Merge 3929d448156e75c74c145e9984d8d4a0642bbe9d into 26ce7e4f2844a445bf77b4b14977d62e6434df08

src/android/app/src/main/java/org/citra/citra_emu/NativeLibrary.kt

@@ -125,6 +125,10 @@ object NativeLibrary {
     external fun surfaceDestroyed()
     external fun doFrame()
 
+    //Second window
+    external fun secondarySurfaceChanged(secondary_surface: Surface)
+    external fun secondarySurfaceDestroyed()
+    external fun disableSecondaryScreen()
     /**
      * Unpauses emulation from a paused state.
      */

src/android/app/src/main/java/org/citra/citra_emu/activities/EmulationActivity.kt

@@ -4,14 +4,18 @@
 
 package org.citra.citra_emu.activities
 
+import SecondScreenPresentation
 import android.Manifest.permission
 import android.annotation.SuppressLint
-import android.app.Activity
+import android.app.Presentation
+import android.content.Context
 import android.content.Intent
 import android.content.SharedPreferences
 import android.content.pm.PackageManager
+import android.hardware.display.DisplayManager
 import android.net.Uri
 import android.os.Bundle
+import android.view.Display
 import android.view.InputDevice
 import android.view.KeyEvent
 import android.view.MotionEvent
@@ -32,6 +36,7 @@ import org.citra.citra_emu.camera.StillImageCameraHelper.OnFilePickerResult
 import org.citra.citra_emu.contracts.OpenFileResultContract
 import org.citra.citra_emu.databinding.ActivityEmulationBinding
 import org.citra.citra_emu.display.ScreenAdjustmentUtil
+import org.citra.citra_emu.display.SecondaryScreenLayout
 import org.citra.citra_emu.features.hotkeys.HotkeyUtility
 import org.citra.citra_emu.features.settings.model.BooleanSetting
 import org.citra.citra_emu.features.settings.model.IntSetting
@@ -56,6 +61,34 @@ class EmulationActivity : AppCompatActivity() {
     private lateinit var binding: ActivityEmulationBinding
     private lateinit var screenAdjustmentUtil: ScreenAdjustmentUtil
     private lateinit var hotkeyUtility: HotkeyUtility
+    private var secondScreenPresentation: Presentation? = null
+    private lateinit var displayManager: DisplayManager
+
+    private fun updatePresentation() {
+        displayManager = getSystemService(Context.DISPLAY_SERVICE) as DisplayManager
+        val display = getCustomerDisplay();
+        if (secondScreenPresentation != null && (IntSetting.SECONDARY_SCREEN_LAYOUT.int == SecondaryScreenLayout.NONE.int || display == null)) {
+            releasePresentation();
+        }
+        if (secondScreenPresentation == null || secondScreenPresentation?.display != display) {
+            secondScreenPresentation?.dismiss()
+            if (display != null && IntSetting.SECONDARY_SCREEN_LAYOUT.int != SecondaryScreenLayout.NONE.int) {
+                secondScreenPresentation = SecondScreenPresentation(this, display)
+                secondScreenPresentation?.show();
+            }
+        }
+    }
+    private fun releasePresentation() {
+        if (secondScreenPresentation != null) {
+            NativeLibrary.disableSecondaryScreen()
+            secondScreenPresentation?.dismiss();
+            secondScreenPresentation = null;
+        }
+    }
+
+    private fun getCustomerDisplay(): Display? {
+        return displayManager?.displays?.firstOrNull { it.isValid && it.displayId != Display.DEFAULT_DISPLAY }
+    }
 
     private val emulationFragment: EmulationFragment
         get() {
@@ -68,10 +101,9 @@ class EmulationActivity : AppCompatActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         ThemeUtil.setTheme(this)
-
         settingsViewModel.settings.loadSettings()
-
         super.onCreate(savedInstanceState)
+        updatePresentation();
 
         binding = ActivityEmulationBinding.inflate(layoutInflater)
         screenAdjustmentUtil = ScreenAdjustmentUtil(this, windowManager, settingsViewModel.settings)
@@ -117,6 +149,11 @@ class EmulationActivity : AppCompatActivity() {
         applyOrientationSettings() // Check for orientation settings changes on runtime
     }
 
+    override fun onStop() {
+        releasePresentation()
+        super.onStop()
+    }
+
     override fun onWindowFocusChanged(hasFocus: Boolean) {
         super.onWindowFocusChanged(hasFocus)
         enableFullscreenImmersive()
@@ -124,6 +161,7 @@ class EmulationActivity : AppCompatActivity() {
 
     public override fun onRestart() {
         super.onRestart()
+        updatePresentation()
         NativeLibrary.reloadCameraDevices()
     }
 
@@ -141,6 +179,7 @@ class EmulationActivity : AppCompatActivity() {
         EmulationLifecycleUtil.clear()
         isEmulationRunning = false
         instance = null
+        releasePresentation()
         super.onDestroy()
     }
 

src/android/app/src/main/java/org/citra/citra_emu/display/ScreenLayout.kt

@@ -49,3 +49,17 @@ enum class PortraitScreenLayout(val int: Int) {
         }
     }
 }
+
+enum class SecondaryScreenLayout(val int: Int) {
+    // These must match what is defined in src/common/settings.h
+    NONE(0),
+    TOP_SCREEN(1),
+    BOTTOM_SCREEN(2),
+    SIDE_BY_SIDE(3);
+
+    companion object {
+        fun from(int: Int): SecondaryScreenLayout {
+            return entries.firstOrNull { it.int == int } ?: NONE
+        }
+    }
+}

src/android/app/src/main/java/org/citra/citra_emu/display/SecondScreenPresentation.kt

