From c3d5b55dcc59c8f61ec97d252658c5a4d9b3f584 Mon Sep 17 00:00:00 2001
From: dfsek <dfsek@protonmail.com>
Date: Sun, 18 Oct 2020 01:52:54 -0700
Subject: [PATCH] Use ping-pong noise for erosion

---
 src/main/java/com/dfsek/terra/biome/ErosionNoise.java    | 9 ++++-----
 src/main/java/com/dfsek/terra/biome/TerraBiomeGrid.java  | 2 +-
 .../java/com/dfsek/terra/config/base/ConfigPack.java     | 2 --
 3 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/src/main/java/com/dfsek/terra/biome/ErosionNoise.java b/src/main/java/com/dfsek/terra/biome/ErosionNoise.java
index 7763f66bc..3a931de8f 100644
--- a/src/main/java/com/dfsek/terra/biome/ErosionNoise.java
+++ b/src/main/java/com/dfsek/terra/biome/ErosionNoise.java
@@ -8,11 +8,11 @@ import org.polydev.gaea.math.FastNoiseLite;
 public class ErosionNoise {
     private final double thresh;
     private final FastNoiseLite noise;
-    public ErosionNoise(float freq1, double thresh, int octaves, long seed) {
+    public ErosionNoise(float freq1, double thresh, long seed) {
         FastNoiseLite main = new FastNoiseLite((int) (seed+1));
         main.setNoiseType(FastNoiseLite.NoiseType.OpenSimplex2);
-        main.setFractalType(FastNoiseLite.FractalType.FBm);
-        main.setFractalOctaves(octaves);
+        main.setFractalType(FastNoiseLite.FractalType.PingPong);
+        main.setFractalOctaves(1);
         main.setFrequency(freq1);
         this.thresh = thresh;
         this.noise = main;
@@ -25,7 +25,6 @@ public class ErosionNoise {
      * @return Whether location is eroded
      */
     boolean isEroded(int x, int z) {
-        double abs = Math.pow(noise.getNoise(x, z), 2);
-        return abs < thresh;
+        return (noise.getNoise(x, z)+1)/2 <= thresh;
     }
 }
diff --git a/src/main/java/com/dfsek/terra/biome/TerraBiomeGrid.java b/src/main/java/com/dfsek/terra/biome/TerraBiomeGrid.java
index 05c3f3349..c083d5bed 100644
--- a/src/main/java/com/dfsek/terra/biome/TerraBiomeGrid.java
+++ b/src/main/java/com/dfsek/terra/biome/TerraBiomeGrid.java
@@ -27,7 +27,7 @@ public class TerraBiomeGrid extends BiomeGrid {
         }
         this.zone = zone;
         if(c.erosionEnable) {
-            erode = new ErosionNoise(c.erosionFreq, c.erosionThresh, c.erosionOctaves, w.getSeed());
+            erode = new ErosionNoise(c.erosionFreq, c.erosionThresh, w.getSeed());
             this.erosionGrid = erosion;
         }
     }
diff --git a/src/main/java/com/dfsek/terra/config/base/ConfigPack.java b/src/main/java/com/dfsek/terra/config/base/ConfigPack.java
index 4f70608b9..4d96d6699 100644
--- a/src/main/java/com/dfsek/terra/config/base/ConfigPack.java
+++ b/src/main/java/com/dfsek/terra/config/base/ConfigPack.java
@@ -60,7 +60,6 @@ public class ConfigPack extends YamlConfiguration {
 
     public final float erosionFreq;
     public final double erosionThresh;
-    public final int erosionOctaves;
     public final boolean erosionEnable;
     public final String erosionName;
 
@@ -108,7 +107,6 @@ public class ConfigPack extends YamlConfiguration {
         erosionEnable = getBoolean("erode.enable", false);
         erosionFreq = (float) getDouble("erode.frequency", 0.01);
         erosionThresh = getDouble("erode.threshold", 0.04);
-        erosionOctaves = getInt("erosion.octaves", 4);
 
         octaves = getInt("noise.octaves", 4);
         frequency = (float) getDouble("noise.frequency", 1f/96);