chore: use libGDX functions instead of System.currentTimeMillis

app/src/main/java/org/vibecoders/moongazer/scenes/Intro.java

@@ -6,6 +6,7 @@ import org.vibecoders.moongazer.Game;
 import org.vibecoders.moongazer.State;
 import org.vibecoders.moongazer.managers.Assets;
 
+import com.badlogic.gdx.Gdx;
 import com.badlogic.gdx.graphics.Color;
 import com.badlogic.gdx.graphics.Texture;
 import com.badlogic.gdx.graphics.g2d.SpriteBatch;
@@ -17,8 +18,8 @@ import com.badlogic.gdx.utils.ScreenUtils;
 public class Intro extends Scene {
     private Texture logo;
     private Game game;
-    private long startTime;
+    private float totalTime = 0;
-    private long endTime = 0;
+    private boolean end = false;
 
     /**
      * Initializes the intro scene, starts loading assets.
@@ -26,7 +27,6 @@ public class Intro extends Scene {
     public Intro(Game game) {
         this.game = game;
         logo = Assets.getAsset("icons/logo.png", Texture.class);
-        startTime = System.currentTimeMillis() + 500;
         log.info("Starting to load all remaining assets...");
         Assets.loadAll();
         // Create scenes
@@ -42,7 +42,9 @@ public class Intro extends Scene {
      */
     @Override
     public void render(SpriteBatch batch) {
-        if (System.currentTimeMillis() > endTime + 2000 && endTime != 0) {
+        totalTime += Gdx.graphics.getDeltaTime();
+        log.trace("Intro total time: {}", totalTime);
+        if (totalTime > 5f) {
             if (game.transition == null) {
                 Assets.waitUntilLoaded();
                 log.info("All assets loaded successfully.");
@@ -53,12 +55,12 @@ public class Intro extends Scene {
         }
         ScreenUtils.clear(Color.BLACK);
         // log.debug("Rendering logo at position: ({}, {})", WINDOW_WIDTH / 2 - logo.getWidth() / 4, WINDOW_HEIGHT / 2 - logo.getHeight() / 4);
-        var currentOpacity = (float) (System.currentTimeMillis() - startTime) / 1000;
+        var currentOpacity = totalTime;
         if (currentOpacity > 1) {
-            if (endTime == 0) {
+            if (!end) {
-                endTime = System.currentTimeMillis() + 2000;
+                end = true;
             }
-            currentOpacity = 1 - ((float) (System.currentTimeMillis() - endTime) / 1000);
+            currentOpacity = 5f - totalTime;
         }
         // Multiply with any externally applied alpha (e.g., Transition)
         float externalAlpha = batch.getColor().a;

app/src/main/java/org/vibecoders/moongazer/scenes/MainMenu.java

@@ -18,6 +18,7 @@ import com.badlogic.gdx.graphics.Texture;
 import com.badlogic.gdx.graphics.g2d.SpriteBatch;
 import com.badlogic.gdx.scenes.scene2d.InputEvent;
 import com.badlogic.gdx.scenes.scene2d.InputListener;
+import com.badlogic.gdx.utils.TimeUtils;
 import com.badlogic.gdx.video.VideoPlayer;
 import com.badlogic.gdx.video.VideoPlayerCreator;
 
@@ -133,7 +134,7 @@ public class MainMenu extends Scene {
             @Override
             public boolean keyDown(InputEvent event, int keycode) {
                 sKeyDown(event, keycode);
-                currentKeyDown.put(keycode, System.currentTimeMillis());
+                currentKeyDown.put(keycode, TimeUtils.millis());
                 return true;
             }
         });
@@ -201,9 +202,9 @@ public class MainMenu extends Scene {
         for (Map.Entry<Integer, Long> entry : currentKeyDown.entrySet()) {
             Integer keyCode = entry.getKey();
             Long timeStamp = entry.getValue();
-            if (System.currentTimeMillis() - timeStamp > 100) {
+            if (TimeUtils.millis() - timeStamp > 100) {
                 sKeyDown(null, keyCode);
-                currentKeyDown.put(keyCode, System.currentTimeMillis());
+                currentKeyDown.put(keyCode, TimeUtils.millis());
             }
         }
         startVideoOnce();

app/src/main/java/org/vibecoders/moongazer/scenes/Transition.java

@@ -3,6 +3,7 @@ package org.vibecoders.moongazer.scenes;
 import org.vibecoders.moongazer.Game;
 import org.vibecoders.moongazer.State;
 
+import com.badlogic.gdx.Gdx;
 import com.badlogic.gdx.graphics.g2d.SpriteBatch;
 
 /**
@@ -12,15 +13,16 @@ public class Transition extends Scene {
     private Scene from;
     private Scene to;
     private State targetState;
-    private long startTime;
+    private float totalTime = 0f;
     private long duration;
 
     /**
      * Creates a new transition between two scenes.
-     * @param from The scene to transition from.
+     * 
-     * @param to The scene to transition to.
+     * @param from        The scene to transition from.
+     * @param to          The scene to transition to.
      * @param targetState The target state of the game after the transition.
-     * @param duration The duration of the transition in milliseconds.
+     * @param duration    The duration of the transition in milliseconds.
      */
     public Transition(Game game, Scene from, Scene to, State targetState, long duration) {
         // Transition does not need to render UI elements
@@ -30,16 +32,17 @@ public class Transition extends Scene {
         this.to = to;
         this.targetState = targetState;
         this.duration = duration;
-        startTime = System.currentTimeMillis();
     }
 
     /**
      * Renders the transition effect.
+     * 
      * @param batch The SpriteBatch to draw with.
      */
     @Override
     public void render(SpriteBatch batch) {
-        var toOpacity = ((float) (System.currentTimeMillis() - startTime)) / duration;
+        totalTime += Gdx.graphics.getDeltaTime();
+        var toOpacity = totalTime / (((float) duration) / 1000);
         if (toOpacity >= 0.99) {
             log.trace("Transition complete to state: {}", targetState);
             game.state = targetState;