@@ -0,0 +1,48 @@
+import android.app.Presentation
+import android.content.Context
+import android.os.Bundle
+import android.view.Display
+import android.view.SurfaceHolder
+import android.view.SurfaceView
+import org.citra.citra_emu.NativeLibrary
+
+
+
+class SecondScreenPresentation(
+    context: Context,
+    display: Display,
+) : Presentation(context, display) {
+    private lateinit var surfaceView: SurfaceView
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+
+        // Initialize SurfaceView
+        surfaceView = SurfaceView(context)
+        surfaceView.holder.addCallback(object : SurfaceHolder.Callback {
+            override fun surfaceCreated(holder: SurfaceHolder) {
+
+            }
+
+            override fun surfaceChanged(
+                holder: SurfaceHolder,
+                format: Int,
+                width: Int,
+                height: Int
+            ) {
+                NativeLibrary.secondarySurfaceChanged(holder.surface)
+            }
+
+            override fun surfaceDestroyed(holder: SurfaceHolder) {
+                NativeLibrary.secondarySurfaceDestroyed()
+            }
+        })
+
+        setContentView(surfaceView) // Set SurfaceView as content
+    }
+
+    // Publicly accessible method to get the SurfaceHolder
+    fun getSurfaceHolder(): SurfaceHolder {
+        return surfaceView.holder
+    }
+}

src/android/app/src/main/java/org/citra/citra_emu/features/settings/model/IntSetting.kt

@@ -34,6 +34,7 @@ enum class IntSetting(
     LANDSCAPE_BOTTOM_WIDTH("custom_bottom_width",Settings.SECTION_LAYOUT,640),
     LANDSCAPE_BOTTOM_HEIGHT("custom_bottom_height",Settings.SECTION_LAYOUT,480),
     PORTRAIT_SCREEN_LAYOUT("portrait_layout_option",Settings.SECTION_LAYOUT,0),
+    SECONDARY_SCREEN_LAYOUT("secondary_screen_layout",Settings.SECTION_LAYOUT,0),
     PORTRAIT_TOP_X("custom_portrait_top_x",Settings.SECTION_LAYOUT,0),
     PORTRAIT_TOP_Y("custom_portrait_top_y",Settings.SECTION_LAYOUT,0),
     PORTRAIT_TOP_WIDTH("custom_portrait_top_width",Settings.SECTION_LAYOUT,800),

src/android/app/src/main/java/org/citra/citra_emu/features/settings/ui/SettingsFragmentPresenter.kt

@@ -962,6 +962,17 @@ class SettingsFragmentPresenter(private val fragmentView: SettingsFragmentView)
                     IntSetting.PORTRAIT_SCREEN_LAYOUT.defaultValue
                 )
             )
+            add(
+                SingleChoiceSetting(
+                    IntSetting.SECONDARY_SCREEN_LAYOUT,
+                    R.string.emulation_switch_secondary_layout,
+                    0,
+                    R.array.secondaryLayouts,
+                    R.array.secondaryLayoutValues,
+                    IntSetting.SECONDARY_SCREEN_LAYOUT.key,
+                    IntSetting.SECONDARY_SCREEN_LAYOUT.defaultValue
+                )
+            )
             add(
                 SingleChoiceSetting(
                     IntSetting.SMALL_SCREEN_POSITION,

src/android/app/src/main/java/org/citra/citra_emu/features/settings/utils/SettingsFile.kt

@@ -272,6 +272,9 @@ object SettingsFile {
         val settings = section.settings
         val keySet: Set<String> = settings.keys
         for (key in keySet) {
+            if (key.equals("secondary_screen_layout")) {
+                println("hi");
+            }
             val setting = settings[key]
             parser.put(header, setting!!.key, setting.valueAsString)
         }

src/android/app/src/main/java/org/citra/citra_emu/fragments/EmulationFragment.kt

@@ -5,9 +5,12 @@
 package org.citra.citra_emu.fragments
 
 import android.annotation.SuppressLint
+import android.app.Presentation
 import android.content.Context
 import android.content.DialogInterface
 import android.content.SharedPreferences
+import android.hardware.display.DisplayManager
+import android.media.MediaRouter
 import android.net.Uri
 import android.os.Bundle
 import android.os.Handler
@@ -16,6 +19,7 @@ import android.os.SystemClock
 import android.text.Editable
 import android.text.TextWatcher
 import android.view.Choreographer
+import android.view.Display
 import android.view.LayoutInflater
 import android.view.MotionEvent
 import android.view.Surface
@@ -26,6 +30,7 @@ import android.widget.PopupMenu
 import android.widget.TextView
 import android.widget.Toast
 import androidx.activity.OnBackPressedCallback
+import androidx.core.content.ContextCompat.getSystemService
 import androidx.core.content.res.ResourcesCompat
 import androidx.core.graphics.Insets
 import androidx.core.view.ViewCompat
@@ -79,6 +84,7 @@ class EmulationFragment : Fragment(), SurfaceHolder.Callback, Choreographer.Fram
     private lateinit var emulationState: EmulationState
     private var perfStatsUpdater: Runnable? = null
 
+
     private lateinit var emulationActivity: EmulationActivity
 
     private var _binding: FragmentEmulationBinding? = null
@@ -146,6 +152,7 @@ class EmulationFragment : Fragment(), SurfaceHolder.Callback, Choreographer.Fram
         retainInstance = true
         emulationState = EmulationState(game.path)
         emulationActivity = requireActivity() as EmulationActivity
+
         screenAdjustmentUtil = ScreenAdjustmentUtil(requireContext(), requireActivity().windowManager, settingsViewModel.settings)
         EmulationLifecycleUtil.addShutdownHook(hook = { emulationState.stop() })
         EmulationLifecycleUtil.addPauseResumeHook(hook = { togglePause() })
@@ -1214,6 +1221,7 @@ class EmulationFragment : Fragment(), SurfaceHolder.Callback, Choreographer.Fram
     private class EmulationState(private val gamePath: String) {
         private var state: State
         private var surface: Surface? = null
+        private var surface2: Surface? = null
 
         init {
             // Starting state is stopped.

