still doesnt work but it works more™️

Override structure location on Fabric

.editorconfig

@@ -342,6 +342,6 @@ ij_json_wrap_long_lines = false
 indent_size = 2
 ij_yaml_keep_indents_on_empty_lines = true
 ij_yaml_keep_line_breaks = true
-ij_yaml_space_before_colon = true
+ij_yaml_space_before_colon = false
 ij_yaml_spaces_within_braces = true
 ij_yaml_spaces_within_brackets = true

.gitignore

@@ -52,6 +52,7 @@ gradle-app.setting
 
 # virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
 hs_err_pid*
+*.hprof
 
 ### JetBrains template
 # Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio, WebStorm and Rider

README.md

@@ -1,21 +1,42 @@
 # Terra
-Terra is a data-driven world generator based on [Gaea](https://github.com/PolyhedralDev/Gaea). Find out more on our
-[Spigot page](https://www.spigotmc.org/resources/85151/)!
 
-## Building and running Terra
-To build, simply run `./gradlew build` on Linux/MacOS, or `gradlew.bat build` on Windows.
-This will produce a jar in `build/libs` called `Terra-[CURRENT VERSION].jar`.
-You can put this right into your plugins dir, along with the correct Gaea version.
+Terra is an incredibly powerful free & open-source data-driven, platform-agnostic world generator. It allows you to create a world exactly
+to your specifications, with no knowledge of Java required.
 
-If you would like to test it with a default server config, just run `./gradlew setupServer` or
-`./gradlew.bat setupServer` to set up the server, then `./gradlew testWithPaper` or `gradlew.bat testWithPaper` to run
-the server. If you want a clean installation of the server, re-run the `setupServer` task.
-This will download a default server config from [here](https://github.com/PolyhedralDev/WorldGenTestServer)
-and install the server in the `target/server` directory, along with all the needed plugins.
-   
-**Note: You will need to adjust the `NAME` variable `bukkit.yml` of the test server if you are not using the default
-Terra config.**
+## Downloads:
 
+* Paper+ servers (Paper, Tuinity, Purpur, etc): [SpigotMC](https://www.spigotmc.org/resources/85151/)
+* Fabric: [Modrinth](https://modrinth.com/mod/terra) / [CurseForge](https://www.curseforge.com/minecraft/mc-mods/terra-world-generator)
+* Forge: [Modrinth](https://modrinth.com/mod/terra) / [CurseForge](https://www.curseforge.com/minecraft/mc-mods/terra-world-generator)
+
+## Building and Running Terra
+
+To build, simply run `./gradlew build` (`gradlew.bat build` on Windows). This will build all platforms, and
+produce JARs in `platforms/<platform>/build/libs`
+
+### Production JARs:
+* Bukkit: `Terra-<version>-shaded.jar`
+* Fabric: `Terra-<version>-shaded-mapped.jar`
+* Forge: `Terra-<version>-shaded.jar`
+
+### Building a Specific Platform
+To build a specific platform, run `gradlew :platforms:<platform>:build`.
+
+JARs are produced in `platforms/<platform>/build/libs`.
+
+### Running Minecraft in the IDE
+To run Minecraft with Terra in the IDE (for testing) use the following tasks:
+* Bukkit
+  * `installPaper` - Install a [Paper](https://github.com/PaperMC/Paper) test server. (Only needs to be run once).
+  * `installPurpur` - Install a [Purpur](https://github.com/pl3xgaming/Purpur) test server. (Only needs to be run once).
+  * `runPaper` - Run the Paper test server with Terra (`installPaper` must have been run previously).
+  * `runPurpur` - Run the Purpur test server with Terra (`installPurpur` must have been run previously).
+* Fabric
+  * `runClient` - Run a Minecraft client with Terra installed.
+  * `runServer` - Run a Minecraft server with Terra installed.
+* Forge
+  * `runClient` - Run a Minecraft client with Terra installed.
+  * `runServer` - Run a Minecraft server with Terra installed.
 ## Contributing
 Contributions are welcome! If you want to see a feature in Terra, please, open an issue, or implement it yourself and
 submit a PR!

build.gradle.kts

@@ -1,10 +1,27 @@
 import com.dfsek.terra.getGitHash
 
-val versionObj = Version("4", "3", "0", true)
+val versionObj = Version("5", "3", "1", true)
 
 allprojects {
     version = versionObj
     group = "com.dfsek.terra"
+
+    tasks.withType<JavaCompile>().configureEach {
+        options.isFork = true
+        options.isIncremental = true
+    }
+    tasks.withType<Test>().configureEach {
+        useJUnitPlatform()
+
+        maxHeapSize = "2G"
+        ignoreFailures = false
+        failFast = true
+        maxParallelForks = (Runtime.getRuntime().availableProcessors() - 1).takeIf { it > 0 } ?: 1
+
+        reports.html.isEnabled = false
+        reports.junitXml.isEnabled = false
+    }
+
 }
 /**
  * Version class that does version stuff.
@@ -18,4 +35,4 @@ class Version(val major: String, val minor: String, val revision: String, val pr
         else //Only use git hash if it's a prerelease.
             "$major.$minor.$revision-BETA+${getGitHash()}"
     }
-}
+}

buildSrc/src/main/kotlin/com/dfsek/terra/CommonConfig.kt

@@ -7,30 +7,15 @@ import org.gradle.kotlin.dsl.withType
 import java.io.ByteArrayOutputStream
 
 fun Project.configureCommon() {
-    apply(plugin = "java-library")
-    apply(plugin = "maven-publish")
-    apply(plugin = "idea")
-
     configureDependencies()
     configureCompilation()
     configureDistribution()
 
     version = rootProject.version
-
-
-
-    tasks.withType<Test>().configureEach {
-        useJUnitPlatform()
-
-        maxHeapSize = "2G"
-        ignoreFailures = false
-        failFast = true
-        maxParallelForks = 12
-    }
 }
 
 fun Project.getGitHash(): String {
-    val stdout = java.io.ByteArrayOutputStream()
+    val stdout = ByteArrayOutputStream()
     exec {
         commandLine = mutableListOf("git", "rev-parse", "--short", "HEAD")
         standardOutput = stdout

buildSrc/src/main/kotlin/com/dfsek/terra/CompilationConfig.kt

@@ -3,12 +3,16 @@ package com.dfsek.terra
 import org.gradle.api.JavaVersion
 import org.gradle.api.Project
 import org.gradle.api.plugins.JavaPluginConvention
+import org.gradle.api.tasks.bundling.Jar
 import org.gradle.api.tasks.compile.JavaCompile
 import org.gradle.api.tasks.javadoc.Javadoc
-import org.gradle.kotlin.dsl.configure
-import org.gradle.kotlin.dsl.withType
+import org.gradle.kotlin.dsl.*
+import org.gradle.language.jvm.tasks.ProcessResources
 
 fun Project.configureCompilation() {
+    apply(plugin = "maven-publish")
+    apply(plugin = "idea")
+
     configure<JavaPluginConvention> {
         sourceCompatibility = JavaVersion.VERSION_1_8
         targetCompatibility = JavaVersion.VERSION_1_8
@@ -17,11 +21,35 @@ fun Project.configureCompilation() {
     tasks.withType<JavaCompile> {
         options.encoding = "UTF-8"
         doFirst {
-            options.compilerArgs = mutableListOf("-Xlint:all")
+            options.compilerArgs.add("-Xlint:all")
         }
     }
 
+    tasks.withType<ProcessResources> {
+        include("**/*.*")
+        filter<org.apache.tools.ant.filters.ReplaceTokens>(
+                "tokens" to mapOf(
+                        "VERSION" to project.version.toString()
+                )
+        )
+    }
+
     tasks.withType<Javadoc> {
         options.encoding = "UTF-8"
     }
+
+    tasks.withType<Jar> {
+        archiveBaseName.set("Terra-${archiveBaseName.get()}")
+        from("../LICENSE", "../../LICENSE")
+    }
+
+    tasks.register<Jar>("sourcesJar") {
+        archiveClassifier.set("sources")
+    }
+
+    tasks.register<Jar>("javadocJar") {
+        dependsOn("javadoc")
+        archiveClassifier.set("javadoc")
+        from(tasks.getByName<Javadoc>("javadoc").destinationDir)
+    }
 }

buildSrc/src/main/kotlin/com/dfsek/terra/DependencyConfig.kt

@@ -1,13 +1,27 @@
 package com.dfsek.terra
 
 import org.gradle.api.Project
+import org.gradle.kotlin.dsl.apply
 import org.gradle.kotlin.dsl.dependencies
+import org.gradle.kotlin.dsl.invoke
 import org.gradle.kotlin.dsl.repositories
 
 fun Project.configureDependencies() {
+    apply(plugin = "java")
+    apply(plugin = "java-library")
+
+    configurations {
+        val shaded = create("shaded")
+        val shadedApi = create("shadedApi")
+        shaded.extendsFrom(shadedApi)
+        getByName("api").extendsFrom(shadedApi)
+        val shadedImplementation = create("shadedImplementation")
+        shaded.extendsFrom(shadedImplementation)
+        getByName("implementation").extendsFrom(shadedImplementation)
+    }
 
     repositories {
-        maven { url = uri("http://maven.enginehub.org/repo/") }
+        maven { url = uri("https://maven.enginehub.org/repo/") }
         maven { url = uri("https://repo.codemc.org/repository/maven-public") }
         maven { url = uri("https://papermc.io/repo/repository/maven-public/") }
         maven { url = uri("https://maven.fabricmc.net/") }
@@ -18,9 +32,7 @@ fun Project.configureDependencies() {
 
     dependencies {
         "testImplementation"("org.junit.jupiter:junit-jupiter-api:5.7.0")
-        "testImplementation"("org.yaml:snakeyaml:1.27")
-        "testImplementation"("com.googlecode.json-simple:json-simple:1.1.1")
-        "testRuntimeOnly"("org.junit.jupiter:junit-jupiter-engine:5.7.0")
-        "compileOnly"("org.jetbrains:annotations:20.1.0")
+        "testImplementation"("org.junit.jupiter:junit-jupiter-engine:5.7.0")
+        "api"("org.jetbrains:annotations:20.1.0")
     }
 }

buildSrc/src/main/kotlin/com/dfsek/terra/DistributionConfig.kt

@@ -14,26 +14,8 @@ fun Project.configureDistribution() {
     apply(plugin = "java-library")
     apply(plugin = "com.github.johnrengelman.shadow")
 
-
-//    configurations.create("shaded")
-
-    configurations {
-        val shaded = create("shaded")
-        getByName("compile").extendsFrom(shaded)
-//        shaded.extendsFrom(getByName("compile"))
-        val shadedApi = create("shadedApi")
-        shaded.extendsFrom(shadedApi)
-        getByName("api").extendsFrom(shadedApi)
-        val shadedImplementation = create("shadedImplementation")
-        shaded.extendsFrom(shadedImplementation)
-        getByName("implementation").extendsFrom(shadedImplementation)
-    }
-
-//    tasks.withType<JavaCompile> {
-//        classpath +=
-//    }
-
     val downloadDefaultPacks = tasks.create("downloadDefaultPacks") {
+        group = "terra"
         doFirst {
             file("${buildDir}/resources/main/packs/").deleteRecursively()
 
@@ -45,21 +27,6 @@ fun Project.configureDistribution() {
     }
     tasks["processResources"].dependsOn(downloadDefaultPacks)
 
-    tasks.withType<Jar> {
-        archiveBaseName.set("Terra-${archiveBaseName.get()}")
-        from("../LICENSE", "../../LICENSE")
-    }
-
-    tasks.register<Jar>("sourcesJar") {
-        archiveClassifier.set("sources")
-    }
-
-    tasks.register<Jar>("javadocJar") {
-        dependsOn("javadoc")
-        archiveClassifier.set("javadoc")
-        from(tasks.getByName<Javadoc>("javadoc").destinationDir)
-    }
-
     tasks.named<ShadowJar>("shadowJar") {
         // Tell shadow to download the packs
         dependsOn(downloadDefaultPacks)
@@ -69,8 +36,14 @@ fun Project.configureDistribution() {
         archiveClassifier.set("shaded")
         setVersion(project.version)
         relocate("org.apache.commons", "com.dfsek.terra.lib.commons")
-        relocate("parsii", "com.dfsek.terra.lib.parsii")
         relocate("net.jafama", "com.dfsek.terra.lib.jafama")
+        relocate("org.objectweb.asm", "com.dfsek.terra.lib.asm")
+        relocate("com.google.errorprone", "com.dfsek.terra.lib.google.errorprone")
+        relocate("com.google.j2objc", "com.dfsek.terra.lib.google.j2objc")
+        relocate("org.checkerframework", "com.dfsek.terra.lib.checkerframework")
+        relocate("org.javax.annotation", "com.dfsek.terra.lib.javax.annotation")
+        relocate("org.json", "com.dfsek.terra.lib.json")
+        relocate("org.yaml", "com.dfsek.terra.lib.yaml")
         minimize()
     }
     convention.getPlugin<BasePluginConvention>().archivesBaseName = project.name

common/build.gradle.kts

@@ -1,11 +1,14 @@
-import com.dfsek.terra.configureCommon
+import com.dfsek.terra.configureCompilation
+import com.dfsek.terra.configureDependencies
 
 plugins {
     `java-library`
     `maven-publish`
+    idea
 }
 
-configureCommon()
+configureCompilation()
+configureDependencies()
 
 group = "com.dfsek.terra.common"
 
@@ -14,14 +17,18 @@ dependencies {
     "shadedApi"("commons-io:commons-io:2.4")
 
     "shadedApi"("com.dfsek:Paralithic:0.3.2")
-    "shadedApi"("com.dfsek:Tectonic:1.2.3")
+    "shadedApi"("com.dfsek:Tectonic:1.3.1")
     "shadedApi"("net.jafama:jafama:2.3.2")
     "shadedApi"("org.yaml:snakeyaml:1.27")
     "shadedApi"("org.ow2.asm:asm:9.0")
+    "shadedApi"("commons-io:commons-io:2.6")
 
