Restore the option for relative touch mode

app/app.pro

@@ -151,6 +151,7 @@ SOURCES += \
     streaming/input/input.cpp \
     streaming/input/keyboard.cpp \
     streaming/input/mouse.cpp \
+    streaming/input/reltouch.cpp \
     streaming/session.cpp \
     streaming/audio/audio.cpp \
     streaming/audio/renderers/sdlaud.cpp \

app/gui/SettingsView.qml

@@ -596,6 +596,22 @@ Flickable {
                                    You can toggle this while streaming using Ctrl+Alt+Shift+M."
                 }
 
+                CheckBox {
+                    id: absoluteTouchCheck
+                    hoverEnabled: true
+                    text: "Use touchscreen as a trackpad"
+                    font.pointSize:  12
+                    checked: !StreamingPreferences.absoluteTouchMode
+                    onCheckedChanged: {
+                        StreamingPreferences.absoluteTouchMode = !checked
+                    }
+
+                    ToolTip.delay: 1000
+                    ToolTip.timeout: 5000
+                    ToolTip.visible: hovered
+                    ToolTip.text: "When checked, the touchscreen acts like a trackpad. When unchecked, the touchscreen will directly control the mouse pointer."
+                }
+
                 CheckBox {
                     id: gamepadMouseCheck
                     hoverEnabled: true

app/settings/streamingpreferences.cpp

@@ -20,6 +20,7 @@
 #define SER_MDNS "mdns"
 #define SER_QUITAPPAFTER "quitAppAfter"
 #define SER_ABSMOUSEMODE "mouseacceleration"
+#define SER_ABSTOUCHMODE "abstouchmode"
 #define SER_STARTWINDOWED "startwindowed"
 #define SER_FRAMEPACING "framepacing"
 #define SER_CONNWARNINGS "connwarnings"
@@ -60,6 +61,7 @@ void StreamingPreferences::reload()
     enableMdns = settings.value(SER_MDNS, true).toBool();
     quitAppAfter = settings.value(SER_QUITAPPAFTER, false).toBool();
     absoluteMouseMode = settings.value(SER_ABSMOUSEMODE, false).toBool();
+    absoluteTouchMode = settings.value(SER_ABSTOUCHMODE, true).toBool();
     startWindowed = settings.value(SER_STARTWINDOWED, true).toBool();
     framePacing = settings.value(SER_FRAMEPACING, false).toBool();
     connectionWarnings = settings.value(SER_CONNWARNINGS, true).toBool();
@@ -104,6 +106,7 @@ void StreamingPreferences::save()
     settings.setValue(SER_MDNS, enableMdns);
     settings.setValue(SER_QUITAPPAFTER, quitAppAfter);
     settings.setValue(SER_ABSMOUSEMODE, absoluteMouseMode);
+    settings.setValue(SER_ABSTOUCHMODE, absoluteTouchMode);
     settings.setValue(SER_STARTWINDOWED, startWindowed);
     settings.setValue(SER_FRAMEPACING, framePacing);
     settings.setValue(SER_CONNWARNINGS, connectionWarnings);

app/settings/streamingpreferences.h

@@ -62,6 +62,7 @@ public:
     Q_PROPERTY(bool enableMdns MEMBER enableMdns NOTIFY enableMdnsChanged)
     Q_PROPERTY(bool quitAppAfter MEMBER quitAppAfter NOTIFY quitAppAfterChanged)
     Q_PROPERTY(bool absoluteMouseMode MEMBER absoluteMouseMode NOTIFY absoluteMouseModeChanged)
+    Q_PROPERTY(bool absoluteTouchMode MEMBER absoluteTouchMode NOTIFY absoluteTouchModeChanged)
     Q_PROPERTY(bool startWindowed MEMBER startWindowed NOTIFY startWindowedChanged)
     Q_PROPERTY(bool framePacing MEMBER framePacing NOTIFY framePacingChanged)
     Q_PROPERTY(bool connectionWarnings MEMBER connectionWarnings NOTIFY connectionWarningsChanged)
@@ -86,6 +87,7 @@ public:
     bool enableMdns;
     bool quitAppAfter;
     bool absoluteMouseMode;
+    bool absoluteTouchMode;
     bool startWindowed;
     bool framePacing;
     bool connectionWarnings;
@@ -109,6 +111,7 @@ signals:
     void enableMdnsChanged();
     void quitAppAfterChanged();
     void absoluteMouseModeChanged();
+    void absoluteTouchModeChanged();
     void audioConfigChanged();
     void videoCodecConfigChanged();
     void videoDecoderSelectionChanged();

app/streaming/input/abstouch.cpp

@@ -27,23 +27,8 @@ Uint32 SdlInputHandler::longPressTimerCallback(Uint32, void*)
     return 0;
 }
 
