Add mutitouch support for touch screens

src/yuzu/bootmanager.cpp

@@ -394,7 +394,7 @@ void GRenderWindow::mousePressEvent(QMouseEvent* event) {
     input_subsystem->GetMouse()->PressButton(x, y, event->button());
 
     if (event->button() == Qt::LeftButton) {
-        this->TouchPressed(x, y);
+        this->TouchPressed(x, y, 0);
     }
 
     emit MouseActivity();
@@ -409,7 +409,7 @@ void GRenderWindow::mouseMoveEvent(QMouseEvent* event) {
     auto pos = event->pos();
     const auto [x, y] = ScaleTouch(pos);
     input_subsystem->GetMouse()->MouseMove(x, y);
-    this->TouchMoved(x, y);
+    this->TouchMoved(x, y, 0);
 
     emit MouseActivity();
 }
@@ -423,36 +423,71 @@ void GRenderWindow::mouseReleaseEvent(QMouseEvent* event) {
     input_subsystem->GetMouse()->ReleaseButton(event->button());
 
     if (event->button() == Qt::LeftButton) {
-        this->TouchReleased();
+        this->TouchReleased(0);
     }
 }
 
 void GRenderWindow::TouchBeginEvent(const QTouchEvent* event) {
-    // TouchBegin always has exactly one touch point, so take the .first()
-    const auto [x, y] = ScaleTouch(event->touchPoints().first().pos());
-    this->TouchPressed(x, y);
+    QList<QTouchEvent::TouchPoint> touch_points = event->touchPoints();
+    for (const auto& touch_point : touch_points) {
+        if (!TouchUpdate(touch_point)) {
+            TouchStart(touch_point);
+        }
+    }
 }
 
 void GRenderWindow::TouchUpdateEvent(const QTouchEvent* event) {
-    QPointF pos;
-    int active_points = 0;
-
-    // average all active touch points
-    for (const auto& tp : event->touchPoints()) {
-        if (tp.state() & (Qt::TouchPointPressed | Qt::TouchPointMoved | Qt::TouchPointStationary)) {
-            active_points++;
-            pos += tp.pos();
+    QList<QTouchEvent::TouchPoint> touch_points = event->touchPoints();
+    for (const auto& touch_point : touch_points) {
+        if (!TouchUpdate(touch_point)) {
+            TouchStart(touch_point);
+        }
+    }
+    // Release all inactive points
+    for (std::size_t id = 0; id < touch_ids.size(); ++id) {
+        if (!TouchExist(touch_ids[id], touch_points)) {
+            touch_ids[id] = 0;
+            this->TouchReleased(id + 1);
         }
     }
-
-    pos /= active_points;
-
-    const auto [x, y] = ScaleTouch(pos);
-    this->TouchMoved(x, y);
 }
 
 void GRenderWindow::TouchEndEvent() {
-    this->TouchReleased();
+    for (std::size_t id = 0; id < touch_ids.size(); ++id) {
+        if (touch_ids[id] != 0) {
+            touch_ids[id] = 0;
+            this->TouchReleased(id + 1);
+        }
+    }
+}
+
+bool GRenderWindow::TouchStart(const QTouchEvent::TouchPoint& touch_point) {
+    for (std::size_t id = 0; id < touch_ids.size(); ++id) {
+        if (touch_ids[id] == 0) {
+            touch_ids[id] = touch_point.id() + 1;
+            const auto [x, y] = ScaleTouch(touch_point.pos());
+            this->TouchPressed(x, y, id + 1);
+            return true;
+        }
+    }
+    return false;
+}
+
+bool GRenderWindow::TouchUpdate(const QTouchEvent::TouchPoint& touch_point) {
+    for (std::size_t id = 0; id < touch_ids.size(); ++id) {
+        if (touch_ids[id] == touch_point.id() + 1) {
+            const auto [x, y] = ScaleTouch(touch_point.pos());
+            this->TouchMoved(x, y, id + 1);
+            return true;
+        }
+    }
+    return false;
+}
+
+bool GRenderWindow::TouchExist(std::size_t id,
+                               const QList<QTouchEvent::TouchPoint>& touch_points) const {
+    return std::any_of(touch_points.begin(), touch_points.end(),
+                       [id](const auto& point) { return id == point.id() + 1; });
 }
 
 bool GRenderWindow::event(QEvent* event) {

src/yuzu/bootmanager.h

@@ -11,6 +11,7 @@
 
 #include <QImage>
 #include <QThread>
+#include <QTouchEvent>
 #include <QWidget>
 #include <QWindow>
 
@@ -21,7 +22,6 @@
 class GRenderWindow;
 class GMainWindow;
 class QKeyEvent;
-class QTouchEvent;
 class QStringList;
 
 namespace InputCommon {
@@ -191,6 +191,10 @@ private:
     void TouchUpdateEvent(const QTouchEvent* event);
     void TouchEndEvent();
 
+    bool TouchStart(const QTouchEvent::TouchPoint& touch_point);
+    bool TouchUpdate(const QTouchEvent::TouchPoint& touch_point);
+    bool TouchExist(std::size_t id, const QList<QTouchEvent::TouchPoint>& touch_points) const;
+
     void OnMinimalClientAreaChangeRequest(std::pair<u32, u32> minimal_size) override;
 
     bool InitializeOpenGL();
@@ -215,6 +219,8 @@ private:
 
     bool first_frame = false;
 
+    std::array<std::size_t, 16> touch_ids{};
+
 protected:
     void showEvent(QShowEvent* event) override;
     bool eventFilter(QObject* object, QEvent* event) override;