feat(scene): implement transition

Should work :D

app/src/main/java/org/vibecoders/moongazer/Assets.java

@@ -1,18 +1,34 @@
 package org.vibecoders.moongazer;
 
+import org.slf4j.Logger;
+
 import com.badlogic.gdx.assets.AssetManager;
 import com.badlogic.gdx.graphics.Texture;
 
 public class Assets {
     private static final AssetManager assetManager = new AssetManager();
+    private static final Logger log = org.slf4j.LoggerFactory.getLogger(Assets.class);
 
     public static <T> T getAsset(String fileName, Class<T> type) {
         return assetManager.get(fileName, type);
     }
 
-    public static void loadAll() {
+    /**
-        // We load all assets here for simplicity :)
+     * Loads assets required for the intro scene only.
+     * 
+     * This is used to load the logo before the main assets are loaded.
+     */
+    public static void loadIntroAndWait() {
         assetManager.load("icons/logo.png", Texture.class);
+        waitUntilLoaded();
+    }
+
+    public static void loadAll() {
+        log.info("Loading all assets....");
+        log.warn("stub");
+    }
+
+    public static void waitUntilLoaded() {
         assetManager.finishLoading();
     }
 

app/src/main/java/org/vibecoders/moongazer/Constants.java

@@ -1,5 +1,9 @@
 package org.vibecoders.moongazer;
 
+import com.badlogic.gdx.graphics.Color;
+import com.badlogic.gdx.graphics.Pixmap;
+import com.badlogic.gdx.graphics.Texture;
+
 /**
  * Client configuration constants and default values
  * used throughout the Moongazer client application.
@@ -12,4 +16,12 @@ public class Constants {
     public static final int WINDOW_WIDTH = 1280;
     public static final int WINDOW_HEIGHT = 720;
     public static final String WINDOW_TITLE = "Moongazer";
+    public static final Texture TEXTURE_WHITE = new Texture(new Pixmap(1, 1, Pixmap.Format.RGBA8888) {{
+        setColor(Color.WHITE);
+        fill();
+    }});
+    public static final Texture TEXTURE_BLACK = new Texture(new Pixmap(1, 1, Pixmap.Format.RGBA8888) {{
+        setColor(Color.BLACK);
+        fill();
+    }});
 }

app/src/main/java/org/vibecoders/moongazer/Game.java

@@ -11,28 +11,38 @@ import org.vibecoders.moongazer.scene.*;
 public class Game extends ApplicationAdapter {
     private static final Logger log = LoggerFactory.getLogger(Game.class);
     public static State state = State.INTRO;
+    public static Transition transition = null;
     SpriteBatch batch;
     Texture logo;
     Scene currentScene;
     Scene introScene;
+    public static Scene mainMenuScene;
 
     @Override
     public void create() {
-        log.info("Loading assets...");
+        log.info("Loading intro assets...");
-        Assets.loadAll();
+        Assets.loadIntroAndWait();
-        log.info("Assets loaded successfully.");
+        log.info("Intro assets loaded successfully.");
         batch = new SpriteBatch();
         currentScene = introScene = new Intro();
+        mainMenuScene = new MainMenu();
     }
 
     @Override
     public void render() {
+        // Handle transition if any
+        if (transition != null) {
+            batch.begin();
+            transition.render(batch);
+            batch.end();
+            return;
+        }
         switch (Game.state) {
             case INTRO:
                 currentScene = introScene;
                 break;
             case MAIN_MENU:
-                // Render main menu scene
+                currentScene = mainMenuScene;
                 break;
             case IN_GAME:
                 // Render in-game scene
@@ -48,6 +58,7 @@ public class Game extends ApplicationAdapter {
     @Override
     public void dispose() {
         introScene.dispose();
+        mainMenuScene.dispose();
         Assets.dispose();
         log.debug("Resources disposed");
     }

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

@@ -1,36 +1,57 @@
 package org.vibecoders.moongazer.scene;
 
