[core, hle, video_core, memory] Improve multi-process, display layers, dynamic shader cache and rework overlay (#4238)

- [x] I have read and followed the [Contribution Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/CONTRIBUTING.md#code-contributions).
- [x] I have read and followed the [AI Policy](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/AI.md)
- [x] I have read and followed the [Coding Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/Coding.md) to the best of my ability.

-------------------

- Dynamic shader cache reloading capability for qlaunch
- Multi-process improvements (thanks to @frank1734), instead of just using the main application we now respect caller process (also did it for HID devices while I was at it)
- Layer stack masks & shared buffer screenshot for video core, added different masks (screenshot, recording, etc.) this was discovered as an issue due to how in qlaunch the transition was not right between applications. May not be perfect but also fixes screenshots while using qlaunch
- Reworked overlay display management (input and visibility) - instead of random numbers as I've previously did, I decided to add an AppletZIndex enum for better readability. Also split capability of input by touch and gamepad.
- etc.

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4238
Reviewed-by: Samuel <lizzie@eden-emu.dev>
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>

src/core/hle/service/am/am_results.h

@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -10,6 +13,7 @@ namespace Service::AM {
 constexpr Result ResultNoDataInChannel{ErrorModule::AM, 2};
 constexpr Result ResultNoMessages{ErrorModule::AM, 3};
 constexpr Result ResultLibraryAppletTerminated{ErrorModule::AM, 22};
+constexpr Result ResultApplicationRecordNotFound{ErrorModule::AM, 37};
 constexpr Result ResultInvalidOffset{ErrorModule::AM, 503};
 constexpr Result ResultInvalidStorageType{ErrorModule::AM, 511};
 constexpr Result ResultFatalSectionCountImbalance{ErrorModule::AM, 512};

src/core/hle/service/am/am_types.h

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 // SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
@@ -201,6 +201,14 @@ enum class ProgramSpecifyKind : u32 {
     RestartProgram = 2,
 };
 
+// Maufeat: Use enums for zindex instead of using random zindex numbers
+enum AppletZIndex : s32 {
+    Background = 0,
+    Foreground = 1,
+    ForegroundVisible = 2,
+    Overlay = 3,
+};
+
 struct CommonArguments {
     CommonArgumentVersion arguments_version;
     CommonArgumentSize size;

src/core/hle/service/am/applet.cpp

@@ -56,22 +56,22 @@ void Applet::UpdateSuspensionStateLocked(bool force_message) {
     }
 }
 
-void Applet::SetInteractibleLocked(bool interactible) {
-    if (is_interactible == interactible) {
+void Applet::SetInteractibleLocked(bool pad_interactible, bool touch_interactible) {
+    if (is_pad_interactible == pad_interactible && is_touch_interactible == touch_interactible) {
         return;
     }
 
-    is_interactible = interactible;
+    is_pad_interactible = pad_interactible;
+    is_touch_interactible = touch_interactible;
 
     const bool exit_requested = lifecycle_manager.GetExitRequested();
-    const bool input_enabled = interactible && !exit_requested;
+    const bool pad_enabled = pad_interactible && !exit_requested;
+    const bool touch_enabled = touch_interactible && !exit_requested;
 
-    if (applet_id == AppletId::OverlayDisplay || applet_id == AppletId::Application) {
-        LOG_DEBUG(Service_AM, "called, applet={} interactible={} exit_requested={} input_enabled={} overlay_in_foreground={}",
-                 static_cast<u32>(applet_id), interactible, exit_requested, input_enabled, overlay_in_foreground);
-    }
+    LOG_DEBUG(Service_AM, "applet={} pad={} touch={} exit_requested={}",
+              static_cast<u32>(applet_id), pad_enabled, touch_enabled, exit_requested);
 
-    hid_registration.EnableAppletToGetInput(input_enabled);
+    hid_registration.EnableAppletToGetInput(pad_enabled, touch_enabled);
 }
 
 void Applet::OnProcessTerminatedLocked() {

src/core/hle/service/am/applet.h

@@ -125,9 +125,11 @@ struct Applet {
     bool album_image_taken_notification_enabled{};
     bool record_volume_muted{};
     bool is_activity_runnable{};
-    bool is_interactible{true};
+    bool is_pad_interactible{true};
+    bool is_touch_interactible{true};
     bool window_visible{true};
-    bool overlay_in_foreground{false};
+    bool overlay_watching_short_home_button{false};
+    bool overlay_handling_touch_input{false};
 
     // Events
     Event overlay_event;
@@ -148,7 +150,7 @@ struct Applet {
 
     // Process state management
     void UpdateSuspensionStateLocked(bool force_message);
-    void SetInteractibleLocked(bool interactible);
+    void SetInteractibleLocked(bool pad_interactible, bool touch_interactible);
     void OnProcessTerminatedLocked();
 };
 

src/core/hle/service/am/display_layer_manager.cpp

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 // SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
@@ -6,6 +6,7 @@
 
