Added accurate planet generation

core/src/mindustry/maps/planet/PlanetGenerator.java

@@ -0,0 +1,37 @@
+package mindustry.maps.planet;
+
+import arc.graphics.*;
+import arc.math.*;
+import arc.math.geom.*;
+import arc.util.*;
+import arc.util.noise.*;
+
+public class PlanetGenerator{
+    Pixmap pix = new Pixmap("planets/colors.png");
+    Simplex noise = new Simplex();
+    int waterLevel = 5;
+    float water = waterLevel / (float)(pix.getHeight());
+    float scl = 5f;
+
+    public float getHeight(Vec3 position){
+        position = Tmp.v33.set(position).scl(scl);
+
+        float height = Mathf.pow((float)noise.octaveNoise3D(7, 0.48f, 1f/3f, position.x, position.y, position.z), 2.4f);
+        if(height <= water){
+            return water;
+        }
+        return height;
+    }
+
+    public Color getColor(Vec3 position, float height){
+        position = Tmp.v33.set(position).scl(scl);
+        float rad = scl;
+        float temp = Mathf.clamp(Math.abs(position.y * 2f) / (rad));
+        float tnoise = (float)noise.octaveNoise3D(7, 0.48f, 1f/3f, position.x, position.y + 999f, position.z);
+        temp = Mathf.lerp(temp, tnoise, 0.5f);
+        height *= 1.2f;
+        height = Mathf.clamp(height);
+
+        return Tmp.c1.set(pix.getPixel((int)(temp * (pix.getWidth()-1)), (int)((1f-height) * (pix.getHeight()-1))));
+    }
+}