rough, this is a waste of tokens...

- VsmxInterpreter.interpretFunction: save/restore pc/exit/stack/callStates so
  re-entrant event firing (FireEventAnim, timers, movie callbacks) no longer
  truncates the outer script. This is what left ss_btn_mm without focus
  (Scenes appeared frozen: no selection, input ignored while audio continued).
- Add default geometric focus traversal for buttons with no direction handler:
  Controller.moveFocus picks the nearest visible focusable object. The PSP does
  this natively; English/Francais buttons have no onUp/onDown events in the RCO
  and relied on it.
- Track page visibility (BaseObject.displayed, set by PageObject.open/close) so
  traversal skips closed pages and collapsed (alpha 0) columns.
- Make BaseObject.trigger null-safe.

.gitignore

@@ -15,3 +15,4 @@ Thumbs.db
 
 # Disc images
 *.iso
+reference/

core/src/main/java/dev/quoije/umd/rco/RcoFile.java

@@ -58,6 +58,7 @@ public final class RcoFile {
         public final List<Entry> subEntries = new ArrayList<>();
         public byte[] data;
         public String[] texts;
+        public ImageObject image;
         public BaseObject obj;
         public VsmxBaseObject vsmxObject;
 
@@ -269,7 +270,9 @@ public final class RcoFile {
                     if (imgData != null && comp != COMPRESSION_NONE) {
                         imgData = decompressImage(imgData, comp, sizeUnpacked);
                     }
-                    images.put(entryOffset, new ImageObject(imgData));
+                    ImageObject imageObject = new ImageObject(imgData);
+                    images.put(entryOffset, imageObject);
+                    entry.image = imageObject;
                 }
             }
             case TABLE_MODEL -> {

core/src/main/java/dev/quoije/umd/rco/anim/MoveToAnim.java

@@ -20,24 +20,26 @@ public class MoveToAnim extends BaseAnim {
     @Override
     protected void doPlay(VsmxBaseObject object) {
         applyTo(ref, target -> {
+            // x/y/z are absolute target positions: objects are authored in their
+            // hidden state (e.g. off-screen) and tweened to the visible position.
             float tx = x.getFloatValue();
             float ty = y.getFloatValue();
             float tz = z.getFloatValue();
             long millis = (long) duration.getFloatValue();
             if (millis <= 0) {
-                target.animX = tx;
-                target.animY = ty;
-                target.animZ = tz;
+                target.posX.setFloatValue(tx);
+                target.posY.setFloatValue(ty);
+                target.posZ.setFloatValue(tz);
                 target.onDisplayUpdated();
                 return;
             }
-            float sx = target.animX;
-            float sy = target.animY;
-            float sz = target.animZ;
+            float sx = target.posX.getFloatValue();
+            float sy = target.posY.getFloatValue();
+            float sz = target.posZ.getFloatValue();
             Animator.getInstance().add(new Tween(millis, accelMode.getIntValue(), p -> {
-                target.animX = sx + (tx - sx) * p;
-                target.animY = sy + (ty - sy) * p;
-                target.animZ = sz + (tz - sz) * p;
+                target.posX.setFloatValue(sx + (tx - sx) * p);
+                target.posY.setFloatValue(sy + (ty - sy) * p);
+                target.posZ.setFloatValue(sz + (tz - sz) * p);
                 target.onDisplayUpdated();
             }));
         });

core/src/main/java/dev/quoije/umd/rco/object/BaseObject.java

@@ -30,6 +30,7 @@ public abstract class BaseObject extends BaseNativeObject implements IDisplay {
     protected Controller controller;
     private String name;
     private BaseNativeObject parent;
+    private boolean displayed;
 
     private Field[] getSortedFields() {
         Field[] fields = getClass().getFields();
@@ -97,6 +98,18 @@ public abstract class BaseObject extends BaseNativeObject implements IDisplay {
     public VsmxBaseObject createVsmxObject(VsmxInterpreter interpreter, VsmxBaseObject parent, RcoFile.Entry entry) {
         VsmxNativeObject object = new VsmxNativeObject(interpreter, this);
         setObject(object);
+        entry.vsmxObject = object;
+
+        // Seed the "texture" property with this object's static image so the
+        // script can read or replace it. Assignment is routed through the
+        // native setTexture setter, when one exists.
+        Object staticImage = getImage();
+        if (staticImage instanceof ImageObject imageObject) {
+            VsmxNativeObject textureObject = new VsmxNativeObject(interpreter, imageObject);
+            imageObject.setObject(textureObject);
+            object.setPropertyValue("texture", textureObject);
+        }
+
         if (entry.label != null) {
             name = entry.label;
             object.setPropertyValue("name", new VsmxString(interpreter, entry.label));
@@ -128,8 +141,17 @@ public abstract class BaseObject extends BaseNativeObject implements IDisplay {
         return name;
     }
 
