From 53c2c612c9e06a84b4d8fcac56181a64e1fa8154 Mon Sep 17 00:00:00 2001
From: Cameron Gutman <aicommander@gmail.com>
Date: Sat, 14 Oct 2023 01:46:50 -0500
Subject: [PATCH] Add Share+PS combo for clickpad button emulation on PS4/5
 controllers

---
 app/streaming/input/gamepad.cpp | 24 +++++++++++++++++++++++-
 app/streaming/input/input.h     |  3 +++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/app/streaming/input/gamepad.cpp b/app/streaming/input/gamepad.cpp
index 80529717..ba255c2e 100644
--- a/app/streaming/input/gamepad.cpp
+++ b/app/streaming/input/gamepad.cpp
@@ -54,9 +54,23 @@ SdlInputHandler::findStateForGamepad(SDL_JoystickID id)
 void SdlInputHandler::sendGamepadState(GamepadState* state)
 {
     SDL_assert(m_GamepadMask == 0x1 || m_MultiController);
+
+    // Handle Select+PS as the clickpad button on PS4/5 controllers without a clickpad mapping
+    int buttons = state->buttons;
+    if (state->clickpadButtonEmulationEnabled) {
+        if (state->buttons == (BACK_FLAG | SPECIAL_FLAG)) {
+            buttons = MISC_FLAG;
+            state->emulatedClickpadButtonDown = true;
+        }
+        else if (state->emulatedClickpadButtonDown) {
+            buttons &= ~MISC_FLAG;
+            state->emulatedClickpadButtonDown = false;
+        }
+    }
+
     LiSendMultiControllerEvent(state->index,
                                m_GamepadMask,
-                               state->buttons,
+                               buttons,
                                state->lt,
                                state->rt,
                                state->lsX,
@@ -639,6 +653,14 @@ void SdlInputHandler::handleControllerDeviceEvent(SDL_ControllerDeviceEvent* eve
             break;
         }
 
+        // If this is a PlayStation controller that doesn't have a touchpad button mapped,
+        // we'll allow the Select+PS button combo to act as the touchpad.
+        state->clickpadButtonEmulationEnabled =
+#if SDL_VERSION_ATLEAST(2, 0, 14)
+            SDL_GameControllerGetBindForButton(state->controller, SDL_CONTROLLER_BUTTON_TOUCHPAD).bindType == SDL_CONTROLLER_BINDTYPE_NONE &&
+#endif
+            type == LI_CTYPE_PS;
+
         LiSendControllerArrivalEvent(state->index, m_GamepadMask, type, supportedButtonFlags, capabilities);
 #else
 
diff --git a/app/streaming/input/input.h b/app/streaming/input/input.h
index 65bd4f9a..ec24070a 100644
--- a/app/streaming/input/input.h
+++ b/app/streaming/input/input.h
@@ -19,6 +19,9 @@ struct GamepadState {
     SDL_TimerID mouseEmulationTimer;
     uint32_t lastStartDownTime;
 
+    bool clickpadButtonEmulationEnabled;
+    bool emulatedClickpadButtonDown;
+
 #if SDL_VERSION_ATLEAST(2, 0, 14)
     uint8_t gyroReportPeriodMs;
     float lastGyroEventData[SDL_arraysize(SDL_ControllerSensorEvent::data)];