /**
+     * Sets the CSS-classes that the element of this marker will have.<br>
+     * All classes must match <code>-?[_a-zA-Z]+[_a-zA-Z0-9-]*</code><br>
+     * Any existing classes on this marker will be removed.
+     * @param styleClasses the style-classes this element-marker will have
+     */
+    void setStyleClasses(Collection<String> styleClasses);
+
+    /**
+     * Adds the CSS-classes that the element of this marker will have.<br>
+     * All classes must match <code>-?[_a-zA-Z]+[_a-zA-Z0-9-]*</code><br>
+     * @param styleClasses the style-classes this element-marker will have
+     */
+    default void addStyleClasses(String... styleClasses) {
+        this.setStyleClasses(Arrays.asList(styleClasses));
+    }
+
+    /**
+     * Adds the CSS-classes that the element of this marker will have.<br>
+     * All classes must match <code>-?[_a-zA-Z]+[_a-zA-Z0-9-]*</code><br>
+     * @param styleClasses the style-classes this element-marker will have
+     */
+    void addStyleClasses(Collection<String> styleClasses);
+
+    interface Builder<B> {
+
+        /**
+         * Sets the position (in pixels) where the element is anchored to the map.
+         * @param anchor the anchor-position in pixels
+         * @return this builder for chaining
+         */
+        B anchor(Vector2i anchor);
+
+        /**
+         * <b>Adds</b> the CSS-classes that the element of this marker will have.<br>
+         * All classes must match <code>-?[_a-zA-Z]+[_a-zA-Z0-9-]*</code><br>
+         * @return this builder for chaining
+         */
+        B styleClasses(String... styleClasses);
+
+        /**
+         * Removes any existing style-classes from this builder.
+         * @see #styleClasses(String...)
+         * @return this builder for chaining
+         */
+        B clearStyleClasses();
+
+        /**
+         * Sets the position (in pixels) where the element is anchored to the map.
+         * @param x the anchor-x-position in pixels
+         * @param y the anchor-y-position in pixels
+         * @return this builder for chaining
+         */
+        default B anchor(int x, int y) {
+            return anchor(new Vector2i(x, y));
+        }
+
+    }
+
+}

src/main/java/de/bluecolored/bluemap/api/markers/ExtrudeMarker.java

@@ -26,17 +26,20 @@ package de.bluecolored.bluemap.api.markers;
 
 import com.flowpowered.math.vector.Vector2d;
 import com.flowpowered.math.vector.Vector3d;
-import de.bluecolored.bluemap.api.debug.DebugDump;
 import de.bluecolored.bluemap.api.math.Color;
 import de.bluecolored.bluemap.api.math.Shape;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.Objects;
 
-@DebugDump
+@SuppressWarnings("FieldMayBeFinal")
 public class ExtrudeMarker extends ObjectMarker {
     private static final Shape DEFAULT_SHAPE = Shape.createRect(0, 0, 1, 1);
 
     private Shape shape;
+    private Collection<Shape> holes = new ArrayList<>();
     private float shapeMinY, shapeMaxY;
     private boolean depthTest = true;
     private int lineWidth = 2;
@@ -138,6 +141,15 @@ public class ExtrudeMarker extends ObjectMarker {
         this.shapeMaxY = maxY;
     }
 
+    /**
+     * Getter for the <b>mutable</b> collection of holes in this {@link ExtrudeMarker}.
+     * <p>Any shape in this collection will be a hole in the main {@link Shape} of this marker</p>
+     * @return A <b>mutable</b> collection of hole-shapes
+     */
+    public Collection<Shape> getHoles() {
+        return holes;
+    }
+
     /**
      * Sets the position of this {@link ExtrudeMarker} to the center of the {@link Shape} (it's bounding box).
      * <p><i>(Invoke this after changing the {@link Shape} to make sure the markers position gets updated as well)</i></p>
@@ -272,6 +284,7 @@ public class ExtrudeMarker extends ObjectMarker {
 
         Shape shape;
         float shapeMinY, shapeMaxY;
+        Collection<Shape> holes = new ArrayList<>();
         Boolean depthTest;
         Integer lineWidth;
         Color lineColor;
@@ -294,6 +307,25 @@ public class ExtrudeMarker extends ObjectMarker {
             return this;
         }
 
+        /**
+         * <b>Adds</b> some hole-{@link Shape}s.
+         * @param holes the additional holes
+         * @return this builder for chaining
+         */
+        public Builder holes(Shape... holes) {
+            this.holes.addAll(Arrays.asList(holes));
+            return this;
+        }
+
+        /**
+         * Removes all hole-shapes from this Builder.
+         * @return this builder for chaining
+         */
+        public Builder clearHoles() {
+            this.holes.clear();
+            return this;
+        }
+
         /**
          * Sets the position of the {@link ExtrudeMarker} to the center of the {@link Shape} (it's bounding box).
          * @return this builder for chaining
@@ -361,6 +393,7 @@ public class ExtrudeMarker extends ObjectMarker {
                     shapeMinY,
                     shapeMaxY
             );
+            marker.getHoles().addAll(holes);
             if (depthTest != null) marker.setDepthTestEnabled(depthTest);
             if (lineWidth != null) marker.setLineWidth(lineWidth);
             if (lineColor != null) marker.setLineColor(lineColor);

src/main/java/de/bluecolored/bluemap/api/markers/HtmlMarker.java

@@ -27,15 +27,16 @@ package de.bluecolored.bluemap.api.markers;
 
 import com.flowpowered.math.vector.Vector2i;
 import com.flowpowered.math.vector.Vector3d;
-import de.bluecolored.bluemap.api.debug.DebugDump;
 