+    /** True while this object is part of an opened page's display list. */
+    public boolean isDisplayed() {
+        return displayed;
+    }
+
+    public void setDisplayed(boolean displayed) {
+        this.displayed = displayed;
+    }
+
     protected void trigger(EventType event) {
-        if (event.getEvent() != null && controller != null) {
+        if (event != null && event.getEvent() != null && controller != null) {
             controller.getInterpreter().interpretScript(getObject(), event.getEvent());
         }
     }

core/src/main/java/dev/quoije/umd/rco/object/BasePositionObject.java

@@ -64,26 +64,14 @@ public class BasePositionObject extends BaseObject {
 
     @Override
     public int getWidth() {
-        float w = width.getFloatValue();
-        if (w == 0f) {
-            Object image = getImage();
-            if (image == null) {
-                w = 0f;
-            }
-        }
-        return Math.round(w * scaleWidth.getFloatValue());
+        // A zero authored size means "use the image's natural size"; the
+        // renderer falls back to the decoded image dimensions when this is 0.
+        return Math.round(width.getFloatValue() * scaleWidth.getFloatValue());
     }
 
     @Override
     public int getHeight() {
-        float h = height.getFloatValue();
-        if (h == 0f) {
-            Object image = getImage();
-            if (image == null) {
-                h = 0f;
-            }
-        }
-        return Math.round(h * scaleHeight.getFloatValue());
+        return Math.round(height.getFloatValue() * scaleHeight.getFloatValue());
     }
 
     @Override

core/src/main/java/dev/quoije/umd/rco/object/ButtonObject.java

@@ -6,6 +6,8 @@ import dev.quoije.umd.rco.type.EventType;
 import dev.quoije.umd.rco.type.ImageType;
 import dev.quoije.umd.rco.type.IntType;
 import dev.quoije.umd.rco.type.TextType;
+import dev.quoije.umd.rco.vsmx.objects.BaseNativeObject;
+import dev.quoije.umd.rco.vsmx.objects.Controller;
 
 /** A button object. */
 public class ButtonObject extends BasePositionObject {
@@ -24,16 +26,38 @@ public class ButtonObject extends BasePositionObject {
     @ObjectField(order = 212) public EventType onContextMenu;
     @ObjectField(order = 213) public IntType unknownInt40;
 
+    /** Runtime texture assigned by the script; overrides the static image. */
+    private ImageObject texture;
+
     @Override
     public Object getImage() {
+        if (texture != null) {
+            return texture;
+        }
         return image.getImage();
     }
 
+    /** Called via the VSMX {@code texture} property setter. */
+    public void setTexture(BaseNativeObject texture) {
+        if (texture instanceof ImageObject imageObject) {
+            this.texture = imageObject;
+        }
+        onDisplayUpdated();
+    }
+
     @Override
     public Object getFocusImage() {
         return focus.getImage();
     }
 
+    @Override
+    public void setController(Controller controller) {
+        super.setController(controller);
+        if (controller != null) {
+            controller.registerFocusable(this);
+        }
+    }
+
     @Override
     public void setFocus() {
         trigger(onFocusIn);
@@ -53,21 +77,37 @@ public class ButtonObject extends BasePositionObject {
 
     @Override
     public void onUp() {
-        trigger(onFocusUp);
+        if (onFocusUp != null && onFocusUp.getEvent() != null) {
+            trigger(onFocusUp);
+        } else if (controller != null) {
+            controller.moveFocus(this, 0, 1);
+        }
     }
 
     @Override
     public void onDown() {
-        trigger(onFocusDown);
+        if (onFocusDown != null && onFocusDown.getEvent() != null) {
+            trigger(onFocusDown);
+        } else if (controller != null) {
+            controller.moveFocus(this, 0, -1);
+        }
     }
 