-    "compileOnly"("com.googlecode.json-simple:json-simple:1.1")
+    "shadedApi"("com.googlecode.json-simple:json-simple:1.1.1")
+    "shadedApi"("org.yaml:snakeyaml:1.27")
 
-    "shadedApi"("com.google.guava:guava:30.0-jre")
+    "compileOnly"("com.google.guava:guava:30.0-jre")
+
+    "testImplementation"("com.google.guava:guava:30.0-jre")
 }
 
 publishing {

common/src/main/java/com/dfsek/terra/addon/AddonClassLoader.java

@@ -0,0 +1,61 @@
+package com.dfsek.terra.addon;
+
+import com.dfsek.terra.api.addons.TerraAddon;
+import com.dfsek.terra.api.addons.annotations.Addon;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.util.Enumeration;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+
+public class AddonClassLoader extends URLClassLoader {
+    static {
+        ClassLoader.registerAsParallelCapable();
+    }
+
+    public AddonClassLoader(URL[] urls, ClassLoader parent) {
+        super(urls, parent);
+    }
+
+    public AddonClassLoader(URL[] urls) {
+        super(urls);
+    }
+
+    @SuppressWarnings("unchecked")
+    public static Set<Class<? extends TerraAddon>> fetchAddonClasses(File file) throws IOException {
+        JarFile jarFile = new JarFile(file);
+        Enumeration<JarEntry> entries = jarFile.entries();
+
+        AddonClassLoader loader = new AddonClassLoader(new URL[] {file.toURI().toURL()}, AddonClassLoader.class.getClassLoader());
+
+        Set<Class<? extends TerraAddon>> set = new HashSet<>();
+        while(entries.hasMoreElements()) {
+            JarEntry entry = entries.nextElement();
+
+            if(entry.isDirectory() || !entry.getName().endsWith(".class")) continue;
+            String className = entry.getName().substring(0, entry.getName().length() - 6).replace('/', '.');
+
+            try {
+                Class<?> clazz = loader.loadClass(className);
+
+                Addon addon = clazz.getAnnotation(Addon.class);
+
+                if(addon == null) continue;
+
+                if(!TerraAddon.class.isAssignableFrom(clazz))
+                    throw new IllegalArgumentException("Addon class \"" + clazz + "\" must extend TerraAddon.");
+
+                set.add((Class<? extends TerraAddon>) clazz);
+            } catch(ClassNotFoundException e) {
+                throw new IllegalStateException(e); // this should literally never happen, if it does something is very wrong
+            }
+        }
+
+        return set;
+    }
+}

common/src/main/java/com/dfsek/terra/addon/AddonPool.java

@@ -0,0 +1,42 @@
+package com.dfsek.terra.addon;
+
+import com.dfsek.terra.addon.exception.AddonLoadException;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+public class AddonPool {
+    private final Map<String, PreLoadAddon> pool = new HashMap<>();
+
+    public void add(PreLoadAddon addon) throws AddonLoadException {
+        if(pool.containsKey(addon.getId())) {
+            String message = "Duplicate addon ID: " +
+                    addon.getId() + "; original ID from file: " +
+                    pool.get(addon.getId()).getFile().getAbsolutePath() +
+                    ", class: " +
+                    pool.get(addon.getId()).getAddonClass().getCanonicalName() +
+                    "Duplicate ID from file: " +
+                    addon.getFile().getAbsolutePath() +
+                    ", class: " +
+                    addon.getAddonClass().getCanonicalName();
+            throw new AddonLoadException(message);
+        }
+        pool.put(addon.getId(), addon);
+    }
+
+    public PreLoadAddon get(String id) {
+        return pool.get(id);
+    }
+
+    public void buildAll() throws AddonLoadException {
+        for(PreLoadAddon value : pool.values()) {
+            value.rebuildDependencies(this, value, true);
+        }
+    }
+
+    public Set<PreLoadAddon> getAddons() {
+        return new HashSet<>(pool.values());
+    }
+}

common/src/main/java/com/dfsek/terra/addon/PreLoadAddon.java

@@ -0,0 +1,58 @@
+package com.dfsek.terra.addon;
+
+import com.dfsek.terra.addon.exception.AddonLoadException;
+import com.dfsek.terra.addon.exception.CircularDependencyException;
+import com.dfsek.terra.addon.exception.DependencyMissingException;
+import com.dfsek.terra.api.addons.TerraAddon;
+import com.dfsek.terra.api.addons.annotations.Addon;
+import com.dfsek.terra.api.addons.annotations.Depends;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+public class PreLoadAddon {
+    private final List<PreLoadAddon> depends = new ArrayList<>();
+    private final Class<? extends TerraAddon> addonClass;
+    private final String id;
+    private final String[] dependencies;
+    private final File file;
+
+    public PreLoadAddon(Class<? extends TerraAddon> addonClass, File file) {
+        this.addonClass = addonClass;
+        this.id = addonClass.getAnnotation(Addon.class).value();
+        this.file = file;
+        Depends depends = addonClass.getAnnotation(Depends.class);
+        this.dependencies = depends == null ? new String[] {} : depends.value();
+    }
+
+    public List<PreLoadAddon> getDepends() {
+        return depends;
+    }
+
+    public void rebuildDependencies(AddonPool pool, PreLoadAddon origin, boolean levelG1) throws AddonLoadException {
+        if(this.equals(origin) && !levelG1)
+            throw new CircularDependencyException("Detected circular dependency in addon \"" + id + "\", dependencies: " + Arrays.toString(dependencies));
+
+        for(String dependency : dependencies) {
+            PreLoadAddon preLoadAddon = pool.get(dependency);
+            if(preLoadAddon == null)
+                throw new DependencyMissingException("Dependency " + dependency + " was not found. Please install " + dependency + " to use " + id + ".");
+            depends.add(preLoadAddon);
+            preLoadAddon.rebuildDependencies(pool, origin, false);
+        }
+    }
+
+    public String getId() {
+        return id;
+    }
+
+    public Class<? extends TerraAddon> getAddonClass() {
+        return addonClass;
+    }
+
+    public File getFile() {
+        return file;
+    }
+}

common/src/main/java/com/dfsek/terra/addon/exception/AddonLoadException.java

@@ -0,0 +1,13 @@
+package com.dfsek.terra.addon.exception;
+
+public class AddonLoadException extends Exception {
+    private static final long serialVersionUID = -4949084729296580176L;
+
+    public AddonLoadException(String message) {
+        super(message);
+    }
+
+    public AddonLoadException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

common/src/main/java/com/dfsek/terra/addon/exception/CircularDependencyException.java

@@ -0,0 +1,13 @@
+package com.dfsek.terra.addon.exception;
+
+public class CircularDependencyException extends AddonLoadException {
+    private static final long serialVersionUID = 7398510879124125121L;
+
+    public CircularDependencyException(String message) {
+        super(message);
+    }
+
+    public CircularDependencyException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

common/src/main/java/com/dfsek/terra/addon/exception/DependencyMissingException.java

@@ -0,0 +1,13 @@
+package com.dfsek.terra.addon.exception;
+
+public class DependencyMissingException extends AddonLoadException {
+    private static final long serialVersionUID = -8419489102208521583L;
+
+    public DependencyMissingException(String message) {
+        super(message);
+    }
+
+    public DependencyMissingException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

common/src/main/java/com/dfsek/terra/api/TerraPlugin.java

@@ -0,0 +1,78 @@
+package com.dfsek.terra.api;
+
+import com.dfsek.terra.api.addons.TerraAddon;
+import com.dfsek.terra.api.event.EventManager;
+import com.dfsek.terra.api.platform.handle.ItemHandle;
+import com.dfsek.terra.api.platform.handle.WorldHandle;
+import com.dfsek.terra.api.platform.world.World;
+import com.dfsek.terra.api.registry.CheckedRegistry;
+import com.dfsek.terra.api.registry.LockedRegistry;
+import com.dfsek.terra.api.util.JarUtil;
+import com.dfsek.terra.api.util.logging.DebugLogger;
+import com.dfsek.terra.api.util.logging.Logger;
+import com.dfsek.terra.config.PluginConfig;
+import com.dfsek.terra.config.lang.Language;
+import com.dfsek.terra.config.pack.ConfigPack;
+import com.dfsek.terra.profiler.Profiler;
+import com.dfsek.terra.world.TerraWorld;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URISyntaxException;
+import java.util.jar.JarFile;
+
+/**
+ * Represents a Terra mod/plugin instance.
+ */
+public interface TerraPlugin extends LoaderRegistrar {
+    WorldHandle getWorldHandle();
+
+    TerraWorld getWorld(World world);
+
+    Logger logger();
+
+    PluginConfig getTerraConfig();
+
+    File getDataFolder();
+
+    boolean isDebug();
+
+    Language getLanguage();
+
+    CheckedRegistry<ConfigPack> getConfigRegistry();
+
+    LockedRegistry<TerraAddon> getAddons();
+
+    boolean reload();
+
+    ItemHandle getItemHandle();
+
+    void saveDefaultConfig();
+
+    String platformName();
+
+    DebugLogger getDebugLogger();
+
+    EventManager getEventManager();
+
+    default String getVersion() {
+        return "@VERSION@";
+    }
+
+    /**
+     * Runs a task that may or may not be thread safe, depending on platform.
+     * <p>
+     * Allows platforms to define what code is safe to be run asynchronously.
+     *
+     * @param task Task to be run.
+     */
+    default void runPossiblyUnsafeTask(Runnable task) {
+        task.run();
+    }
+
+    Profiler getProfiler();
+
+    default JarFile getModJar() throws URISyntaxException, IOException {
+        return JarUtil.getJarFile();
+    }
+}

common/src/main/java/com/dfsek/terra/api/addons/TerraAddon.java

@@ -0,0 +1,49 @@
+package com.dfsek.terra.api.addons;
+
+
+import com.dfsek.terra.api.addons.annotations.Addon;
+import com.dfsek.terra.api.addons.annotations.Author;
+import com.dfsek.terra.api.addons.annotations.Version;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Represents an entry point for an addon. Implementations must be annotated with {@link Addon}.
+ */
+public abstract class TerraAddon {
+    /**
+     * Gets the version of this addon.
+     *
+     * @return Addon version.
+     */
+    public final @NotNull String getVersion() {
+        Version version = getClass().getAnnotation(Version.class);
+        return version == null ? "0.1.0" : version.value();
+    }
+
+    /**
+     * Gets the author of this addon.
+     *
+     * @return Addon author.
+     */
+    public final @NotNull String getAuthor() {
+        Author author = getClass().getAnnotation(Author.class);
+        return author == null ? "Anon Y. Mous" : author.value();
+    }
+
+    /**
+     * Gets the name (ID) of this addon.
+     *
+     * @return Addon ID.
+     */
+    public final @NotNull String getName() {
+        Addon addon = getClass().getAnnotation(Addon.class);
+        if(addon == null)
+            throw new IllegalStateException("Addon annotation not present"); // This should never happen; the presence of this annotation is checked by the addon loader.
+        return addon.value();
+    }
+
+    /**
+     * Invoked immediately after an addon is loaded.
+     */
+    public abstract void initialize();
+}

common/src/main/java/com/dfsek/terra/api/addons/annotations/Addon.java

@@ -0,0 +1,20 @@
+package com.dfsek.terra.api.addons.annotations;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Specifies that the annotated class is an entry point for a Terra addon.
+ */
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface Addon {
+    /**
+     * @return The ID of the addon.
+     */
+    @NotNull String value();
+}

common/src/main/java/com/dfsek/terra/api/addons/annotations/Author.java

@@ -0,0 +1,20 @@
+package com.dfsek.terra.api.addons.annotations;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Optional annotation that specifies the author of an addon.
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+public @interface Author {
+    /**
+     * @return Name of the addon author.
+     */
+    @NotNull String value();
+}

common/src/main/java/com/dfsek/terra/api/addons/annotations/Depends.java

@@ -0,0 +1,20 @@
+package com.dfsek.terra.api.addons.annotations;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Optional annotation that specifies dependencies of an addon.
+ */
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface Depends {
+    /**
+     * @return All addons this addon is dependent upon.
+     */
+    @NotNull String[] value();
+}

common/src/main/java/com/dfsek/terra/api/addons/annotations/Version.java

@@ -0,0 +1,20 @@
+package com.dfsek.terra.api.addons.annotations;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Optional annotation that specifies the version of an addon.
+ */
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface Version {
+    /**
+     * @return Version of the addon.
+     */
+    @NotNull String value();
+}

common/src/main/java/com/dfsek/terra/api/command/CommandManager.java

@@ -0,0 +1,17 @@
+package com.dfsek.terra.api.command;
+
+import com.dfsek.terra.api.command.exception.CommandException;
+import com.dfsek.terra.api.command.exception.MalformedCommandException;
+import com.dfsek.terra.api.platform.CommandSender;
+
+import java.util.List;
+
+public interface CommandManager {
+    void execute(String command, CommandSender sender, List<String> args) throws CommandException;
+
+    void register(String name, Class<? extends CommandTemplate> clazz) throws MalformedCommandException;
+
+    List<String> tabComplete(String command, CommandSender sender, List<String> args) throws CommandException;
+
+    int getMaxArgumentDepth();
+}

common/src/main/java/com/dfsek/terra/api/command/CommandTemplate.java

@@ -0,0 +1,7 @@
+package com.dfsek.terra.api.command;
+
+import com.dfsek.terra.api.platform.CommandSender;
+
+public interface CommandTemplate {
+    void execute(CommandSender sender);
+}