-void SdlInputHandler::handleTouchFingerEvent(SDL_TouchFingerEvent* event)
+void SdlInputHandler::handleAbsoluteFingerEvent(SDL_TouchFingerEvent* event)
 {
-#if SDL_VERSION_ATLEAST(2, 0, 10)
-    if (SDL_GetTouchDeviceType(event->touchId) != SDL_TOUCH_DEVICE_DIRECT) {
-        // Ignore anything that isn't a touchscreen. We may get callbacks
-        // for trackpads, but we want to handle those in the mouse path.
-        return;
-    }
-#elif defined(Q_OS_DARWIN)
-    // SDL2 sends touch events from trackpads by default on
-    // macOS. This totally screws our actual mouse handling,
-    // so we must explicitly ignore touch events on macOS
-    // until SDL 2.0.10 where we have SDL_GetTouchDeviceType()
-    // to tell them apart.
-    return;
-#endif
-
     // Observations on Windows 10: x and y appear to be relative to 0,0 of the window client area.
     // Although SDL documentation states they are 0.0 - 1.0 float values, they can actually be higher
     // or lower than those values as touch events continue for touches started within the client area that

app/streaming/input/input.cpp

@@ -17,7 +17,13 @@ SdlInputHandler::SdlInputHandler(StreamingPreferences& prefs, NvComputer*, int s
       m_LongPressTimer(0),
       m_StreamWidth(streamWidth),
       m_StreamHeight(streamHeight),
-      m_AbsoluteMouseMode(prefs.absoluteMouseMode)
+      m_AbsoluteMouseMode(prefs.absoluteMouseMode),
+      m_AbsoluteTouchMode(prefs.absoluteTouchMode),
+      m_LeftButtonReleaseTimer(0),
+      m_RightButtonReleaseTimer(0),
+      m_DragTimer(0),
+      m_DragButton(0),
+      m_NumFingersDown(0)
 {
     // Allow gamepad input when the app doesn't have focus
     SDL_SetHint(SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS, "1");
@@ -94,6 +100,8 @@ SdlInputHandler::SdlInputHandler(StreamingPreferences& prefs, NvComputer*, int s
     SDL_zero(m_GamepadState);
     SDL_zero(m_LastTouchDownEvent);
     SDL_zero(m_LastTouchUpEvent);
+    SDL_zero(m_TouchDownEvent);
+    SDL_zero(m_CumulativeDelta);
 
     SDL_AtomicSet(&m_MouseDeltaX, 0);
     SDL_AtomicSet(&m_MouseDeltaY, 0);
@@ -130,6 +138,9 @@ SdlInputHandler::~SdlInputHandler()
 
     SDL_RemoveTimer(m_MouseMoveTimer);
     SDL_RemoveTimer(m_LongPressTimer);
+    SDL_RemoveTimer(m_LeftButtonReleaseTimer);
+    SDL_RemoveTimer(m_RightButtonReleaseTimer);
+    SDL_RemoveTimer(m_DragTimer);
 
 #if !SDL_VERSION_ATLEAST(2, 0, 9)
     SDL_QuitSubSystem(SDL_INIT_HAPTIC);
@@ -258,3 +269,28 @@ void SdlInputHandler::setCaptureActive(bool active)
         SDL_SetWindowGrab(m_Window, SDL_FALSE);
     }
 }
+
+void SdlInputHandler::handleTouchFingerEvent(SDL_TouchFingerEvent* event)
+{
+#if SDL_VERSION_ATLEAST(2, 0, 10)
+    if (SDL_GetTouchDeviceType(event->touchId) != SDL_TOUCH_DEVICE_DIRECT) {
+        // Ignore anything that isn't a touchscreen. We may get callbacks
+        // for trackpads, but we want to handle those in the mouse path.
+        return;
+    }
+#elif defined(Q_OS_DARWIN)
+    // SDL2 sends touch events from trackpads by default on
+    // macOS. This totally screws our actual mouse handling,
+    // so we must explicitly ignore touch events on macOS
+    // until SDL 2.0.10 where we have SDL_GetTouchDeviceType()
+    // to tell them apart.
+    return;
+#endif
+
+    if (m_AbsoluteTouchMode) {
+        handleAbsoluteFingerEvent(event);
+    }
+    else {
+        handleRelativeFingerEvent(event);
+    }
+}

app/streaming/input/input.h

@@ -86,6 +86,10 @@ private:
 
     void sendGamepadState(GamepadState* state);
 
