From 928854ffd399c5fba218d2c6e44bee4bbca1440f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Henrik=20Rydg=C3=A5rd?= <hrydgard@gmail.com>
Date: Fri, 14 Feb 2025 12:40:44 -0600
Subject: [PATCH] Hold only the first button, allow other buttons to toggle
 with dragging as normal.

---
 Common/Input/InputState.h |  2 ++
 UI/GamepadEmu.cpp         | 19 +++++++++++++++++--
 UI/GamepadEmu.h           |  2 ++
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/Common/Input/InputState.h b/Common/Input/InputState.h
index 2edb14210e..6aa30cb23e 100644
--- a/Common/Input/InputState.h
+++ b/Common/Input/InputState.h
@@ -145,6 +145,8 @@ enum {
 	TOUCH_TOOL_STYLUS = 2 << 10,
 	TOUCH_TOOL_MOUSE = 3 << 10,
 	TOUCH_TOOL_ERASER = 4 << 10,
+
+	TOUCH_MAX_POINTERS = 10,
 };
 
 // Used for asynchronous touch input.
diff --git a/UI/GamepadEmu.cpp b/UI/GamepadEmu.cpp
index 90633be5d4..134169aca6 100644
--- a/UI/GamepadEmu.cpp
+++ b/UI/GamepadEmu.cpp
@@ -42,6 +42,8 @@ static uint32_t analogPointerMask = 0;
 static float g_gamepadOpacity;
 static double g_lastTouch;
 
+MultiTouchButton *primaryButton[TOUCH_MAX_POINTERS]{};
+
 void GamepadUpdateOpacity(float force) {
 	if (force >= 0.0f) {
 		g_gamepadOpacity = force;
@@ -100,23 +102,36 @@ void MultiTouchButton::GetContentDimensions(const UIContext &dc, float &w, float
 	}
 }
 
+bool MultiTouchButton::CanGlide() const {
+	return g_Config.bTouchGliding;
+}
+
 bool MultiTouchButton::Touch(const TouchInput &input) {
+	_dbg_assert_(input.id >= 0 && input.id < TOUCH_MAX_POINTERS);
+
 	bool retval = GamepadView::Touch(input);
 	if ((input.flags & TOUCH_DOWN) && bounds_.Contains(input.x, input.y)) {
 		pointerDownMask_ |= 1 << input.id;
 		usedPointerMask |= 1 << input.id;
+		if (CanGlide() && !primaryButton[input.id])
+			primaryButton[input.id] = this;
 	}
 	if (input.flags & TOUCH_MOVE) {
 		if (!(input.flags & TOUCH_MOUSE) || input.buttons) {
-			if (bounds_.Contains(input.x, input.y) && !(analogPointerMask & (1 << input.id)))
+			if (bounds_.Contains(input.x, input.y) && !(analogPointerMask & (1 << input.id))) {
+				if (CanGlide() && !primaryButton[input.id]) {
+					primaryButton[input.id] = this;
+				}
 				pointerDownMask_ |= 1 << input.id;
-			else if (!g_Config.bTouchGliding)
+			} else if (primaryButton[input.id] != this) {
 				pointerDownMask_ &= ~(1 << input.id);
+			}
 		}
 	}
 	if (input.flags & TOUCH_UP) {
 		pointerDownMask_ &= ~(1 << input.id);
 		usedPointerMask &= ~(1 << input.id);
+		primaryButton[input.id] = nullptr;
 	}
 	if (input.flags & TOUCH_RELEASE_ALL) {
 		pointerDownMask_ = 0;
diff --git a/UI/GamepadEmu.h b/UI/GamepadEmu.h
index b4ad53c81c..a23a678674 100644
--- a/UI/GamepadEmu.h
+++ b/UI/GamepadEmu.h
@@ -54,6 +54,8 @@ public:
 	MultiTouchButton *SetAngle(float angle) { angle_ = angle; bgAngle_ = angle; return this; }
 	MultiTouchButton *SetAngle(float angle, float bgAngle) { angle_ = angle; bgAngle_ = bgAngle; return this; }
 
+	bool CanGlide() const;
+
 protected:
 	uint32_t pointerDownMask_ = 0;
 	float scale_;