common/src/main/java/com/dfsek/terra/api/command/ExecutionState.java

@@ -0,0 +1,38 @@
+package com.dfsek.terra.api.command;
+
+import com.dfsek.terra.api.platform.CommandSender;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+public final class ExecutionState {
+    private final Set<String> switches = new HashSet<>();
+    private final Map<String, String> args = new HashMap<>();
+    private final CommandSender sender;
+
+    protected ExecutionState(CommandSender sender) {
+        this.sender = sender;
+    }
+
+    protected void addSwitch(String flag) {
+        switches.add(flag);
+    }
+
+    protected void addArgument(String arg, String value) {
+        args.put(arg, value);
+    }
+
+    public String getArgument(String argument) {
+        return args.get(argument);
+    }
+
+    public boolean hasSwitch(String flag) {
+        return switches.contains(flag);
+    }
+
+    public CommandSender getSender() {
+        return sender;
+    }
+}

common/src/main/java/com/dfsek/terra/api/command/TerraCommandManager.java

@@ -0,0 +1,283 @@
+package com.dfsek.terra.api.command;
+
+import com.dfsek.terra.api.TerraPlugin;
+import com.dfsek.terra.api.command.annotation.Argument;
+import com.dfsek.terra.api.command.annotation.Command;
+import com.dfsek.terra.api.command.annotation.Subcommand;
+import com.dfsek.terra.api.command.annotation.Switch;
+import com.dfsek.terra.api.command.annotation.inject.ArgumentTarget;
+import com.dfsek.terra.api.command.annotation.inject.SwitchTarget;
+import com.dfsek.terra.api.command.annotation.type.DebugCommand;
+import com.dfsek.terra.api.command.annotation.type.PlayerCommand;
+import com.dfsek.terra.api.command.annotation.type.WorldCommand;
+import com.dfsek.terra.api.command.arg.ArgumentParser;
+import com.dfsek.terra.api.command.exception.CommandException;
+import com.dfsek.terra.api.command.exception.ExecutionException;
+import com.dfsek.terra.api.command.exception.InvalidArgumentsException;
+import com.dfsek.terra.api.command.exception.MalformedCommandException;
+import com.dfsek.terra.api.command.exception.SwitchFormatException;
+import com.dfsek.terra.api.command.tab.TabCompleter;
+import com.dfsek.terra.api.injection.Injector;
+import com.dfsek.terra.api.injection.exception.InjectionException;
+import com.dfsek.terra.api.platform.CommandSender;
+import com.dfsek.terra.api.platform.entity.Player;
+import com.dfsek.terra.api.util.ReflectionUtil;
+import com.dfsek.terra.world.TerraWorld;
+import net.jafama.FastMath;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.InvocationTargetException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+public class TerraCommandManager implements CommandManager {
+    private final Map<String, CommandHolder> commands = new HashMap<>();
+    private final Injector<TerraPlugin> pluginInjector;
+    private final TerraPlugin main;
+
+    public TerraCommandManager(TerraPlugin main) {
+        this.main = main;
+        this.pluginInjector = new Injector<>(main);
+        pluginInjector.addExplicitTarget(TerraPlugin.class);
+    }
+
+    @Override
+    public void execute(String commandName, CommandSender sender, List<String> argsIn) throws CommandException {
+        if(!commands.containsKey(commandName)) throw new InvalidArgumentsException("No such command \"" + commandName + "\"");
+        execute(commands.get(commandName), sender, new ArrayList<>(argsIn));
+    }
+
+    private void execute(CommandHolder commandHolder, CommandSender sender, List<String> args) throws CommandException {
+        Class<? extends CommandTemplate> commandClass = commandHolder.clazz;
+
+        if(commandClass.isAnnotationPresent(DebugCommand.class) && !main.isDebug()) {
+            sender.sendMessage("Command must be executed with debug mode enabled.");
+            return;
+        }
+
+        if(commandClass.isAnnotationPresent(PlayerCommand.class) && !(sender instanceof Player)) {
+            sender.sendMessage("Command must be executed by player.");
+            return;
+        }
+
+        if(commandClass.isAnnotationPresent(WorldCommand.class) && (!(sender instanceof Player) || !(((Player) sender).getWorld()).isTerraWorld())) {
+            sender.sendMessage("Command must be executed in a Terra world.");
+            return;
+        }
+
+        List<String> ogArgs = new ArrayList<>(args);
+
+        ExecutionState state = new ExecutionState(sender);
+
+        if(!commandClass.isAnnotationPresent(Command.class)) {
+            invoke(commandClass, state, commandHolder);
+            return;
+        }
+
+        Command command = commandClass.getAnnotation(Command.class);
+
+        if(command.arguments().length == 0 && command.subcommands().length == 0) {
+            if(args.isEmpty()) {
+                invoke(commandClass, state, commandHolder);
+                return;
+            } else throw new InvalidArgumentsException("Expected 0 arguments, found " + args.size());
+        }
+
+        if(!args.isEmpty() && commandHolder.subcommands.containsKey(args.get(0))) {
+            String c = args.get(0);
+            args.remove(0);
+            execute(commandHolder.subcommands.get(c), sender, args);
+            return;
+        }
+
+        boolean req = true;
+        for(Argument argument : command.arguments()) {
+            if(!req && argument.required()) {
+                throw new MalformedCommandException("Required arguments must come first! Arguments: " + Arrays.toString(command.arguments()));
+            }
+            req = argument.required();
+
+            if(args.isEmpty()) {
+                if(req) throw new InvalidArgumentsException("Invalid arguments: " + ogArgs + ", usage: " + command.usage());
+                break;
+            }
+
+            String arg = args.get(0);
+
+            if(arg.startsWith("-")) { // switches have started.
+                if(req) throw new InvalidArgumentsException("Switches must come after arguments.");
+                break;
+            }
+
+            state.addArgument(argument.value(), args.remove(0));
+        }
+
+        while(!args.isEmpty()) {
+            String aSwitch = args.remove(0);
+            if(!aSwitch.startsWith("-")) throw new SwitchFormatException("Invalid switch \"" + aSwitch + "\"");
+
+            String val = aSwitch.substring(1); // remove dash
+
+            if(!commandHolder.switches.containsKey(val)) throw new SwitchFormatException("No such switch \"" + aSwitch + "\"");
+
+            state.addSwitch(commandHolder.switches.get(val));
+        }
+
+        invoke(commandClass, state, commandHolder);
+    }
+
+    private void invoke(Class<? extends CommandTemplate> clazz, ExecutionState state, CommandHolder holder) throws CommandException {
+        try {
+            CommandTemplate template = clazz.getConstructor().newInstance();
+
+            pluginInjector.inject(template);
+
+            for(Field field : ReflectionUtil.getFields(clazz)) {
+                if(field.isAnnotationPresent(ArgumentTarget.class)) {
+                    ArgumentTarget argumentTarget = field.getAnnotation(ArgumentTarget.class);
+                    if(!holder.argumentMap.containsKey(argumentTarget.value())) {
+                        throw new MalformedCommandException("Argument Target specifies nonexistent argument \"" + argumentTarget.value() + "\"");
+                    }
+
+                    String argument = argumentTarget.value();
+
+                    ArgumentParser<?> argumentParser = holder.argumentMap.get(argumentTarget.value()).argumentParser().getConstructor().newInstance();
+
+                    pluginInjector.inject(argumentParser);
+
+                    field.setAccessible(true);
+                    String value = state.getArgument(argument);
+
+                    if(value == null) value = holder.argumentMap.get(argumentTarget.value()).defaultValue();
+
+                    field.set(template, argumentParser.parse(state.getSender(), value));
+                }
+                if(field.isAnnotationPresent(SwitchTarget.class)) {
+                    SwitchTarget switchTarget = field.getAnnotation(SwitchTarget.class);
+                    if(!holder.switches.containsValue(switchTarget.value())) {
+                        throw new MalformedCommandException("Switch Target specifies nonexistent switch \"" + switchTarget.value() + "\"");
+                    }
+
+                    if(!(field.getType() == boolean.class)) {
+                        throw new MalformedCommandException("Switch Target must be of type boolean.");
+                    }
+
+                    field.setAccessible(true);
+                    field.setBoolean(template, state.hasSwitch(switchTarget.value()));
+                }
+            }
+
+            try {
+                template.execute(state.getSender());
+            } catch(Throwable e) {
+                throw new ExecutionException("Failed to execute command: " + e.getMessage(), e);
+            }
+        } catch(InstantiationException | IllegalAccessException | InvocationTargetException | NoSuchMethodException | InjectionException e) {
+            throw new MalformedCommandException("Unable to reflectively instantiate command: ", e);
+        }
+    }
+
+    @Override
+    public void register(String name, Class<? extends CommandTemplate> clazz) throws MalformedCommandException {
+        commands.put(name, new CommandHolder(clazz));
+    }
+
+    @Override
+    public List<String> tabComplete(String command, CommandSender sender, List<String> args) throws CommandException {
+        if(args.isEmpty()) return new ArrayList<>(commands.keySet()).stream().sorted(String::compareTo).collect(Collectors.toList());
+        if(!commands.containsKey(command)) return Collections.emptyList();
+        return tabComplete(commands.get(command), sender, new ArrayList<>(args)).stream().filter(s -> s.toLowerCase().startsWith(args.get(args.size() - 1).toLowerCase())).sorted(String::compareTo).collect(Collectors.toList());
+    }
+
+    @Override
+    public int getMaxArgumentDepth() {
+        int max = 0;
+        for(CommandHolder value : commands.values()) {
+            max = FastMath.max(getMaxArgumentDepth(value), max);
+        }
+        return max;
+    }
+
+    private int getMaxArgumentDepth(CommandHolder holder) {
+        int max = 0;
+        max = FastMath.max(holder.arguments.size() + holder.switchList.size(), max);
+        for(CommandHolder value : holder.subcommands.values()) {
+            max = FastMath.max(max, getMaxArgumentDepth(value) + 1);
+        }
+        return max;
+    }
+
+    private List<String> tabComplete(CommandHolder holder, CommandSender sender, List<String> args) throws CommandException {
+        if(args.isEmpty()) return Collections.emptyList();
+        List<String> completions = new ArrayList<>();
+
+        if(args.size() == 1) {
+            completions.addAll(holder.subcommands.keySet());
+        }
+
+        if(holder.subcommands.containsKey(args.get(0))) {
+            List<String> newArgs = new ArrayList<>(args);
+            newArgs.remove(0);
+            completions.addAll(tabComplete(holder.subcommands.get(args.get(0)), sender, newArgs));
+        }
+        try {
+            if(args.size() <= holder.arguments.size()) {
+                TabCompleter completer = holder.arguments.get(args.size() - 1).tabCompleter().getConstructor().newInstance();
+                pluginInjector.inject(completer);
+                completions.addAll(completer.complete(sender));
+            }
+        } catch(InstantiationException | IllegalAccessException | InvocationTargetException | NoSuchMethodException | InjectionException e) {
+            throw new MalformedCommandException("Unable to reflectively instantiate tab-completer: ", e);
+        }
+        return completions;
+    }
+
+    /**
+     * Pre-processes command metadata.
+     */
+    private static final class CommandHolder {
+        private final Class<? extends CommandTemplate> clazz;
+        private final Map<String, CommandHolder> subcommands = new HashMap<>();
+        private final Map<String, String> switches = new HashMap<>();
+        private final List<Argument> arguments;
+        private final List<Switch> switchList;
+        private final Map<String, Argument> argumentMap = new HashMap<>();
+
+        private CommandHolder(Class<? extends CommandTemplate> clazz) throws MalformedCommandException {
+            this.clazz = clazz;
+            if(clazz.isAnnotationPresent(Command.class)) {
+                Command command = clazz.getAnnotation(Command.class);
+                for(Subcommand subcommand : command.subcommands()) {
+                    if(subcommands.containsKey(subcommand.value()))
+                        throw new MalformedCommandException("Duplicate subcommand: " + subcommand);
+                    CommandHolder holder = new CommandHolder(subcommand.clazz());
+                    subcommands.put(subcommand.value(), holder);
+                    for(String alias : subcommand.aliases()) {
+                        subcommands.put(alias, holder);
+                    }
+                }
+                for(Switch aSwitch : command.switches()) {
+                    if(switches.containsKey(aSwitch.value())) throw new MalformedCommandException("Duplicate switch: " + aSwitch);
+                    switches.put(aSwitch.value(), aSwitch.value());
+                    for(String alias : aSwitch.aliases()) {
+                        switches.put(alias, aSwitch.value());
+                    }
+                }
+                for(Argument argument : command.arguments()) {
+                    if(argumentMap.containsKey(argument.value())) throw new MalformedCommandException("Duplicate argument: " + argument);
+                    argumentMap.put(argument.value(), argument);
+                }
+                arguments = Arrays.asList(command.arguments());
+                switchList = Arrays.asList(command.switches());
+            } else {
+                arguments = Collections.emptyList();
+                switchList = Collections.emptyList();
+            }
+        }
+    }
+}

common/src/main/java/com/dfsek/terra/api/command/annotation/Argument.java

@@ -0,0 +1,25 @@
+package com.dfsek.terra.api.command.annotation;
+
+import com.dfsek.terra.api.command.arg.ArgumentParser;
+import com.dfsek.terra.api.command.arg.StringArgumentParser;
+import com.dfsek.terra.api.command.tab.NothingCompleter;
+import com.dfsek.terra.api.command.tab.TabCompleter;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target(ElementType.ANNOTATION_TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface Argument {
+    String value();
+
+    boolean required() default true;
+
+    Class<? extends TabCompleter> tabCompleter() default NothingCompleter.class;
+
+    Class<? extends ArgumentParser<?>> argumentParser() default StringArgumentParser.class;
+
+    String defaultValue() default "";
+}

common/src/main/java/com/dfsek/terra/api/command/annotation/Command.java

@@ -0,0 +1,18 @@
+package com.dfsek.terra.api.command.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface Command {
+    Argument[] arguments() default {};
+
+    Switch[] switches() default {};
+
+    Subcommand[] subcommands() default {};
+
+    String usage() default "";
+}

common/src/main/java/com/dfsek/terra/api/command/annotation/Subcommand.java

@@ -0,0 +1,18 @@
+package com.dfsek.terra.api.command.annotation;
+
+import com.dfsek.terra.api.command.CommandTemplate;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.ANNOTATION_TYPE)
+public @interface Subcommand {
+    String value();
+
+    String[] aliases() default {};
+
+    Class<? extends CommandTemplate> clazz();
+}

common/src/main/java/com/dfsek/terra/api/command/annotation/Switch.java

@@ -0,0 +1,14 @@
+package com.dfsek.terra.api.command.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.ANNOTATION_TYPE)
+public @interface Switch {
+    String value();
+
+    String[] aliases() default {};
+}

common/src/main/java/com/dfsek/terra/api/command/annotation/inject/ArgumentTarget.java