     @Override
     public void onLeft() {
-        trigger(onFocusLeft);
+        if (onFocusLeft != null && onFocusLeft.getEvent() != null) {
+            trigger(onFocusLeft);
+        } else if (controller != null) {
+            controller.moveFocus(this, -1, 0);
+        }
     }
 
     @Override
     public void onRight() {
-        trigger(onFocusRight);
+        if (onFocusRight != null && onFocusRight.getEvent() != null) {
+            trigger(onFocusRight);
+        } else if (controller != null) {
+            controller.moveFocus(this, 1, 0);
+        }
     }
 }

core/src/main/java/dev/quoije/umd/rco/object/IconObject.java

@@ -3,6 +3,7 @@ package dev.quoije.umd.rco.object;
 
 import dev.quoije.umd.rco.ObjectField;
 import dev.quoije.umd.rco.type.ImageType;
+import dev.quoije.umd.rco.vsmx.objects.BaseNativeObject;
 
 /** An icon object. */
 public class IconObject extends BasePositionObject {
@@ -11,8 +12,22 @@ public class IconObject extends BasePositionObject {
     @ObjectField(order = 202) public ImageType unknownImage18;
     @ObjectField(order = 203) public ImageType unknownImage20;
 
+    /** Runtime texture assigned by the script; overrides the static image. */
+    private ImageObject texture;
+
     @Override
     public Object getImage() {
+        if (texture != null) {
+            return texture;
+        }
         return unknownImage16.getImage();
     }
+
+    /** Called via the VSMX {@code texture} property setter. */
+    public void setTexture(BaseNativeObject texture) {
+        if (texture instanceof ImageObject imageObject) {
+            this.texture = imageObject;
+        }
+        onDisplayUpdated();
+    }
 }

core/src/main/java/dev/quoije/umd/rco/object/ImageObject.java

@@ -1,8 +1,10 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 package dev.quoije.umd.rco.object;
 
+import dev.quoije.umd.rco.vsmx.objects.BaseNativeObject;
+
 /** An image entry from the RCO IMG table (raw bytes until decoded by the UI). */
-public final class ImageObject {
+public class ImageObject extends BaseNativeObject {
 
     private final byte[] data;
 

core/src/main/java/dev/quoije/umd/rco/object/PageObject.java

@@ -35,6 +35,7 @@ public class PageObject extends BaseObject {
         VsmxBaseObject children = object.getPropertyValue(Resource.childrenName);
         for (String childName : children.getPropertyNames()) {
             VsmxBaseObject child = children.getPropertyValue(childName);
+            setDisplayed(child, true);
             display.add(child);
             display(child);
         }
@@ -47,11 +48,18 @@ public class PageObject extends BaseObject {
         VsmxBaseObject children = object.getPropertyValue(Resource.childrenName);
         for (String childName : children.getPropertyNames()) {
             VsmxBaseObject child = children.getPropertyValue(childName);
+            setDisplayed(child, false);
             display.remove(child);
             hide(child);
         }
     }
 
+    private static void setDisplayed(VsmxBaseObject object, boolean displayed) {
+        if (object instanceof VsmxNativeObject nativeObject && nativeObject.getObject() instanceof BaseObject baseObject) {
+            baseObject.setDisplayed(displayed);
+        }
+    }
+
     private BasePositionObject getFirstButton(VsmxBaseObject object) {
         if (!object.hasPropertyValue(Resource.childrenName)) {
             return null;

core/src/main/java/dev/quoije/umd/rco/object/PlaneObject.java

@@ -4,6 +4,7 @@ package dev.quoije.umd.rco.object;
 import dev.quoije.umd.rco.ObjectField;
 import dev.quoije.umd.rco.type.ImageType;
 import dev.quoije.umd.rco.type.IntType;
+import dev.quoije.umd.rco.vsmx.objects.BaseNativeObject;
 
 /** A plane (textured rectangle). */
 public class PlaneObject extends BasePositionObject {
@@ -11,8 +12,22 @@ public class PlaneObject extends BasePositionObject {
     @ObjectField(order = 201) public ImageType image;
     @ObjectField(order = 202) public IntType unknownInt18;
 