src/android/app/src/main/jni/config.cpp

@@ -204,6 +204,10 @@ void Config::ReadValues() {
         static_cast<Settings::PortraitLayoutOption>(sdl2_config->GetInteger(
             "Layout", "portrait_layout_option",
             static_cast<int>(Settings::PortraitLayoutOption::PortraitTopFullWidth)));
+    Settings::values.secondary_screen_layout =
+            static_cast<Settings::SecondaryScreenLayout>(sdl2_config->GetInteger(
+                    "Layout", "secondary_screen_layout",
+                    static_cast<int>(Settings::SecondaryScreenLayout::None)));
     ReadSetting("Layout", Settings::values.custom_portrait_top_x);
     ReadSetting("Layout", Settings::values.custom_portrait_top_y);
     ReadSetting("Layout", Settings::values.custom_portrait_top_width);

src/android/app/src/main/jni/default_ini.h

@@ -251,6 +251,15 @@ custom_portrait_bottom_height =
 # 0 (default): Top Screen is prominent, 1: Bottom Screen is prominent
 swap_screen =
 
+# Secondary Screen Layout
+# What the game should do if a secondary screen is connected physically or using
+# Miracast / Chromecast screen mirroring
+# 0 (default) - Use System Default (mirror)
+# 1 - Show Top Screen Only
+# 2 - Show Bottom Screen Only
+# 3 - Show both screens side by side
+secondary_screen_layout =
+
 # Screen placement settings when using Cardboard VR (render3d = 4)
 # 30 - 100: Screen size as a percentage of the viewport. 85 (default)
 cardboard_screen_size =

src/android/app/src/main/jni/emu_window/emu_window.cpp

@@ -49,16 +49,17 @@ void EmuWindow_Android::OnFramebufferSizeChanged() {
 
     const int bigger{window_width > window_height ? window_width : window_height};
     const int smaller{window_width < window_height ? window_width : window_height};
-    if (is_portrait_mode) {
+    if (is_portrait_mode && !is_secondary) {
         UpdateCurrentFramebufferLayout(smaller, bigger, is_portrait_mode);
     } else {
         UpdateCurrentFramebufferLayout(bigger, smaller, is_portrait_mode);
     }
 }
 
-EmuWindow_Android::EmuWindow_Android(ANativeWindow* surface) : host_window{surface} {
+EmuWindow_Android::EmuWindow_Android(ANativeWindow *surface, bool is_secondary) : EmuWindow{
+        is_secondary}, host_window(surface) {
     LOG_DEBUG(Frontend, "Initializing EmuWindow_Android");
-
+    if (is_secondary) LOG_DEBUG(Frontend, "Initializing secondary window Android");
     if (!surface) {
         LOG_CRITICAL(Frontend, "surface is nullptr");
         return;

src/android/app/src/main/jni/emu_window/emu_window.h

@@ -5,6 +5,7 @@
 #pragma once
 
 #include <vector>
+#include <EGL/egl.h>
 #include "core/frontend/emu_window.h"
 
 namespace Core {
@@ -13,7 +14,7 @@ class System;
 
 class EmuWindow_Android : public Frontend::EmuWindow {
 public:
-    EmuWindow_Android(ANativeWindow* surface);
+    EmuWindow_Android(ANativeWindow* surface, bool is_secondary = false);
     ~EmuWindow_Android();
 
     /// Called by the onSurfaceChanges() method to change the surface
@@ -30,7 +31,10 @@ public:
     void DoneCurrent() override;
 
     virtual void TryPresenting() {}
-
+    // EGL Context must be shared
+    // could probably use the existing
+    // SharedContext for this instead, this is maybe temporary
+    virtual EGLContext* GetEGLContext() {return NULL;}
     virtual void StopPresenting() {}
 
 protected:

src/android/app/src/main/jni/emu_window/emu_window_gl.cpp

@@ -72,8 +72,8 @@ private:
     EGLContext egl_context{};
 };
 
-EmuWindow_Android_OpenGL::EmuWindow_Android_OpenGL(Core::System& system_, ANativeWindow* surface)
+EmuWindow_Android_OpenGL::EmuWindow_Android_OpenGL(Core::System& system_, ANativeWindow* surface, bool is_secondary, EGLContext* sharedContext)
-    : EmuWindow_Android{surface}, system{system_} {
+    : EmuWindow_Android{surface,is_secondary}, system{system_} {
     if (egl_display = eglGetDisplay(EGL_DEFAULT_DISPLAY); egl_display == EGL_NO_DISPLAY) {
         LOG_CRITICAL(Frontend, "eglGetDisplay() failed");
         return;
@@ -96,8 +96,9 @@ EmuWindow_Android_OpenGL::EmuWindow_Android_OpenGL(Core::System& system_, ANativ
     if (eglQuerySurface(egl_display, egl_surface, EGL_HEIGHT, &window_height) != EGL_TRUE) {
         return;
     }
-
+    if (sharedContext) {
-    if (egl_context = eglCreateContext(egl_display, egl_config, 0, egl_context_attribs.data());
+        egl_context = *sharedContext;
+    }else if (egl_context = eglCreateContext(egl_display, egl_config, 0, egl_context_attribs.data());
         egl_context == EGL_NO_CONTEXT) {
         LOG_CRITICAL(Frontend, "eglCreateContext() failed");
         return;
@@ -127,6 +128,10 @@ EmuWindow_Android_OpenGL::EmuWindow_Android_OpenGL(Core::System& system_, ANativ
     OnFramebufferSizeChanged();
 }
 
