added falling sand - dirt actually

Scripts/Elements/Dirt.cs

@@ -3,7 +3,18 @@
 namespace FOU.Scripts.Elements;
 
 public class Dirt : Solid {
-    public Dirt() {
+
+    public Dirt(int x, int y, ref Level level) : base(x, y, ref level) {
         Color = Colors.Brown;
     }
+
+    public override bool Update(int currentFrame) {
+        if (!base.Update(currentFrame)) return false;
+
+        if (CheckBelow(X, Y)) {
+            _level.Swap(this, X, Y+1);
+        }
+        return true;
+    }
+
 }

Scripts/Elements/Element.cs

@@ -2,6 +2,44 @@
 
 namespace FOU.Scripts.Elements;
 
-public abstract class Element {
+public class Element {
     public Color Color = Colors.Black;
+
+    public int X;
+    public int Y;
+
+    protected Level _level;
+
+    private int _lastUpdate = -1;
+
+    public Element(int x, int y, ref Level level) {
+        X = x;
+        Y = y;
+        _level = level;
+    }
+
+    /// <summary>
+    /// base update method, checks if anything is to do at all
+    /// </summary>
+    /// <param name="currentFrame"></param>
+    /// <returns>false if there is nothing to do</returns>
+    public virtual bool Update(int currentFrame) {
+        if (_lastUpdate == currentFrame) return false; // already updated this frame
+        _lastUpdate = currentFrame;
+
+        return true;
+    }
+
+    public override string ToString() {
+        return $"{X}:{Y}";
+    }
+
+    protected bool CheckBelow(int x, int y) {
+        if (y+1 >= _level.SizeY) return false;
+
+        if (_level.Get(x, y+1).GetType() == GetType())
+            return false;
+
+        return true;
+    }
 }

Scripts/Elements/Solid.cs

@@ -1,5 +1,5 @@
 namespace FOU.Scripts.Elements;
 
 public abstract class Solid : Element {
-
+    protected Solid(int x, int y, ref Level level) : base(x, y, ref level) { }
 }

Scripts/Level.cs

@@ -4,41 +4,83 @@ using Godot;
 namespace FOU.Scripts;
 
 public class Level {
-    private int mSizeX;
-    private int mSizeY;
+    public int SizeX;
+    public int SizeY;
     private Image mImage;
+    private int _frame;
 
-    private Element[,] mPixels;
+    private Element[,] _elements;
+    private Level _this;
 
     public Level(int x, int y) {
         GD.Print($"Generating level ({x}:{y})");
+        _this = this;
 
-        mSizeX = x;
-        mSizeY = y;
+        SizeX = x;
+        SizeY = y;
 
-        mPixels = new Element[x, y];
-        mImage = Image.Create(mSizeX, mSizeY, false, Image.Format.Rgb8);
+        _elements = new Element[x, y];
+        for (int i = 0; i < SizeX; i++) {
+            for (int j = 0; j < SizeY; j++) {
+                _elements[i,j] = new Element(i, j, ref _this);
+            }
+        }
+
+        mImage = Image.Create(SizeX, SizeY, false, Image.Format.Rgb8);
         mImage.Fill(Colors.Black);
     }
 
+    public void Update() {
+        for (int x = 0; x < SizeX; x++) {
+            for (int y = 0; y < SizeY; y++) {
+                if (_elements[x,y] != null)
+                    _elements[x,y].Update(_frame);
+            }
+        }
+        _frame++;
+    }
+
     public void WritePixel(int x, int y, int size) {
         for (int i = -size/2; i < size/2; i++) {
             for (int j = -size/2; j < size/2; j++) {
-                int X = Mathf.Clamp(x + i, 0, mSizeX);
-                int Y = Mathf.Clamp(y + j, 0, mSizeY);
-                mPixels[X,Y] = new Dirt();
+                int X = Mathf.Clamp(x + i, 0, SizeX);
+                int Y = Mathf.Clamp(y + j, 0, SizeY);
+                _elements[X,Y] = new Dirt(X, Y, ref _this);
             }
         }
     }
 
     public Image DrawLevel() {
-        for (int x = 0; x < mSizeX; x++) {
-            for (int y = 0; y < mSizeY; y++) {
-                if (mPixels[x,y] == null) continue;
+        for (int x = 0; x < SizeX; x++) {
+            for (int y = 0; y < SizeY; y++) {
+                // if (_elements[x,y] == null) continue;
 
-                mImage.SetPixel(x,y, mPixels[x,y].Color);
+                mImage.SetPixel(x,y, _elements[x,y].Color);
             }
         }
         return mImage;
     }
+
+    public void Swap(Element what, int toSwapX, int toSwapY) {
+        Element old = Get(toSwapX, toSwapY);
+        Set(old, what.X, what.Y);
+        Set(what, toSwapX, toSwapY);
+    }
+
+
+    public Element Get(int x, int y) {
+        if (x < 0 || x >= SizeX) return null;
+        if (y < 0 || y >= SizeY) return null;
+
+        return _elements[x,y];
+    }
+
+    private void Set(Element what, int x, int y) {
+        if (what == null) return;
+
+        what.X = x;
+        what.Y = y;
+        _elements[x,y] = what;
+    }
+
 }

Scripts/Main.cs

@@ -2,7 +2,7 @@ using FOU.Scripts;
 using Godot;
 
 public partial class Main : Node2D {
-	[Export] public int BrushSize = 10;
+	[Export] public int BrushSize = 5;
 
 	private TextureRect mLevelDrawer;
 	private Level mLevel;
@@ -13,6 +13,8 @@ public partial class Main : Node2D {
 	}
 
 	public override void _Process(double delta) {
+
+		mLevel.Update();
 		mLevelDrawer.Texture = ImageTexture.CreateFromImage(mLevel.DrawLevel());
 	}