 #include "core/core.h"
 #include "core/hle/service/am/display_layer_manager.h"
+#include "core/hle/service/nvnflinger/hwc_layer.h"
 #include "core/hle/service/sm/sm.h"
 #include "core/hle/service/vi/application_display_service.h"
 #include "core/hle/service/vi/container.h"
@@ -33,6 +34,7 @@ void DisplayLayerManager::Initialize(Core::System& system, Kernel::KProcess* pro
     m_system_shared_buffer_id = 0;
     m_system_shared_layer_id = 0;
     m_applet_id = applet_id;
+    m_library_applet_mode = mode;
     m_buffer_sharing_enabled = false;
     m_blending_enabled = mode == LibraryAppletMode::PartialForeground ||
                          mode == LibraryAppletMode::PartialForegroundIndirectDisplay;
@@ -72,14 +74,16 @@ Result DisplayLayerManager::CreateManagedDisplayLayer(u64* out_layer_id) {
         out_layer_id, 0, display_id, Service::AppletResourceUserId{m_process->GetProcessId()}));
 
     m_manager_display_service->SetLayerVisibility(m_visible, *out_layer_id);
+    (void)m_display_service->GetContainer()->SetLayerStackMask(*out_layer_id,
+                                                              this->GetLayerStackMask());
 
     if (m_applet_id != AppletId::Application) {
         (void)m_manager_display_service->SetLayerBlending(m_blending_enabled, *out_layer_id);
         if (m_applet_id == AppletId::OverlayDisplay) {
-            (void)m_manager_display_service->SetLayerZIndex(-1, *out_layer_id);
+            (void)m_manager_display_service->SetLayerZIndex(Overlay, *out_layer_id);
             (void)m_display_service->GetContainer()->SetLayerIsOverlay(*out_layer_id, true);
         } else {
-            (void)m_manager_display_service->SetLayerZIndex(1, *out_layer_id);
+            (void)m_manager_display_service->SetLayerZIndex(Foreground, *out_layer_id);
         }
     }
 
@@ -122,10 +126,12 @@ Result DisplayLayerManager::IsSystemBufferSharingEnabled() {
 
     // Ensure the overlay layer is visible
     m_manager_display_service->SetLayerVisibility(m_visible, m_system_shared_layer_id);
+    (void)m_display_service->GetContainer()->SetLayerStackMask(m_system_shared_layer_id,
+                                                              this->GetLayerStackMask());
     m_manager_display_service->SetLayerBlending(m_blending_enabled, m_system_shared_layer_id);
-    s32 initial_z = 1;
+    s32 initial_z = Foreground;
     if (m_applet_id == AppletId::OverlayDisplay) {
-        initial_z = -1;
+        initial_z = Overlay;
         (void)m_display_service->GetContainer()->SetLayerIsOverlay(m_system_shared_layer_id, true);
     }
     m_manager_display_service->SetLayerZIndex(initial_z, m_system_shared_layer_id);
@@ -142,6 +148,36 @@ Result DisplayLayerManager::GetSystemSharedLayerHandle(u64* out_system_shared_bu
     R_SUCCEED();
 }
 
+u32 DisplayLayerManager::GetLayerStackMask() const {
+    using Nvnflinger::LayerStackBit;
+    using Nvnflinger::LayerStackId;
+
+    constexpr u32 Displayed = LayerStackBit(LayerStackId::Default);
+    constexpr u32 Screenshot = LayerStackBit(LayerStackId::Screenshot);
+    constexpr u32 Recording = LayerStackBit(LayerStackId::Recording);
+    constexpr u32 LastFrame = LayerStackBit(LayerStackId::LastFrame);
+    constexpr u32 Debug = LayerStackBit(LayerStackId::ApplicationForDebug);
+
+    switch (m_applet_id) {
+        case AppletId::Application:
+            return Displayed | Screenshot | Recording | LastFrame | Debug;
+        case AppletId::OverlayDisplay:
+            return Displayed;
+        case AppletId::QLaunch:
+            return Displayed;
+        default:
+            break;
+    }
+
+    switch (m_library_applet_mode) {
+    case LibraryAppletMode::AllForeground:
+    case LibraryAppletMode::AllForegroundInitiallyHidden:
+        return Displayed | Screenshot | LastFrame;
+    default:
+        return Displayed | Screenshot;
+    }
+}
+
 void DisplayLayerManager::SetWindowVisibility(bool visible) {
     if (m_visible == visible) {
         return;
@@ -185,10 +221,17 @@ void DisplayLayerManager::SetOverlayZIndex(s32 z_index) {
 }
 
