Implement erosion

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

@@ -0,0 +1,30 @@
+package com.dfsek.terra.biome;
+
+import org.polydev.gaea.math.FastNoise;
+
+/**
+ * Class to hold noise function to determine erosion.
+ */
+public class ErosionNoise {
+    private final double thresh;
+    private final FastNoise noise;
+    public ErosionNoise(float freq1, double thresh, long seed) {
+        FastNoise main = new FastNoise((int) (seed+1));
+        main.setNoiseType(FastNoise.NoiseType.SimplexFractal);
+        main.setFractalOctaves(2);
+        main.setFrequency(freq1);
+        this.thresh = thresh;
+        this.noise = main;
+    }
+
+    /**
+     * Get whether a location is eroded
+     * @param x X coordinate
+     * @param z Z coordinate
+     * @return Whether location is eroded
+     */
+    boolean isEroded(int x, int z) {
+        double abs = Math.pow(noise.getNoise(x, z), 2);
+        return abs < thresh;
+    }
+}