-import java.util.Objects;
+import java.util.*;
 
 /**
  * A marker that is a html-element placed somewhere on the map.
  */
-@DebugDump
-public class HtmlMarker extends DistanceRangedMarker {
+@SuppressWarnings("FieldMayBeFinal")
+public class HtmlMarker extends DistanceRangedMarker implements ElementMarker {
+
+    private Set<String> classes = new HashSet<>();
 
     private Vector2i anchor;
     private String html;
@@ -82,31 +83,16 @@ public class HtmlMarker extends DistanceRangedMarker {
         this.anchor = Objects.requireNonNull(anchor, "anchor must not be null");
     }
 
-    /**
-     * Getter for the position (in pixels) where the html-element is anchored to the map.
-     * @return the anchor-position in pixels
-     */
+    @Override
     public Vector2i getAnchor() {
         return anchor;
     }
 
-    /**
-     * Sets the position (in pixels) where the html-element is anchored to the map.
-     * @param anchor the anchor-position in pixels
-     */
+    @Override
     public void setAnchor(Vector2i anchor) {
         this.anchor = Objects.requireNonNull(anchor, "anchor must not be null");
     }
 
-    /**
-     * Sets the position (in pixels) where the html-element is anchored to the map.
-     * @param x the anchor-x-position in pixels
-     * @param y the anchor-y-position in pixels
-     */
-    public void setAnchor(int x, int y) {
-        setAnchor(new Vector2i(x, y));
-    }
-
     /**
      * Getter for the html-code of this HTML marker
      * @return the html-code
@@ -130,6 +116,28 @@ public class HtmlMarker extends DistanceRangedMarker {
         this.html = Objects.requireNonNull(html, "html must not be null");
     }
 
+    @Override
+    public Collection<String> getStyleClasses() {
+        return Collections.unmodifiableCollection(this.classes);
+    }
+
+    @Override
+    public void setStyleClasses(Collection<String> styleClasses) {
+        if (!styleClasses.stream().allMatch(STYLE_CLASS_PATTERN.asMatchPredicate()))
+            throw new IllegalArgumentException("One of the provided style-classes has an invalid format!");
+
+        this.classes.clear();
+        this.classes.addAll(styleClasses);
+    }
+
+    @Override
+    public void addStyleClasses(Collection<String> styleClasses) {
+        if (!styleClasses.stream().allMatch(STYLE_CLASS_PATTERN.asMatchPredicate()))
+            throw new IllegalArgumentException("One of the provided style-classes has an invalid format!");
+
+        this.classes.addAll(styleClasses);
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;
@@ -158,32 +166,20 @@ public class HtmlMarker extends DistanceRangedMarker {
         return new Builder();
     }
 
-    public static class Builder extends DistanceRangedMarker.Builder<HtmlMarker, Builder> {
+    public static class Builder extends DistanceRangedMarker.Builder<HtmlMarker, Builder>
+        implements ElementMarker.Builder<Builder> {
+
+        Set<String> classes = new HashSet<>();
 
         Vector2i anchor;
         String html;
 
-        /**
-         * Sets the position (in pixels) where the html-element is anchored to the map.
-         * @param anchor the anchor-position in pixels
-         * @return this builder for chaining
-         */
+        @Override
         public Builder anchor(Vector2i anchor) {
             this.anchor = anchor;
             return this;
         }
 
-        /**
-         * Sets the position (in pixels) where the html-element is anchored to the map.
-         * @param x the anchor-x-position in pixels
-         * @param y the anchor-y-position in pixels
-         * @return this builder for chaining
-         */
-        public Builder anchor(int x, int y) {
-            this.anchor = new Vector2i(x, y);
-            return this;
-        }
-
         /**
          * Sets the html for the {@link HtmlMarker}.
          *
@@ -200,6 +196,22 @@ public class HtmlMarker extends DistanceRangedMarker {
             return this;
         }
 
+        @Override
+        public Builder styleClasses(String... styleClasses) {
+            Collection<String> styleClassesCollection = Arrays.asList(styleClasses);
+            if (!styleClassesCollection.stream().allMatch(STYLE_CLASS_PATTERN.asMatchPredicate()))
+                throw new IllegalArgumentException("One of the provided style-classes has an invalid format!");
+
+            this.classes.addAll(styleClassesCollection);
+            return this;
+        }
+
+        @Override
+        public Builder clearStyleClasses() {
+            this.classes.clear();
+            return this;
+        }
+
         /**
          * Creates a new {@link HtmlMarker} with the current builder-settings.<br>
          * The minimum required settings to build this marker are:
@@ -218,6 +230,7 @@ public class HtmlMarker extends DistanceRangedMarker {
                     checkNotNull(html, "html")
             );
             if (anchor != null) marker.setAnchor(anchor);
+            marker.setStyleClasses(classes);
             return build(marker);
         }
 

src/main/java/de/bluecolored/bluemap/api/markers/LineMarker.java

@@ -25,13 +25,11 @@
 package de.bluecolored.bluemap.api.markers;
 
 import com.flowpowered.math.vector.Vector3d;
-import de.bluecolored.bluemap.api.debug.DebugDump;
 import de.bluecolored.bluemap.api.math.Color;
 import de.bluecolored.bluemap.api.math.Line;
 
 import java.util.Objects;
 