 Result DisplayLayerManager::WriteAppletCaptureBuffer(bool* out_was_written,
-                                                     s32* out_fbshare_layer_index) {
+                                                     s32* out_fbshare_layer_index,
+                                                     VI::CaptureKind kind) {
     R_UNLESS(m_buffer_sharing_enabled, VI::ResultPermissionDenied);
     R_RETURN(m_display_service->GetContainer()->GetSharedBufferManager()->WriteAppletCaptureBuffer(
-        out_was_written, out_fbshare_layer_index));
+        out_was_written, out_fbshare_layer_index, kind));
+}
+
+Result DisplayLayerManager::ClearAppletCaptureBuffer(s32 fbshare_layer_index, u32 color) {
+    R_UNLESS(m_buffer_sharing_enabled, VI::ResultPermissionDenied);
+    R_RETURN(m_display_service->GetContainer()->GetSharedBufferManager()->ClearAppletCaptureBuffer(
+        fbshare_layer_index, color));
 }
 
 } // namespace Service::AM

src/core/hle/service/am/display_layer_manager.h

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 // SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
@@ -23,6 +23,7 @@ class KProcess;
 namespace Service::VI {
 class IApplicationDisplayService;
 class IManagerDisplayService;
+enum class CaptureKind : u32;
 } // namespace Service::VI
 
 namespace Service::AM {
@@ -48,9 +49,13 @@ public:
 
     void SetOverlayZIndex(s32 z_index);
 
-    Result WriteAppletCaptureBuffer(bool* out_was_written, s32* out_fbshare_layer_index);
+    Result WriteAppletCaptureBuffer(bool* out_was_written, s32* out_fbshare_layer_index,
+                                    VI::CaptureKind kind);
+    Result ClearAppletCaptureBuffer(s32 fbshare_layer_index, u32 color);
 
 private:
+    u32 GetLayerStackMask() const;
+
     Kernel::KProcess* m_process{};
     std::shared_ptr<VI::IApplicationDisplayService> m_display_service{};
     std::shared_ptr<VI::IManagerDisplayService> m_manager_display_service{};
@@ -59,6 +64,7 @@ private:
     u64 m_system_shared_buffer_id{};
     u64 m_system_shared_layer_id{};
     AppletId m_applet_id{};
+    LibraryAppletMode m_library_applet_mode{};
     bool m_buffer_sharing_enabled{};
     bool m_blending_enabled{};
     bool m_visible{true};

src/core/hle/service/am/hid_registration.cpp

@@ -36,12 +36,17 @@ HidRegistration::~HidRegistration() {
     }
 }
 
-void HidRegistration::EnableAppletToGetInput(bool enable) {
-    if (m_process.IsInitialized()) {
-        m_hid_server->GetResourceManager()->SetAruidValidForVibration(m_process.GetProcessId(),
-                                                                      enable);
-        m_hid_server->GetResourceManager()->EnableInput(m_process.GetProcessId(), enable);
-    }
+void HidRegistration::EnableAppletToGetInput(bool enable_pad, bool enable_touch) {
+    if (!m_process.IsInitialized())
+        return;
+
+    const auto resource_manager = m_hid_server->GetResourceManager();
+    const u64 aruid = m_process.GetProcessId();
+
+    resource_manager->EnablePadInput(aruid, enable_pad);
+    resource_manager->EnableTouchScreen(aruid, enable_touch);
+
+    resource_manager->SetAruidValidForVibration(aruid, enable_pad);
 }
 
 } // namespace Service::AM

src/core/hle/service/am/hid_registration.h

@@ -28,7 +28,7 @@ public:
     ~HidRegistration();
 
     void RegisterCurrentProcess();
-    void EnableAppletToGetInput(bool enable);
+    void EnableAppletToGetInput(bool enable_pad, bool enable_touch);
 
 private:
     Process& m_process;

src/core/hle/service/am/service/applet_common_functions.cpp

@@ -4,6 +4,8 @@
 // SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+#include "core/core.h"
+#include "core/file_sys/common_funcs.h"
 #include "core/hle/service/am/applet.h"
 #include "core/hle/service/am/service/applet_common_functions.h"
 #include "core/hle/service/cmif_serialization.h"
@@ -78,7 +80,7 @@ Result IAppletCommonFunctions::SetCpuBoostRequestPriority(s32 priority) {
 
 Result IAppletCommonFunctions::GetCurrentApplicationId(Out<u64> out_application_id) {
     LOG_WARNING(Service_AM, "(STUBBED) called");
-    *out_application_id = system.GetApplicationProcessProgramID() & ~0xFFFULL;
+    *out_application_id = FileSys::GetBaseTitleID(system.GetApplicationProcessProgramID());
     R_SUCCEED();
 }
 

src/core/hle/service/am/service/application_functions.cpp

@@ -6,8 +6,10 @@
 
 #include <openssl/evp.h>
 
+#include "common/hex_util.h"
 #include "common/settings.h"
 #include "common/uuid.h"
+#include "core/file_sys/common_funcs.h"
 #include "core/file_sys/control_metadata.h"
 #include "core/file_sys/patch_manager.h"
 #include "core/file_sys/registered_cache.h"
@@ -28,6 +30,27 @@
 