+    void handleAbsoluteFingerEvent(SDL_TouchFingerEvent* event);
+
+    void handleRelativeFingerEvent(SDL_TouchFingerEvent* event);
+
     static
     Uint32 longPressTimerCallback(Uint32 interval, void* param);
 
@@ -95,6 +99,15 @@ private:
     static
     Uint32 mouseEmulationTimerCallback(Uint32 interval, void* param);
 
+    static
+    Uint32 releaseLeftButtonTimerCallback(Uint32 interval, void* param);
+
+    static
+    Uint32 releaseRightButtonTimerCallback(Uint32 interval, void* param);
+
+    static
+    Uint32 dragTimerCallback(Uint32 interval, void* param);
+
     SDL_Window* m_Window;
     bool m_MultiController;
     bool m_GamepadMouse;
@@ -112,6 +125,15 @@ private:
     int m_StreamWidth;
     int m_StreamHeight;
     bool m_AbsoluteMouseMode;
+    bool m_AbsoluteTouchMode;
+
+    SDL_TouchFingerEvent m_TouchDownEvent[MAX_FINGERS];
+    float m_CumulativeDelta[MAX_FINGERS];
+    SDL_TimerID m_LeftButtonReleaseTimer;
+    SDL_TimerID m_RightButtonReleaseTimer;
+    SDL_TimerID m_DragTimer;
+    char m_DragButton;
+    int m_NumFingersDown;
 
     static const int k_ButtonMap[];
 };