+    /** Runtime texture assigned by the script; overrides the static image. */
+    private ImageObject texture;
+
     @Override
     public Object getImage() {
+        if (texture != null) {
+            return texture;
+        }
         return image.getImage();
     }
+
+    /** Called via the VSMX {@code texture} property setter. */
+    public void setTexture(BaseNativeObject texture) {
+        if (texture instanceof ImageObject imageObject) {
+            this.texture = imageObject;
+        }
+        onDisplayUpdated();
+    }
 }

core/src/main/java/dev/quoije/umd/rco/object/UButtonObject.java

@@ -5,6 +5,8 @@ import dev.quoije.umd.rco.ObjectField;
 import dev.quoije.umd.rco.type.EventType;
 import dev.quoije.umd.rco.type.ImageType;
 import dev.quoije.umd.rco.type.IntType;
+import dev.quoije.umd.rco.vsmx.objects.BaseNativeObject;
+import dev.quoije.umd.rco.vsmx.objects.Controller;
 
 /** A user button object (navigation with onLeft/onRight/onUp/onDown events). */
 public class UButtonObject extends BasePositionObject {
@@ -19,11 +21,33 @@ public class UButtonObject extends BasePositionObject {
     @ObjectField(order = 208) public EventType onDown;
     @ObjectField(order = 209) public IntType unknownInt32;
 
+    /** Runtime texture assigned by the script; overrides the static image. */
+    private ImageObject texture;
+
     @Override
     public Object getImage() {
+        if (texture != null) {
+            return texture;
+        }
         return image.getImage();
     }
 
+    /** Called via the VSMX {@code texture} property setter. */
+    public void setTexture(BaseNativeObject texture) {
+        if (texture instanceof ImageObject imageObject) {
+            this.texture = imageObject;
+        }
+        onDisplayUpdated();
+    }
+
+    @Override
+    public void setController(Controller controller) {
+        super.setController(controller);
+        if (controller != null) {
+            controller.registerFocusable(this);
+        }
+    }
+
     @Override
     public void setFocus() {
         trigger(onFocusIn);
@@ -43,21 +67,37 @@ public class UButtonObject extends BasePositionObject {
 
     @Override
     public void onUp() {
-        trigger(onUp);
+        if (onUp != null && onUp.getEvent() != null) {
+            trigger(onUp);
+        } else if (controller != null) {
+            controller.moveFocus(this, 0, 1);
+        }
     }
 
     @Override
     public void onDown() {
-        trigger(onDown);
+        if (onDown != null && onDown.getEvent() != null) {
+            trigger(onDown);
+        } else if (controller != null) {
+            controller.moveFocus(this, 0, -1);
+        }
     }
 
     @Override
     public void onLeft() {
-        trigger(onLeft);
+        if (onLeft != null && onLeft.getEvent() != null) {
+            trigger(onLeft);
+        } else if (controller != null) {
+            controller.moveFocus(this, -1, 0);
+        }
     }
 
     @Override
     public void onRight() {
-        trigger(onRight);
+        if (onRight != null && onRight.getEvent() != null) {
+            trigger(onRight);
+        } else if (controller != null) {
+            controller.moveFocus(this, 1, 0);
+        }
     }
 }

core/src/main/java/dev/quoije/umd/rco/vsmx/interpreter/VsmxInterpreter.java

@@ -458,9 +458,23 @@ public final class VsmxInterpreter {
 
     /** Runs the script's main body, populating the given global variables object. */
     public synchronized void run(VsmxObject globalVariables) {
+        // This can be invoked re-entrantly (Controller.changeResource loads and
+        // runs a new resource while the previous resource's script is still on
+        // the stack), so the outer execution state must be preserved and
+        // restored exactly like interpretFunction does. Without this, the
+        // nested run clobbers pc/exit/stack/callStates and the outer script
+        // crashes with a null operand stack after the nested run returns.
+        int savedPc = pc;
+        boolean savedExit = exit;
+        Deque<VsmxBaseObject> savedStack = stack;
+        Deque<VsmxCallState> savedCallStates = callStates;
+        VsmxCallState savedCallState = callState;
+
         pc = 0;
         exit = false;
         callStates = new ArrayDeque<>();
+        stack = null;
+        callState = null;
         pushCallState(VsmxNull.singleton, 0, false, true);
         this.globalVariables = globalVariables;
 
@@ -470,8 +484,16 @@ public final class VsmxInterpreter {
 
         interpret();
 
-        callStates.clear();
-        callState = null;
+        pc = savedPc;
+        exit = savedExit;
+        stack = savedStack;
+        callStates = savedCallStates;
+        callState = savedCallState;
+    }
+
+    /** Requests the currently-running script to stop after the current instruction. */
+    public void stop() {
+        exit = true;
     }
 
     private void callFunction(VsmxFunction function, VsmxBaseObject thisObject, VsmxBaseObject[] arguments,
@@ -498,6 +520,19 @@ public final class VsmxInterpreter {
 