 namespace Service::AM {
 
+namespace {
+
+FileSys::PatchManager::Metadata GetApplicationMetadata(Core::System& system, u64 program_id) {
+    auto metadata = FileSys::PatchManager::GetMetadataFromBaseOrUpdate(system, program_id);
+    if (metadata.first != nullptr) {
+        return metadata;
+    }
+
+    const auto application_id = FileSys::GetBaseTitleID(program_id);
+    if (application_id == program_id) {
+        return metadata;
+    }
+
+    LOG_DEBUG(Service_AM,
+              "no metadata for program_id={:016X}, falling back to application_id={:016X}",
+              program_id, application_id);
+    return FileSys::PatchManager::GetMetadataFromBaseOrUpdate(system, application_id);
+}
+
+} // Anonymous namespace
+
 IApplicationFunctions::IApplicationFunctions(Core::System& system_, std::shared_ptr<Applet> applet)
     : ServiceFramework{system_, "IApplicationFunctions"}, m_applet{std::move(applet)} {
     // clang-format off
@@ -156,7 +179,7 @@ Result IApplicationFunctions::GetDesiredLanguage(Out<u64> out_language_code) {
     // Default to 0 (all languages supported)
     u32 supported_languages = 0;
 
-    const auto res = FileSys::PatchManager::GetMetadataFromBaseOrUpdate(system, m_applet->program_id);
+    const auto res = GetApplicationMetadata(system, m_applet->program_id);
     if (res.first != nullptr) {
         supported_languages = res.first->GetSupportedLanguages();
     }
@@ -194,7 +217,7 @@ Result IApplicationFunctions::SetTerminateResult(Result terminate_result) {
 Result IApplicationFunctions::GetDisplayVersion(Out<DisplayVersion> out_display_version) {
     LOG_DEBUG(Service_AM, "called");
 
-    const auto res = FileSys::PatchManager::GetMetadataFromBaseOrUpdate(system, m_applet->program_id);
+    const auto res = GetApplicationMetadata(system, m_applet->program_id);
     if (res.first != nullptr) {
         const auto& version = res.first->GetVersionString();
         std::memcpy(out_display_version->string.data(), version.data(),
@@ -431,15 +454,21 @@ Result IApplicationFunctions::ExecuteProgram(ProgramSpecifyKind kind, u64 value)
 
 // https://switchbrew.org/wiki/Applet_Manager_services#CreateApplicationAndRequestToStart
 Result IApplicationFunctions::CreateApplicationAndRequestToStart(u64 application_id) {
-    LOG_INFO(Service_AM, "called, application_id={:016X}", application_id);
+    LOG_INFO(Service_AM, "called, application_id={:016X} current_program_id={:016X}", application_id, m_applet->program_id);
 
-    // If application_id is 0, relaunch the current application
-    const u64 target_application_id =
-        (application_id == 0) ? m_applet->program_id : application_id;
+    if (application_id == 0 ||
+        FileSys::GetBaseTitleID(application_id) == FileSys::GetBaseTitleID(m_applet->program_id)) {
+        const auto program_index = application_id == 0
+                                       ? 0
+                                       : application_id - FileSys::GetBaseTitleID(application_id);
 
-    system.GetUserChannel() = m_applet->user_channel_launch_parameter;
-    system.ExecuteProgram(target_application_id);
-    R_SUCCEED();
+        system.GetUserChannel() = m_applet->user_channel_launch_parameter;
+        system.ExecuteProgram(program_index);
+        R_SUCCEED();
+    }
+
+    LOG_ERROR(Service_AM, "Launching a different application ({:016X}) is not implemented!", application_id);
+    R_THROW(ResultUnknown);
 }
 
 Result IApplicationFunctions::ClearUserChannel() {

src/core/hle/service/am/service/display_controller.cpp

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 // SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
@@ -8,6 +8,7 @@
 #include "core/hle/service/am/applet.h"
 #include "core/hle/service/am/service/display_controller.h"
 #include "core/hle/service/cmif_serialization.h"
+#include "core/hle/service/vi/shared_buffer_manager.h"
 
 namespace Service::AM {
 
@@ -71,16 +72,16 @@ Result IDisplayController::TakeScreenShotOfOwnLayer(bool unknown0, s32 fbshare_l
 }
 
 Result IDisplayController::ClearCaptureBuffer(bool unknown0, s32 fbshare_layer_index, u32 color) {
-    LOG_WARNING(Service_AM, "(STUBBED) called, unknown0={} fbshare_layer_index={} color={:#x}",
-                unknown0, fbshare_layer_index, color);
-    R_SUCCEED();
+    LOG_DEBUG(Service_AM, "called, unknown0={} fbshare_layer_index={} color={:#x}", unknown0,
+              fbshare_layer_index, color);
+    R_RETURN(applet->display_layer_manager.ClearAppletCaptureBuffer(fbshare_layer_index, color));
 }
 