app/streaming/input/reltouch.cpp

@@ -0,0 +1,178 @@
+#include "input.h"
+
+#include <Limelight.h>
+#include <SDL.h>
+
+// How long the mouse button will be pressed for a tap to click gesture
+#define TAP_BUTTON_RELEASE_DELAY 100
+
+// How long the fingers must be stationary to start a drag
+#define DRAG_ACTIVATION_DELAY 650
+
+// How far the finger can move before it cancels a drag or tap
+#define DEAD_ZONE_DELTA 0.1f
+
+Uint32 SdlInputHandler::releaseLeftButtonTimerCallback(Uint32, void*)
+{
+    LiSendMouseButtonEvent(BUTTON_ACTION_RELEASE, BUTTON_LEFT);
+    return 0;
+}
+
+Uint32 SdlInputHandler::releaseRightButtonTimerCallback(Uint32, void*)
+{
+    LiSendMouseButtonEvent(BUTTON_ACTION_RELEASE, BUTTON_RIGHT);
+    return 0;
+}
+
+Uint32 SdlInputHandler::dragTimerCallback(Uint32, void *param)
+{
+    auto me = reinterpret_cast<SdlInputHandler*>(param);
+
+    // Check how many fingers are down now to decide
+    // which button to hold down
+    if (me->m_NumFingersDown == 2) {
+        me->m_DragButton = BUTTON_RIGHT;
+    }
+    else if (me->m_NumFingersDown == 1) {
+        me->m_DragButton = BUTTON_LEFT;
+    }
+
+    LiSendMouseButtonEvent(BUTTON_ACTION_PRESS, me->m_DragButton);
+
+    return 0;
+}
+
+void SdlInputHandler::handleRelativeFingerEvent(SDL_TouchFingerEvent* event)
+{
+    int fingerIndex = -1;
+
+    // Observations on Windows 10: x and y appear to be relative to 0,0 of the window client area.
+    // Although SDL documentation states they are 0.0 - 1.0 float values, they can actually be higher
+    // or lower than those values as touch events continue for touches started within the client area that
+    // leave the client area during a drag motion.
+    // dx and dy are deltas from the last touch event, not the first touch down.
+
+    // Determine the index of this finger using our list
+    // of fingers that are currently active on screen.
+    // This is also required to handle finger up which
+    // where the finger will not be in SDL_GetTouchFinger()
+    // anymore.
+    if (event->type != SDL_FINGERDOWN) {
+        for (int i = 0; i < MAX_FINGERS; i++) {
+            if (event->fingerId == m_TouchDownEvent[i].fingerId) {
+                fingerIndex = i;
+                break;
+            }
+        }
+    }
+    else {
+        // Resolve the new finger by determining the ID of each
+        // finger on the display.
+        int numTouchFingers = SDL_GetNumTouchFingers(event->touchId);
+        for (int i = 0; i < numTouchFingers; i++) {
+            SDL_Finger* finger = SDL_GetTouchFinger(event->touchId, i);
+            SDL_assert(finger != nullptr);
+            if (finger != nullptr) {
+                if (finger->id == event->fingerId) {
+                    fingerIndex = i;
+                    break;
+                }
+            }
+        }
+    }
+
+    if (fingerIndex < 0 || fingerIndex >= MAX_FINGERS) {
+        // Too many fingers
+        return;
+    }
+
+    // Handle cursor motion based on the position of the
+    // primary finger on screen
+    if (fingerIndex == 0) {
+        // The event x and y values are relative to our window width
+        // and height. However, we want to scale them to be relative
+        // to the host resolution. Fortunately this is easy since we
+        // already have normalized values. We'll just multiply them
+        // by the stream dimensions to get real X and Y values rather
+        // than the client window dimensions.
+        short deltaX = static_cast<short>(event->dx * m_StreamWidth);
+        short deltaY = static_cast<short>(event->dy * m_StreamHeight);
+        if (deltaX != 0 || deltaY != 0) {
+            LiSendMouseMoveEvent(deltaX, deltaY);
+        }
+    }
+
+    // Start a drag timer when primary or secondary
+    // fingers go down
+    if (event->type == SDL_FINGERDOWN &&
+            (fingerIndex == 0 || fingerIndex == 1)) {
+        SDL_RemoveTimer(m_DragTimer);
+        m_DragTimer = SDL_AddTimer(DRAG_ACTIVATION_DELAY,
+                                   dragTimerCallback,
+                                   this);
+    }
+
+    if (event->type == SDL_FINGERMOTION) {
+        // Count the total cumulative dx/dy that the finger
+        // has moved.
+        m_CumulativeDelta[fingerIndex] += qAbs(event->x);
+        m_CumulativeDelta[fingerIndex] += qAbs(event->y);
+
+        // If it's outside the deadzone delta, cancel drags and taps
+        if (m_CumulativeDelta[fingerIndex] > DEAD_ZONE_DELTA) {
+            SDL_RemoveTimer(m_DragTimer);
+            m_DragTimer = 0;
+
+            // This effectively cancels the tap logic below
+            m_TouchDownEvent[fingerIndex].timestamp = 0;
+        }
+    }
+
+    if (event->type == SDL_FINGERUP) {
+        // Cancel the drag timer on finger up
+        SDL_RemoveTimer(m_DragTimer);
+        m_DragTimer = 0;
+
+        // Release any drag
+        if (m_DragButton != 0) {
+            LiSendMouseButtonEvent(BUTTON_ACTION_RELEASE, m_DragButton);
+            m_DragButton = 0;
+        }
+        // 2 finger tap
+        else if (event->timestamp - m_TouchDownEvent[1].timestamp < 250) {
+            // Zero timestamp of the primary finger to ensure we won't
+            // generate a left click if the primary finger comes up soon.
+            m_TouchDownEvent[0].timestamp = 0;
+
+            // Press down the right mouse button
+            LiSendMouseButtonEvent(BUTTON_ACTION_PRESS, BUTTON_RIGHT);
+
+            // Queue a timer to release it in 100 ms
+            SDL_RemoveTimer(m_RightButtonReleaseTimer);
+            m_RightButtonReleaseTimer = SDL_AddTimer(TAP_BUTTON_RELEASE_DELAY,
+                                                     releaseRightButtonTimerCallback,
+                                                     nullptr);
+        }
+        // 1 finger tap
+        else if (event->timestamp - m_TouchDownEvent[0].timestamp < 250) {
+            // Press down the left mouse button
+            LiSendMouseButtonEvent(BUTTON_ACTION_PRESS, BUTTON_LEFT);
+
+            // Queue a timer to release it in 100 ms
+            SDL_RemoveTimer(m_LeftButtonReleaseTimer);
+            m_LeftButtonReleaseTimer = SDL_AddTimer(TAP_BUTTON_RELEASE_DELAY,
+                                                    releaseLeftButtonTimerCallback,
+                                                    nullptr);
+        }
+    }
+
+    m_NumFingersDown = SDL_GetNumTouchFingers(event->touchId);
+
+    if (event->type == SDL_FINGERDOWN) {
+        m_TouchDownEvent[fingerIndex] = *event;
+        m_CumulativeDelta[fingerIndex] = 0;
+    }
+    else if (event->type == SDL_FINGERUP) {
+        m_TouchDownEvent[fingerIndex] = {};
+    }
+}