@@ -0,0 +1,12 @@
+package com.dfsek.terra.api.command.annotation.inject;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.FIELD)
+public @interface ArgumentTarget {
+    String value();
+}

common/src/main/java/com/dfsek/terra/api/command/annotation/inject/SwitchTarget.java

@@ -0,0 +1,12 @@
+package com.dfsek.terra.api.command.annotation.inject;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.FIELD)
+public @interface SwitchTarget {
+    String value();
+}

common/src/main/java/com/dfsek/terra/api/command/annotation/type/DebugCommand.java

@@ -0,0 +1,14 @@
+package com.dfsek.terra.api.command.annotation.type;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Command may only be executed with debug mode enabled.
+ */
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface DebugCommand {
+}

common/src/main/java/com/dfsek/terra/api/command/annotation/type/PlayerCommand.java

@@ -0,0 +1,14 @@
+package com.dfsek.terra.api.command.annotation.type;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Marks command as player-only
+ */
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface PlayerCommand {
+}

common/src/main/java/com/dfsek/terra/api/command/annotation/type/WorldCommand.java

@@ -0,0 +1,14 @@
+package com.dfsek.terra.api.command.annotation.type;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Command may only be executed in a Terra world.
+ */
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface WorldCommand {
+}

common/src/main/java/com/dfsek/terra/api/command/arg/ArgumentParser.java

@@ -0,0 +1,7 @@
+package com.dfsek.terra.api.command.arg;
+
+import com.dfsek.terra.api.platform.CommandSender;
+
+public interface ArgumentParser<T> {
+    T parse(CommandSender sender, String arg);
+}

common/src/main/java/com/dfsek/terra/api/command/arg/DoubleArgumentParser.java

@@ -0,0 +1,10 @@
+package com.dfsek.terra.api.command.arg;
+
+import com.dfsek.terra.api.platform.CommandSender;
+
+public class DoubleArgumentParser implements ArgumentParser<Double> {
+    @Override
+    public Double parse(CommandSender sender, String arg) {
+        return arg == null ? null : Double.parseDouble(arg);
+    }
+}

common/src/main/java/com/dfsek/terra/api/command/arg/IntegerArgumentParser.java

@@ -0,0 +1,10 @@
+package com.dfsek.terra.api.command.arg;
+
+import com.dfsek.terra.api.platform.CommandSender;
+
+public class IntegerArgumentParser implements ArgumentParser<Integer> {
+    @Override
+    public Integer parse(CommandSender sender, String arg) {
+        return arg == null ? null : Integer.parseInt(arg);
+    }
+}

common/src/main/java/com/dfsek/terra/api/command/arg/StringArgumentParser.java

@@ -0,0 +1,10 @@
+package com.dfsek.terra.api.command.arg;
+
+import com.dfsek.terra.api.platform.CommandSender;
+
+public class StringArgumentParser implements ArgumentParser<String> {
+    @Override
+    public String parse(CommandSender sender, String arg) {
+        return arg;
+    }
+}

common/src/main/java/com/dfsek/terra/api/command/exception/CommandException.java

@@ -0,0 +1,13 @@
+package com.dfsek.terra.api.command.exception;
+
+public abstract class CommandException extends Exception {
+    private static final long serialVersionUID = -2955328495045879822L;
+
+    public CommandException(String message) {
+        super(message);
+    }
+
+    public CommandException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

common/src/main/java/com/dfsek/terra/api/command/exception/ExecutionException.java

@@ -0,0 +1,13 @@
+package com.dfsek.terra.api.command.exception;
+
+public class ExecutionException extends CommandException {
+    private static final long serialVersionUID = -6345523475880607959L;
+
+    public ExecutionException(String message) {
+        super(message);
+    }
+
+    public ExecutionException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

common/src/main/java/com/dfsek/terra/api/command/exception/InvalidArgumentsException.java

@@ -0,0 +1,13 @@
+package com.dfsek.terra.api.command.exception;
+
+public class InvalidArgumentsException extends CommandException {
+    private static final long serialVersionUID = 7563619667472569824L;
+
+    public InvalidArgumentsException(String message) {
+        super(message);
+    }
+
+    public InvalidArgumentsException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

common/src/main/java/com/dfsek/terra/api/command/exception/MalformedCommandException.java

@@ -0,0 +1,16 @@
+package com.dfsek.terra.api.command.exception;
+
+/**
+ * Thrown when command is incorrectly defined.
+ */
+public class MalformedCommandException extends CommandException {
+    private static final long serialVersionUID = -5417760860407895496L;
+
+    public MalformedCommandException(String message) {
+        super(message);
+    }
+
+    public MalformedCommandException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

common/src/main/java/com/dfsek/terra/api/command/exception/SwitchFormatException.java

@@ -0,0 +1,13 @@
+package com.dfsek.terra.api.command.exception;
+
+public class SwitchFormatException extends CommandException {
+    private static final long serialVersionUID = -965858989317844628L;
+
+    public SwitchFormatException(String message) {
+        super(message);
+    }
+
+    public SwitchFormatException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

common/src/main/java/com/dfsek/terra/api/command/tab/NothingCompleter.java

@@ -0,0 +1,13 @@
+package com.dfsek.terra.api.command.tab;
+
+import com.dfsek.terra.api.platform.CommandSender;
+
+import java.util.Collections;
+import java.util.List;
+
+public class NothingCompleter implements TabCompleter {
+    @Override
+    public List<String> complete(CommandSender sender) {
+        return Collections.emptyList();
+    }
+}

common/src/main/java/com/dfsek/terra/api/command/tab/TabCompleter.java

@@ -0,0 +1,9 @@
+package com.dfsek.terra.api.command.tab;
+
+import com.dfsek.terra.api.platform.CommandSender;
+
+import java.util.List;
+
+public interface TabCompleter {
+    List<String> complete(CommandSender sender);
+}

common/src/main/java/com/dfsek/terra/api/core/TerraPlugin.java

@@ -1,48 +0,0 @@
-package com.dfsek.terra.api.core;
-
-import com.dfsek.terra.api.LoaderRegistrar;
-import com.dfsek.terra.api.core.event.EventManager;
-import com.dfsek.terra.api.platform.handle.ItemHandle;
-import com.dfsek.terra.api.platform.handle.WorldHandle;
-import com.dfsek.terra.api.platform.world.World;
-import com.dfsek.terra.config.PluginConfig;
-import com.dfsek.terra.config.lang.Language;
-import com.dfsek.terra.debug.DebugLogger;
-import com.dfsek.terra.registry.ConfigRegistry;
-import com.dfsek.terra.world.TerraWorld;
-
-import java.io.File;
-import java.util.logging.Logger;
-
-public interface TerraPlugin extends LoaderRegistrar {
-    WorldHandle getWorldHandle();
-
-    boolean isEnabled();
-
-    TerraWorld getWorld(World world);
-
-    Logger getLogger();
-
-    PluginConfig getTerraConfig();
-
-    File getDataFolder();
-
-    boolean isDebug();
-
-    Language getLanguage();
-
-    ConfigRegistry getRegistry();
-
-    void reload();
-
-    ItemHandle getItemHandle();
-
-    void saveDefaultConfig();
-
-    String platformName();
-
-
-    DebugLogger getDebugLogger();
-
-    EventManager getEventManager();
-}

common/src/main/java/com/dfsek/terra/api/core/event/EventListener.java

@@ -1,4 +0,0 @@
-package com.dfsek.terra.api.core.event;
-
-public interface EventListener {
-}

common/src/main/java/com/dfsek/terra/api/core/event/EventManager.java

@@ -1,14 +0,0 @@
-package com.dfsek.terra.api.core.event;
-
-import com.dfsek.terra.api.core.event.events.Event;
-
-public interface EventManager {
-    /**
-     * Call an event, and return the execution status.
-     * @param event Event to pass to all registered EventListeners.
-     * @return False if the event is cancellable and has been cancelled, otherwise true.
-     */
-    boolean callEvent(Event event);
-
-    void registerListener(EventListener listener);
-}

common/src/main/java/com/dfsek/terra/api/core/event/events/Cancellable.java

@@ -1,11 +0,0 @@
-package com.dfsek.terra.api.core.event.events;
-
-/**
- * Events that implement this interface may be cancelled.
- *
- * Cancelling an event is assumed to stop the execution of whatever action triggered the event.
- */
-public interface Cancellable extends Event {
-    boolean isCancelled();
-    void setCancelled();
-}

common/src/main/java/com/dfsek/terra/api/core/event/events/Event.java

@@ -1,4 +0,0 @@
-package com.dfsek.terra.api.core.event.events;
-
-public interface Event {
-}

common/src/main/java/com/dfsek/terra/api/core/event/events/config/ConfigPackLoadEvent.java

@@ -1,16 +0,0 @@
-package com.dfsek.terra.api.core.event.events.config;
-
-import com.dfsek.terra.api.core.event.events.Event;
-import com.dfsek.terra.config.pack.ConfigPack;
-
-public abstract class ConfigPackLoadEvent implements Event {
-    private final ConfigPack pack;
-
-    public ConfigPackLoadEvent(ConfigPack pack) {
-        this.pack = pack;
-    }
-
-    public ConfigPack getPack() {
-        return pack;
-    }
-}

common/src/main/java/com/dfsek/terra/api/core/event/events/world/TerraWorldLoadEvent.java

@@ -1,19 +0,0 @@
-package com.dfsek.terra.api.core.event.events.world;
-
-import com.dfsek.terra.api.core.event.events.Event;
-import com.dfsek.terra.world.TerraWorld;
-
-/**
- * Called upon initialization of a TerraWorld.
- */
-public class TerraWorldLoadEvent implements Event {
-    private final TerraWorld world;
-
-    public TerraWorldLoadEvent(TerraWorld world) {
-        this.world = world;
-    }
-
-    public TerraWorld getWorld() {
-        return world;
-    }
-}

common/src/main/java/com/dfsek/terra/api/event/EventListener.java

@@ -0,0 +1,12 @@
+package com.dfsek.terra.api.event;
+
+import com.dfsek.terra.api.event.events.Event;
+
+/**
+ * Marker interface for a class that contains event listener methods.
+ *
+ * @see Event
+ * @see EventManager
+ */
+public interface EventListener {
+}

common/src/main/java/com/dfsek/terra/api/event/EventManager.java

@@ -0,0 +1,25 @@
+package com.dfsek.terra.api.event;
+
+import com.dfsek.terra.api.addons.TerraAddon;
+import com.dfsek.terra.api.event.events.Event;
+
+/**
+ * Manages event registration and triggering.
+ */
+public interface EventManager {
+    /**
+     * Call an event, and return the execution status.
+     *
+     * @param event Event to pass to all registered EventListeners.
+     * @return False if the event is cancellable and has been cancelled, otherwise true.
+     */
+    boolean callEvent(Event event);
+
+    /**
+     * Register an {@link EventListener} under an {@link TerraAddon}.
+     *
+     * @param addon    Addon to register listener for.
+     * @param listener Listener to register.
+     */
+    void registerListener(TerraAddon addon, EventListener listener);
+}

common/src/main/java/com/dfsek/terra/api/event/TerraEventManager.java

@@ -1,9 +1,12 @@
-package com.dfsek.terra.api.core.event;
+package com.dfsek.terra.api.event;
 
-import com.dfsek.terra.api.core.TerraPlugin;
-import com.dfsek.terra.api.core.event.annotations.Priority;
-import com.dfsek.terra.api.core.event.events.Cancellable;
-import com.dfsek.terra.api.core.event.events.Event;
+import com.dfsek.terra.api.TerraPlugin;
+import com.dfsek.terra.api.addons.TerraAddon;
+import com.dfsek.terra.api.event.annotations.Global;
+import com.dfsek.terra.api.event.annotations.Priority;
+import com.dfsek.terra.api.event.events.Cancellable;
+import com.dfsek.terra.api.event.events.Event;
+import com.dfsek.terra.api.event.events.PackEvent;
 import com.dfsek.terra.api.util.ReflectionUtil;
 
 import java.io.PrintWriter;
@@ -29,19 +32,30 @@ public class TerraEventManager implements EventManager {
     public boolean callEvent(Event event) {
         listeners.getOrDefault(event.getClass(), Collections.emptyList()).forEach(listenerHolder -> {
                     try {
-                        listenerHolder.method.invoke(listenerHolder.listener, event);
+                        if(event instanceof PackEvent && !listenerHolder.global) {
+                            PackEvent packEvent = (PackEvent) event;
+                            if(packEvent
+                                    .getPack()
+                                    .getTemplate()
+                                    .getAddons()
+                                    .contains(listenerHolder.addon)) {
+                                listenerHolder.method.invoke(listenerHolder.listener, event);
+                            }
+                        } else {
+                            listenerHolder.method.invoke(listenerHolder.listener, event);
+                        }
                     } catch(InvocationTargetException e) {
                         StringWriter writer = new StringWriter();
                         e.getTargetException().printStackTrace(new PrintWriter(writer));
-                        main.getLogger().warning("Exception occurred during event handling:");
-                        main.getLogger().warning(writer.toString());
-                        main.getLogger().warning("Report this to the maintainers of " + listenerHolder.method.getName());
+                        main.logger().warning("Exception occurred during event handling:");
+                        main.logger().warning(writer.toString());
+                        main.logger().warning("Report this to the maintainers of " + listenerHolder.method.getName());
                     } catch(Exception e) {
                         StringWriter writer = new StringWriter();
                         e.printStackTrace(new PrintWriter(writer));
-                        main.getLogger().warning("Exception occurred during event handling:");
-                        main.getLogger().warning(writer.toString());
-                        main.getLogger().warning("Report this to the maintainers of " + listenerHolder.method.getName());
+                        main.logger().warning("Exception occurred during event handling:");
+                        main.logger().warning(writer.toString());
+                        main.logger().warning("Report this to the maintainers of " + listenerHolder.method.getName());
                     }
                 }
         );
@@ -51,7 +65,7 @@ public class TerraEventManager implements EventManager {
 