-@DebugDump
 public class LineMarker extends ObjectMarker {
     private static final Line DEFAULT_LINE = new Line(Vector3d.ZERO, Vector3d.ONE);
 

src/main/java/de/bluecolored/bluemap/api/markers/Marker.java

@@ -25,7 +25,6 @@
 package de.bluecolored.bluemap.api.markers;
 
 import com.flowpowered.math.vector.Vector3d;
-import de.bluecolored.bluemap.api.debug.DebugDump;
 
 import java.util.Objects;
 
@@ -38,17 +37,20 @@ import java.util.Objects;
  * @see ExtrudeMarker
  * @see LineMarker
  */
-@DebugDump
 public abstract class Marker {
 
     private final String type;
     private String label;
     private Vector3d position;
+    private int sorting;
+    private boolean listed;
 
     public Marker(String type, String label, Vector3d position) {
         this.type = Objects.requireNonNull(type, "type cannot be null");
         this.label = Objects.requireNonNull(label, "label cannot be null");
         this.position = Objects.requireNonNull(position, "position cannot be null");
+        this.sorting = 0;
+        this.listed = true;
     }
 
     /**
@@ -103,10 +105,50 @@ public abstract class Marker {
      * @param y the y-coordinate of the new position
      * @param z the z-coordinate of the new position
      */
-    public void setPosition(int x, int y, int z) {
+    public void setPosition(double x, double y, double z) {
         setPosition(new Vector3d(x, y, z));
     }
 
+    /**
+     * Returns the sorting-value that will be used by the webapp to sort the markers ("default"-sorting).<br>
+     * A lower value makes the marker sorted first (in lists and menus), a higher value makes it sorted later.<br>
+     * If multiple markers have the same sorting-value, their order will be arbitrary.<br>
+     * This value defaults to 0.
+     * @return this markers sorting-value
+     */
+    public int getSorting() {
+        return sorting;
+    }
+
+    /**
+     * Sets the sorting-value that will be used by the webapp to sort the markers ("default"-sorting).<br>
+     * A lower value makes the marker sorted first (in lists and menus), a higher value makes it sorted later.<br>
+     * If multiple markers have the same sorting-value, their order will be arbitrary.<br>
+     * This value defaults to 0.
+     * @param sorting the new sorting-value for this marker
+     */
+    public void setSorting(int sorting) {
+        this.sorting = sorting;
+    }
+
+    /**
+     * This value defines whether the marker will be listed (true) in markers and lists by the webapp (additionally to being
+     * displayed on the map) or not (false).
+     * @return whether the marker will be listed or not
+     */
+    public boolean isListed() {
+        return listed;
+    }
+
+    /**
+     * Defines whether the marker will be listed (true) in markers and lists by the webapp (additionally to being
+     * displayed on the map) or not (false).
+     * @param listed whether the marker will be listed or not
+     */
+    public void setListed(boolean listed) {
+        this.listed = listed;
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;
@@ -131,6 +173,8 @@ public abstract class Marker {
 
         String label;
         Vector3d position;
+        Integer sorting;
+        Boolean listed;
 
         /**
          * Sets the label of the {@link Marker}.
@@ -160,10 +204,32 @@ public abstract class Marker {
          * @param z the z-coordinate of the new position
          * @return this builder for chaining
          */
-        public B position(int x, int y, int z) {
+        public B position(double x, double y, double z) {
             return position(new Vector3d(x, y, z));
         }
 
+        /**
+         * Sets the sorting-value that will be used by the webapp to sort the markers ("default"-sorting).<br>
+         * A lower value makes the marker sorted first (in lists and menus), a higher value makes it sorted later.<br>
+         * If multiple markers have the same sorting-value, their order will be arbitrary.<br>
+         * This value defaults to 0.
+         * @param sorting the new sorting-value for this marker
+         */
+        public B sorting(Integer sorting) {
+            this.sorting = sorting;
+            return self();
+        }
+
+        /**
+         * Defines whether the marker will be listed (true) in markers and lists by the webapp (additionally to being
+         * displayed on the map) or not (false).
+         * @param listed whether the marker will be listed or not
+         */
+        public B listed(Boolean listed) {
+            this.listed = listed;
+            return self();
+        }
+
         /**
          * Creates a new {@link Marker} with the current builder-settings
          * @return The new {@link Marker}-instance
@@ -173,6 +239,8 @@ public abstract class Marker {
         T build(T marker) {
             if (label != null) marker.setLabel(label);
             if (position != null) marker.setPosition(position);
+            if (sorting != null) marker.setSorting(sorting);
+            if (listed != null) marker.setListed(listed);
             return marker;
         }
 