 Result IDisplayController::AcquireLastForegroundCaptureSharedBuffer(
     Out<bool> out_was_written, Out<s32> out_fbshare_layer_index) {
-    LOG_WARNING(Service_AM, "(STUBBED) called");
-    R_RETURN(applet->display_layer_manager.WriteAppletCaptureBuffer(out_was_written,
-                                                                    out_fbshare_layer_index));
+    LOG_DEBUG(Service_AM, "called");
+    R_RETURN(applet->display_layer_manager.WriteAppletCaptureBuffer(
+        out_was_written, out_fbshare_layer_index, VI::CaptureKind::LastForeground));
 }
 
 Result IDisplayController::ReleaseLastForegroundCaptureSharedBuffer() {
@@ -90,9 +91,9 @@ Result IDisplayController::ReleaseLastForegroundCaptureSharedBuffer() {
 
 Result IDisplayController::AcquireCallerAppletCaptureSharedBuffer(
     Out<bool> out_was_written, Out<s32> out_fbshare_layer_index) {
-    LOG_WARNING(Service_AM, "(STUBBED) called");
-    R_RETURN(applet->display_layer_manager.WriteAppletCaptureBuffer(out_was_written,
-                                                                    out_fbshare_layer_index));
+    LOG_DEBUG(Service_AM, "called");
+    R_RETURN(applet->display_layer_manager.WriteAppletCaptureBuffer(
+        out_was_written, out_fbshare_layer_index, VI::CaptureKind::CallerApplet));
 }
 
 Result IDisplayController::ReleaseCallerAppletCaptureSharedBuffer() {
@@ -102,9 +103,9 @@ Result IDisplayController::ReleaseCallerAppletCaptureSharedBuffer() {
 
 Result IDisplayController::AcquireLastApplicationCaptureSharedBuffer(
     Out<bool> out_was_written, Out<s32> out_fbshare_layer_index) {
-    LOG_WARNING(Service_AM, "(STUBBED) called");
-    R_RETURN(applet->display_layer_manager.WriteAppletCaptureBuffer(out_was_written,
-                                                                    out_fbshare_layer_index));
+    LOG_DEBUG(Service_AM, "called");
+    R_RETURN(applet->display_layer_manager.WriteAppletCaptureBuffer(
+        out_was_written, out_fbshare_layer_index, VI::CaptureKind::LastApplication));
 }
 
 Result IDisplayController::ReleaseLastApplicationCaptureSharedBuffer() {

src/core/hle/service/am/service/overlay_functions.cpp

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 #include "core/hle/service/am/applet.h"
@@ -22,7 +22,7 @@ namespace Service::AM {
         {10, nullptr, "StartShutdownSequenceForOverlay"},
         {11, nullptr, "StartRebootSequenceForOverlay"},
         {20, D<&IOverlayFunctions::SetHandlingHomeButtonShortPressedEnabled>, "SetHandlingHomeButtonShortPressedEnabled"},
-        {21, nullptr, "SetHandlingTouchScreenInputEnabled"},
+        {21, D<&IOverlayFunctions::SetHandlingTouchScreenInputEnabled>, "SetHandlingTouchScreenInputEnabled"},
         {30, nullptr, "SetHealthWarningShowingState"},
         {31, D<&IOverlayFunctions::IsHealthWarningRequired>, "IsHealthWarningRequired"},
         {40, nullptr, "GetApplicationNintendoLogo"},
@@ -43,10 +43,12 @@ namespace Service::AM {
     Result IOverlayFunctions::BeginToWatchShortHomeButtonMessage() {
         LOG_DEBUG(Service_AM, "called");
 
-        m_applet->overlay_in_foreground = true;
-        m_applet->home_button_short_pressed_blocked = false;
+        {
+            std::scoped_lock lk{m_applet->lock};
+            m_applet->overlay_watching_short_home_button = true;
+        }
 
-        if (auto *window_system = system.GetAppletManager().GetWindowSystem()) {
+        if (auto* window_system = system.GetAppletManager().GetWindowSystem()) {
             window_system->RequestUpdate();
         }
 
@@ -56,16 +58,26 @@ namespace Service::AM {
     Result IOverlayFunctions::EndToWatchShortHomeButtonMessage() {
         LOG_DEBUG(Service_AM, "called");
 
-        m_applet->overlay_in_foreground = false;
-        m_applet->home_button_short_pressed_blocked = false;
+        {
+            std::scoped_lock lk{m_applet->lock};
+            m_applet->overlay_watching_short_home_button = false;
+        }
 
-        if (auto *window_system = system.GetAppletManager().GetWindowSystem()) {
+        if (auto* window_system = system.GetAppletManager().GetWindowSystem()) {
             window_system->RequestUpdate();
         }
 