+EGLContext* EmuWindow_Android_OpenGL::GetEGLContext() {
+    return &egl_context;
+}
+
 bool EmuWindow_Android_OpenGL::CreateWindowSurface() {
     if (!host_window) {
         return true;
@@ -204,14 +209,15 @@ void EmuWindow_Android_OpenGL::TryPresenting() {
         return;
     }
     if (presenting_state == PresentingState::Initial) [[unlikely]] {
-        eglMakeCurrent(egl_display, egl_surface, egl_surface, egl_context);
-        glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
         presenting_state = PresentingState::Running;
     }
-    if (presenting_state != PresentingState::Running) [[unlikely]] {
+//    if (presenting_state != PresentingState::Running) [[unlikely]] {
-        return;
+//        return;
-    }
+//    }
+    eglMakeCurrent(egl_display, egl_surface, egl_surface, egl_context);
+    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
     eglSwapInterval(egl_display, Settings::values.use_vsync_new ? 1 : 0);
-    system.GPU().Renderer().TryPresent(0);
+    system.GPU().Renderer().TryPresent(100,is_secondary);
     eglSwapBuffers(egl_display, egl_surface);
+
 }

src/android/app/src/main/jni/emu_window/emu_window_gl.h

@@ -19,13 +19,13 @@ struct ANativeWindow;
 
 class EmuWindow_Android_OpenGL : public EmuWindow_Android {
 public:
-    EmuWindow_Android_OpenGL(Core::System& system, ANativeWindow* surface);
+    EmuWindow_Android_OpenGL(Core::System& system, ANativeWindow* surface, bool is_secondary, EGLContext* sharedContext = NULL);
     ~EmuWindow_Android_OpenGL() override = default;
 
     void TryPresenting() override;
     void StopPresenting() override;
     void PollEvents() override;
-
+    EGLContext* GetEGLContext() override;
     std::unique_ptr<GraphicsContext> CreateSharedContext() const override;
 
 private:

src/android/app/src/main/jni/emu_window/emu_window_vk.cpp

@@ -24,8 +24,8 @@ private:
 };
 
 EmuWindow_Android_Vulkan::EmuWindow_Android_Vulkan(
-    ANativeWindow* surface, std::shared_ptr<Common::DynamicLibrary> driver_library_)
+    ANativeWindow* surface, std::shared_ptr<Common::DynamicLibrary> driver_library_, bool is_secondary)
-    : EmuWindow_Android{surface}, driver_library{driver_library_} {
+    : EmuWindow_Android{surface,is_secondary}, driver_library{driver_library_} {
     CreateWindowSurface();
 
     if (core_context = CreateSharedContext(); !core_context) {

src/android/app/src/main/jni/emu_window/emu_window_vk.h

@@ -11,7 +11,7 @@ struct ANativeWindow;
 class EmuWindow_Android_Vulkan : public EmuWindow_Android {
 public:
     EmuWindow_Android_Vulkan(ANativeWindow* surface,
-                             std::shared_ptr<Common::DynamicLibrary> driver_library);
+                             std::shared_ptr<Common::DynamicLibrary> driver_library, bool is_secondary);
     ~EmuWindow_Android_Vulkan() override = default;
 
     void PollEvents() override {}

src/android/app/src/main/jni/native.cpp

@@ -16,11 +16,15 @@
 #include <core/hle/service/cfg/cfg.h>
 #include "audio_core/dsp_interface.h"
 #include "common/arch.h"
+
 #if CITRA_ARCH(arm64)
+
 #include "common/aarch64/cpu_detect.h"
+
 #elif CITRA_ARCH(x86_64)
 #include "common/x64/cpu_detect.h"
 #endif
+
 #include "common/common_paths.h"
 #include "common/dynamic_library/dynamic_library.h"
 #include "common/file_util.h"
@@ -44,12 +48,18 @@
 #include "jni/camera/ndk_camera.h"
 #include "jni/camera/still_image_camera.h"
 #include "jni/config.h"
+
 #ifdef ENABLE_OPENGL
+
 #include "jni/emu_window/emu_window_gl.h"
+
 #endif
 #ifdef ENABLE_VULKAN
+
 #include "jni/emu_window/emu_window_vk.h"
+
 #endif
+
 #include "jni/id_cache.h"
 #include "jni/input_manager.h"
 #include "jni/ndk_motion.h"
@@ -59,15 +69,20 @@
 #include "video_core/renderer_base.h"
 
 #if defined(ENABLE_VULKAN) && CITRA_ARCH(arm64)
+
 #include <adrenotools/driver.h>
+
 #endif
 
 namespace {
 
     ANativeWindow *s_surf;
+    ANativeWindow *s_secondary_surface;
+    bool secondary_enabled = false;
 
     std::shared_ptr<Common::DynamicLibrary> vulkan_library{};
     std::unique_ptr<EmuWindow_Android> window;
+    std::unique_ptr<EmuWindow_Android> second_window;
 
     std::atomic<bool> stop_run{true};
     std::atomic<bool> pause_emulation{false};
@@ -118,8 +133,10 @@ static void TryShutdown() {
     }
 