     @SuppressWarnings("unchecked")
     @Override
-    public void registerListener(EventListener listener) {
+    public void registerListener(TerraAddon addon, EventListener listener) {
         Class<? extends EventListener> listenerClass = listener.getClass();
         Method[] methods = ReflectionUtil.getMethods(listenerClass);
 
@@ -68,7 +82,7 @@ public class TerraEventManager implements EventManager {
 
             List<ListenerHolder> holders = listeners.computeIfAbsent((Class<? extends Event>) eventParam, e -> new ArrayList<>());
 
-            holders.add(new ListenerHolder(method, listener, priority));
+            holders.add(new ListenerHolder(method, listener, priority, addon, method.getAnnotation(Global.class) != null));
 
             holders.sort(Comparator.comparingInt(ListenerHolder::getPriority)); // Sort priorities.
         }
@@ -78,11 +92,15 @@ public class TerraEventManager implements EventManager {
         private final Method method;
         private final EventListener listener;
         private final int priority;
+        private final TerraAddon addon;
+        private final boolean global;
 
-        private ListenerHolder(Method method, EventListener listener, int priority) {
+        private ListenerHolder(Method method, EventListener listener, int priority, TerraAddon addon, boolean global) {
             this.method = method;
             this.listener = listener;
             this.priority = priority;
+            this.addon = addon;
+            this.global = global;
         }
 
         public int getPriority() {

common/src/main/java/com/dfsek/terra/api/event/annotations/Global.java

@@ -0,0 +1,17 @@
+package com.dfsek.terra.api.event.annotations;
+
+import com.dfsek.terra.api.event.events.PackEvent;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Specifies that an event handler is to handle all {@link PackEvent}s, regardless of whether the pack
+ * depends on the addon's listener.
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.METHOD)
+public @interface Global {
+}

common/src/main/java/com/dfsek/terra/api/event/annotations/Priority.java

@@ -1,4 +1,4 @@
-package com.dfsek.terra.api.core.event.annotations;
+package com.dfsek.terra.api.event.annotations;
 
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
@@ -12,11 +12,11 @@ import java.lang.annotation.Target;
 @Target(ElementType.METHOD)
 public @interface Priority {
     /**
-     * Highest possible priority. Listeners with this priority will always be invoked first.
+     * Highest possible priority. Listeners with this priority will always be invoked last.
      */
     int HIGHEST = Integer.MAX_VALUE;
     /**
-     * Lowest possible priority. Listeners with this priority will always be invoked last.
+     * Lowest possible priority. Listeners with this priority will always be invoked first.
      */
     int LOWEST = Integer.MIN_VALUE;
     /**

common/src/main/java/com/dfsek/terra/api/event/events/AbstractCancellable.java

@@ -0,0 +1,20 @@
+package com.dfsek.terra.api.event.events;
+
+import com.dfsek.terra.api.util.mutable.MutableBoolean;
+
+/**
+ * Abstract class containing basic {@link Cancellable} implementation.
+ */
+public abstract class AbstractCancellable implements Cancellable {
+    private final MutableBoolean cancelled = new MutableBoolean(false);
+
+    @Override
+    public boolean isCancelled() {
+        return cancelled.get();
+    }
+
+    @Override
+    public void setCancelled(boolean cancelled) {
+        this.cancelled.set(cancelled);
+    }
+}

common/src/main/java/com/dfsek/terra/api/event/events/Cancellable.java

@@ -0,0 +1,22 @@
+package com.dfsek.terra.api.event.events;
+
+/**
+ * Events that implement this interface may be cancelled.
+ * <p>
+ * Cancelling an event is assumed to stop the execution of whatever action triggered the event.
+ */
+public interface Cancellable extends Event {
+    /**
+     * Get the cancellation status of the event.
+     *
+     * @return Whether event is cancelled.
+     */
+    boolean isCancelled();
+
+    /**
+     * Set the cancellation status of the event.
+     *
+     * @param cancelled Whether event is cancelled.
+     */
+    void setCancelled(boolean cancelled);
+}

common/src/main/java/com/dfsek/terra/api/event/events/Event.java

@@ -0,0 +1,7 @@
+package com.dfsek.terra.api.event.events;
+
+/**
+ * An event that addons may listen to.
+ */
+public interface Event {
+}

common/src/main/java/com/dfsek/terra/api/event/events/PackEvent.java

@@ -0,0 +1,20 @@
+package com.dfsek.terra.api.event.events;
+
+import com.dfsek.terra.api.event.annotations.Global;
+import com.dfsek.terra.config.pack.ConfigPack;
+
+/**
+ * An event with functionality directly linked to a {@link ConfigPack}.
+ * <p>
+ * PackEvents are only invoked when the pack specifies the addon in its
+ * {@code addon} key (or when the listener is annotated {@link Global}).
+ */
+@SuppressWarnings("InterfaceMayBeAnnotatedFunctional")
+public interface PackEvent extends Event {
+    /**
+     * Get the {@link ConfigPack} associated with this event.
+     *
+     * @return ConfigPack associated with the event.
+     */
+    ConfigPack getPack();
+}

common/src/main/java/com/dfsek/terra/api/event/events/config/ConfigPackLoadEvent.java

@@ -0,0 +1,20 @@
+package com.dfsek.terra.api.event.events.config;
+
+import com.dfsek.terra.api.event.events.PackEvent;
+import com.dfsek.terra.config.pack.ConfigPack;
+
+/**
+ * An event related to the loading process of config packs.
+ */
+public abstract class ConfigPackLoadEvent implements PackEvent {
+    private final ConfigPack pack;
+
+    public ConfigPackLoadEvent(ConfigPack pack) {
+        this.pack = pack;
+    }
+
+    @Override
+    public ConfigPack getPack() {
+        return pack;
+    }
+}

common/src/main/java/com/dfsek/terra/api/event/events/config/ConfigPackPostLoadEvent.java

@@ -1,4 +1,4 @@
-package com.dfsek.terra.api.core.event.events.config;
+package com.dfsek.terra.api.event.events.config;
 
 import com.dfsek.terra.config.pack.ConfigPack;
 

common/src/main/java/com/dfsek/terra/api/event/events/config/ConfigPackPreLoadEvent.java

@@ -1,4 +1,4 @@
-package com.dfsek.terra.api.core.event.events.config;
+package com.dfsek.terra.api.event.events.config;
 
 import com.dfsek.terra.config.pack.ConfigPack;
 

common/src/main/java/com/dfsek/terra/api/event/events/world/TerraWorldLoadEvent.java

@@ -0,0 +1,31 @@
+package com.dfsek.terra.api.event.events.world;
+
+import com.dfsek.terra.api.event.events.PackEvent;
+import com.dfsek.terra.config.pack.ConfigPack;
+import com.dfsek.terra.config.pack.WorldConfig;
+import com.dfsek.terra.world.TerraWorld;
+
+/**
+ * Called upon initialization of a TerraWorld.
+ */
+public class TerraWorldLoadEvent implements PackEvent {
+    private final TerraWorld world;
+    private final ConfigPack pack;
+
+    public TerraWorldLoadEvent(TerraWorld world, ConfigPack pack) {
+        this.world = world;
+        this.pack = pack;
+    }
+
+    public TerraWorld getWorld() {
+        return world;
+    }
+
+    public ConfigPack getPack() {
+        return pack;
+    }
+
+    public WorldConfig getWorldConfig() {
+        return world.getConfig();
+    }
+}

common/src/main/java/com/dfsek/terra/api/event/events/world/generation/EntitySpawnEvent.java

@@ -0,0 +1,45 @@
+package com.dfsek.terra.api.event.events.world.generation;
+
+import com.dfsek.terra.api.event.events.PackEvent;
+import com.dfsek.terra.api.math.vector.Location;
+import com.dfsek.terra.api.platform.entity.Entity;
+import com.dfsek.terra.api.structures.structure.buffer.items.BufferedEntity;
+import com.dfsek.terra.config.pack.ConfigPack;
+
+/**
+ * Called when an entity is spawned via {@link BufferedEntity}.
+ */
+public class EntitySpawnEvent implements PackEvent {
+    private final ConfigPack pack;
+    private final Entity entity;
+    private final Location location;
+
+    public EntitySpawnEvent(ConfigPack pack, Entity entity, Location location) {
+        this.pack = pack;
+        this.entity = entity;
+        this.location = location;
+    }
+
+    @Override
+    public ConfigPack getPack() {
+        return pack;
+    }
+
+    /**
+     * Get the entity that triggered the event.
+     *
+     * @return The entity.
+     */
+    public Entity getEntity() {
+        return entity;
+    }
+
+    /**
+     * Get the location of the entity.
+     *
+     * @return Location of the entity.
+     */
+    public Location getLocation() {
+        return location;
+    }
+}

common/src/main/java/com/dfsek/terra/api/event/events/world/generation/LootPopulateEvent.java

@@ -0,0 +1,80 @@
+package com.dfsek.terra.api.event.events.world.generation;
+
+import com.dfsek.terra.api.event.events.AbstractCancellable;
+import com.dfsek.terra.api.event.events.Cancellable;
+import com.dfsek.terra.api.event.events.PackEvent;
+import com.dfsek.terra.api.platform.block.Block;
+import com.dfsek.terra.api.platform.block.state.Container;
+import com.dfsek.terra.api.structures.loot.LootTable;
+import com.dfsek.terra.api.structures.script.StructureScript;
+import com.dfsek.terra.api.structures.structure.buffer.items.BufferedLootApplication;
+import com.dfsek.terra.config.pack.ConfigPack;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * Called when loot is populated via {@link BufferedLootApplication}.
+ */
+public class LootPopulateEvent extends AbstractCancellable implements PackEvent, Cancellable {
+    private final Block block;
+    private final Container container;
+    private LootTable table;
+    private final ConfigPack pack;
+    private final StructureScript script;
+
+    public LootPopulateEvent(Block block, Container container, LootTable table, ConfigPack pack, StructureScript script) {
+        this.block = block;
+        this.container = container;
+        this.table = table;
+        this.pack = pack;
+        this.script = script;
+    }
+
+    @Override
+    public ConfigPack getPack() {
+        return pack;
+    }
+
+    /**
+     * Get the block containing the tile entity loot is applied to.
+     *
+     * @return Block at which loot is applied.
+     */
+    public Block getBlock() {
+        return block;
+    }
+
+    /**
+     * Get the {@link Container} representing the inventory.
+     *
+     * @return Inventory recieving loot.
+     */
+    public Container getContainer() {
+        return container;
+    }
+
+    /**
+     * Get the loot table to be populated.
+     * @return Loot table.
+     */
+    public LootTable getTable() {
+        return table;
+    }
+
+    /**
+     * Set the loot table to be populated.
+     *
+     * @param table New loot table.
+     */
+    public void setTable(@NotNull LootTable table) {
+        this.table = table;
+    }
+
+    /**
+     * Get the script used to generate the structure.
+     *
+     * @return Structure script.
+     */
+    public StructureScript getStructureScript() {
+        return script;
+    }
+}

common/src/main/java/com/dfsek/terra/api/injection/Injector.java

@@ -0,0 +1,78 @@
+package com.dfsek.terra.api.injection;
+
+import com.dfsek.terra.api.injection.annotations.Inject;
+import com.dfsek.terra.api.injection.exception.InjectionException;
+import com.dfsek.terra.api.util.ReflectionUtil;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Dynamic dependency injector.
+ * <p>
+ * Stores an object to inject, and injects it into objects passed to {@link #inject(Object)}.
+ *
+ * @param <T> Type of object to inject.
+ */
+public class Injector<T> {
+    private final T value;
+    private final Set<Class<? extends T>> targets = new HashSet<>();
+
+    /**
+     * Instantiate an Injector with a value to inject
+     *
+     * @param value Value to inject
+     */
+    public Injector(T value) {
+        this.value = value;
+    }
+
+    /**
+     * Add an explicit class as a target. Useful for applications where subclasses may cause issues with DI.
+     *
+     * @param target Target class type.
+     */
+    public void addExplicitTarget(Class<? extends T> target) {
+        targets.add(target);
+    }
+
+    /**
+     * Inject the stored object into an object.
+     * <p>
+     * Injects the stored object into any non-static, non-final fields
+     * annotated with {@link Inject},
+     * with type matching the stored object or any explicit targets
+     * ({@link #addExplicitTarget(Class)}.
+     *
+     * @param object Object to inject into
+     * @throws InjectionException If:
+     *                            <ul>
+     *                                <li>Matching field annotated with {@link Inject} is final</li>
+     *                                <li>Matching field annotated with {@link Inject} is static</li>
+     *                                <li>A reflective access exception occurs</li>
+     *                            </ul>
+     */
+    public void inject(Object object) throws InjectionException {
+        for(Field field : ReflectionUtil.getFields(object.getClass())) {
+            Inject inject = field.getAnnotation(Inject.class);
+            if(inject == null) continue;
+            if(value.getClass().equals(field.getType()) || targets.contains(field.getType())) {
+                int mod = field.getModifiers();
+                if(Modifier.isFinal(mod)) {
+                    throw new InjectionException("Attempted to inject final field: " + field);
+                }
+                if(Modifier.isStatic(mod)) {
+                    throw new InjectionException("Attempted to inject static field: " + field);
+                }
+                field.setAccessible(true);
+                try {
+                    field.set(object, value);
+                } catch(IllegalAccessException e) {
+                    throw new InjectionException("Failed to inject field: " + field, e);
+                }
+            }
+        }
+    }
+}

common/src/main/java/com/dfsek/terra/api/injection/annotations/Inject.java

@@ -0,0 +1,14 @@
+package com.dfsek.terra.api.injection.annotations;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Specifies that a field is a target for dependency injection.
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.FIELD)
+public @interface Inject {
+}

common/src/main/java/com/dfsek/terra/api/injection/exception/InjectionException.java