         R_SUCCEED();
     }
 
+    Result IOverlayFunctions::SetHandlingTouchScreenInputEnabled(bool enabled) {
+        LOG_DEBUG(Service_AM, "called, enabled={}", enabled);
+
+        std::scoped_lock lk{m_applet->lock};
+        m_applet->overlay_handling_touch_input = enabled;
+        R_SUCCEED();
+    }
+
     Result IOverlayFunctions::GetApplicationIdForLogo(Out<u64> out_application_id) {
         LOG_DEBUG(Service_AM, "called");
 

src/core/hle/service/am/service/overlay_functions.h

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 #pragma once
@@ -20,6 +20,7 @@ namespace Service::AM {
         Result SetAutoSleepTimeAndDimmingTimeEnabled(bool enabled);
         Result IsHealthWarningRequired(Out<bool> is_required);
         Result SetHandlingHomeButtonShortPressedEnabled(bool enabled);
+        Result SetHandlingTouchScreenInputEnabled(bool enabled);
         Result Unknown70();
 
     private:

src/core/hle/service/am/window_system.cpp

@@ -4,7 +4,11 @@
 // SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+#include <utility>
+
+#include "common/settings.h"
 #include "core/core.h"
+#include "core/hle/kernel/kernel.h"
 #include "core/hle/service/am/am_results.h"
 #include "core/hle/service/am/applet.h"
 #include "core/hle/service/am/applet_manager.h"
@@ -32,46 +36,82 @@ void WindowSystem::RequestUpdate() {
 }
 
 void WindowSystem::Update() {
-    std::scoped_lock lk{m_lock};
+    {
+        std::scoped_lock lk{m_lock};
 
-    LOG_DEBUG(Service_AM, "called, home_menu={} application={} overlay={}",
-              m_home_menu != nullptr, m_application != nullptr, m_overlay_display != nullptr);
+        LOG_DEBUG(Service_AM, "called, home_menu={} application={} overlay={}",
+                  m_home_menu != nullptr, m_application != nullptr, m_overlay_display != nullptr);
 
-    // Loop through all applets and remove terminated applets.
-    this->PruneTerminatedAppletsLocked();
+        // Loop through all applets and remove terminated applets.
+        this->PruneTerminatedAppletsLocked();
 
-    // If the home menu is being locked into the foreground, handle that.
-    if (this->LockHomeMenuIntoForegroundLocked()) {
-        return;
+        // If the home menu is being locked into the foreground, handle that.
+        if (!this->LockHomeMenuIntoForegroundLocked()) {
+            const bool overlay_takes_input = this->DoesOverlayTakeInputLocked();
+
+            this->UpdateAppletStateLocked(m_overlay_display, true, overlay_takes_input);
+            this->UpdateAppletStateLocked(m_home_menu, m_foreground_requested_applet == m_home_menu, overlay_takes_input);
+            this->UpdateAppletStateLocked(m_application, m_foreground_requested_applet == m_application, overlay_takes_input);
+        }
     }
 
-    bool overlay_blocks_input = false;
-    if (m_overlay_display) {
-        std::scoped_lock lk_overlay{m_overlay_display->lock};
-        overlay_blocks_input = m_overlay_display->overlay_in_foreground;
-    }
-
-    // Recursively update each applet root.
-    this->UpdateAppletStateLocked(m_home_menu, m_foreground_requested_applet == m_home_menu, overlay_blocks_input);
-    this->UpdateAppletStateLocked(m_application, m_foreground_requested_applet == m_application, overlay_blocks_input);
-    this->UpdateAppletStateLocked(m_overlay_display, true, false); // overlay is always updated, never blocked
+    this->NotifyApplicationChangedIfNeeded();
 }
 
 void WindowSystem::TrackApplet(std::shared_ptr<Applet> applet, bool is_application) {
-    std::scoped_lock lk{m_lock};
+    {
+        std::scoped_lock lk{m_lock};
 
-    if (applet->applet_id == AppletId::QLaunch) {
-        ASSERT(m_home_menu == nullptr);
-        m_home_menu = applet.get();
-    } else if (applet->applet_id == AppletId::OverlayDisplay) {
-        m_overlay_display = applet.get();
-    } else if (is_application) {
-        ASSERT(m_application == nullptr);
-        m_application = applet.get();
+        if (applet->applet_id == AppletId::QLaunch) {
+            ASSERT(m_home_menu == nullptr);
+            m_home_menu = applet.get();
+        } else if (applet->applet_id == AppletId::OverlayDisplay) {
+            m_overlay_display = applet.get();
+        } else if (is_application) {
+            ASSERT(m_application == nullptr);
+            m_application = applet.get();
+        }
+
+        this->UpdateCurrentApplicationLocked();
+
+        m_event_observer->TrackAppletProcess(*applet);
+        m_applets.emplace(applet->aruid.pid, std::move(applet));
     }
 
