[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/hid_core/hidbus/hidbus_base.cpp

@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2021 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -62,8 +65,9 @@ void HidbusBase::DisablePollingMode() {
     polling_mode_enabled = false;
 }
 
-void HidbusBase::SetTransferMemoryAddress(Common::ProcessAddress t_mem) {
+void HidbusBase::SetTransferMemoryAddress(Common::ProcessAddress t_mem, Kernel::KProcess* owner) {
     transfer_memory = t_mem;
+    transfer_memory_owner = owner;
 }
 
 Kernel::KReadableEvent& HidbusBase::GetSendCommandAsycEvent() const {

src/hid_core/hidbus/hidbus_base.h

@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2021 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -14,6 +17,7 @@ class System;
 
 namespace Kernel {
 class KEvent;
+class KProcess;
 class KReadableEvent;
 } // namespace Kernel
 
@@ -138,7 +142,7 @@ public:
     void DisablePollingMode();
 
     // Called on EnableJoyPollingReceiveMode
-    void SetTransferMemoryAddress(Common::ProcessAddress t_mem);
+    void SetTransferMemoryAddress(Common::ProcessAddress t_mem, Kernel::KProcess* owner);
 
     Kernel::KReadableEvent& GetSendCommandAsycEvent() const;
 
@@ -175,6 +179,7 @@ protected:
     ButtonOnlyPollingDataAccessor button_only_data{};
 
     Common::ProcessAddress transfer_memory{};
+    Kernel::KProcess* transfer_memory_owner{};
 
     Core::System& system;
     Kernel::KEvent* send_command_async_event;

src/hid_core/hidbus/ringcon.cpp

@@ -6,6 +6,7 @@
 
 #include "core/core.h"
 #include "core/hle/kernel/k_event.h"
+#include "core/hle/kernel/k_process.h"
 #include "core/hle/kernel/k_readable_event.h"
 #include "core/memory.h"
 #include "hid_core/frontend/emulated_controller.h"
@@ -67,8 +68,10 @@ void RingController::OnUpdate() {
         curr_entry.polling_data.out_size = sizeof(ringcon_value);
         std::memcpy(curr_entry.polling_data.data.data(), &ringcon_value, sizeof(ringcon_value));
 
-        system.ApplicationMemory().WriteBlock(transfer_memory, &enable_sixaxis_data,
-                                              sizeof(enable_sixaxis_data));
+        if (transfer_memory_owner != nullptr) {
+            transfer_memory_owner->GetMemory().WriteBlock(transfer_memory, &enable_sixaxis_data,
+                                                          sizeof(enable_sixaxis_data));
+        }
         break;
     }
     default:

src/hid_core/irsensor/image_transfer_processor.cpp

@@ -1,10 +1,11 @@
-// 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 2022 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 #include "core/core.h"
+#include "core/hle/kernel/k_process.h"
 #include "core/memory.h"
 #include "hid_core/frontend/emulated_controller.h"
 #include "hid_core/hid_core.h"
@@ -48,10 +49,12 @@ void ImageTransferProcessor::OnControllerUpdate(Core::HID::ControllerTriggerType
     if (type != Core::HID::ControllerTriggerType::IrSensor) {
         return;
     }
-    if (transfer_memory == 0) {
+    if (transfer_memory == 0 || transfer_memory_owner == nullptr) {
         return;
     }
 
+    auto& memory = transfer_memory_owner->GetMemory();
+
     const auto& camera_data = npad_device->GetCamera();
 