@@ -0,0 +1,18 @@
+package com.dfsek.terra.api.injection.exception;
+
+import com.dfsek.terra.api.injection.Injector;
+
+/**
+ * Thrown when dynamic dependency injection cannot be completed by an {@link Injector}.
+ */
+public class InjectionException extends Exception {
+    private static final long serialVersionUID = -6929631447064215387L;
+
+    public InjectionException(String message) {
+        super(message);
+    }
+
+    public InjectionException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

common/src/main/java/com/dfsek/terra/api/math/MathUtil.java

@@ -1,7 +1,7 @@
 package com.dfsek.terra.api.math;
 
 import com.dfsek.terra.api.util.FastRandom;
-import com.dfsek.terra.world.generation.math.Sampler;
+import com.dfsek.terra.world.generation.math.samplers.Sampler;
 import net.jafama.FastMath;
 
 import java.util.List;

common/src/main/java/com/dfsek/terra/api/math/ProbabilityCollection.java

@@ -1,96 +0,0 @@
-package com.dfsek.terra.api.math;
-
-import com.dfsek.terra.api.math.noise.NoiseSampler;
-
-import java.util.Collections;
-import java.util.HashSet;
-import java.util.Random;
-import java.util.Set;
-
-@SuppressWarnings("unchecked")
-public class ProbabilityCollection<E> {
-    private final Set<E> cont = new HashSet<>();
-    private Object[] array = new Object[0];
-    private int size;
-
-    public com.dfsek.terra.api.math.ProbabilityCollection<E> add(E item, int probability) {
-        if(!cont.contains(item)) size++;
-        cont.add(item);
-        int oldLength = array.length;
-        Object[] newArray = new Object[array.length + probability];
-        System.arraycopy(array, 0, newArray, 0, array.length); // Expand array.
-        array = newArray;
-        for(int i = oldLength; i < array.length; i++) array[i] = item;
-        return this;
-    }
-
-    public E get(Random r) {
-        if(array.length == 0) return null;
-        return (E) array[r.nextInt(array.length)];
-    }
-
-    public E get(NoiseSampler n, double x, double y, double z) {
-        if(array.length == 0) return null;
-        return (E) array[MathUtil.normalizeIndex(n.getNoise(x, y, z), array.length)];
-    }
-
-    public E get(NoiseSampler n, double x, double z) {
-        if(array.length == 0) return null;
-        return (E) array[MathUtil.normalizeIndex(n.getNoise(x, z), array.length)];
-    }
-
-    public int getTotalProbability() {
-        return array.length;
-    }
-
-    public int size() {
-        return size;
-    }
-
-    public Set<E> getContents() {
-        return new HashSet<>(cont);
-    }
-
-    public static final class Singleton<T> extends ProbabilityCollection<T> {
-        private final T single;
-
-        public Singleton(T single) {
-            this.single = single;
-        }
-
-        @Override
-        public ProbabilityCollection<T> add(T item, int probability) {
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public T get(Random r) {
-            return single;
-        }
-
-        @Override
-        public T get(NoiseSampler n, double x, double y, double z) {
-            return single;
-        }
-
-        @Override
-        public T get(NoiseSampler n, double x, double z) {
-            return single;
-        }
-
-        @Override
-        public int getTotalProbability() {
-            return 1;
-        }
-
-        @Override
-        public int size() {
-            return 1;
-        }
-
-        @Override
-        public Set<T> getContents() {
-            return Collections.singleton(single);
-        }
-    }
-}

common/src/main/java/com/dfsek/terra/api/math/Range.java

@@ -24,7 +24,7 @@ public class Range implements Iterable<Integer> {
         return max;
     }
 
-    public com.dfsek.terra.api.math.Range setMax(int max) {
+    public Range setMax(int max) {
         this.max = max;
         return this;
     }
@@ -33,7 +33,7 @@ public class Range implements Iterable<Integer> {
         return min;
     }
 
-    public com.dfsek.terra.api.math.Range setMin(int min) {
+    public Range setMin(int min) {
         this.min = min;
         return this;
     }
@@ -42,35 +42,35 @@ public class Range implements Iterable<Integer> {
         return max - min;
     }
 
-    public com.dfsek.terra.api.math.Range multiply(int mult) {
+    public Range multiply(int mult) {
         min *= mult;
         max *= mult;
         return this;
     }
 
-    public com.dfsek.terra.api.math.Range reflect(int pt) {
-        return new com.dfsek.terra.api.math.Range(2 * pt - this.getMax(), 2 * pt - this.getMin());
+    public Range reflect(int pt) {
+        return new Range(2 * pt - this.getMax(), 2 * pt - this.getMin());
     }
 
     public int get(Random r) {
         return r.nextInt((max - min) + 1) + min;
     }
 
-    public com.dfsek.terra.api.math.Range intersects(com.dfsek.terra.api.math.Range other) {
+    public Range intersects(com.dfsek.terra.api.math.Range other) {
         try {
-            return new com.dfsek.terra.api.math.Range(FastMath.max(this.getMin(), other.getMin()), FastMath.min(this.getMax(), other.getMax()));
+            return new Range(FastMath.max(this.getMin(), other.getMin()), FastMath.min(this.getMax(), other.getMax()));
         } catch(IllegalArgumentException e) {
             return null;
         }
     }
 
-    public com.dfsek.terra.api.math.Range add(int add) {
+    public Range add(int add) {
         this.min += add;
         this.max += add;
         return this;
     }
 
-    public com.dfsek.terra.api.math.Range sub(int sub) {
+    public Range sub(int sub) {
         this.min -= sub;
         this.max -= sub;
         return this;
@@ -89,7 +89,7 @@ public class Range implements Iterable<Integer> {
     @Override
     public boolean equals(Object obj) {
         if(!(obj instanceof com.dfsek.terra.api.math.Range)) return false;
-        com.dfsek.terra.api.math.Range other = (com.dfsek.terra.api.math.Range) obj;
+        Range other = (com.dfsek.terra.api.math.Range) obj;
         return other.getMin() == this.getMin() && other.getMax() == this.getMax();
     }
 
@@ -100,10 +100,10 @@ public class Range implements Iterable<Integer> {
     }
 
     private static class RangeIterator implements Iterator<Integer> {
-        private final com.dfsek.terra.api.math.Range m;
+        private final Range m;
         private Integer current;
 
-        public RangeIterator(com.dfsek.terra.api.math.Range m) {
+        public RangeIterator(Range m) {
             this.m = m;
             current = m.getMin();
         }

common/src/main/java/com/dfsek/terra/api/math/noise/samplers/ExpressionSampler.java

@@ -14,7 +14,7 @@ import com.dfsek.terra.config.loaders.config.function.FunctionTemplate;
 import java.util.Map;
 
 /**
- * Sampler implementation using Paralithic expression
+ * Sampler3D implementation using Paralithic expression
  */
 public class ExpressionSampler implements NoiseSampler {
     private final Expression expression;

common/src/main/java/com/dfsek/terra/api/math/noise/samplers/noise/ConstantSampler.java

@@ -1,7 +1,7 @@
 package com.dfsek.terra.api.math.noise.samplers.noise;
 
 /**
- * Sampler implementation that returns a constant.
+ * Sampler3D implementation that returns a constant.
  */
 public class ConstantSampler extends NoiseFunction {
     private final double constant;

common/src/main/java/com/dfsek/terra/api/math/noise/samplers/noise/GaborNoiseSampler.java

@@ -0,0 +1,105 @@
+package com.dfsek.terra.api.math.noise.samplers.noise;
+
+import com.dfsek.terra.api.math.noise.samplers.noise.random.WhiteNoiseSampler;
+import net.jafama.FastMath;
+
+public class GaborNoiseSampler extends NoiseFunction {
+    private final WhiteNoiseSampler rand;
+    private double k = 1.0;
+    private double a = 0.1;
+    private double f0 = 0.625;
+    private double kernelRadius = (FastMath.sqrt(-FastMath.log(0.05) / Math.PI) / a);
+    private double omega0 = Math.PI * 0.25;
+    private boolean isotropic = true;
+    private double impulsesPerKernel = 64d;
+    private double impulseDensity = (impulsesPerKernel / (Math.PI * kernelRadius * kernelRadius));
+
+    private double impulsesPerCell = impulseDensity * kernelRadius * kernelRadius;
+    private double g = FastMath.exp(-impulsesPerCell);
+
+
+    public GaborNoiseSampler(int seed) {
+        super(seed);
+        rand = new WhiteNoiseSampler(seed);
+    }
+
+    public void setIsotropic(boolean isotropic) {
+        this.isotropic = isotropic;
+    }
+
+    public void setImpulsesPerKernel(double impulsesPerKernel) {
+        this.impulsesPerKernel = impulsesPerKernel;
+        recalculateRadiusAndDensity();
+    }
+
+    public void setA(double a) {
+        this.a = a;
+        recalculateRadiusAndDensity();
+    }
+
+    public void setFrequency0(double f0) {
+        this.f0 = f0;
+    }
+
+    public void setRotation(double omega0) {
+        this.omega0 = Math.PI * omega0;
+    }
+
+    public void setDeviation(double k) {
+        this.k = k;
+    }
+
+    private void recalculateRadiusAndDensity() {
+        kernelRadius = (FastMath.sqrt(-FastMath.log(0.05) / Math.PI) / this.a);
+        impulseDensity = (impulsesPerKernel / (Math.PI * kernelRadius * kernelRadius));
+        impulsesPerCell = impulseDensity * kernelRadius * kernelRadius;
+        g = FastMath.exp(-impulsesPerCell);
+    }
+
+    @Override
+    public double getNoiseRaw(int seed, double x, double z) {
+        return gaborNoise(seed, x, z);
+    }
+
+    @Override
+    public double getNoiseRaw(int seed, double x, double y, double z) {
+        return gaborNoise(seed, x, z);
+    }
+
+    private double gaborNoise(int seed, double x, double y) {
+        x /= kernelRadius;
+        y /= kernelRadius;
+        int xi = fastFloor(x);
+        int yi = fastFloor(y);
+        double xf = x - xi;
+        double yf = y - yi;
+        double noise = 0;
+        for(int dx = -1; dx <= 1; dx++) {
+            for(int dz = -1; dz <= 1; dz++) {
+                noise += calculateCell(seed, xi + dx, yi + dz, xf - dx, yf - dz);
+            }
+        }
+        return noise;
+    }
+
+    private double calculateCell(int seed, int xi, int yi, double x, double y) {
+        long mashedSeed = murmur64(31L * xi + yi) + seed;
+
+        double gaussianSource = (rand.getNoiseRaw(mashedSeed++) + 1) / 2;
+        int impulses = 0;
+        while(gaussianSource > g) {
+            impulses++;
+            gaussianSource *= (rand.getNoiseRaw(mashedSeed++) + 1) / 2;
+        }
+
+        double noise = 0;
+        for(int i = 0; i < impulses; i++) {
+            noise += rand.getNoiseRaw(mashedSeed++) * gabor(isotropic ? (rand.getNoiseRaw(mashedSeed++) + 1) * Math.PI : omega0, x * kernelRadius, y * kernelRadius);
+        }
+        return noise;
+    }
+
+    private double gabor(double omega_0, double x, double y) {
+        return k * (FastMath.exp(-Math.PI * (a * a) * (x * x + y * y)) * fastCos(2 * Math.PI * f0 * (x * fastCos(omega_0) + y * fastSin(omega_0))));
+    }
+}

common/src/main/java/com/dfsek/terra/api/math/noise/samplers/noise/NoiseFunction.java

@@ -22,6 +22,8 @@ public abstract class NoiseFunction implements NoiseSampler {
         return f >= 0 ? (int) f : (int) f - 1;
     }
 
+    static final int precision = 100;
+
     protected static int hash(int seed, int xPrimed, int yPrimed, int zPrimed) {
         int hash = seed ^ xPrimed ^ yPrimed ^ zPrimed;
 
@@ -36,6 +38,8 @@ public abstract class NoiseFunction implements NoiseSampler {
         return hash;
     }
 
+    static final int modulus = 360 * precision;
+
     protected static int fastRound(double f) {
         return f >= 0 ? (int) (f + 0.5f) : (int) (f - 0.5);
     }
@@ -73,6 +77,48 @@ public abstract class NoiseFunction implements NoiseSampler {
         return FastMath.sqrt(f);
     }
 