@@ -186,6 +254,26 @@ public abstract class Marker {
             return object;
         }
 
+        // -----
+
+        /**
+         * @deprecated use {@link #position(double, double, double)} instead
+         */
+        @Deprecated(forRemoval = true)
+        public B position(int x, int y, int z) {
+            return position(new Vector3d(x, y, z));
+        }
+
+    }
+
+    // -----
+
+    /**
+     * @deprecated use {@link #setPosition(double, double, double)} instead
+     */
+    @Deprecated(forRemoval = true)
+    public void setPosition(int x, int y, int z) {
+        setPosition(new Vector3d(x, y, z));
     }
 
 }

src/main/java/de/bluecolored/bluemap/api/markers/MarkerSet.java

@@ -24,8 +24,6 @@
  */
 package de.bluecolored.bluemap.api.markers;
 
-import de.bluecolored.bluemap.api.debug.DebugDump;
-
 import java.util.Map;
 import java.util.Objects;
 import java.util.concurrent.ConcurrentHashMap;
@@ -33,11 +31,11 @@ import java.util.concurrent.ConcurrentHashMap;
 /**
  * A set of {@link Marker}s that are displayed on the maps in the web-app.
  */
-@DebugDump
 public class MarkerSet {
 
     private String label;
     private boolean toggleable, defaultHidden;
+    private int sorting;
     private final ConcurrentHashMap<String, Marker> markers;
 
     /**
@@ -56,10 +54,7 @@ public class MarkerSet {
      * @see #setLabel(String)
      */
     public MarkerSet(String label) {
-        this.label = Objects.requireNonNull(label);
-        this.toggleable = true;
-        this.defaultHidden = false;
-        this.markers = new ConcurrentHashMap<>();
+        this(label, true, false);
     }
 
     /**
@@ -77,6 +72,7 @@ public class MarkerSet {
         this.label = Objects.requireNonNull(label);
         this.toggleable = toggleable;
         this.defaultHidden = defaultHidden;
+        this.sorting = 0;
         this.markers = new ConcurrentHashMap<>();
     }
 
@@ -149,6 +145,28 @@ public class MarkerSet {
         this.defaultHidden = defaultHidden;
     }
 
+    /**
+     * Returns the sorting-value that will be used by the webapp to sort the marker-sets.<br>
+     * A lower value makes the marker-set sorted first (in lists and menus), a higher value makes it sorted later.<br>
+     * If multiple marker-sets have the same sorting-value, their order will be arbitrary.<br>
+     * This value defaults to 0.
+     * @return This marker-sets sorting-value
+     */
+    public int getSorting() {
+        return sorting;
+    }
+
+    /**
+     * Sets the sorting-value that will be used by the webapp to sort the marker-sets ("default"-sorting).<br>
+     * A lower value makes the marker-set sorted first (in lists and menus), a higher value makes it sorted later.<br>
+     * If multiple marker-sets have the same sorting-value, their order will be arbitrary.<br>
+     * This value defaults to 0.
+     * @param sorting the new sorting-value for this marker-set
+     */
+    public void setSorting(int sorting) {
+        this.sorting = sorting;
+    }
+
     /**
      * Getter for a (modifiable) {@link Map} of all {@link Marker}s in this {@link MarkerSet}.
      * The keys of the map are the id's of the {@link Marker}s.
@@ -220,6 +238,7 @@ public class MarkerSet {
 
         private String label;
         private Boolean toggleable, defaultHidden;
+        private Integer sorting;
 
         /**
          * Sets the label of the {@link MarkerSet}.
@@ -262,6 +281,18 @@ public class MarkerSet {
             return this;
         }
 
+        /**
+         * Sets the sorting-value that will be used by the webapp to sort the marker-sets ("default"-sorting).<br>
+         * A lower value makes the marker-set sorted first (in lists and menus), a higher value makes it sorted later.<br>
+         * If multiple marker-sets have the same sorting-value, their order will be arbitrary.<br>
+         * This value defaults to 0.
+         * @param sorting the new sorting-value for this marker-set
+         */
+        public Builder sorting(Integer sorting) {
+            this.sorting = sorting;
+            return this;
+        }
+
         /**
          * Creates a new {@link MarkerSet} with the current builder-settings.<br>
          * The minimum required settings to build this marker-set are:
@@ -276,6 +307,7 @@ public class MarkerSet {
             );
             if (toggleable != null) markerSet.setToggleable(toggleable);
             if (defaultHidden != null) markerSet.setDefaultHidden(defaultHidden);
+            if (sorting != null) markerSet.setSorting(sorting);
             return markerSet;
         }
 

src/main/java/de/bluecolored/bluemap/api/markers/ObjectMarker.java

@@ -25,14 +25,17 @@
 package de.bluecolored.bluemap.api.markers;
 
 import com.flowpowered.math.vector.Vector3d;
-import de.bluecolored.bluemap.api.debug.DebugDump;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.Objects;
 import java.util.Optional;
 
-@DebugDump
-public abstract class ObjectMarker extends DistanceRangedMarker {
+/**
+ * @see ShapeMarker
+ * @see ExtrudeMarker
+ * @see LineMarker
+ */
+public abstract class ObjectMarker extends DistanceRangedMarker implements DetailMarker {
 
     private String detail;
 
