From a9ce316d282790c4a9b12526a291952486d27ea7 Mon Sep 17 00:00:00 2001
From: Daniel Mills <danielmillst@gmail.com>
Date: Wed, 22 Jul 2020 15:04:28 -0400
Subject: [PATCH] Rarity System

---
 .../bytecode/iris/layer/GenLayerBiome.java    | 13 ++---
 .../ninja/bytecode/iris/object/IrisBiome.java |  6 ++-
 .../java/ninja/bytecode/iris/util/IRare.java  |  6 +++
 .../iris/util/RarityCellGenerator.java        | 50 +++++++++++++++++++
 4 files changed, 68 insertions(+), 7 deletions(-)
 create mode 100644 src/main/java/ninja/bytecode/iris/util/IRare.java
 create mode 100644 src/main/java/ninja/bytecode/iris/util/RarityCellGenerator.java

diff --git a/src/main/java/ninja/bytecode/iris/layer/GenLayerBiome.java b/src/main/java/ninja/bytecode/iris/layer/GenLayerBiome.java
index 49ffc187b..d3ce4a0a1 100644
--- a/src/main/java/ninja/bytecode/iris/layer/GenLayerBiome.java
+++ b/src/main/java/ninja/bytecode/iris/layer/GenLayerBiome.java
@@ -11,15 +11,16 @@ import ninja.bytecode.iris.util.BiomeResult;
 import ninja.bytecode.iris.util.CellGenerator;
 import ninja.bytecode.iris.util.GenLayer;
 import ninja.bytecode.iris.util.RNG;
+import ninja.bytecode.iris.util.RarityCellGenerator;
 import ninja.bytecode.shuriken.collections.KList;
 
 public class GenLayerBiome extends GenLayer
 {
 	private CellGenerator region;
 	private CellGenerator bridge;
-	private CellGenerator land;
-	private CellGenerator shore;
-	private CellGenerator sea;
+	private RarityCellGenerator<IrisBiome> land;
+	private RarityCellGenerator<IrisBiome> shore;
+	private RarityCellGenerator<IrisBiome> sea;
 	private DimensionChunkGenerator iris;
 
 	public GenLayerBiome(DimensionChunkGenerator iris, RNG rng)
@@ -28,9 +29,9 @@ public class GenLayerBiome extends GenLayer
 		this.iris = iris;
 		region = new CellGenerator(rng.nextParallelRNG(1188519));
 		bridge = new CellGenerator(rng.nextParallelRNG(1541462));
-		land = new CellGenerator(rng.nextParallelRNG(9045162));
-		shore = new CellGenerator(rng.nextParallelRNG(2342812));
-		sea = new CellGenerator(rng.nextParallelRNG(6135621));
+		land = new RarityCellGenerator<>(rng.nextParallelRNG(9045162));
+		shore = new RarityCellGenerator<>(rng.nextParallelRNG(2342812));
+		sea = new RarityCellGenerator<>(rng.nextParallelRNG(6135621));
 	}
 
 	public IrisRegion getRegion(double bx, double bz)
diff --git a/src/main/java/ninja/bytecode/iris/object/IrisBiome.java b/src/main/java/ninja/bytecode/iris/object/IrisBiome.java
index fc708fda7..debcc3b2c 100644
--- a/src/main/java/ninja/bytecode/iris/object/IrisBiome.java
+++ b/src/main/java/ninja/bytecode/iris/object/IrisBiome.java
@@ -10,6 +10,7 @@ import lombok.EqualsAndHashCode;
 import ninja.bytecode.iris.util.CNG;
 import ninja.bytecode.iris.util.CellGenerator;
 import ninja.bytecode.iris.util.Desc;
+import ninja.bytecode.iris.util.IRare;
 import ninja.bytecode.iris.util.RNG;
 import ninja.bytecode.shuriken.collections.KList;
 import ninja.bytecode.shuriken.logging.L;
@@ -17,11 +18,14 @@ import ninja.bytecode.shuriken.logging.L;
 @Desc("Represents a biome in iris.")
 @Data
 @EqualsAndHashCode(callSuper = false)
-public class IrisBiome extends IrisRegistrant
+public class IrisBiome extends IrisRegistrant implements IRare
 {
 	@Desc("This is the human readable name for this biome. This can and should be different than the file name. This is not used for loading biomes in other objects.")
 	private String name = "A Biome";
 
+	@Desc("The weight of this biome. Higher than 1 is more common, less than 1 (above 0) is rarer")
+	private double weight = 1D;
+
 	@Desc("This changes the dispersion of the biome colors if multiple derivatives are chosen")
 	private Dispersion biomeDispersion = Dispersion.SCATTER;
 
diff --git a/src/main/java/ninja/bytecode/iris/util/IRare.java b/src/main/java/ninja/bytecode/iris/util/IRare.java
new file mode 100644
index 000000000..ba314589e
--- /dev/null
+++ b/src/main/java/ninja/bytecode/iris/util/IRare.java
@@ -0,0 +1,6 @@
+package ninja.bytecode.iris.util;
+
+public interface IRare
+{
+	public double getWeight();
+}
diff --git a/src/main/java/ninja/bytecode/iris/util/RarityCellGenerator.java b/src/main/java/ninja/bytecode/iris/util/RarityCellGenerator.java
new file mode 100644
index 000000000..cb952df1d
--- /dev/null
+++ b/src/main/java/ninja/bytecode/iris/util/RarityCellGenerator.java
@@ -0,0 +1,50 @@
+package ninja.bytecode.iris.util;
+
+import org.apache.commons.lang.math.DoubleRange;
+
+import ninja.bytecode.shuriken.collections.KList;
+import ninja.bytecode.shuriken.collections.KMap;
+
+public class RarityCellGenerator<T extends IRare> extends CellGenerator
+{
+	public RarityCellGenerator(RNG rng)
+	{
+		super(rng);
+	}
+
+	public T get(double x, double z, KList<T> t)
+	{
+		int totalWeight = 0;
+		KMap<DoubleRange, T> ranges = new KMap<>();
+
+		for(T i : t)
+		{
+			int weight = (int) Math.round(1000 * i.getWeight());
+
+			if(weight < 1)
+			{
+				continue;
+			}
+
+			ranges.put(new DoubleRange(totalWeight, totalWeight + weight), i);
+			totalWeight += weight;
+		}
+
+		int r = getIndex(x, z, totalWeight);
+
+		for(DoubleRange i : ranges.keySet())
+		{
+			if(i.containsDouble(r))
+			{
+				return ranges.get(i);
+			}
+		}
+
+		if(!t.isEmpty())
+		{
+			return t.get(0);
+		}
+
+		return null;
+	}
+}