     /** Interprets a function body in a fresh call frame. */
     public synchronized void interpretFunction(VsmxFunction function, VsmxBaseObject object, VsmxBaseObject[] arguments) {
+        // This entry point can be invoked re-entrantly (FireEventAnim, timers,
+        // movie callbacks all run from inside an already-running script), so the
+        // outer execution state must be preserved and restored. Without this,
+        // the inner RETURN would set {@code exit} and truncate the outer script.
+        int savedPc = pc;
+        boolean savedExit = exit;
+        Deque<VsmxBaseObject> savedStack = stack;
+        Deque<VsmxCallState> savedCallStates = callStates;
+        VsmxCallState savedCallState = callState;
+
+        callStates = new ArrayDeque<>();
+        stack = null;
+        callState = null;
         pushCallState(object, function.getLocalVars(), false, true);
         for (int i = 1; i <= function.getArgs(); i++) {
             if (arguments == null || i > arguments.length) {
@@ -508,6 +543,12 @@ public final class VsmxInterpreter {
         }
         pc = function.getStartLine();
         interpret();
+
+        pc = savedPc;
+        exit = savedExit;
+        stack = savedStack;
+        callStates = savedCallStates;
+        callState = savedCallState;
     }
 
     /** Interprets a script event handler by name (e.g. "script:/main/onPush"). */

core/src/main/java/dev/quoije/umd/rco/vsmx/interpreter/VsmxNativeObject.java

@@ -3,6 +3,8 @@ package dev.quoije.umd.rco.vsmx.interpreter;
 
 import dev.quoije.umd.rco.vsmx.objects.BaseNativeObject;
 
+import java.lang.reflect.Method;
+
 /** A VSMX object wrapping a native Java object. */
 public class VsmxNativeObject extends VsmxObject {
 
@@ -17,6 +19,27 @@ public class VsmxNativeObject extends VsmxObject {
         return object;
     }
 
+    /**
+     * Assigning a native object to a property is routed through a matching
+     * {@code set<Name>(BaseNativeObject)} method when the wrapped object
+     * declares one. This is how {@code plane.texture = image} reaches
+     * {@code PlaneObject.setTexture}.
+     */
+    @Override
+    public void setPropertyValue(String name, VsmxBaseObject value) {
+        if (object != null && name != null && !name.isEmpty() && value instanceof VsmxNativeObject nativeValue) {
+            String setterName = "set" + Character.toUpperCase(name.charAt(0)) + name.substring(1);
+            try {
+                Method setter = object.getClass().getMethod(setterName, BaseNativeObject.class);
+                setter.invoke(object, nativeValue.getObject());
+                return;
+            } catch (ReflectiveOperationException e) {
+                // No matching setter; fall back to storing the property.
+            }
+        }
+        super.setPropertyValue(name, value);
+    }
+
     @Override
     public String toString() {
         return object == null ? super.toString() : object.toString() + super.toString();

core/src/main/java/dev/quoije/umd/rco/vsmx/objects/Controller.java

@@ -10,6 +10,9 @@ import dev.quoije.umd.rco.vsmx.interpreter.VsmxNativeObject;
 import dev.quoije.umd.rco.vsmx.interpreter.VsmxNull;
 import dev.quoije.umd.rco.vsmx.interpreter.VsmxString;
 
+import java.util.ArrayList;
+import java.util.List;
+
 /** The controller native object: input focus and resource management. */
 public class Controller extends BaseNativeObject {
 
@@ -20,6 +23,7 @@ public class Controller extends BaseNativeObject {
     private VsmxBaseObject userData;
     private String resource;
     private BasePositionObject focus;
+    private final List<BasePositionObject> focusables = new ArrayList<>();
 
     public static VsmxNativeObject create(VsmxInterpreter interpreter, MenuHost menuHost, String resource) {
         Controller controller = new Controller(interpreter, menuHost);
@@ -64,6 +68,10 @@ public class Controller extends BaseNativeObject {
         if (!resource.equals(resourceName)) {
             resource = resourceName;
             menuHost.changeResource(resourceName);
+            // The resource switch abandons this interpreter; stop the script
+            // that requested it so it does not keep running against a stale
+            // menu (the PSP drops the old resource's script at this point).
+            interpreter.stop();
         }
         return VsmxBoolean.getValue(true);
     }
@@ -79,6 +87,63 @@ public class Controller extends BaseNativeObject {
         return focus;
     }
 