     // This indicates how much ambient light is present
@@ -61,16 +64,14 @@ void ImageTransferProcessor::OnControllerUpdate(Core::HID::ControllerTriggerType
     if (camera_data.format != current_config.origin_format) {
         LOG_WARNING(Service_IRS, "Wrong Input format {} expected {}", camera_data.format,
                     current_config.origin_format);
-        system.ApplicationMemory().ZeroBlock(transfer_memory,
-                                             GetDataSize(current_config.trimming_format));
+        memory.ZeroBlock(transfer_memory, GetDataSize(current_config.trimming_format));
         return;
     }
 
     if (current_config.origin_format > current_config.trimming_format) {
         LOG_WARNING(Service_IRS, "Origin format {} is smaller than trimming format {}",
                     current_config.origin_format, current_config.trimming_format);
-        system.ApplicationMemory().ZeroBlock(transfer_memory,
-                                             GetDataSize(current_config.trimming_format));
+        memory.ZeroBlock(transfer_memory, GetDataSize(current_config.trimming_format));
         return;
     }
 
@@ -87,8 +88,7 @@ void ImageTransferProcessor::OnControllerUpdate(Core::HID::ControllerTriggerType
                     "Trimming area ({}, {}, {}, {}) is outside of origin area ({}, {})",
                     current_config.trimming_start_x, current_config.trimming_start_y,
                     trimming_width, trimming_height, origin_width, origin_height);
-        system.ApplicationMemory().ZeroBlock(transfer_memory,
-                                             GetDataSize(current_config.trimming_format));
+        memory.ZeroBlock(transfer_memory, GetDataSize(current_config.trimming_format));
         return;
     }
 
@@ -102,8 +102,8 @@ void ImageTransferProcessor::OnControllerUpdate(Core::HID::ControllerTriggerType
         }
     }
 
-    system.ApplicationMemory().WriteBlock(transfer_memory, window_data.data(),
-                                          GetDataSize(current_config.trimming_format));
+    memory.WriteBlock(transfer_memory, window_data.data(),
+                      GetDataSize(current_config.trimming_format));
 
     if (!IsProcessorActive()) {
         StartProcessor();
@@ -143,14 +143,19 @@ void ImageTransferProcessor::SetConfig(
     npad_device->SetCameraFormat(current_config.origin_format);
 }
 
-void ImageTransferProcessor::SetTransferMemoryAddress(Common::ProcessAddress t_mem) {
+void ImageTransferProcessor::SetTransferMemoryAddress(Common::ProcessAddress t_mem,
+                                                      Kernel::KProcess* owner) {
     transfer_memory = t_mem;
+    transfer_memory_owner = owner;
 }
 
 Core::IrSensor::ImageTransferProcessorState ImageTransferProcessor::GetState(
     std::span<u8> data) const {
+    if (transfer_memory_owner == nullptr)
+        return processor_state;
+
     const auto size = (std::min)(GetDataSize(current_config.trimming_format), data.size());
-    system.ApplicationMemory().ReadBlock(transfer_memory, data.data(), size);
+    transfer_memory_owner->GetMemory().ReadBlock(transfer_memory, data.data(), size);
     return processor_state;
 }
 

src/hid_core/irsensor/image_transfer_processor.h

@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
@@ -9,6 +12,10 @@
 #include "hid_core/irsensor/irs_types.h"
 #include "hid_core/irsensor/processor_base.h"
 
+namespace Kernel {
+class KProcess;
+}
+
 namespace Core {
 class System;
 }
@@ -39,7 +46,7 @@ public:
     void SetConfig(Core::IrSensor::PackedImageTransferProcessorExConfig config);
 
     // Transfer memory where the image data will be stored
-    void SetTransferMemoryAddress(Common::ProcessAddress t_mem);
+    void SetTransferMemoryAddress(Common::ProcessAddress t_mem, Kernel::KProcess* owner);
 
     Core::IrSensor::ImageTransferProcessorState GetState(std::span<u8> data) const;
 
@@ -75,5 +82,6 @@ private:
 
