Fix white screen, center video, and advance after playback

- Rejoin whitespace-split program args so ISO paths with spaces work
  (Gradle --args splits on spaces, which caused a silent load failure
  and a blank white window).
- Black scene background and black video canvas fill; scale video to
  fit and center it instead of drawing top-left at native size.
- Playback completion now invokes MoviePlayer.onPlayListEnd so the menu
  advances past the anti-piracy warning instead of freezing.

ui/src/main/java/dev/quoije/umd/ui/PlayerApp.java

@@ -21,9 +21,12 @@ import javafx.application.Application;
 import javafx.application.Platform;
 import javafx.scene.Scene;
 import javafx.scene.canvas.Canvas;
+import javafx.scene.canvas.GraphicsContext;
 import javafx.scene.image.PixelFormat;
+import javafx.scene.image.WritableImage;
 import javafx.scene.input.KeyCode;
 import javafx.scene.layout.StackPane;
+import javafx.scene.paint.Color;
 import javafx.stage.Stage;
 
 import java.io.IOException;
@@ -39,16 +42,21 @@ public final class PlayerApp extends Application {
     private Canvas videoCanvas;
     private RcoRenderer renderer;
     private volatile Controller controller;
+    private volatile MoviePlayer moviePlayer;
 
     @Override
     public void start(Stage stage) {
-        String isoPath = getParameters().getRaw().isEmpty() ? null : getParameters().getRaw().get(0);
+        // Gradle's --args splits on whitespace; rejoin so paths with spaces work.
+        String isoPath = getParameters().getRaw().isEmpty()
+                ? null
+                : String.join(" ", getParameters().getRaw());
 
         menuCanvas = new Canvas(WIDTH, HEIGHT);
         videoCanvas = new Canvas(WIDTH, HEIGHT);
 
         StackPane root = new StackPane(videoCanvas, menuCanvas);
         Scene scene = new Scene(root, WIDTH, HEIGHT);
+        scene.setFill(Color.BLACK);
         stage.setTitle("useless-umd-player");
         stage.setScene(scene);
         stage.show();
@@ -105,7 +113,7 @@ public final class PlayerApp extends Application {
                                       int audioFlag, int subtitleNumber, int subtitleFlag) {
                     Playlist.Stream stream = playlist.streamForPlayListNumber(playListNumber);
                     if (stream != null) {
-                        startPlayback(isoPath, stream.name());
+                        startPlayback(isoPath, stream.name(), playListNumber);
                     }
                 }
 
@@ -130,13 +138,14 @@ public final class PlayerApp extends Application {
 
             interpreter.run(globals);
             controller = (Controller) controllerObject.getObject();
+            moviePlayer = (MoviePlayer) movieplayer.getObject();
             controller.callCallback(interpreter, "onAutoPlay", null);
         } catch (Exception e) {
             e.printStackTrace();
         }
     }
 
-    private void startPlayback(String isoPath, String streamName) {
+    private void startPlayback(String isoPath, String streamName, int playListNumber) {
         Thread player = new Thread(() -> {
             try (UmdIsoReader iso = new UmdIsoReader(Path.of(isoPath));
                  PlaybackEngine engine = PlaybackEngine.open(iso, streamName, 0)) {
@@ -164,6 +173,11 @@ public final class PlayerApp extends Application {
                         Thread.sleep(millis, nanos);
                     }
                 }
+
+                MoviePlayer mp = moviePlayer;
+                if (mp != null) {
+                    mp.onPlayListEnd(playListNumber);
+                }
             } catch (Exception e) {
                 e.printStackTrace();
             }
@@ -173,10 +187,23 @@ public final class PlayerApp extends Application {
     }
 
     private void blitVideo(int[] argb, int width, int height) {
+        WritableImage image = new WritableImage(width, height);
+        image.getPixelWriter().setPixels(0, 0, width, height, PixelFormat.getIntArgbInstance(), argb, 0, width);
+
         Platform.runLater(() -> {
-            videoCanvas.getGraphicsContext2D()
+            GraphicsContext g = videoCanvas.getGraphicsContext2D();
-                    .getPixelWriter()
+            double canvasWidth = videoCanvas.getWidth();
-                    .setPixels(0, 0, width, height, PixelFormat.getIntArgbInstance(), argb, 0, width);
+            double canvasHeight = videoCanvas.getHeight();
+
+            g.setFill(Color.BLACK);
+            g.fillRect(0, 0, canvasWidth, canvasHeight);
+
+            double scale = java.lang.Math.min(canvasWidth / image.getWidth(), canvasHeight / image.getHeight());
+            double drawWidth = image.getWidth() * scale;
+            double drawHeight = image.getHeight() * scale;
+            double x = (canvasWidth - drawWidth) / 2;
+            double y = (canvasHeight - drawHeight) / 2;
+            g.drawImage(image, x, y, drawWidth, drawHeight);
         });
     }