+    static final double[] sin = new double[360 * 100]; // lookup table
+
+    static {
+        for(int i = 0; i < sin.length; i++) {
+            sin[i] = (float) Math.sin((double) (i) / (precision));
+        }
+    }
+
+    protected static int fastCeil(double f) {
+        int i = (int) f;
+        if(i < f) i++;
+        return i;
+    }
+
+    /**
+     * Murmur64 hashing function
+     *
+     * @param h Input value
+     * @return Hashed value
+     */
+    protected static long murmur64(long h) {
+        h ^= h >>> 33;
+        h *= 0xff51afd7ed558ccdL;
+        h ^= h >>> 33;
+        h *= 0xc4ceb9fe1a85ec53L;
+        h ^= h >>> 33;
+        return h;
+    }
+
+    private static double sinLookup(int a) {
+        return a >= 0 ? sin[a % (modulus)] : -sin[-a % (modulus)];
+    }
+
+    protected static double fastSin(double a) {
+        return sinLookup((int) (a * precision + 0.5f));
+    }
+
+    protected static double fastCos(double a) {
+        return sinLookup((int) ((a + Math.PI / 2) * precision + 0.5f));
+    }
+
+
     public void setSeed(int seed) {
         this.seed = seed;
     }

common/src/main/java/com/dfsek/terra/api/math/noise/samplers/noise/random/WhiteNoiseSampler.java

@@ -12,38 +12,41 @@ public class WhiteNoiseSampler extends NoiseFunction {
         super(seed);
     }
 
+    public double getNoiseRaw(long seed) {
+        return (Double.longBitsToDouble((murmur64(seed) & 0x000fffffffffffffL) | POSITIVE_POW1) - 1.5) * 2;
+    }
+
     @Override
     public double getNoiseRaw(int seed, double x, double y) {
-        long hashX = Double.doubleToRawLongBits(x) ^ seed;
-        long hashZ = Double.doubleToRawLongBits(y) ^ seed;
-        long hash = ((hashX ^ (hashX >>> 32)) + ((hashZ ^ (hashZ >>> 32)) << 32)) ^ seed;
-        long base = (murmur64(hash) & 0x000fffffffffffffL)
-                | POSITIVE_POW1; // Sign and exponent
-        return (Double.longBitsToDouble(base) - 1.5) * 2;
+        return (getNoiseUnmapped(seed, x, y) - 1.5) * 2;
     }
 
     @Override
     public double getNoiseRaw(int seed, double x, double y, double z) {
+        return (getNoiseUnmapped(seed, x, y, z) - 1.5) * 2;
+    }
+
+    public double getNoiseUnmapped(int seed, double x, double y, double z) {
+        long base = ((randomBits(seed, x, y, z)) & 0x000fffffffffffffL) | POSITIVE_POW1; // Sign and exponent
+        return Double.longBitsToDouble(base);
+    }
+
+    public double getNoiseUnmapped(int seed, double x, double y) {
+        long base = (randomBits(seed, x, y) & 0x000fffffffffffffL) | POSITIVE_POW1; // Sign and exponent
+        return Double.longBitsToDouble(base);
+    }
+
+    public long randomBits(int seed, double x, double y, double z) {
         long hashX = Double.doubleToRawLongBits(x) ^ seed;
         long hashZ = Double.doubleToRawLongBits(y) ^ seed;
         long hash = (((hashX ^ (hashX >>> 32)) + ((hashZ ^ (hashZ >>> 32)) << 32)) ^ seed) + Double.doubleToRawLongBits(z);
-        long base = ((murmur64(hash)) & 0x000fffffffffffffL)
-                | POSITIVE_POW1; // Sign and exponent
-        return (Double.longBitsToDouble(base) - 1.5) * 2;
+        return murmur64(hash);
     }
 
-    /**
-     * Murmur64 hashing function
-     *
-     * @param h Input value
-     * @return Hashed value
-     */
-    private static long murmur64(long h) {
-        h ^= h >>> 33;
-        h *= 0xff51afd7ed558ccdL;
-        h ^= h >>> 33;
-        h *= 0xc4ceb9fe1a85ec53L;
-        h ^= h >>> 33;
-        return h;
+    public long randomBits(int seed, double x, double y) {
+        long hashX = Double.doubleToRawLongBits(x) ^ seed;
+        long hashZ = Double.doubleToRawLongBits(y) ^ seed;
+        long hash = ((hashX ^ (hashX >>> 32)) + ((hashZ ^ (hashZ >>> 32)) << 32)) ^ seed;
+        return murmur64(hash);
     }
 }

common/src/main/java/com/dfsek/terra/api/math/noise/samplers/noise/simplex/SimplexSampler.java

@@ -0,0 +1,243 @@
+package com.dfsek.terra.api.math.noise.samplers.noise.simplex;
+
+public class SimplexSampler extends SimplexStyleSampler {
+    private static final Double2[] GRAD_2D = {
+            new Double2(-1, -1), new Double2(1, -1), new Double2(-1, 1), new Double2(1, 1),
+            new Double2(0, -1), new Double2(-1, 0), new Double2(0, 1), new Double2(1, 0),
+    };
+    private static final Double3[] GRAD_3D = {
+            new Double3(1, 1, 0), new Double3(-1, 1, 0), new Double3(1, -1, 0), new Double3(-1, -1, 0),
+            new Double3(1, 0, 1), new Double3(-1, 0, 1), new Double3(1, 0, -1), new Double3(-1, 0, -1),
+            new Double3(0, 1, 1), new Double3(0, -1, 1), new Double3(0, 1, -1), new Double3(0, -1, -1),
+            new Double3(1, 1, 0), new Double3(0, -1, 1), new Double3(-1, 1, 0), new Double3(0, -1, -1),
+    };
+
+    private static final double F2 = 1.0 / 2.0;
+    private static final double F3 = (1.0 / 3.0);
+    private static final double G2 = 1.0 / 4.0;
+    private static final double G3 = (1.0 / 6.0);
+    private static final double G33 = G3 * 3 - 1;
+
+    private static final int X_PRIME = 1619;
+    private static final int Y_PRIME = 31337;
+    private static final int Z_PRIME = 6971;
+
+
+    public SimplexSampler(int seed) {
+        super(seed);
+    }
+
+    private static double gradCoord3D(int seed, int x, int y, int z, double xd, double yd, double zd) {
+        int hash = seed;
+        hash ^= X_PRIME * x;
+        hash ^= Y_PRIME * y;
+        hash ^= Z_PRIME * z;
+
+        hash = hash * hash * hash * 60493;
+        hash = (hash >> 13) ^ hash;
+
+        Double3 g = GRAD_3D[hash & 15];
+
+        return xd * g.x + yd * g.y + zd * g.z;
+    }
+
+    private static double gradCoord2D(int seed, int x, int y, double xd, double yd) {
+        int hash = seed;
+        hash ^= X_PRIME * x;
+        hash ^= Y_PRIME * y;
+
+        hash = hash * hash * hash * 60493;
+        hash = (hash >> 13) ^ hash;
+
+        Double2 g = GRAD_2D[hash & 7];
+
+        return xd * g.x + yd * g.y;
+    }
+
+    @Override
+    public double getNoiseRaw(int seed, double x, double y) {
+        double t = (x + y) * F2;
+        int i = fastFloor(x + t);
+        int j = fastFloor(y + t);
+
+        t = (i + j) * G2;
+        double X0 = i - t;
+        double Y0 = j - t;
+
+        double x0 = x - X0;
+        double y0 = y - Y0;
+
+        int i1, j1;
+        if(x0 > y0) {
+            i1 = 1;
+            j1 = 0;
+        } else {
+            i1 = 0;
+            j1 = 1;
+        }
+
+        double x1 = x0 - i1 + G2;
+        double y1 = y0 - j1 + G2;
+        double x2 = x0 - 1 + F2;
+        double y2 = y0 - 1 + F2;
+
+        double n0, n1, n2;
+
+        t = 0.5 - x0 * x0 - y0 * y0;
+        if(t < 0) {
+            n0 = 0;
+        } else {
+            t *= t;
+            n0 = t * t * gradCoord2D(seed, i, j, x0, y0);
+        }
+
+        t = 0.5 - x1 * x1 - y1 * y1;
+        if(t < 0) {
+            n1 = 0;
+        } else {
+            t *= t;
+            n1 = t * t * gradCoord2D(seed, i + i1, j + j1, x1, y1);
+        }
+
+        t = 0.5 - x2 * x2 - y2 * y2;
+        if(t < 0) {
+            n2 = 0;
+        } else {
+            t *= t;
+            n2 = t * t * gradCoord2D(seed, i + 1, j + 1, x2, y2);
+        }
+
+        return 50 * (n0 + n1 + n2);
+    }
+
+    @Override
+    public double getNoiseRaw(int seed, double x, double y, double z) {
+        double t = (x + y + z) * F3;
+        int i = fastFloor(x + t);
+        int j = fastFloor(y + t);
+        int k = fastFloor(z + t);
+
+        t = (i + j + k) * G3;
+        double x0 = x - (i - t);
+        double y0 = y - (j - t);
+        double z0 = z - (k - t);
+
+        int i1, j1, k1;
+        int i2, j2, k2;
+
+        if(x0 >= y0) {
+            if(y0 >= z0) {
+                i1 = 1;
+                j1 = 0;
+                k1 = 0;
+                i2 = 1;
+                j2 = 1;
+                k2 = 0;
+            } else if(x0 >= z0) {
+                i1 = 1;
+                j1 = 0;
+                k1 = 0;
+                i2 = 1;
+                j2 = 0;
+                k2 = 1;
+            } else // x0 < z0
+            {
+                i1 = 0;
+                j1 = 0;
+                k1 = 1;
+                i2 = 1;
+                j2 = 0;
+                k2 = 1;
+            }
+        } else // x0 < y0
+        {
+            if(y0 < z0) {
+                i1 = 0;
+                j1 = 0;
+                k1 = 1;
+                i2 = 0;
+                j2 = 1;
+                k2 = 1;
+            } else if(x0 < z0) {
+                i1 = 0;
+                j1 = 1;
+                k1 = 0;
+                i2 = 0;
+                j2 = 1;
+                k2 = 1;
+            } else // x0 >= z0
+            {
+                i1 = 0;
+                j1 = 1;
+                k1 = 0;
+                i2 = 1;
+                j2 = 1;
+                k2 = 0;
+            }
+        }
+
+        double x1 = x0 - i1 + G3;
+        double y1 = y0 - j1 + G3;
+        double z1 = z0 - k1 + G3;
+        double x2 = x0 - i2 + F3;
+        double y2 = y0 - j2 + F3;
+        double z2 = z0 - k2 + F3;
+        double x3 = x0 + G33;
+        double y3 = y0 + G33;
+        double z3 = z0 + G33;
+
+        double n0, n1, n2, n3;
+
+        t = 0.6 - x0 * x0 - y0 * y0 - z0 * z0;
+        if(t < 0) n0 = 0;
+        else {
+            t *= t;
+            n0 = t * t * gradCoord3D(seed, i, j, k, x0, y0, z0);
+        }
+
+        t = 0.6 - x1 * x1 - y1 * y1 - z1 * z1;
+        if(t < 0) {
+            n1 = 0;
+        } else {
+            t *= t;
+            n1 = t * t * gradCoord3D(seed, i + i1, j + j1, k + k1, x1, y1, z1);
+        }
+
+        t = 0.6 - x2 * x2 - y2 * y2 - z2 * z2;
+        if(t < 0) {
+            n2 = 0;
+        } else {
+            t *= t;
+            n2 = t * t * gradCoord3D(seed, i + i2, j + j2, k + k2, x2, y2, z2);
+        }
+
+        t = 0.6 - x3 * x3 - y3 * y3 - z3 * z3;
+        if(t < 0) {
+            n3 = 0;
+        } else {
+            t *= t;
+            n3 = t * t * gradCoord3D(seed, i + 1, j + 1, k + 1, x3, y3, z3);
+        }
+
+        return 32 * (n0 + n1 + n2 + n3);
+    }
+
+    private static class Double2 {
+        public final double x, y;
+
+        public Double2(double x, double y) {
+            this.x = x;
+            this.y = y;
+        }
+    }
+
+    private static class Double3 {
+        public final double x, y, z;
+
+        public Double3(double x, double y, double z) {
+            this.x = x;
+            this.y = y;
+            this.z = z;
+        }
+    }
+}

common/src/main/java/com/dfsek/terra/api/math/paralithic/noise/NoiseFunction2.java

@@ -1,7 +1,7 @@
 package com.dfsek.terra.api.math.paralithic.noise;
 
 import com.dfsek.terra.api.math.noise.NoiseSampler;
-import com.dfsek.terra.util.hash.HashMapDoubleDouble;
+import com.dfsek.terra.api.util.hash.HashMapDoubleDouble;
 
 
 

common/src/main/java/com/dfsek/terra/api/math/vector/Location.java

@@ -170,4 +170,9 @@ public class Location implements Cloneable {
     public String toString() {
         return "[" + world + ": (" + getX() + ", " + getY() + ", " + getZ() + ")]";
     }
+
+    public Location multiply(double v) {
+        vector.multiply(v);
+        return this;
+    }
 }

common/src/main/java/com/dfsek/terra/api/platform/Player.java

@@ -1,6 +0,0 @@
-package com.dfsek.terra.api.platform;
-
-import com.dfsek.terra.api.platform.entity.Entity;
-
-public interface Player extends Entity {
-}

common/src/main/java/com/dfsek/terra/api/platform/block/Block.java

@@ -11,7 +11,9 @@ public interface Block extends Handle {
 
     BlockState getState();
 
-    Block getRelative(BlockFace face);
+    default Block getRelative(BlockFace face) {
+        return getRelative(face, 1);
+    }
 
     Block getRelative(BlockFace face, int len);
 
@@ -19,7 +21,9 @@ public interface Block extends Handle {
 
     Location getLocation();
 
-    MaterialData getType();
+    default BlockType getType() {
+        return getBlockData().getBlockType();
+    }
 
     int getX();
 

common/src/main/java/com/dfsek/terra/api/platform/block/BlockData.java

@@ -3,11 +3,16 @@ package com.dfsek.terra.api.platform.block;
 import com.dfsek.terra.api.platform.Handle;
 
 public interface BlockData extends Cloneable, Handle {
-    MaterialData getMaterial();
 
