added density

code improvements

Scripts/Elements/Dirt.cs

@@ -5,8 +5,8 @@ namespace FOU.Scripts.Elements;
 public class Dirt : Solid {
 
     public Dirt(int x, int y, ref Level level) : base(x, y, ref level) {
-        Color = Colors.Brown;
-        Color = AddColorVariance(Color);
+        Color = AddColorVariance(Colors.Brown);
+        Density = 10;
     }
 
     public override bool Update(int currentFrame) {

Scripts/Elements/Element.cs

@@ -6,6 +6,7 @@ public class Element {
     public Color Color = Colors.Black;
 
     public Vector2I Position;
+    public int Density;
 
     protected readonly float MaxColorVariance = 0.1f;
     protected readonly Level Level;
@@ -40,9 +41,7 @@ public class Element {
     }
 
     protected virtual void Tick() {
-        int randomDirection = 1;
-        if (GD.Randi() % 2 != 0)
-            randomDirection *= -1;
+        int randomDirection = GD.Randi() % 2 != 0 ? 1 : -1;
 
         if (Level.IsEmpty(Position + Vector2I.Down)) {
             Level.Swap(this, Position + Vector2I.Down);
@@ -53,6 +52,15 @@ public class Element {
         } else if (Level.IsEmpty(Position + Vector2I.Down + Vector2I.Right * randomDirection * -1)) {
             Level.Swap(this, Position + Vector2I.Right*randomDirection);
         }
+
+        if (GD.Randi() % 10 > 1) return; // ascend slower
+
+        if (Level.Get(Position + Vector2I.Down
+                               // maybe also side
+                               + (GD.Randi() % 2 != 0 ?
+                                   Vector2I.Zero : Vector2I.Right * randomDirection)
+            )?.Density < Density)
+            Level.Swap(this, Position + Vector2I.Down);
     }
 
     protected Color AddColorVariance(Color baseColor) {

Scripts/Elements/Water.cs

@@ -4,8 +4,8 @@ namespace FOU.Scripts.Elements;
 
 public class Water : Solid {
     public Water(int x, int y, ref Level level) : base(x, y, ref level) {
-        Color = Colors.Blue;
-        Color = AddColorVariance(Color);
+        Color = AddColorVariance(Colors.Blue);
+        Density = 1;
     }
 
     public override bool Update(int currentFrame) {
@@ -17,9 +17,8 @@ public class Water : Solid {
     }
 
     protected override void Tick() {
-        int randomDirection = 1;
-        if (GD.Randi() % 2 != 0)
-            randomDirection *= -1;
+        int randomDirection = GD.Randi() % 2 != 0 ? 1 : -1;
+        randomDirection *= GD.Randi() % 2 != 0 ? 1 : 2;
 
         if (Level.IsEmpty(Position + Vector2I.Down)) {
             Level.Swap(this, Position + Vector2I.Down);
@@ -31,5 +30,8 @@ public class Water : Solid {
             Level.Swap(this, Position + Vector2I.Right*randomDirection);
             return;
         }
+
+
+
     }
 }

Scripts/Level.cs

@@ -78,6 +78,8 @@ public class Level {
     public void Swap(Element what, Element swapTo) {
         Element swap = new Element(what);
 
+        if (what == null || swapTo == null) return;
+
         what.Position = swapTo.Position;
         _elements[swapTo.Position.X, swapTo.Position.Y] = what;