simplified filters and enhanced error reporting

src/main/java/amidst/mojangapi/file/json/filter/WorldFilterJson_Biome.java

@@ -1,10 +1,13 @@
 package amidst.mojangapi.file.json.filter;
 
 import java.util.Collections;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 
 import amidst.documentation.GsonConstructor;
 import amidst.documentation.Immutable;
+import amidst.mojangapi.world.biome.Biome;
 import amidst.mojangapi.world.filter.WorldFilter_Biome;
 
 @Immutable
@@ -19,10 +22,24 @@ public class WorldFilterJson_Biome {
 	public void validate(List<String> notifications) {
 		if (biomes.isEmpty()) {
 			notifications.add("No biomes for filter");
+		} else {
+			for (String name : biomes) {
+				if (Biome.exists(name)) {
+					notifications.add("invalid biome name: '" + name + "'");
+				}
+			}
 		}
 	}
 
 	public WorldFilter_Biome createBiomeFilter() {
-		return new WorldFilter_Biome(distance, biomes);
+		return new WorldFilter_Biome(distance, createValidBiomeIndexes());
+	}
+
+	private Set<Short> createValidBiomeIndexes() {
+		Set<Short> result = new HashSet<>();
+		for (String name : biomes) {
+			result.add((short) Biome.getByName(name).getIndex());
+		}
+		return result;
 	}
 }

src/main/java/amidst/mojangapi/file/json/filter/WorldFilterJson_Structure.java

@@ -5,6 +5,7 @@ import java.util.List;
 import amidst.documentation.GsonConstructor;
 import amidst.documentation.Immutable;
 import amidst.mojangapi.world.filter.WorldFilter_Structure;
+import amidst.mojangapi.world.icon.type.DefaultWorldIconTypes;
 
 @Immutable
 public class WorldFilterJson_Structure {
@@ -17,10 +18,15 @@ public class WorldFilterJson_Structure {
 	}
 
 	public void validate(List<String> notifications) {
-		// noop
+		if (!DefaultWorldIconTypes.exists(structure)) {
+			notifications.add("invalid structure: '" + structure + "'");
+		}
+		if (minimum <= 0) {
+			notifications.add("invalid minimum: " + minimum);
+		}
 	}
 
 	public WorldFilter_Structure createStructureFilter() {
-		return new WorldFilter_Structure(distance, structure, minimum);
+		return new WorldFilter_Structure(distance, DefaultWorldIconTypes.getByName(structure), minimum);
 	}
 }

src/main/java/amidst/mojangapi/world/filter/WorldFilter_Biome.java

@@ -1,66 +1,31 @@
 package amidst.mojangapi.world.filter;
 
-import java.util.ArrayList;
-import java.util.List;
+import java.util.Set;
 
+import amidst.documentation.NotThreadSafe;
 import amidst.mojangapi.world.World;
-import amidst.mojangapi.world.biome.Biome;
 
+@NotThreadSafe
 public class WorldFilter_Biome extends WorldFilter {
-	private short[][] evaluatedRegion = null;
-	private final List<Biome> biomes;
+	private final Set<Short> validBiomeIndexes;
+	private short[][] region;
 
-	public WorldFilter_Biome(long worldFilterSize, List<String> biomeNames) {
+	public WorldFilter_Biome(long worldFilterSize, Set<Short> validBiomeIndexes) {
 		super(worldFilterSize);
-
-		List<Biome> biomes = new ArrayList<>();
-		for (String name : biomeNames) {
-			Biome biome = Biome.getByName(name);
-			if (biome == null) {
-				List<String> possibleNames = new ArrayList<String>();
-				for (Biome possibleBiome : Biome.allBiomes()) {
-					possibleNames.add(possibleBiome.getName());
-				}
-				throw new IllegalArgumentException("Biome name '" + name + "' should be one of: "
-						+ String.join(", ", possibleNames));
-			}
-			biomes.add(biome);
-		}
-
-		this.biomes = biomes;
+		this.validBiomeIndexes = validBiomeIndexes;
+		this.region = new short[(int) this.quarterFilterSize * 2][(int) this.quarterFilterSize * 2];
 	}
 
 	@Override
 	public boolean isValid(World world) {
-		return isValid(world, getUpdatedRegion(world));
-	}
-
-	protected short[][] getUpdatedRegion(World world) {
-		if (this.evaluatedRegion == null) {
-			this.evaluatedRegion = new short[(int) this.quarterFilterSize * 2][(int) this.quarterFilterSize * 2];
-		}
-
-		world.getBiomeDataOracle().populateArray(corner, evaluatedRegion, true);
-		return evaluatedRegion;
-	}
-
-	protected boolean isValid(World world, short[][] region) {
+		world.getBiomeDataOracle().populateArray(corner, region, true);
 		for (short[] row : region) {
 			for (short entry : row) {
-				if (isValidBiome(entry)) {
+				if (validBiomeIndexes.contains(entry)) {
 					return true;
 				}
 			}
 		}
 		return false;
 	}
-
-	private boolean isValidBiome(short biomeIndex) {
-		for (Biome biome : biomes) {
-			if (biomeIndex == biome.getIndex()) {
-				return true;
-			}
-		}
-		return false;
-	}
 }

src/main/java/amidst/mojangapi/world/filter/WorldFilter_Structure.java

@@ -13,26 +13,25 @@ public class WorldFilter_Structure extends WorldFilter {
 	private final DefaultWorldIconTypes structure;
 	private final int count;
 
-	public WorldFilter_Structure(long worldFilterSize, String structureName, int count) {
+	public WorldFilter_Structure(long worldFilterSize, DefaultWorldIconTypes structure, int count) {
 		super(worldFilterSize);
-
-		this.structure = DefaultWorldIconTypes.getByName(structureName);
+		this.structure = structure;
 		this.count = count;
 	}
 
 	@Override
 	public boolean isValid(World world) {
 		WorldIconCollector structureCollector = getCollector();
-		WorldIconProducer<Void> structureProducer = getProducer(world);
+		procudeAndCollect(getProducer(world), structureCollector);
+		return structureCollector.get().size() > count;
+	}
 
+	private void procudeAndCollect(WorldIconProducer<Void> structureProducer, WorldIconCollector structureCollector) {
 		for (long x = 0; x < 2 * worldFilterSize; x += 512) {
 			for (long y = 0; y < 2 * worldFilterSize; y += 512) {
-				CoordinatesInWorld subCorner = CoordinatesInWorld.from(x, y).add(corner);
-				structureProducer.produce(subCorner, structureCollector, null);
+				structureProducer.produce(CoordinatesInWorld.from(x, y).add(corner), structureCollector, null);
 			}
 		}
-
-		return structureCollector.get().size() > count;
 	}
 
 	private WorldIconProducer<Void> getProducer(World world) {

src/main/java/amidst/mojangapi/world/icon/type/DefaultWorldIconTypes.java

@@ -45,6 +45,10 @@ public enum DefaultWorldIconTypes {
 		return typeMap.get(name);
 	}
 
+	public static boolean exists(String name) {
+		return typeMap.containsKey(name);
+	}
+
 	private static String getFilename(String name) {
 		return "/amidst/gui/main/icon/" + name + ".png";
 	}