From 3212b036a1822c7225673c7c1eb742998700a03f Mon Sep 17 00:00:00 2001
From: Erick C <ekchang@users.noreply.github.com>
Date: Sun, 22 Oct 2023 15:03:33 -0400
Subject: [PATCH] Manual DS4 mode: Allow Back/Select to trigger Touchpad click
 (#1772)

Co-authored-by: ReenigneArcher <42013603+ReenigneArcher@users.noreply.github.com>
---
 docs/source/about/advanced_usage.rst     | 17 +++++++++++++++++
 src/config.cpp                           |  2 ++
 src/config.h                             |  1 +
 src/platform/windows/input.cpp           |  5 ++++-
 src_assets/common/assets/web/config.html | 24 ++++++++++++++++++++++++
 5 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/docs/source/about/advanced_usage.rst b/docs/source/about/advanced_usage.rst
index e9bba6781f1..c9d9ebae3b4 100644
--- a/docs/source/about/advanced_usage.rst
+++ b/docs/source/about/advanced_usage.rst
@@ -152,6 +152,23 @@ gamepad
    .. code-block:: text
 
       gamepad = auto
+      
+ds4_back_as_touchpad_click
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+**Description**
+   .. Hint:: Only applies when gamepad is set to ds4 manually. Unused in other gamepad modes. 
+
+   Allow Select/Back inputs to also trigger DS4 touchpad click. Useful for clients looking to emulate touchpad click
+   on Xinput devices.
+
+**Default**
+   ``enabled``
+
+**Example**
+   .. code-block:: text
+
+      ds4_back_as_touchpad_click = enabled
 
 back_button_timeout
 ^^^^^^^^^^^^^^^^^^^
diff --git a/src/config.cpp b/src/config.cpp
index 726f67f8ca7..d5932d62cfe 100644
--- a/src/config.cpp
+++ b/src/config.cpp
@@ -418,6 +418,7 @@ namespace config {
       platf::supported_gamepads().front().data(),
       platf::supported_gamepads().front().size(),
     },  // Default gamepad
+    true,  // back as touchpad click enabled (manual DS4 only)
 
     true,  // keyboard enabled
     true,  // mouse enabled
@@ -1041,6 +1042,7 @@ namespace config {
     }
 
     string_restricted_f(vars, "gamepad"s, input.gamepad, platf::supported_gamepads());
+    bool_f(vars, "ds4_back_as_touchpad_click", input.ds4_back_as_touchpad_click);
 
     bool_f(vars, "mouse", input.mouse);
     bool_f(vars, "keyboard", input.keyboard);
diff --git a/src/config.h b/src/config.h
index 090e6b6864d..749a8556d11 100644
--- a/src/config.h
+++ b/src/config.h
@@ -112,6 +112,7 @@ namespace config {
     std::chrono::duration<double> key_repeat_period;
 
     std::string gamepad;
+    bool ds4_back_as_touchpad_click;
 
     bool keyboard;
     bool mouse;
diff --git a/src/platform/windows/input.cpp b/src/platform/windows/input.cpp
index ca9cfba7b93..29dd758acc1 100644
--- a/src/platform/windows/input.cpp
+++ b/src/platform/windows/input.cpp
@@ -1174,7 +1174,7 @@ namespace platf {
       BOOST_LOG(info) << "Gamepad " << id.globalIndex << " will be Xbox 360 controller (manual selection)"sv;
       selectedGamepadType = Xbox360Wired;
     }
-    else if (config::input.gamepad == "ps4"sv || config::input.gamepad == "ds4"sv) {
+    else if (config::input.gamepad == "ds4"sv) {
       BOOST_LOG(info) << "Gamepad " << id.globalIndex << " will be DualShock 4 controller (manual selection)"sv;
       selectedGamepadType = DualShock4Wired;
     }
@@ -1334,6 +1334,9 @@ namespace platf {
     // Allow either PS4/PS5 clickpad button or Xbox Series X share button to activate DS4 clickpad
     if (gamepad_state.buttonFlags & (TOUCHPAD_BUTTON | MISC_BUTTON)) buttons |= DS4_SPECIAL_BUTTON_TOUCHPAD;
 
+    // Manual DS4 emulation: check if BACK button should also trigger DS4 touchpad click
+    if (config::input.gamepad == "ds4"sv && config::input.ds4_back_as_touchpad_click && (gamepad_state.buttonFlags & BACK)) buttons |= DS4_SPECIAL_BUTTON_TOUCHPAD;
+
     return (DS4_SPECIAL_BUTTONS) buttons;
   }
 
diff --git a/src_assets/common/assets/web/config.html b/src_assets/common/assets/web/config.html
index 6f9e89de027..6e2b61b760c 100644
--- a/src_assets/common/assets/web/config.html
+++ b/src_assets/common/assets/web/config.html
@@ -105,6 +105,29 @@ <h1 class="my-4">Configuration</h1>
         </select>
         <div class="form-text">Choose which type of gamepad to emulate on the host</div>
       </div>
+      <div class="accordion" v-if="config.gamepad === 'ds4'">
+        <div class="accordion-item">
+          <h2 class="accordion-header">
+            <button class="accordion-button" type="button" data-bs-toggle="collapse"
+              data-bs-target="#panelsStayOpen-collapseOne">
+              Manual DS4 options
+            </button>
+          </h2>
+          <div id="panelsStayOpen-collapseOne" class="accordion-collapse collapse show"
+            aria-labelledby="panelsStayOpen-headingOne">
+            <div class="accordion-body">
+              <div>
+                <label for="ds4_back_as_touchpad_click" class="form-label">Map Back/Select to Touchpad Click</label>
+                <select id="ds4_back_as_touchpad_click" class="form-select" v-model="config.ds4_back_as_touchpad_click">
+                  <option value="disabled">Disabled</option>
+                  <option value="enabled">Enabled (default)</option>
+                </select>
+                <div class="form-text">When forcing DS4 emulation, map Back/Select to Touchpad Click</div>
+              </div>
+            </div>
+          </div>
+        </div>
+      </div>
       <!--Ping Timeout-->
       <div class="mb-3">
         <label for="ping_timeout" class="form-label">Ping Timeout</label>
@@ -1136,6 +1159,7 @@ <h2 class="accordion-header">
     "capture": "",
     "controller": "enabled",
     "install_steam_audio_drivers": "enabled",
+    "ds4_back_as_touchpad_click": "enabled",
     "dwmflush": "enabled",
     "encoder": "",
     "fps": "[10,30,60,90,120]",