@@ -45,26 +48,12 @@ public abstract class ObjectMarker extends DistanceRangedMarker {
         this.detail = Objects.requireNonNull(label, "label must not be null");
     }
 
-    /**
-     * Getter for the detail of this marker. The label can include html-tags.
-     * @return the detail of this {@link Marker}
-     */
+    @Override
     public String getDetail() {
         return detail;
     }
 
-    /**
-     * Sets the detail of this {@link Marker}. The detail can include html-tags.<br>
-     * This is the text that will be displayed on the popup when you click on this marker.
-     * <p>
-     * 	<b>Important:</b><br>
-     * 	Html-tags in the label will not be escaped, so you can use them to style the {@link Marker}-detail.<br>
-     * 	Make sure you escape all html-tags from possible user inputs to prevent possible
-     * 	<a href="https://en.wikipedia.org/wiki/Cross-site_scripting">XSS-Attacks</a> on the web-client!
-     * </p>
-     *
-     * @param detail the new detail for this {@link ObjectMarker}
-     */
+    @Override
     public void setDetail(String detail) {
         this.detail = Objects.requireNonNull(detail);
     }
@@ -131,25 +120,14 @@ public abstract class ObjectMarker extends DistanceRangedMarker {
     }
 
     public static abstract class Builder<T extends ObjectMarker, B extends ObjectMarker.Builder<T, B>>
-            extends DistanceRangedMarker.Builder<T, B> {
+            extends DistanceRangedMarker.Builder<T, B>
+            implements DetailMarker.Builder<B> {
 
         String detail;
         String link;
         boolean newTab;
 
-        /**
-         * Sets the detail of the {@link Marker}. The detail can include html-tags.<br>
-         * This is the text that will be displayed on the popup when you click on the marker.
-         * <p>
-         * 	<b>Important:</b><br>
-         * 	Html-tags in the label will not be escaped, so you can use them to style the {@link Marker}-detail.<br>
-         * 	Make sure you escape all html-tags from possible user inputs to prevent possible
-         * 	<a href="https://en.wikipedia.org/wiki/Cross-site_scripting">XSS-Attacks</a> on the web-client!
-         * </p>
-         *
-         * @param detail the new detail for the {@link Marker}
-         * @return this builder for chaining
-         */
+        @Override
         public B detail(String detail) {
             this.detail = detail;
             return self();

src/main/java/de/bluecolored/bluemap/api/markers/POIMarker.java

@@ -26,13 +26,16 @@ package de.bluecolored.bluemap.api.markers;
 
 import com.flowpowered.math.vector.Vector2i;
 import com.flowpowered.math.vector.Vector3d;
-import de.bluecolored.bluemap.api.WebApp;
-import de.bluecolored.bluemap.api.debug.DebugDump;
+import de.bluecolored.bluemap.api.BlueMapMap;
 
-import java.util.Objects;
+import java.util.*;
 
-@DebugDump
-public class POIMarker extends DistanceRangedMarker {
+@SuppressWarnings("FieldMayBeFinal")
+public class POIMarker extends DistanceRangedMarker implements DetailMarker, ElementMarker {
+
+    private Set<String> classes = new HashSet<>();
+
+    private String detail;
 
     private String icon;
     private Vector2i anchor;
@@ -72,10 +75,21 @@ public class POIMarker extends DistanceRangedMarker {
      */
     public POIMarker(String label, Vector3d position, String iconAddress, Vector2i anchor) {
         super("poi", label, position);
+        this.detail = Objects.requireNonNull(label, "label must not be null");
         this.icon = Objects.requireNonNull(iconAddress, "iconAddress must not be null");
         this.anchor = Objects.requireNonNull(anchor, "anchor must not be null");
     }
 
+    @Override
+    public String getDetail() {
+        return detail;
+    }
+
+    @Override
+    public void setDetail(String detail) {
+        this.detail = detail;
+    }
+
     /**
      * Getter for the relative address of the icon used to display this {@link POIMarker}
      * @return the relative web-address of the icon
@@ -84,18 +98,20 @@ public class POIMarker extends DistanceRangedMarker {
         return icon;
     }
 
-    /**
-     * Getter for the position (in pixels) where the icon is anchored to the map.
-     * @return the anchor-position in pixels
-     */
+    @Override
     public Vector2i getAnchor() {
         return anchor;
     }
 
+    @Override
+    public void setAnchor(Vector2i anchor) {
+        this.anchor = Objects.requireNonNull(anchor, "anchor must not be null");
+    }
+
     /**
      * Sets the icon for this {@link POIMarker}.
      * @param iconAddress the web-address of the icon-image. Can be an absolute or relative.
-     *                    You can also use an address returned by {@link WebApp#createImage(java.awt.image.BufferedImage, String)}.
+     *                    (See: {@link BlueMapMap#getAssetStorage()})
      * @param anchorX the x-position of the position (in pixels) where the icon is anchored to the map
      * @param anchorY the y-position of the position (in pixels) where the icon is anchored to the map
      */
@@ -106,7 +122,7 @@ public class POIMarker extends DistanceRangedMarker {
     /**
      * Sets the icon for this {@link POIMarker}.
      * @param iconAddress the web-address of the icon-image. Can be an absolute or relative.
-     *                    You can also use an address returned by {@link WebApp#createImage(java.awt.image.BufferedImage, String)}.
+     *                    (See: {@link BlueMapMap#getAssetStorage()})
      * @param anchor the position of the position (in pixels) where the icon is anchored to the map
      */
     public void setIcon(String iconAddress, Vector2i anchor) {
@@ -114,6 +130,28 @@ public class POIMarker extends DistanceRangedMarker {
         this.anchor = Objects.requireNonNull(anchor, "anchor must not be null");
     }
 