     window->DoneCurrent();
+    if (second_window) second_window->DoneCurrent();
     Core::System::GetInstance().Shutdown();
     window.reset();
+    if (second_window) second_window.reset();
     InputManager::Shutdown();
     MicroProfileShutdown();
 }
@@ -148,12 +165,21 @@ static Core::System::ResultStatus RunCitra(const std::string& filepath) {
     switch (graphics_api) {
 #ifdef ENABLE_OPENGL
         case Settings::GraphicsAPI::OpenGL:
-        window = std::make_unique<EmuWindow_Android_OpenGL>(system, s_surf);
+            window = std::make_unique<EmuWindow_Android_OpenGL>(system, s_surf, false);
+            if (secondary_enabled) {
+                EGLContext *c = window->GetEGLContext();
+                second_window = std::make_unique<EmuWindow_Android_OpenGL>(system,
+                                                                           s_secondary_surface,
+                                                                           true, c);
+            }
             break;
 #endif
 #ifdef ENABLE_VULKAN
         case Settings::GraphicsAPI::Vulkan:
-        window = std::make_unique<EmuWindow_Android_Vulkan>(s_surf, vulkan_library);
+            window = std::make_unique<EmuWindow_Android_Vulkan>(s_surf, vulkan_library, false);
+            if (secondary_enabled)
+                second_window = std::make_unique<EmuWindow_Android_Vulkan>(s_secondary_surface,
+                                                                           vulkan_library, true);
             break;
 #endif
         default:
@@ -161,9 +187,16 @@ static Core::System::ResultStatus RunCitra(const std::string& filepath) {
                          "Unknown or unsupported graphics API {}, falling back to available default",
                          graphics_api);
 #ifdef ENABLE_OPENGL
-        window = std::make_unique<EmuWindow_Android_OpenGL>(system, s_surf);
+            window = std::make_unique<EmuWindow_Android_OpenGL>(system, s_surf, false);
+            if (secondary_enabled) {
+                EGLContext *c = window->GetEGLContext();
+                second_window = std::make_unique<EmuWindow_Android_OpenGL>(system,
+                                                                           s_secondary_surface,
+                                                                           true, c);
+            }
 #elif ENABLE_VULKAN
             window = std::make_unique<EmuWindow_Android_Vulkan>(s_surf, vulkan_library);
+            if (secondary_enabled) second_window = std::make_unique<EmuWindow_Android_Vulkan>(s_secondary_surface, vulkan_library, true);
 #else
     // TODO: Add a null renderer backend for this, perhaps.
 #error "At least one renderer must be enabled."
@@ -202,7 +235,8 @@ static Core::System::ResultStatus RunCitra(const std::string& filepath) {
     InputManager::Init();
 
     window->MakeCurrent();
-    const Core::System::ResultStatus load_result{system.Load(*window, filepath)};
+    const Core::System::ResultStatus load_result{
+            system.Load(*window, filepath, second_window.get())};
     if (load_result != Core::System::ResultStatus::Success) {
         return load_result;
     }
@@ -249,6 +283,7 @@ static Core::System::ResultStatus RunCitra(const std::string& filepath) {
             std::unique_lock pause_lock{paused_mutex};
             running_cv.wait(pause_lock, [] { return !pause_emulation || stop_run; });
             window->PollEvents();
+            //if (second_window) second_window->PollEvents();
         }
     }
 
@@ -300,12 +335,83 @@ void Java_org_citra_citra_1emu_NativeLibrary_surfaceChanged(JNIEnv* env,
 
     auto &system = Core::System::GetInstance();
     if (notify && system.IsPoweredOn()) {
-        system.GPU().Renderer().NotifySurfaceChanged();
+        system.GPU().Renderer().NotifySurfaceChanged(false);
     }
 
     LOG_INFO(Frontend, "Surface changed");
 }
 
+void Java_org_citra_citra_1emu_NativeLibrary_secondarySurfaceChanged(JNIEnv *env,
+                                                                [[maybe_unused]] jobject obj,
+                                                                jobject surf) {
+    auto &system = Core::System::GetInstance();
+    s_secondary_surface = ANativeWindow_fromSurface(env, surf);
+    secondary_enabled = true;
+    bool notify = false;
+    if (!s_secondary_surface) {
+        // did not create the surface, so disable second screen
+        secondary_enabled = false;
+        if (system.IsPoweredOn()) {
+            system.GPU().Renderer().setSecondaryWindow(nullptr);
+        }
+        return;
+    }
+    if (second_window) {
+        //second window already created, so update it
+        notify = second_window->OnSurfaceChanged(s_secondary_surface);
+    } else if (system.IsPoweredOn() && window) {
+        // emulation running, window is new
+        // create a new window and set it
+        const auto graphics_api = Settings::values.graphics_api.GetValue();
+        if (graphics_api == Settings::GraphicsAPI::OpenGL) {
+            EGLContext *c = window->GetEGLContext();
+            second_window = std::make_unique<EmuWindow_Android_OpenGL>(system,
+                                                                       s_secondary_surface,true, c);
+        }else{
+            second_window = std::make_unique<EmuWindow_Android_Vulkan>(s_secondary_surface,
+                                                                           vulkan_library, true);
+        }
+        system.GPU().Renderer().setSecondaryWindow(second_window.get());
+    }
+
+    if (notify && system.IsPoweredOn()) {
+        system.GPU().Renderer().NotifySurfaceChanged(true);
+    }
+
+    LOG_INFO(Frontend, "Secondary Surface changed");
+}
+
+
+void Java_org_citra_citra_1emu_NativeLibrary_secondarySurfaceDestroyed(JNIEnv *env,
+                                                                 [[maybe_unused]] jobject obj) {
+    //auto &system = Core::System::GetInstance();
+    secondary_enabled = false;
+    if (s_secondary_surface != nullptr) {
+        ANativeWindow_release(s_secondary_surface);
+        s_secondary_surface = nullptr;
+    }
+
+    LOG_INFO(Frontend, "Secondary Surface Destroyed");
+}
+
+void Java_org_citra_citra_1emu_NativeLibrary_disableSecondaryScreen(JNIEnv *env,
+                                                                       [[maybe_unused]] jobject obj) {
+    auto &system = Core::System::GetInstance();
+    secondary_enabled = false;
+    if (s_secondary_surface != nullptr) {
+        ANativeWindow_release(s_secondary_surface);
+        s_secondary_surface = nullptr;
+    }
+    if (system.IsPoweredOn()) {
+        system.GPU().Renderer().setSecondaryWindow(nullptr);
+    }
+    if (second_window) {
+        second_window.release();
+        second_window = nullptr;
+    }
+    LOG_INFO(Frontend, "Secondary Window Disabled");
+
+}
 void Java_org_citra_citra_1emu_NativeLibrary_surfaceDestroyed([[maybe_unused]] JNIEnv *env,
                                                               [[maybe_unused]] jobject obj) {
     if (s_surf != nullptr) {
@@ -325,6 +431,9 @@ void Java_org_citra_citra_1emu_NativeLibrary_doFrame([[maybe_unused]] JNIEnv* en
     if (window) {
         window->TryPresenting();
     }
+    if (second_window) {
+        second_window->TryPresenting();
+    }
 }
 
