custom claszes

Author: Frakits

src/docs/Modding The Engine/Scripting/Custom Classes.md

@@ -1,3 +1,30 @@
 # Custom Classes
 
-well it seems like i have no idea how these work myself
+Custom classes can be made either inside the script you need it in or you can make a script file coresponding with the name of the class in ``./source``, and using `import` to import it.
+
+Here is a basic Song Script code that uses it:
+```hx
+class SpecialSprite extends FlxSprite {
+    public var customValue:String = null;
+    public function new(x:Float, y:Float, customValue:String) {
+        super(x, y);
+        this.customValue = customValue;
+        //other code stuff
+    }
+
+    public override function update(elapsed) {
+        super.update(elapsed);
+    }
+}
+
+function create() {
+    var spr = new SpecialSprite(200, 400, "powerful");
+    add(spr);
+}
+```
+
+### Particularities
+As of writing this, this system is very limited and also presents some defects. For example:
+- You cannot extend FlxGroups or other typed classes *(the ones that end with a ``<T>``)*.
+- Certain classes like FlxText needs to have their ``update`` function manually called.
+- all variables need to be public in order to be accessed inside the class.