+    /** Registers a focusable object so default (geometric) focus traversal can reach it. */
+    public void registerFocusable(BasePositionObject object) {
+        synchronized (focusables) {
+            if (!focusables.contains(object)) {
+                focusables.add(object);
+            }
+        }
+    }
+
+    /**
+     * Moves focus to the nearest visible, focusable object in the given direction
+     * when a button has no script handler for that direction. {@code dx}/{@code dy}
+     * use the framebuffer coordinate system (+X right, +Y up).
+     */
+    public void moveFocus(BasePositionObject from, int dx, int dy) {
+        int fromX = from.getX() + from.getWidth() / 2;
+        int fromY = from.getY() + from.getHeight() / 2;
+
+        BasePositionObject best = null;
+        double bestScore = Double.MAX_VALUE;
+        synchronized (focusables) {
+            for (BasePositionObject candidate : focusables) {
+                if (candidate == from || !candidate.isDisplayed() || candidate.getAlpha() <= 0f
+                        || candidate.getImage() == null) {
+                    continue;
+                }
+                int candidateX = candidate.getX() + candidate.getWidth() / 2;
+                int candidateY = candidate.getY() + candidate.getHeight() / 2;
+                int offsetX = candidateX - fromX;
+                int offsetY = candidateY - fromY;
+                if (dy < 0 && offsetY >= 0) {
+                    continue;
+                }
+                if (dy > 0 && offsetY <= 0) {
+                    continue;
+                }
+                if (dx < 0 && offsetX >= 0) {
+                    continue;
+                }
+                if (dx > 0 && offsetX <= 0) {
+                    continue;
+                }
+                double primary = dx != 0 ? java.lang.Math.abs(offsetX) : java.lang.Math.abs(offsetY);
+                double secondary = dx != 0 ? java.lang.Math.abs(offsetY) : java.lang.Math.abs(offsetX);
+                double score = primary * 10 + secondary;
+                if (score < bestScore) {
+                    bestScore = score;
+                    best = candidate;
+                }
+            }
+        }
+
+        if (best != null) {
+            best.setFocus();
+        }
+    }
+
     public void onUp() {
         if (focus != null) {
             focus.onUp();

core/src/main/java/dev/quoije/umd/rco/vsmx/objects/GlobalVariables.java

@@ -50,7 +50,7 @@ public class GlobalVariables extends BaseNativeObject {
     }
 
     public void writeln(VsmxBaseObject object, VsmxBaseObject s1, VsmxBaseObject s2, VsmxBaseObject s3) {
-        log.append(s1.getStringValue()).append(s3.getStringValue()).append('\n');
+        log.append(s1.getStringValue()).append(s2.getStringValue()).append(s3.getStringValue()).append('\n');
     }
 
     public VsmxBaseObject parseFloat(VsmxBaseObject object, VsmxBaseObject value) {

core/src/main/java/dev/quoije/umd/rco/vsmx/objects/Resource.java

@@ -7,6 +7,7 @@ import dev.quoije.umd.rco.vsmx.interpreter.VsmxBaseObject;
 import dev.quoije.umd.rco.vsmx.interpreter.VsmxInterpreter;
 import dev.quoije.umd.rco.vsmx.interpreter.VsmxNativeObject;
 import dev.quoije.umd.rco.vsmx.interpreter.VsmxObject;
+import dev.quoije.umd.rco.vsmx.interpreter.VsmxString;
 
 /**
  * The resource native object, exposing the RCO object tables to the script.
@@ -50,6 +51,15 @@ public class Resource extends BaseNativeObject {
 