 void JNICALL Java_org_citra_citra_1emu_NativeLibrary_initializeGpuDriver(
@@ -389,7 +498,8 @@ jobjectArray Java_org_citra_citra_1emu_NativeLibrary_getInstalledGamePaths(
         JNIEnv *env, [[maybe_unused]] jclass clazz) {
     std::vector<std::string> games;
     const FileUtil::DirectoryEntryCallable ScanDir =
-        [&games, &ScanDir](u64*, const std::string& directory, const std::string& virtual_name) {
+            [&games, &ScanDir](u64 *, const std::string &directory,
+                               const std::string &virtual_name) {
                 std::string path = directory + virtual_name;
                 if (FileUtil::IsDirectory(path)) {
                     path += '/';
@@ -481,6 +591,7 @@ void Java_org_citra_citra_1emu_NativeLibrary_stopEmulation([[maybe_unused]] JNIE
     stop_run = true;
     pause_emulation = false;
     window->StopPresenting();
+    if (second_window) second_window->StopPresenting();
     running_cv.notify_all();
 }
 
@@ -511,7 +622,8 @@ jboolean Java_org_citra_citra_1emu_NativeLibrary_onGamePadEvent([[maybe_unused]]
 }
 
 jboolean Java_org_citra_citra_1emu_NativeLibrary_onGamePadMoveEvent(
-    [[maybe_unused]] JNIEnv* env, [[maybe_unused]] jobject obj, [[maybe_unused]] jstring j_device,
+        [[maybe_unused]] JNIEnv *env, [[maybe_unused]] jobject obj,
+        [[maybe_unused]] jstring j_device,
         jint axis, jfloat x, jfloat y) {
     // Clamp joystick movement to supported minimum and maximum
     // Citra uses an inverted y axis sent by the frontend
@@ -530,7 +642,8 @@ jboolean Java_org_citra_citra_1emu_NativeLibrary_onGamePadMoveEvent(
 }
 
 jboolean Java_org_citra_citra_1emu_NativeLibrary_onGamePadAxisEvent(
-    [[maybe_unused]] JNIEnv* env, [[maybe_unused]] jobject obj, [[maybe_unused]] jstring j_device,
+        [[maybe_unused]] JNIEnv *env, [[maybe_unused]] jobject obj,
+        [[maybe_unused]] jstring j_device,
         jint axis_id, jfloat axis_val) {
     return static_cast<jboolean>(
             InputManager::ButtonHandler()->AnalogButtonEvent(axis_id, axis_val));
@@ -686,7 +799,8 @@ JNIEXPORT jobject JNICALL Java_org_citra_citra_1emu_utils_CiaInstallWorker_insta
     Service::AM::InstallStatus res = Service::AM::InstallCIA(
             path, [env, jobj](std::size_t total_bytes_read, std::size_t file_size) {
                 env->CallVoidMethod(jobj, IDCache::GetCiaInstallHelperSetProgress(),
-                                static_cast<jint>(file_size), static_cast<jint>(total_bytes_read));
+                                    static_cast<jint>(file_size),
+                                    static_cast<jint>(total_bytes_read));
             });
 
     return IDCache::GetJavaCiaInstallStatus(res);
@@ -713,7 +827,8 @@ jobjectArray Java_org_citra_citra_1emu_NativeLibrary_getSavestateInfo(
 
     const auto savestates = Core::ListSaveStates(title_id, system.Movie().GetCurrentMovieID());
     const jobjectArray array =
-        env->NewObjectArray(static_cast<jsize>(savestates.size()), savestate_info_class, nullptr);
+            env->NewObjectArray(static_cast<jsize>(savestates.size()), savestate_info_class,
+                                nullptr);
     for (std::size_t i = 0; i < savestates.size(); ++i) {
         const jobject object = env->AllocObject(savestate_info_class);
         env->SetIntField(object, slot_field, static_cast<jint>(savestates[i].slot));
@@ -745,4 +860,4 @@ void Java_org_citra_citra_1emu_NativeLibrary_logDeviceInfo([[maybe_unused]] JNIE
     LOG_INFO(Frontend, "Host OS: Android API level {}", android_get_device_api_level());
 }
 
-} // extern "C"
+}

src/android/app/src/main/res/values/arrays.xml

@@ -34,11 +34,25 @@
         <item>@string/emulation_screen_layout_custom</item>
     </string-array>
 
+    <string-array name="secondaryLayouts">
+        <item>@string/emulation_secondary_screen_default</item>
+        <item>@string/emulation_top_screen</item>
+        <item>@string/emulation_bottom_screen</item>
+        <item>@string/emulation_screen_layout_sidebyside</item>
+    </string-array>
+
     <integer-array name="portraitLayoutValues">
         <item>0</item>
         <item>1</item>
     </integer-array>
 
+    <integer-array name="secondaryLayoutValues">
+        <item>0</item>
+        <item>1</item>
+        <item>2</item>
+        <item>3</item>
+    </integer-array>
+
     <string-array name="smallScreenPositions">
         <item>@string/small_screen_position_top_right</item>
         <item>@string/small_screen_position_middle_right</item>

src/android/app/src/main/res/values/strings.xml

@@ -373,6 +373,7 @@
     <string name="emulation_open_cheats">Open Cheats</string>
     <string name="emulation_switch_screen_layout">Landscape Screen Layout</string>
     <string name="emulation_switch_portrait_layout">Portrait Screen Layout</string>
+    <string name="emulation_switch_secondary_layout">Secondary Screen Layout</string>
     <string name="emulation_screen_layout_largescreen">Large Screen</string>
     <string name="emulation_screen_layout_portrait">Portrait</string>
     <string name="emulation_screen_layout_single">Single Screen</string>
@@ -380,6 +381,7 @@
     <string name="emulation_screen_layout_hybrid">Hybrid Screens</string>
     <string name="emulation_screen_layout_original">Original</string>
     <string name="emulation_portrait_layout_top_full">Default</string>
+    <string name="emulation_secondary_screen_default">System Default (mirror)</string>
     <string name="emulation_screen_layout_custom">Custom Layout</string>
     <string name="emulation_small_screen_position">Small Screen Position</string>
     <string name="small_screen_position_description">Where should the small screen appear relative to the large one in Large Screen Layout?</string>