-import static org.vibecoders.moongazer.Constants.WINDOW_HEIGHT;
+import static org.vibecoders.moongazer.Constants.*;
-import static org.vibecoders.moongazer.Constants.WINDOW_WIDTH;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.vibecoders.moongazer.Assets;
+import org.vibecoders.moongazer.Game;
+import org.vibecoders.moongazer.State;
 
 import com.badlogic.gdx.graphics.Color;
 import com.badlogic.gdx.graphics.Texture;
 import com.badlogic.gdx.graphics.g2d.SpriteBatch;
 import com.badlogic.gdx.utils.ScreenUtils;
 
+/**
+ * Intro scene displaying the game logo and handling asset loading.
+ */
 public class Intro extends Scene {
     private Texture logo;
     private long startTime;
     private long endTime = 0;
     private static final Logger log = LoggerFactory.getLogger(Intro.class);
 
+    /**
+     * Initializes the intro scene, starts loading assets.
+     */
     public Intro() {
         logo = Assets.getAsset("icons/logo.png", Texture.class);
         startTime = System.currentTimeMillis() + 500;
+        log.info("Starting to load all remaining assets...");
+        Assets.loadAll();
     }
 
+    /**
+     * Renders the intro scene.
+     * @param batch The SpriteBatch to draw with.
+     */
+    @Override
     public void render(SpriteBatch batch) {
+        if (System.currentTimeMillis() > endTime + 2000 && endTime != 0) {
+            Assets.waitUntilLoaded();
+            if (Game.transition == null) {
+                Game.transition = new Transition(this, Game.mainMenuScene, State.MAIN_MENU, 1000);
+            }
+            batch.draw(TEXTURE_BLACK, 0, 0, WINDOW_WIDTH, WINDOW_HEIGHT);
+            return;
+        }
         ScreenUtils.clear(Color.BLACK);
-        log.debug("Rendering logo at position: ({}, {})", WINDOW_WIDTH / 2 - logo.getWidth() / 4,
+        // log.debug("Rendering logo at position: ({}, {})", WINDOW_WIDTH / 2 - logo.getWidth() / 4, WINDOW_HEIGHT / 2 - logo.getHeight() / 4);
-                WINDOW_HEIGHT / 2 - logo.getHeight() / 4);
         var currentOpacity = (float) (System.currentTimeMillis() - startTime) / 1000;
         if (currentOpacity > 1) {
             if (endTime == 0) {
-                endTime = System.currentTimeMillis() + 3000;
+                endTime = System.currentTimeMillis() + 2000;
             }
             currentOpacity = 1 - ((float) (System.currentTimeMillis() - endTime) / 1000);
         }
@@ -38,8 +59,4 @@ public class Intro extends Scene {
         batch.draw(logo, WINDOW_WIDTH / 2 - logo.getWidth() / 4, WINDOW_HEIGHT / 2 - logo.getHeight() / 4,
                 logo.getWidth() / 2, logo.getHeight() / 2);
     }
-
-    public void dispose() {
-        log.debug("sybau");
-    }
 }

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

@@ -0,0 +1,56 @@
+package org.vibecoders.moongazer.scene;
+
+import org.slf4j.Logger;
+import org.vibecoders.moongazer.Game;
+import org.vibecoders.moongazer.State;
+
+import com.badlogic.gdx.graphics.g2d.SpriteBatch;
+
+/**
+ * Handles transitions between scenes with a linear transition effect.
+ */
+public class Transition extends Scene {
+    private Scene from;
+    private Scene to;
+    private State targetState;
+    private long startTime;
+    private long duration;
+
+    private static final Logger log = org.slf4j.LoggerFactory.getLogger(Transition.class);
+
+    /**
+     * Creates a new transition between two scenes.
+     * @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.
+     */
+    public Transition(Scene from, Scene to, State targetState, long duration) {
+        this.from = from;
+        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;
+        if (toOpacity >= 0.99) {
+            log.debug("Transition complete to state: {}", targetState);
+            Game.state = targetState;
+            Game.transition = null;
+            return;
+        }
+        var fromOpacity = 1 - toOpacity;
+        log.debug("Transition opacities - from: {}, to: {}", fromOpacity, toOpacity);
+        batch.setColor(1, 1, 1, fromOpacity);
+        from.render(batch);
+        batch.setColor(1, 1, 1, toOpacity);
+        to.render(batch);
+    }
+}