     private static void createObjectFromEntry(VsmxInterpreter interpreter, Display display, Controller controller,
                                               VsmxBaseObject parent, RcoFile.Entry entry) {
+        if (entry.image != null) {
+            VsmxNativeObject object = new VsmxNativeObject(interpreter, entry.image);
+            entry.image.setObject(object);
+            if (entry.label != null) {
+                object.setPropertyValue("name", new VsmxString(interpreter, entry.label));
+                parent.setPropertyValue(entry.label, object);
+            }
+            return;
+        }
         if (entry.obj == null) {
             return;
         }
@@ -60,7 +70,14 @@ public class Resource extends BaseNativeObject {
         if (!entry.subEntries.isEmpty()) {
             VsmxObject children = new VsmxObject(interpreter, null);
             object.setPropertyValue(childrenName, children);
-            for (RcoFile.Entry child : entry.subEntries) {
+            for (int i = 0; i < entry.subEntries.size(); i++) {
+                RcoFile.Entry child = entry.subEntries.get(i);
+                // Unlabeled children (e.g. animation records) still need to be
+                // registered under "children" so scripts/anim playback can reach
+                // them. Assign a synthetic zero-padded name, as JPCSP does.
+                if (child.label == null) {
+                    child.label = String.format("%04d", i);
+                }
                 createObjectFromEntry(interpreter, display, controller, children, child);
             }
         }

core/src/main/java/dev/quoije/umd/rco/vsmx/objects/Timer.java

@@ -76,7 +76,10 @@ public class Timer extends BaseNativeObject {
             if (due != null) {
                 if (due.function instanceof VsmxFunction f) {
                     synchronized (callbackLock) {
-                        interpreter.interpretFunction(f, due.object, due.params);
+                        // Fire on the interpreter that compiled the callback so
+                        // timers survive a resource switch (each resource owns
+                        // its own interpreter).
+                        f.getInterpreter().interpretFunction(f, due.object, due.params);
                     }
                 }
                 continue;

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

@@ -72,6 +72,17 @@ public final class PlayerApp extends Application {
     private volatile VsmxNativeObject controllerObject;
     private long lastMenuKeyNanos = 0;
 
+    /** The open disc image, kept for the lifetime of the app so menu resources
+     *  (RCO files) can be switched at runtime. */
+    private volatile UmdIsoReader iso;
+    private volatile String isoPath;
+    private volatile Playlist playlist;
+    /** The script global scope, shared across resource switches so globals
+     *  (e.g. {@code g_nResChangeInfo}) survive. */
+    private volatile VsmxNativeObject globalVariables;
+    /** False until the first resource has run; later loads fire onChangeResource. */
+    private boolean resourceInitialized;
+
     /** The active decode engine, closed when a new stream starts. */
     private volatile PlaybackEngine currentEngine;
     /** Bumped each time playback starts so stale streams stop themselves. */
@@ -173,25 +184,55 @@ public final class PlayerApp extends Application {
     }
 
     private void loadMenu(String isoPath) {
-        try (UmdIsoReader iso = new UmdIsoReader(Path.of(isoPath))) {
-            Playlist playlist = Playlist.parse(iso);
-            byte[] rcoData = readFile(iso, "UMD_VIDEO/RESOURCE/EN100000.RCO");
+        try {
+            this.iso = new UmdIsoReader(Path.of(isoPath));
+            this.isoPath = isoPath;
+            this.playlist = Playlist.parse(iso);
+            this.resourceInitialized = false;
+            loadResource("EN100000");
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+
+    /** Loads (or switches to) a menu resource and starts its script. */
+    private void loadResource(String resourceName) {
+        UmdIsoReader disc = iso;
+        if (disc == null) {
+            return;
+        }
+
+        try {
+            byte[] rcoData = readFile(disc, "UMD_VIDEO/RESOURCE/" + resourceName + ".RCO");
             if (rcoData == null) {
-                System.err.println("EN100000.RCO not found");
+                System.err.println("Menu resource not found: " + resourceName + ".RCO");
                 return;
             }
 
             RcoFile rco = new RcoFile(rcoData);
             if (!rco.isValid()) {
-                System.err.println("RCO invalid");
+                System.err.println("RCO invalid: " + resourceName);
                 return;
             }
 
-            Vsmx vsmx = new Vsmx(rco.vsmxData(), "main");
+            // Each resource gets a fresh interpreter so that switching
+            // resources never swaps the bytecode out from under an already
+            // running script (the old script keeps its own code and state).
             VsmxInterpreter interpreter = new VsmxInterpreter();
+            Vsmx vsmx = new Vsmx(rco.vsmxData(), "main");
             interpreter.setVsmx(vsmx);
+            this.menuInterpreter = interpreter;
+            if (this.globalVariables == null) {
+                this.globalVariables = GlobalVariables.create(interpreter, SCREEN_WIDTH, SCREEN_HEIGHT);
+            }
 