+    @Override
+    public Collection<String> getStyleClasses() {
+        return Collections.unmodifiableCollection(this.classes);
+    }
+
+    @Override
+    public void setStyleClasses(Collection<String> styleClasses) {
+        if (!styleClasses.stream().allMatch(STYLE_CLASS_PATTERN.asMatchPredicate()))
+            throw new IllegalArgumentException("One of the provided style-classes has an invalid format!");
+
+        this.classes.clear();
+        this.classes.addAll(styleClasses);
+    }
+
+    @Override
+    public void addStyleClasses(Collection<String> styleClasses) {
+        if (!styleClasses.stream().allMatch(STYLE_CLASS_PATTERN.asMatchPredicate()))
+            throw new IllegalArgumentException("One of the provided style-classes has an invalid format!");
+
+        this.classes.addAll(styleClasses);
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;
@@ -142,15 +180,25 @@ public class POIMarker extends DistanceRangedMarker {
         return new Builder();
     }
 
-    public static class Builder extends DistanceRangedMarker.Builder<POIMarker, Builder> {
+    public static class Builder extends DistanceRangedMarker.Builder<POIMarker, Builder>
+        implements DetailMarker.Builder<Builder>, ElementMarker.Builder<Builder> {
 
+        Set<String> classes = new HashSet<>();
+
+        String detail;
         String icon;
         Vector2i anchor;
 
+        @Override
+        public Builder detail(String detail) {
+            this.detail = detail;
+            return this;
+        }
+
         /**
          * Sets the icon for the {@link POIMarker}.
          * @param iconAddress the web-address of the icon-image. Can be an absolute or relative.
-         *                    You can also use an address returned by {@link WebApp#createImage(java.awt.image.BufferedImage, String)}.
+         *                    (See: {@link BlueMapMap#getAssetStorage()})
          * @param anchorX the x-position of the position (in pixels) where the icon is anchored to the map
          * @param anchorY the y-position of the position (in pixels) where the icon is anchored to the map
          * @return this builder for chaining
@@ -162,7 +210,7 @@ public class POIMarker extends DistanceRangedMarker {
         /**
          * Sets the icon for the {@link POIMarker}.
          * @param iconAddress the web-address of the icon-image. Can be an absolute or relative.
-         *                    You can also use an address returned by {@link WebApp#createImage(java.awt.image.BufferedImage, String)}.
+         *                    (See: {@link BlueMapMap#getAssetStorage()})
          * @param anchor the position of the position (in pixels) where the icon is anchored to the map
          * @return this builder for chaining
          */
@@ -172,6 +220,12 @@ public class POIMarker extends DistanceRangedMarker {
             return this;
         }
 
+        @Override
+        public Builder anchor(Vector2i anchor) {
+            this.anchor = Objects.requireNonNull(anchor, "anchor must not be null");
+            return this;
+        }
+
         /**
          * The {@link POIMarker} will use the default icon. (See: {@link #icon(String, Vector2i)})
          * @return this builder for chaining
@@ -182,6 +236,22 @@ public class POIMarker extends DistanceRangedMarker {
             return this;
         }
 
+        @Override
+        public Builder styleClasses(String... styleClasses) {
+            Collection<String> styleClassesCollection = Arrays.asList(styleClasses);
+            if (!styleClassesCollection.stream().allMatch(STYLE_CLASS_PATTERN.asMatchPredicate()))
+                throw new IllegalArgumentException("One of the provided style-classes has an invalid format!");
+
+            this.classes.addAll(styleClassesCollection);
+            return this;
+        }
+
+        @Override
+        public Builder clearStyleClasses() {
+            this.classes.clear();
+            return this;
+        }
+
         /**
          * Creates a new {@link POIMarker} with the current builder-settings.<br>
          * The minimum required settings to build this marker are:
@@ -196,7 +266,10 @@ public class POIMarker extends DistanceRangedMarker {
                     checkNotNull(label, "label"),
                     checkNotNull(position, "position")
             );
+            if (detail != null) marker.setDetail(detail);
             if (icon != null) marker.setIcon(icon, anchor);
+            else if (anchor != null) marker.setAnchor(anchor);
+            marker.setStyleClasses(classes);
             return build(marker);
         }
 