-    m_event_observer->TrackAppletProcess(*applet);
-    m_applets.emplace(applet->aruid.pid, std::move(applet));
+    this->NotifyApplicationChangedIfNeeded();
+}
+
+void WindowSystem::UpdateCurrentApplicationLocked() {
+    const Applet* const candidate = m_application != nullptr ? m_application : m_home_menu;
+    if (candidate == nullptr) {
+        return;
+    }
+
+    auto* const process = candidate->process->GetHandle();
+    if (process == nullptr || process == m_system.Kernel().ApplicationProcess()) {
+        return;
+    }
+
+    LOG_INFO(Service_AM, "Current application is now {:016X}", candidate->program_id);
+
+    m_system.Kernel().SetApplicationProcess(process);
+    Settings::SetCurrentProgramID(candidate->program_id);
+
+    m_pending_application_notification = candidate->program_id;
+}
+
+void WindowSystem::NotifyApplicationChangedIfNeeded() {
+    std::optional<u64> program_id;
+    {
+        std::scoped_lock lk{m_lock};
+        program_id = std::exchange(m_pending_application_notification, std::nullopt);
+    }
+
+    if (!program_id.has_value()) {
+        return;
+    }
+
+    m_system.NotifyApplicationChanged(*program_id);
 }
 
 std::shared_ptr<Applet> WindowSystem::GetByAppletResourceUserId(u64 aruid) {
@@ -169,18 +209,40 @@ void WindowSystem::OnExitRequested() {
 }
 
 void WindowSystem::SendButtonAppletMessageLocked(AppletMessage message) {
-    if (m_home_menu) {
-        std::scoped_lock lk_home{m_home_menu->lock};
-        m_home_menu->lifecycle_manager.PushUnorderedMessage(m_system.Kernel(), message);
-    }
-    if (m_overlay_display) {
-        std::scoped_lock lk_overlay{m_overlay_display->lock};
-        m_overlay_display->lifecycle_manager.PushUnorderedMessage(m_system.Kernel(), message);
-    }
-    if (m_application) {
-        std::scoped_lock lk_application{m_application->lock};
-        m_application->lifecycle_manager.PushUnorderedMessage(m_system.Kernel(), message);
-    }
+    const auto is_blocked = [message](const Applet& applet) {
+        if (message == AppletMessage::DetectShortPressingHomeButton &&
+            applet.applet_id == AppletId::OverlayDisplay &&
+            !applet.overlay_watching_short_home_button) {
+            return true;
+        }
+
+        switch (message) {
+        case AppletMessage::DetectShortPressingHomeButton:
+            return applet.home_button_short_pressed_blocked;
+        case AppletMessage::DetectLongPressingHomeButton:
+            return applet.home_button_long_pressed_blocked;
+        default:
+            return false;
+        }
+    };
+
+    const auto send_to = [&](Applet* applet) {
+        if (!applet) {
+            return;
+        }
+        std::scoped_lock lk{applet->lock};
+        if (is_blocked(*applet)) {
+            LOG_DEBUG(Service_AM, "Applet {} is blocking message {}",
+                      static_cast<u32>(applet->applet_id), static_cast<u32>(message));
+            return;
+        }
+        applet->lifecycle_manager.PushUnorderedMessage(m_system.Kernel(), message);
+    };
+
+    send_to(m_home_menu);
+    send_to(m_overlay_display);
+    send_to(m_application);
+
     if (m_event_observer) {
         m_event_observer->RequestUpdate();
     }
@@ -192,19 +254,9 @@ void WindowSystem::OnSystemButtonPress(SystemButtonType type) {
     case SystemButtonType::HomeButtonShortPressing:
         SendButtonAppletMessageLocked(AppletMessage::DetectShortPressingHomeButton);
         break;
-    case SystemButtonType::HomeButtonLongPressing: {
-        // Toggle overlay foreground visibility on long home press
-        if (m_overlay_display) {
-            std::scoped_lock lk_overlay{m_overlay_display->lock};
-            m_overlay_display->overlay_in_foreground = !m_overlay_display->overlay_in_foreground;
-            LOG_INFO(Service_AM, "Overlay long-press toggle: overlay_in_foreground={} window_visible={}", m_overlay_display->overlay_in_foreground, m_overlay_display->window_visible);
-        }
+    case SystemButtonType::HomeButtonLongPressing:
         SendButtonAppletMessageLocked(AppletMessage::DetectLongPressingHomeButton);
-        // Force a state update after toggling overlay
-        if (m_event_observer) {
-            m_event_observer->RequestUpdate();
-        }
-        break; }
+        break;
     case SystemButtonType::CaptureButtonShortPressing:
         SendButtonAppletMessageLocked(AppletMessage::DetectShortPressingCaptureButton);
         break;
@@ -317,6 +369,8 @@ void WindowSystem::PruneTerminatedAppletsLocked() {
             m_overlay_display = nullptr;
         }
 
+        this->UpdateCurrentApplicationLocked();
+
         // Finalize applet.
         applet->OnProcessTerminatedLocked();
 
@@ -389,7 +443,20 @@ void WindowSystem::TerminateChildAppletsLocked(Applet* applet) {
     applet->lock.lock();
 }
 