src/common/settings.cpp

@@ -113,6 +113,7 @@ void LogSettings() {
     }
     log_setting("Layout_LayoutOption", values.layout_option.GetValue());
     log_setting("Layout_PortraitLayoutOption", values.portrait_layout_option.GetValue());
+    log_setting("Layout_SecondScreenLayout",values.secondary_screen_layout.GetValue());
     log_setting("Layout_SwapScreen", values.swap_screen.GetValue());
     log_setting("Layout_UprightScreen", values.upright_screen.GetValue());
     log_setting("Layout_LargeScreenProportion", values.large_screen_proportion.GetValue());
@@ -205,6 +206,7 @@ void RestoreGlobalState(bool is_powered_on) {
     values.delay_game_render_thread_us.SetGlobal(true);
     values.layout_option.SetGlobal(true);
     values.portrait_layout_option.SetGlobal(true);
+    values.secondary_screen_layout.SetGlobal(true);
     values.swap_screen.SetGlobal(true);
     values.upright_screen.SetGlobal(true);
     values.large_screen_proportion.SetGlobal(true);

src/common/settings.h

@@ -53,6 +53,12 @@ enum class PortraitLayoutOption : u32 {
     PortraitCustomLayout,
 };
 
+enum class SecondaryScreenLayout : u32 {
+    None,
+    TopScreenOnly,
+    BottomScreenOnly,
+    SideBySide
+};
 /** Defines where the small screen will appear relative to the large screen
  * when in Large Screen mode
  */
@@ -503,6 +509,7 @@ struct Values {
     SwitchableSetting<LayoutOption> layout_option{LayoutOption::Default, "layout_option"};
     SwitchableSetting<bool> swap_screen{false, "swap_screen"};
     SwitchableSetting<bool> upright_screen{false, "upright_screen"};
+    SwitchableSetting<SecondaryScreenLayout> secondary_screen_layout{SecondaryScreenLayout::None, "secondary_screen_layout"};
     SwitchableSetting<float, true> large_screen_proportion{4.f, 1.f, 16.f,
                                                            "large_screen_proportion"};
     SwitchableSetting<SmallScreenPosition> small_screen_position{SmallScreenPosition::BottomRight,

src/core/frontend/emu_window.cpp

@@ -251,6 +251,9 @@ void EmuWindow::UpdateCurrentFramebufferLayout(u32 width, u32 height, bool is_po
             break;
         }
     }
+#ifdef ANDROID
+    if (is_secondary) layout = Layout::AndroidSecondaryLayout(width,height);
+#endif
     UpdateMinimumWindowSize(min_size);
 
     if (Settings::values.render_3d.GetValue() == Settings::StereoRenderOption::CardboardVR) {

src/core/frontend/framebuffer_layout.cpp

@@ -71,7 +71,7 @@ FramebufferLayout SingleFrameLayout(u32 width, u32 height, bool swapped, bool up
 
     const bool stretched = (Settings::values.screen_top_stretch.GetValue() && !swapped) ||
                            (Settings::values.screen_bottom_stretch.GetValue() && swapped);
-    const float window_aspect_ratio = static_cast<float>(height) / width;
+    const float window_aspect_ratio = static_cast<float>(height) / static_cast<float>(width);
 
     if (stretched) {
         top_screen = {Settings::values.screen_top_leftright_padding.GetValue(),
@@ -113,7 +113,7 @@ FramebufferLayout LargeFrameLayout(u32 width, u32 height, bool swapped, bool upr
     FramebufferLayout res{width, height, true, true, {}, {}, !upright};
     // Split the window into two parts. Give proportional width to the smaller screen
     // To do that, find the total emulation box and maximize that based on window size
-    const float window_aspect_ratio = static_cast<float>(height) / width;
+    const float window_aspect_ratio = static_cast<float>(height) / static_cast<float>(width);
     float emulation_aspect_ratio;
 
     float large_height =
@@ -297,6 +297,22 @@ FramebufferLayout SeparateWindowsLayout(u32 width, u32 height, bool is_secondary
     return SingleFrameLayout(width, height, is_secondary, upright);
 }
 
+FramebufferLayout AndroidSecondaryLayout(u32 width, u32 height) {
+    const Settings::SecondaryScreenLayout layout = Settings::values.secondary_screen_layout.GetValue();
+    switch (layout) {
+
+        case Settings::SecondaryScreenLayout::BottomScreenOnly:
+            return SingleFrameLayout(width, height, true, Settings::values.upright_screen.GetValue());
+        case Settings::SecondaryScreenLayout::SideBySide:
+            return LargeFrameLayout(width,height,false,Settings::values.upright_screen.GetValue(),1.0f,Settings::SmallScreenPosition::MiddleRight);
+        case Settings::SecondaryScreenLayout::None:
+            // this should never happen, but if it does, somehow, send the top screen
+        case Settings::SecondaryScreenLayout::TopScreenOnly:
+        default:
+            return SingleFrameLayout(width, height, false, Settings::values.upright_screen.GetValue());
+    }
+}
+
 FramebufferLayout CustomFrameLayout(u32 width, u32 height, bool is_swapped, bool is_portrait_mode) {
     ASSERT(width > 0);
     ASSERT(height > 0);

src/core/frontend/framebuffer_layout.h

@@ -119,6 +119,16 @@ FramebufferLayout HybridScreenLayout(u32 width, u32 height, bool swapped, bool u
  */
 FramebufferLayout SeparateWindowsLayout(u32 width, u32 height, bool is_secondary, bool upright);
 