     Core::System& system;
     Common::ProcessAddress transfer_memory{};
+    Kernel::KProcess* transfer_memory_owner{};
 };
 } // namespace Service::IRS

src/hid_core/resources/six_axis/seven_six_axis.cpp

@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
@@ -6,6 +9,7 @@
 #include "core/core.h"
 #include "core/core_timing.h"
 #include "core/frontend/emu_window.h"
+#include "core/hle/kernel/k_process.h"
 #include "core/memory.h"
 #include "hid_core/frontend/emulated_console.h"
 #include "hid_core/frontend/emulated_devices.h"
@@ -24,7 +28,7 @@ void SevenSixAxis::OnInit() {}
 void SevenSixAxis::OnRelease() {}
 
 void SevenSixAxis::OnUpdate(const Core::Timing::CoreTiming& core_timing) {
-    if (!IsControllerActivated() || transfer_memory == 0) {
+    if (!IsControllerActivated() || transfer_memory == 0 || transfer_memory_owner == nullptr) {
         seven_sixaxis_lifo.buffer_count = 0;
         seven_sixaxis_lifo.buffer_tail = 0;
         return;
@@ -51,12 +55,13 @@ void SevenSixAxis::OnUpdate(const Core::Timing::CoreTiming& core_timing) {
     };
 
     seven_sixaxis_lifo.WriteNextEntry(next_seven_sixaxis_state);
-    system.ApplicationMemory().WriteBlock(transfer_memory, &seven_sixaxis_lifo,
-                                          sizeof(seven_sixaxis_lifo));
+    transfer_memory_owner->GetMemory().WriteBlock(transfer_memory, &seven_sixaxis_lifo,
+                                                  sizeof(seven_sixaxis_lifo));
 }
 
-void SevenSixAxis::SetTransferMemoryAddress(Common::ProcessAddress t_mem) {
+void SevenSixAxis::SetTransferMemoryAddress(Common::ProcessAddress t_mem, Kernel::KProcess* owner) {
     transfer_memory = t_mem;
+    transfer_memory_owner = owner;
 }
 
 void SevenSixAxis::ResetTimestamp() {

src/hid_core/resources/six_axis/seven_six_axis.h

@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
@@ -9,6 +12,10 @@
 #include "hid_core/resources/controller_base.h"
 #include "hid_core/resources/ring_lifo.h"
 
+namespace Kernel {
+class KProcess;
+}
+
 namespace Core {
 class System;
 } // namespace Core
@@ -33,7 +40,7 @@ public:
     void OnUpdate(const Core::Timing::CoreTiming& core_timing) override;
 
     // Called on InitializeSevenSixAxisSensor
-    void SetTransferMemoryAddress(Common::ProcessAddress t_mem);
+    void SetTransferMemoryAddress(Common::ProcessAddress t_mem, Kernel::KProcess* owner);
 
     // Called on ResetSevenSixAxisSensorTimestamp
     void ResetTimestamp();
@@ -58,6 +65,7 @@ private:
 
     SevenSixAxisState next_seven_sixaxis_state{};
     Common::ProcessAddress transfer_memory{};
+    Kernel::KProcess* transfer_memory_owner{};
     Core::HID::EmulatedConsole* console = nullptr;
 
     Core::System& system;

src/hid_core/resources/touch_screen/touch_screen_resource.cpp

@@ -548,8 +548,18 @@ void TouchResource::OnTouchUpdate(s64 timestamp) {
             }
 
             auto& touch_shared = applet_data->shared_memory_format->touch_screen;
-            StorePreviousTouchState(previous_touch_state, data.finger_map, current_touch_state, bool(applet_data->flag.enable_touchscreen));
-            touch_shared.touch_screen_lifo.WriteNextEntry(current_touch_state);
+
+            if (applet_data->flag.enable_touchscreen) {
+                StorePreviousTouchState(previous_touch_state, data.finger_map, current_touch_state, true);
+                touch_shared.touch_screen_lifo.WriteNextEntry(current_touch_state);
+            } else {
+                TouchScreenState denied{};
+                denied.sampling_number = current_touch_state.sampling_number;
+                denied.entry_count = 0;
+                data.finger_map.finger_count = 0;
+                data.finger_map.finger_ids = {};
+                touch_shared.touch_screen_lifo.WriteNextEntry(denied);
+            }
         }
     }
 }