feat: added FPS counter

core/src/sagittarius/model/FPS.java

@@ -0,0 +1,31 @@
+package sagittarius.model;
+
+import com.badlogic.gdx.Gdx;
+import com.badlogic.gdx.graphics.g2d.Batch;
+import com.badlogic.gdx.graphics.g2d.BitmapFont;
+import com.badlogic.gdx.scenes.scene2d.Actor;
+
+import sagittarius.SagittariusGame;
+
+public class FPS extends Actor {
+
+// ---------- ATTRIBUTEs ----------
+
+    private BitmapFont font = new BitmapFont();
+    private int frameRate;
+
+// ---------- METHODs ----------
+
+    @Override
+    public void act(float delta) {
+        super.act(delta);
+        frameRate = Gdx.graphics.getFramesPerSecond();
+    }
+
+    @Override
+    public void draw(Batch batch, float parentAlpha) {
+        super.draw(batch, parentAlpha);
+        font.draw(batch, frameRate + " fps", 3, SagittariusGame.getActiveScreen().getUIStage().getViewport().getWorldHeight() - 3);
+    }
+
+}