Update to libGDX 1.9.13-SNAPSHOT

plugin-9patch/src/main/java/games/rednblack/editor/plugin/ninepatch/EditingZone.java

@@ -233,7 +233,7 @@ public class EditingZone extends Actor {
         batch.setColor(Color.WHITE.r, Color.WHITE.g, Color.WHITE.b, Color.WHITE.a * parentAlpha);
     }
 
-    public void zoomBy(int amount) {
+    public void zoomBy(float amount) {
         float defaultSize = 1.0f - amount*0.12f;
         currZoom*=defaultSize;
     }

plugin-9patch/src/main/java/games/rednblack/editor/plugin/ninepatch/MainPanel.java

@@ -99,8 +99,8 @@ public class MainPanel extends H2DDialog {
     public void setListeners(Stage stage) {
         stage.addListener(new InputListener() {
             @Override
-            public boolean scrolled(InputEvent event, float x, float y, int amount) {
-                editingZone.zoomBy(amount);
+            public boolean scrolled(InputEvent event, float x, float y, float amountX, float amountY) {
+                editingZone.zoomBy(amountX);
                 return false;
             }
         });