-void WindowSystem::UpdateAppletStateLocked(Applet* applet, bool is_foreground, bool overlay_blocking) {
+bool WindowSystem::IsOverlayOpenLocked(const Applet& overlay) const {
+    return overlay.window_visible && overlay.overlay_watching_short_home_button;
+}
+
+bool WindowSystem::DoesOverlayTakeInputLocked() const {
+    if (m_overlay_display == nullptr) {
+        return false;
+    }
+
+    std::scoped_lock lk{m_overlay_display->lock};
+    return this->IsOverlayOpenLocked(*m_overlay_display);
+}
+
+void WindowSystem::UpdateAppletStateLocked(Applet* applet, bool is_foreground, bool overlay_takes_input) {
     // With no applet, we don't have anything to do.
     if (!applet) {
         return;
@@ -420,24 +487,18 @@ void WindowSystem::UpdateAppletStateLocked(Applet* applet, bool is_foreground, b
         return false;
     }();
 
+    const bool is_overlay = applet->applet_id == AppletId::OverlayDisplay;
+
     // Update visibility state.
-    // Overlay applets should always be visible when window_visible is true, regardless of foreground state
-    const bool should_be_visible = (applet->applet_id == AppletId::OverlayDisplay)
-                                     ? applet->window_visible
-                                     : (is_foreground && applet->window_visible);
+    const bool should_be_visible =
+        is_overlay ? applet->window_visible : (is_foreground && applet->window_visible);
     applet->display_layer_manager.SetWindowVisibility(should_be_visible);
 
+    const bool needs_hid_input =
+        is_overlay ? this->IsOverlayOpenLocked(*applet)
+                   : (is_foreground && applet->window_visible && !overlay_takes_input);
 
-    const bool should_be_interactible = (applet->applet_id == AppletId::OverlayDisplay)
-                                          ? applet->overlay_in_foreground
-                                          : (is_foreground && applet->window_visible && !overlay_blocking);
-
-    if (applet->applet_id == AppletId::OverlayDisplay || applet->applet_id == AppletId::Application) {
-        LOG_DEBUG(Service_AM, "UpdateAppletStateLocked: applet={} overlay_in_foreground={} is_foreground={} window_visible={} overlay_blocking={} should_be_interactible={}",
-                 static_cast<u32>(applet->applet_id), applet->overlay_in_foreground, is_foreground, applet->window_visible, overlay_blocking, should_be_interactible);
-    }
-
-    applet->SetInteractibleLocked(should_be_interactible);
+    applet->SetInteractibleLocked(needs_hid_input, needs_hid_input);
 
     // Update focus state and suspension.
     const bool is_obscured = has_obscuring_child_applets || !applet->window_visible;
@@ -453,23 +514,18 @@ void WindowSystem::UpdateAppletStateLocked(Applet* applet, bool is_foreground, b
         applet->UpdateSuspensionStateLocked(true);
     }
 
-    // Z-index logic like in reference C# implementation (tuned for overlay extremes)
-    s32 z_index = 0;
-    const bool now_foreground = inherited_foreground;
-    if (applet->applet_id == AppletId::OverlayDisplay) {
-        z_index = applet->overlay_in_foreground ? 100000 : -1;
-    } else if (now_foreground && !is_obscured) {
-        z_index = 2;
-    } else if (now_foreground) {
-        z_index = 1;
-    } else {
-        z_index = 0;
+    // Layer ordering. Composition sorts back-to-front. Now with enums for calrity.
+    s32 z_index = Background;
+    if (is_overlay) {
+        z_index = Overlay;
+    } else if (inherited_foreground) {
+        z_index = is_obscured ? Foreground : ForegroundVisible;
     }
     applet->display_layer_manager.SetOverlayZIndex(z_index);
 
     // Recurse into child applets.
     for (const auto& child_applet : applet->child_applets) {
-        this->UpdateAppletStateLocked(child_applet.get(), is_foreground, overlay_blocking);
+        this->UpdateAppletStateLocked(child_applet.get(), is_foreground, overlay_takes_input);
     }
 }
 

src/core/hle/service/am/window_system.h

@@ -9,6 +9,7 @@
 #include <map>
 #include <memory>
 #include <mutex>
+#include <optional>
 
 #include "common/common_types.h"
 #include "core/hle/service/am/am_types.h"
@@ -60,11 +61,16 @@ public:
     void OnPowerButtonPressed(ButtonPressDuration type) {}
 
 private:
+    void UpdateCurrentApplicationLocked();
+    void NotifyApplicationChangedIfNeeded();
     void PruneTerminatedAppletsLocked();
     bool RestartAppletProcessLocked(Applet* applet);
     bool LockHomeMenuIntoForegroundLocked();
     void TerminateChildAppletsLocked(Applet* applet);
-    void UpdateAppletStateLocked(Applet* applet, bool is_foreground, bool overlay_blocking = false);
+    bool IsOverlayOpenLocked(const Applet& overlay) const;
+    bool DoesOverlayTakeInputLocked() const;
+
+    void UpdateAppletStateLocked(Applet* applet, bool is_foreground, bool overlay_takes_input);
     void SendButtonAppletMessageLocked(AppletMessage message);
 
 private:
@@ -88,6 +94,7 @@ private:
 
     // Applet map by aruid.
     std::map<u64, std::shared_ptr<Applet>> m_applets{};
+    std::optional<u64> m_pending_application_notification{};
 };
 
 } // namespace Service::AM