Implement load-dependent population

src/main/java/com/dfsek/terra/population/TreePopulator.java

@@ -0,0 +1,45 @@
+package com.dfsek.terra.population;
+
+import com.dfsek.terra.Terra;
+import com.dfsek.terra.biome.TerraBiomeGrid;
+import com.dfsek.terra.biome.UserDefinedDecorator;
+import org.bukkit.Chunk;
+import org.bukkit.Location;
+import org.bukkit.World;
+import org.jetbrains.annotations.NotNull;
+import org.polydev.gaea.biome.Biome;
+import org.polydev.gaea.population.GaeaBlockPopulator;
+import org.polydev.gaea.population.PopulationManager;
+import org.polydev.gaea.util.WorldUtil;
+
+import java.util.Random;
+
+public class TreePopulator extends GaeaBlockPopulator {
+
+    public TreePopulator(PopulationManager manager) {
+        super(manager);
+    }
+
+    @Override
+    public void populate(@NotNull World world, @NotNull Random random, @NotNull Chunk chunk) {
+        int x = random.nextInt(16); // Decrease chances of chunk-crossing trees
+        int z = random.nextInt(16);
+        Location origin = chunk.getBlock(x, 0, z).getLocation();
+        Biome b = TerraBiomeGrid.fromWorld(world).getBiome(origin);
+        if(((UserDefinedDecorator) b.getDecorator()).getTreeChance() < random.nextInt(100)) return;
+        int numTrees = 0;
+        for(int i = 0; i < 10; i++) {
+            int y = WorldUtil.getHighestValidSpawnAt(chunk, x, z);
+            if(y <= 0) continue;
+            origin = chunk.getBlock(x, y, z).getLocation().add(0, 1, 0);
+            b = TerraBiomeGrid.fromWorld(world).getBiome(origin);
+            numTrees++;
+            try {
+                b.getDecorator().getTrees().get(random).plant(origin, random, false, Terra.getInstance());
+            } catch(NullPointerException ignored) {}
+            if(numTrees >= b.getDecorator().getTreeDensity()) return;
+            x = random.nextInt(16); // Decrease chances of chunk-crossing trees
+            z = random.nextInt(16);
+        }
+    }
+}