@@ -207,7 +280,7 @@ public class POIMarker extends DistanceRangedMarker {
     /**
      * @deprecated use {@link #builder()} instead.
      */
-    @Deprecated
+    @Deprecated(forRemoval = true)
     public static Builder toBuilder() {
         return new Builder();
     }

src/main/java/de/bluecolored/bluemap/api/markers/ShapeMarker.java

@@ -27,17 +27,20 @@ package de.bluecolored.bluemap.api.markers;
 
 import com.flowpowered.math.vector.Vector2d;
 import com.flowpowered.math.vector.Vector3d;
-import de.bluecolored.bluemap.api.debug.DebugDump;
 import de.bluecolored.bluemap.api.math.Color;
 import de.bluecolored.bluemap.api.math.Shape;
 
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
 import java.util.Objects;
 
-@DebugDump
+@SuppressWarnings("FieldMayBeFinal")
 public class ShapeMarker extends ObjectMarker {
     private static final Shape DEFAULT_SHAPE = Shape.createRect(0, 0, 1, 1);
 
     private Shape shape;
+    private Collection<Shape> holes = new ArrayList<>();
     private float shapeY;
     private boolean depthTest = true;
     private int lineWidth = 2;
@@ -49,7 +52,7 @@ public class ShapeMarker extends ObjectMarker {
      */
     @SuppressWarnings("unused")
     private ShapeMarker() {
-        this("shape", DEFAULT_SHAPE, 0);
+        this("", DEFAULT_SHAPE, 0);
     }
 
     /**
@@ -119,6 +122,15 @@ public class ShapeMarker extends ObjectMarker {
         this.shapeY = y;
     }
 
+    /**
+     * Getter for the <b>mutable</b> collection of holes in this {@link ShapeMarker}.
+     * <p>Any shape in this collection will be a hole in the main {@link Shape} of this marker</p>
+     * @return A <b>mutable</b> collection of hole-shapes
+     */
+    public Collection<Shape> getHoles() {
+        return holes;
+    }
+
     /**
      * Sets the position of this {@link ShapeMarker} to the center of the {@link Shape} (it's bounding box).
      * <p><i>(Invoke this after changing the {@link Shape} to make sure the markers position gets updated as well)</i></p>
@@ -250,6 +262,7 @@ public class ShapeMarker extends ObjectMarker {
 
         Shape shape;
         float shapeY;
+        Collection<Shape> holes = new ArrayList<>();
         Boolean depthTest;
         Integer lineWidth;
         Color lineColor;
@@ -269,6 +282,25 @@ public class ShapeMarker extends ObjectMarker {
             return this;
         }
 
+        /**
+         * <b>Adds</b> some hole-{@link Shape}s.
+         * @param holes the additional holes
+         * @return this builder for chaining
+         */
+        public Builder holes(Shape... holes) {
+            this.holes.addAll(Arrays.asList(holes));
+            return this;
+        }
+
+        /**
+         * Removes all hole-shapes from this Builder.
+         * @return this builder for chaining
+         */
+        public Builder clearHoles() {
+            this.holes.clear();
+            return this;
+        }
+
         /**
          * Sets the position of the {@link ShapeMarker} to the center of the {@link Shape} (it's bounding box).
          * @return this builder for chaining
@@ -334,6 +366,7 @@ public class ShapeMarker extends ObjectMarker {
                     checkNotNull(shape, "shape"),
                     shapeY
             );
+            marker.getHoles().addAll(holes);
             if (depthTest != null) marker.setDepthTestEnabled(depthTest);
             if (lineWidth != null) marker.setLineWidth(lineWidth);
             if (lineColor != null) marker.setLineColor(lineColor);

src/main/java/de/bluecolored/bluemap/api/math/Color.java

@@ -24,11 +24,8 @@
  */
 package de.bluecolored.bluemap.api.math;
 
-import de.bluecolored.bluemap.api.debug.DebugDump;
-
 import java.util.Objects;
 
-@DebugDump
 public class Color {
 
     private final int r, g, b;
@@ -128,7 +125,8 @@ public class Color {
         return a;
     }
 
-    private static int parseColorString(String val) {
+    private static int parseColorString(String value) {
+        String val = value;
         if (val.charAt(0) == '#') {
             val = val.substring(1);
             if (val.length() == 3) val = val + "f";
@@ -136,7 +134,7 @@ public class Color {
                     val.charAt(0) + val.charAt(0) + val.charAt(1) + val.charAt(1) +
                     val.charAt(2) + val.charAt(2) + val.charAt(3) + val.charAt(3);
             if (val.length() == 6) val = val + "ff";
-            if (val.length() != 8) throw new NumberFormatException("Invalid color format!");
+            if (val.length() != 8) throw new NumberFormatException("Invalid color format: '" + value + "'!");
             val = val.substring(6, 8) + val.substring(0, 6); // move alpha to front
             return Integer.parseUnsignedInt(val, 16);
         }
@@ -166,4 +164,13 @@ public class Color {
         return result;
     }
 
+    @Override
+    public String toString() {
+        return "Color{" +
+                "r=" + r +
+                ", g=" + g +
+                ", b=" + b +
+                ", a=" + a +
+                '}';
+    }
 }

src/main/java/de/bluecolored/bluemap/api/math/Line.java

@@ -25,7 +25,6 @@
 package de.bluecolored.bluemap.api.math;
 
 import com.flowpowered.math.vector.Vector3d;
-import de.bluecolored.bluemap.api.debug.DebugDump;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
@@ -36,7 +35,6 @@ import java.util.List;
 /**
  * A line consisting of 2 or more {@link Vector3d}-points.
  */
-@DebugDump
 public class Line {
 
     private final Vector3d[] points;
@@ -160,6 +158,16 @@ public class Line {
             return this;
         }
 
