Implement BiomeZone

src/main/java/com/dfsek/terra/biome/BiomeZone.java

@@ -0,0 +1,51 @@
+package com.dfsek.terra.biome;
+
+import com.dfsek.terra.config.WorldConfig;
+import org.bukkit.World;
+import org.polydev.gaea.biome.BiomeGrid;
+import org.polydev.gaea.math.FastNoise;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class BiomeZone {
+    private BiomeGrid[] grids;
+    private final World w;
+    private final FastNoise noise;
+    private static final Map<World, BiomeZone> zones = new HashMap<>();
+
+    public BiomeZone(World w, float freq) {
+        this.w = w;
+        this.noise = new FastNoise((int) w.getSeed()+2);
+        noise.setNoiseType(FastNoise.NoiseType.Value);
+        noise.setFrequency(freq);
+        setZones(WorldConfig.fromWorld(w).definedGrids);
+        zones.put(w, this);
+    }
+
+    public void setZones(BiomeGrid[] grids) {
+        if(grids.length != 16) throw new IllegalArgumentException("Illegal number of grids!");
+        this.grids = grids;
+    }
+
+    public BiomeGrid getGrid(int x, int z) {
+        return grids[normalize(noise.getValue(x, z))];
+    }
+
+    public static BiomeZone fromWorld(World w) {
+        if(zones.containsKey(w)) return zones.get(w);
+        else return new BiomeZone(w, WorldConfig.fromWorld(w).zoneFreq);
+    }
+
+    /**
+     * Takes a noise input and normalizes it to a value between 0 and 15 inclusive.
+     *
+     * @param i - The noise value to normalize.
+     * @return int - The normalized value.
+     */
+    private static int normalize(double i) {
+        if(i > 0) i = Math.pow(i, 0.8125); // Redistribute
+        else i = -Math.pow(-i, 0.8125); // Redistribute
+        return Math.min((int) Math.floor((i+1)*8), 15);
+    }
+}