+
+/**
+ * Method for constructing the secondary layout for Android, based on
+ * the appropriate setting.
+ * @param width Window framebuffer width in pixels
+ * @param height Window framebuffer height in pixels
+ */
+FramebufferLayout AndroidSecondaryLayout(u32 width, u32 height);
+
+
 /**
  * Factory method for constructing a custom FramebufferLayout
  * @param width Window framebuffer width in pixels

src/video_core/renderer_base.cpp

@@ -35,7 +35,7 @@ void RendererBase::UpdateCurrentFramebufferLayout(bool is_portrait_mode) {
         window.UpdateCurrentFramebufferLayout(layout.width, layout.height, is_portrait_mode);
     };
     update_layout(render_window);
-    if (secondary_window) {
+    if (secondary_window != nullptr) {
         update_layout(*secondary_window);
     }
 }
@@ -67,4 +67,13 @@ void RendererBase::RequestScreenshot(void* data, std::function<void(bool)> callb
     settings.screenshot_requested = true;
 }
 
+    Frontend::EmuWindow *RendererBase::getSecondaryWindow() const {
+        return secondary_window;
+    }
+
+    void RendererBase::setSecondaryWindow(Frontend::EmuWindow *secondaryWindow) {
+        secondary_window = secondaryWindow;
+        if (secondary_window) secondary_window->PollEvents();
+    }
+
 } // namespace VideoCore

src/video_core/renderer_base.h

@@ -64,7 +64,8 @@ public:
     virtual void Sync() {}
 
     /// This is called to notify the rendering backend of a surface change
-    virtual void NotifySurfaceChanged() {}
+    // if second == true then it is the second screen
+    virtual void NotifySurfaceChanged(bool second) {}
 
     /// Returns the resolution scale factor relative to the native 3DS screen resolution
     u32 GetResolutionScaleFactor();
@@ -110,7 +111,14 @@ protected:
     Core::System& system;
     RendererSettings settings;
     Frontend::EmuWindow& render_window;    ///< Reference to the render window handle.
-    Frontend::EmuWindow* secondary_window; ///< Reference to the secondary render window handle.
+    Frontend::EmuWindow* secondary_window;
+public:
+    Frontend::EmuWindow *getSecondaryWindow() const;
+
+    virtual void setSecondaryWindow(Frontend::EmuWindow *secondaryWindow);
+
+protected:
+    ///< Reference to the secondary render window handle.
     f32 current_fps = 0.0f;                ///< Current framerate, should be set by the renderer
     s32 current_frame = 0;                 ///< Current frame, should be set by the renderer
 };

src/video_core/renderer_opengl/renderer_opengl.cpp

@@ -87,6 +87,15 @@ RendererOpenGL::RendererOpenGL(Core::System& system, Pica::PicaCore& pica_,
 }
 
 RendererOpenGL::~RendererOpenGL() = default;
+void RendererOpenGL::setSecondaryWindow(Frontend::EmuWindow *secondaryWindow) {
+    if (secondaryWindow) {
+        secondary_window = secondaryWindow;
+        secondary_window->mailbox = std::make_unique<OGLTextureMailbox>(driver.HasDebugTool());
+    }else {
+        secondary_window = nullptr;
+        // should I release something here? The mailbox??
+    }
+}
 
 void RendererOpenGL::SwapBuffers() {
     // Maintain the rasterizer's state as a priority
@@ -106,6 +115,15 @@ void RendererOpenGL::SwapBuffers() {
         RenderToMailbox(secondary_layout, secondary_window->mailbox, false);
         secondary_window->PollEvents();
     }
+#endif
+#ifdef ANDROID
+    // on android, if secondary_window is defined at all
+    // it means we have a second display
+    if (secondary_window) {
+        const auto &secondary_layout = secondary_window->GetFramebufferLayout();
+        RenderToMailbox(secondary_layout, secondary_window->mailbox, false);
+        secondary_window->PollEvents();
+    }
 #endif
     if (frame_dumper.IsDumping()) {
         try {

src/video_core/renderer_opengl/renderer_opengl.h

@@ -54,6 +54,7 @@ public:
     void PrepareVideoDumping() override;
     void CleanupVideoDumping() override;
     void Sync() override;
+    void setSecondaryWindow(Frontend::EmuWindow *secondaryWindow) override;
 
 private:
     void InitOpenGLObjects();

src/video_core/renderer_vulkan/renderer_vulkan.cpp

@@ -829,6 +829,16 @@ void RendererVulkan::SwapBuffers() {
         RenderToWindow(*second_window, secondary_layout, false);
         secondary_window->PollEvents();
     }
+#endif
+#ifdef ANDROID
+    if (secondary_window) {
+        const auto &secondary_layout = secondary_window->GetFramebufferLayout();
+        if (!second_window) {
+            second_window = std::make_unique<PresentWindow>(*secondary_window, instance, scheduler);
+        }
+        RenderToWindow(*second_window, secondary_layout, false);
+        secondary_window->PollEvents();
+    }
 #endif
     rasterizer.TickFrame();
     EndFrame();
@@ -1119,4 +1129,10 @@ bool RendererVulkan::TryRenderScreenshotWithHostMemory() {
     return true;
 }
 
+    void RendererVulkan::NotifySurfaceChanged(bool second) {
+    if (second && second_window) second_window->NotifySurfaceChanged();
+    if (!second) main_window.NotifySurfaceChanged();
+
+    }
+
 } // namespace Vulkan

src/video_core/renderer_vulkan/renderer_vulkan.h

@@ -74,9 +74,7 @@ public:
         return &rasterizer;
     }
 
-    void NotifySurfaceChanged() override {
+    void NotifySurfaceChanged(bool second) override;
-        main_window.NotifySurfaceChanged();
-    }
 
     void SwapBuffers() override;
     void TryPresent(int timeout_ms, bool is_secondary) override {}