+        /**
+         * Adds multiple points to the end of line.
+         * @param points the points to be added.
+         * @return this builder for chaining
+         */
+        public Builder addPoints(Collection<Vector3d> points) {
+            this.points.addAll(points);
+            return this;
+        }
+
         /**
          * Builds a new {@link Line} with the points set in this builder.<br>
          * There need to be at least 2 points to build a {@link Line}.

src/main/java/de/bluecolored/bluemap/api/math/Shape.java

@@ -25,7 +25,6 @@
 package de.bluecolored.bluemap.api.math;
 
 import com.flowpowered.math.vector.Vector2d;
-import de.bluecolored.bluemap.api.debug.DebugDump;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
@@ -36,7 +35,6 @@ import java.util.List;
 /**
  * A shape consisting of 3 or more {@link Vector2d}-points on a plane.
  */
-@DebugDump
 public class Shape {
 
     private final Vector2d[] points;
@@ -248,6 +246,16 @@ public class Shape {
             return this;
         }
 
+        /**
+         * Adds multiple points to the end of line.
+         * @param points the points to be added.
+         * @return this builder for chaining
+         */
+        public Builder addPoints(Collection<Vector2d> points) {
+            this.points.addAll(points);
+            return this;
+        }
+
         /**
          * Builds a new {@link Shape} with the points set in this builder.<br>
          * There need to be at least 3 points to build a {@link Shape}.

src/main/java/de/bluecolored/bluemap/api/plugin/PlayerIconFactory.java

@@ -0,0 +1,42 @@
+/*
+ * This file is part of BlueMap, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) Blue (Lukas Rieger) <https://bluecolored.de>
+ * Copyright (c) contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package de.bluecolored.bluemap.api.plugin;
+
+import java.awt.image.BufferedImage;
+import java.util.UUID;
+import java.util.function.BiFunction;
+
+@FunctionalInterface
+public interface PlayerIconFactory extends BiFunction<UUID, BufferedImage, BufferedImage> {
+
+    /**
+     * Takes a players UUID and skin-image and creates an icon
+     * @param playerUuid the players UUID
+     * @param playerSkin the input image
+     * @return a <b>new</b> {@link BufferedImage} generated based on the input image
+     */
+    BufferedImage apply(UUID playerUuid, BufferedImage playerSkin);
+
+}

src/main/java/de/bluecolored/bluemap/api/plugin/Plugin.java

@@ -0,0 +1,56 @@
+/*
+ * This file is part of BlueMap, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) Blue (Lukas Rieger) <https://bluecolored.de>
+ * Copyright (c) contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package de.bluecolored.bluemap.api.plugin;
+
+@SuppressWarnings("unused")
+public interface Plugin {
+
+    /**
+     * Get the {@link SkinProvider} that bluemap is using to fetch player-skins
+     * @return the {@link SkinProvider} instance bluemap is using
+     */
+    SkinProvider getSkinProvider();
+
+    /**
+     * Sets the {@link SkinProvider} that bluemap will use to fetch new player-skins.
+     * @param skinProvider The new {@link SkinProvider} bluemap should use
+     */
+    void setSkinProvider(SkinProvider skinProvider);
+
+    /**
+     * Get the {@link PlayerIconFactory} that bluemap is using to convert a player-skin into the icon-image that is used
+     * for the Player-Markers
+     * @return The {@link PlayerIconFactory} bluemap uses to convert skins into player-marker icons
+     */
+    PlayerIconFactory getPlayerMarkerIconFactory();
+
+    /**
+     * Set the {@link PlayerIconFactory} that bluemap will use to convert a player-skin into the icon-image that is used
+     * for the Player-Markers
+     * @param playerMarkerIconFactory The {@link PlayerIconFactory} bluemap uses to convert skins into player-marker icons
+     */
+    void setPlayerMarkerIconFactory(PlayerIconFactory playerMarkerIconFactory);
+
+}

src/main/java/de/bluecolored/bluemap/api/plugin/SkinProvider.java

@@ -0,0 +1,46 @@
+/*
+ * This file is part of BlueMap, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) Blue (Lukas Rieger) <https://bluecolored.de>
+ * Copyright (c) contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package de.bluecolored.bluemap.api.plugin;
+
+import java.awt.image.BufferedImage;
+import java.io.IOException;
+import java.util.Optional;
+import java.util.UUID;
+
+/**
+ * A skin-provider capable of loading minecraft player-skins for a given UUID
+ */
+@FunctionalInterface
+public interface SkinProvider {
+
+    /**
+     * Attempts to load a minecraft-skin from this skin-provider.
+     * @return an {@link Optional} containing a {@link BufferedImage} with the skin-image or an empty Optional if there is no
+     * skin for this UUID
+     * @throws IOException if something went wrong trying to load the skin
+     */
+    Optional<BufferedImage> load(UUID playerUUID) throws IOException;
+
+}