-            renderer = new RcoRenderer(menuCanvas);
+            if (renderer == null) {
+                renderer = new RcoRenderer(menuCanvas);
+            } else {
+                // The previous resource's object tree belongs to a different
+                // script; drop it before the new page tree is registered.
+                renderer.changeResource();
+            }
 
             MenuHost menuHost = new MenuHost() {
                 @Override
@@ -199,7 +240,7 @@ public final class PlayerApp extends Application {
                                       int audioFlag, int subtitleNumber, int subtitleFlag) {
                     Playlist.Stream stream = playlist.streamForPlayListNumber(playListNumber);
                     if (stream != null) {
-                        startPlayback(isoPath, stream, playListNumber);
+                        startPlayback(PlayerApp.this.isoPath, stream, playListNumber);
                     }
                 }
 
@@ -214,26 +255,32 @@ public final class PlayerApp extends Application {
                 }
 
                 @Override
-                public void changeResource(String resourceName) {
+                public void changeResource(String newResource) {
+                    loadResource(newResource);
                 }
             };
 
-            VsmxNativeObject globals = GlobalVariables.create(interpreter, SCREEN_WIDTH, SCREEN_HEIGHT);
-            VsmxNativeObject controllerObject = Controller.create(interpreter, menuHost, "EN100000");
+            VsmxNativeObject controllerObject = Controller.create(interpreter, menuHost, resourceName);
             VsmxNativeObject movieplayer = MoviePlayer.create(interpreter, menuHost, controllerObject);
             VsmxNativeObject resource = Resource.create(interpreter, renderer, controllerObject, rco);
             VsmxNativeObject math = Math.create(interpreter);
-            globals.setPropertyValue(Controller.objectName, controllerObject);
-            globals.setPropertyValue(MoviePlayer.objectName, movieplayer);
-            globals.setPropertyValue(Resource.objectName, resource);
-            globals.setPropertyValue(Math.objectName, math);
+            globalVariables.setPropertyValue(Controller.objectName, controllerObject);
+            globalVariables.setPropertyValue(MoviePlayer.objectName, movieplayer);
+            globalVariables.setPropertyValue(Resource.objectName, resource);
+            globalVariables.setPropertyValue(Math.objectName, math);
+
+            interpreter.run(globalVariables);
 
-            interpreter.run(globals);
             controller = (Controller) controllerObject.getObject();
             moviePlayer = (MoviePlayer) movieplayer.getObject();
-            menuInterpreter = interpreter;
             this.controllerObject = controllerObject;
-            controller.callCallback(interpreter, "onAutoPlay", null);
+
+            if (!resourceInitialized) {
+                resourceInitialized = true;
+                controller.callCallback(interpreter, "onAutoPlay", null);
+            } else {
+                controller.callCallback(interpreter, "onChangeResource", null);
+            }
         } catch (Exception e) {
             e.printStackTrace();
         }

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

@@ -11,6 +11,7 @@ import javafx.application.Platform;
 import javafx.scene.canvas.Canvas;
 import javafx.scene.canvas.GraphicsContext;
 import javafx.scene.image.Image;
+import javafx.scene.image.WritableImage;
 
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
@@ -158,10 +159,28 @@ public final class RcoRenderer implements Display {
         if (data == null || data.length == 0) {
             return null;
         }
+        // Decode synchronously through ImageIO. JavaFX's `new Image(InputStream)`
+        // loads in the background and `GraphicsContext.drawImage` silently skips
+        // images whose pixels have not been uploaded yet, which leaves the whole
+        // menu invisible even though the image headers are readable.
         try (ByteArrayInputStream in = new ByteArrayInputStream(data)) {
-            return new Image(in);
+            java.awt.image.BufferedImage buffered = javax.imageio.ImageIO.read(in);
+            if (buffered == null) {
+                return null;
+            }
+            return toFxImage(buffered);
         } catch (IOException e) {
             return null;
         }
     }
+
+    private static Image toFxImage(java.awt.image.BufferedImage buffered) {
+        int w = buffered.getWidth();
+        int h = buffered.getHeight();
+        int[] argb = new int[w * h];
+        buffered.getRGB(0, 0, w, h, argb, 0, w);
+        WritableImage image = new WritableImage(w, h);
+        image.getPixelWriter().setPixels(0, 0, w, h, javafx.scene.image.PixelFormat.getIntArgbInstance(), argb, 0, w);
+        return image;
+    }
 }