-    boolean matches(MaterialData materialData);
+    BlockType getBlockType();
+
+    boolean matches(BlockData other);
 
     BlockData clone();
 
     String getAsString();
+
+    boolean isAir();
+
+    boolean isStructureVoid();
 }

common/src/main/java/com/dfsek/terra/api/platform/block/BlockType.java

@@ -0,0 +1,11 @@
+package com.dfsek.terra.api.platform.block;
+
+import com.dfsek.terra.api.platform.Handle;
+
+public interface BlockType extends Handle {
+    BlockData getDefaultData();
+
+    boolean isSolid();
+
+    boolean isWater();
+}

common/src/main/java/com/dfsek/terra/api/platform/block/MaterialData.java

@@ -1,17 +0,0 @@
-package com.dfsek.terra.api.platform.block;
-
-import com.dfsek.terra.api.platform.Handle;
-
-public interface MaterialData extends Handle {
-    boolean matches(MaterialData other);
-
-    boolean matches(BlockData other);
-
-    boolean isSolid();
-
-    boolean isAir();
-
-    double getMaxDurability();
-
-    BlockData createBlockData();
-}

common/src/main/java/com/dfsek/terra/api/platform/entity/Entity.java

@@ -3,7 +3,12 @@ package com.dfsek.terra.api.platform.entity;
 import com.dfsek.terra.api.math.vector.Location;
 import com.dfsek.terra.api.platform.CommandSender;
 import com.dfsek.terra.api.platform.Handle;
+import com.dfsek.terra.api.platform.world.World;
 
 public interface Entity extends Handle, CommandSender {
     Location getLocation();
+
+    void setLocation(Location location);
+
+    World getWorld();
 }

common/src/main/java/com/dfsek/terra/api/platform/entity/Player.java

@@ -0,0 +1,4 @@
+package com.dfsek.terra.api.platform.entity;
+
+public interface Player extends Entity {
+}

common/src/main/java/com/dfsek/terra/api/platform/handle/ItemHandle.java

@@ -1,13 +1,13 @@
 package com.dfsek.terra.api.platform.handle;
 
-import com.dfsek.terra.api.platform.block.MaterialData;
-import com.dfsek.terra.api.platform.inventory.ItemStack;
+import com.dfsek.terra.api.platform.inventory.Item;
 import com.dfsek.terra.api.platform.inventory.item.Enchantment;
 
 import java.util.Set;
 
 public interface ItemHandle {
-    ItemStack newItemStack(MaterialData material, int amount);
+
+    Item createItem(String data);
 
     Enchantment getEnchantment(String id);
 

common/src/main/java/com/dfsek/terra/api/platform/handle/WorldHandle.java

@@ -1,23 +1,26 @@
 package com.dfsek.terra.api.platform.handle;
 
-import com.dfsek.terra.api.platform.block.Block;
+import com.dfsek.terra.api.math.vector.Location;
 import com.dfsek.terra.api.platform.block.BlockData;
-import com.dfsek.terra.api.platform.block.MaterialData;
 import com.dfsek.terra.api.platform.entity.EntityType;
+import com.dfsek.terra.api.platform.entity.Player;
+import com.dfsek.terra.api.util.generic.pair.Pair;
 
 /**
  * Interface to be implemented for world manipulation.
  */
 public interface WorldHandle {
-    void setBlockData(Block block, BlockData data, boolean physics);
-
-    BlockData getBlockData(Block block);
-
-    MaterialData getType(Block block);
-
     BlockData createBlockData(String data);
 
-    MaterialData createMaterialData(String data);
-
     EntityType getEntity(String id);
+
+    /**
+     * Get the locations selected by a player. (Usually via WorldEdit)
+     *
+     * @param player Player to get locations for
+     * @return Pair of locations.
+     */
+    default Pair<Location, Location> getSelectedLocation(Player player) {
+        throw new UnsupportedOperationException("Cannot get selection on this platform.");
+    }
 }

common/src/main/java/com/dfsek/terra/api/platform/inventory/Item.java

@@ -0,0 +1,12 @@
+package com.dfsek.terra.api.platform.inventory;
+
+import com.dfsek.terra.api.platform.Handle;
+
+/**
+ * An inventory item.
+ */
+public interface Item extends Handle {
+    ItemStack newItemStack(int amount);
+
+    double getMaxDurability();
+}

common/src/main/java/com/dfsek/terra/api/platform/inventory/ItemStack.java

@@ -1,19 +1,21 @@
 package com.dfsek.terra.api.platform.inventory;
 
 import com.dfsek.terra.api.platform.Handle;
-import com.dfsek.terra.api.platform.block.MaterialData;
+import com.dfsek.terra.api.platform.inventory.item.Damageable;
 import com.dfsek.terra.api.platform.inventory.item.ItemMeta;
 
-public interface ItemStack extends Handle, Cloneable {
+public interface ItemStack extends Handle {
     int getAmount();
 
     void setAmount(int i);
 
-    MaterialData getType();
-
-    ItemStack clone();
+    Item getType();
 
     ItemMeta getItemMeta();
 
     void setItemMeta(ItemMeta meta);
+
+    default boolean isDamageable() {
+        return getItemMeta() instanceof Damageable;
+    }
 }

common/src/main/java/com/dfsek/terra/api/platform/package-info.java

@@ -1,4 +1,6 @@
 /**
  * API for platform implementations. Mostly interfaces to be implemented by platform delegates.
+ * <p>
+ * Interfaces in this package generally should <b>not</b> be implemented by addons.
  */
 package com.dfsek.terra.api.platform;

common/src/main/java/com/dfsek/terra/api/platform/world/Tree.java

@@ -0,0 +1,13 @@
+package com.dfsek.terra.api.platform.world;
+
+
+import com.dfsek.terra.api.math.vector.Location;
+import com.dfsek.terra.api.util.collections.MaterialSet;
+
+import java.util.Random;
+
+public interface Tree {
+    boolean plant(Location l, Random r);
+
+    MaterialSet getSpawnable();
+}

common/src/main/java/com/dfsek/terra/api/platform/world/World.java

@@ -6,6 +6,8 @@ import com.dfsek.terra.api.platform.block.Block;
 import com.dfsek.terra.api.platform.entity.Entity;
 import com.dfsek.terra.api.platform.entity.EntityType;
 import com.dfsek.terra.api.platform.world.generator.ChunkGenerator;
+import com.dfsek.terra.api.platform.world.generator.GeneratorWrapper;
+import com.dfsek.terra.api.world.generation.TerraChunkGenerator;
 
 import java.io.File;
 import java.util.UUID;
@@ -17,19 +19,27 @@ public interface World extends Handle {
 
     ChunkGenerator getGenerator();
 
-    String getName();
-
-    UUID getUID();
-
-    boolean isChunkGenerated(int x, int z);
-
     Chunk getChunkAt(int x, int z);
 
-    File getWorldFolder();
+    default Chunk getChunkAt(Location location) {
+        return getChunkAt(location.getBlockX() >> 4, location.getBlockZ() >> 4);
+    }
 
     Block getBlockAt(int x, int y, int z);
 
-    Block getBlockAt(Location l);
+    default Block getBlockAt(Location l) {
+        return getBlockAt(l.getBlockX(), l.getBlockY(), l.getBlockZ());
+    }
 
     Entity spawnEntity(Location location, EntityType entityType);
+
+    int getMinHeight();
+
+    default boolean isTerraWorld() {
+        return getGenerator().getHandle() instanceof GeneratorWrapper;
+    }
+
+    default TerraChunkGenerator getTerraGenerator() {
+        return ((GeneratorWrapper) getGenerator().getHandle()).getHandle();
+    }
 }

common/src/main/java/com/dfsek/terra/api/platform/world/generator/ChunkData.java

@@ -0,0 +1,14 @@
+package com.dfsek.terra.api.platform.world.generator;
+
+import com.dfsek.terra.api.platform.world.ChunkAccess;
+
+public interface ChunkData extends ChunkAccess {
+    /**
+     * Get the maximum height for the chunk.
+     * <p>
+     * Setting blocks at or above this height will do nothing.
+     *
+     * @return the maximum height
+     */
+    int getMaxHeight();
+}

common/src/main/java/com/dfsek/terra/api/platform/world/generator/ChunkGenerator.java

@@ -1,43 +1,7 @@
 package com.dfsek.terra.api.platform.world.generator;
 
 import com.dfsek.terra.api.platform.Handle;
-import com.dfsek.terra.api.platform.world.BiomeGrid;
-import com.dfsek.terra.api.platform.world.ChunkAccess;
-import com.dfsek.terra.api.platform.world.World;
-import com.dfsek.terra.api.world.generation.TerraChunkGenerator;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-
-import java.util.List;
-import java.util.Random;
 
 public interface ChunkGenerator extends Handle {
-    boolean isParallelCapable();
 
-    boolean shouldGenerateCaves();
-
-    boolean shouldGenerateDecorations();
-
-    boolean shouldGenerateMobs();
-
-    boolean shouldGenerateStructures();
-
-    ChunkData generateChunkData(@NotNull World world, @NotNull Random random, int x, int z, @NotNull BiomeGrid biome);
-
-
-    List<BlockPopulator> getDefaultPopulators(World world);
-
-    @Nullable
-    TerraChunkGenerator getTerraGenerator();
-
-    interface ChunkData extends ChunkAccess {
-        /**
-         * Get the maximum height for the chunk.
-         * <p>
-         * Setting blocks at or above this height will do nothing.
-         *
-         * @return the maximum height
-         */
-        int getMaxHeight();
-    }
 }

common/src/main/java/com/dfsek/terra/api/platform/world/generator/GeneratorWrapper.java

@@ -1,6 +1,9 @@
 package com.dfsek.terra.api.platform.world.generator;
 
 import com.dfsek.terra.api.platform.Handle;
+import com.dfsek.terra.api.world.generation.TerraChunkGenerator;
 
 public interface GeneratorWrapper extends Handle {
+    @Override
+    TerraChunkGenerator getHandle();
 }

common/src/main/java/com/dfsek/terra/api/registry/CheckedRegistry.java

@@ -0,0 +1,84 @@
+package com.dfsek.terra.api.registry;
+
+import com.dfsek.tectonic.exception.LoadException;
+import com.dfsek.tectonic.loading.ConfigLoader;
+import com.dfsek.terra.registry.OpenRegistry;
+import com.dfsek.terra.registry.exception.DuplicateEntryException;
+
+import java.lang.reflect.Type;
+import java.util.Set;
+import java.util.function.BiConsumer;
+import java.util.function.Consumer;
+
+/**
+ * Wrapper for a registry that ensures checked additions.
+ *
+ * @param <T> Type in registry
+ */
+public class CheckedRegistry<T> implements Registry<T> {
+    private final OpenRegistry<T> registry;
+
+    public CheckedRegistry(OpenRegistry<T> registry) {
+        this.registry = registry;
+    }
+
+    /**
+     * Add a value to this registry, checking whether it is present first.
+     *
+     * @param identifier Identifier to assign value.
+     * @param value      Value to add.
+     * @throws DuplicateEntryException If an entry with the same identifier is already present.
+     */
+    public void add(String identifier, T value) throws DuplicateEntryException {
+        registry.addChecked(identifier, value);
+    }
+
+    /**
+     * Add a value to the registry, without checking presence beforehand.
+     * <p>
+     * Use of this method is generally discouraged, as it is bad practice to overwrite registry values.
+     *
+     * @param identifier Identifier to assign value.
+     * @param value      Value to add.
+     * @deprecated Use of {@link #add(String, Object)} is encouraged.
+     */
+    @Deprecated
+    public void addUnchecked(String identifier, T value) {
+        registry.add(identifier, value);
+    }
+
+    @Override
+    public T get(String identifier) {
+        return registry.get(identifier);
+    }
+
+    @Override
+    public boolean contains(String identifier) {
+        return registry.contains(identifier);
+    }
+
+    @Override
+    public void forEach(Consumer<T> consumer) {
+        registry.forEach(consumer);
+    }
+
+    @Override
+    public void forEach(BiConsumer<String, T> consumer) {
+        registry.forEach(consumer);
+    }
+
+    @Override
+    public Set<T> entries() {
+        return registry.entries();
+    }
+
+    @Override
+    public Set<String> keys() {
+        return registry.keys();
+    }
+
+    @Override
+    public T load(Type t, Object c, ConfigLoader loader) throws LoadException {
+        return registry.load(t, c, loader);
+    }
+}

common/src/main/java/com/dfsek/terra/api/registry/LockedRegistry.java

@@ -0,0 +1,57 @@
+package com.dfsek.terra.api.registry;
+
+import com.dfsek.tectonic.exception.LoadException;
+import com.dfsek.tectonic.loading.ConfigLoader;
+
+import java.lang.reflect.Type;
+import java.util.Set;
+import java.util.function.BiConsumer;
+import java.util.function.Consumer;
+
+/**
+ * Wrapper for a registry that forbids all write access.
+ *
+ * @param <T> Type in registry
+ */
+public class LockedRegistry<T> implements Registry<T> {
+    private final Registry<T> registry;
+
+    public LockedRegistry(Registry<T> registry) {
+        this.registry = registry;
+    }
+
+    @Override
+    public T get(String identifier) {
+        return registry.get(identifier);
+    }
+
+    @Override
+    public boolean contains(String identifier) {
+        return registry.contains(identifier);
+    }
+
+    @Override
+    public void forEach(Consumer<T> consumer) {
+        registry.forEach(consumer);
+    }
+
+    @Override
+    public void forEach(BiConsumer<String, T> consumer) {
+        registry.forEach(consumer);
+    }
+
+    @Override
+    public Set<T> entries() {
+        return registry.entries();
+    }
+
+    @Override
+    public Set<String> keys() {
+        return registry.keys();
+    }
+
+    @Override
+    public T load(Type t, Object c, ConfigLoader loader) throws LoadException {
+        return registry.load(t, c, loader);
+    }
+}