1 files changed, 260 insertions, 0 deletions
diff --git a/src/hid_core/resources/touch_screen/gesture_handler.cpp b/src/hid_core/resources/touch_screen/gesture_handler.cpp
new file mode 100644
index 000000000..4fcaf6ecf
--- /dev/null
+++ b/src/hid_core/resources/touch_screen/gesture_handler.cpp
@@ -0,0 +1,260 @@
+// SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "common/math_util.h"
+#include "hid_core/resources/touch_screen/gesture_handler.h"
+
+namespace Service::HID {
+
+constexpr f32 Square(s32 num) {
+    return static_cast<f32>(num * num);
+}
+
+GestureHandler::GestureHandler() {}
+
+GestureHandler::~GestureHandler() {}
+
+void GestureHandler::SetTouchState(std::span<TouchState> touch_state, u32 count, s64 timestamp) {
+    gesture = {};
+    gesture.active_points = std::min(MaxPoints, static_cast<std::size_t>(count));
+
+    for (size_t id = 0; id < gesture.active_points; ++id) {
+        const auto& [active_x, active_y] = touch_state[id].position;
+        gesture.points[id] = {
+            .x = static_cast<s32>(active_x),
+            .y = static_cast<s32>(active_y),
+        };
+
+        gesture.mid_point.x += static_cast<s32>(gesture.points[id].x / gesture.active_points);
+        gesture.mid_point.y += static_cast<s32>(gesture.points[id].y / gesture.active_points);
+    }
+
+    for (size_t id = 0; id < gesture.active_points; ++id) {
+        const f32 distance = std::sqrt(Square(gesture.mid_point.x - gesture.points[id].x) +
+                                       Square(gesture.mid_point.y - gesture.points[id].y));
+        gesture.average_distance += distance / static_cast<f32>(gesture.active_points);
+    }
+
+    gesture.angle = std::atan2(static_cast<f32>(gesture.mid_point.y - gesture.points[0].y),
+                               static_cast<f32>(gesture.mid_point.x - gesture.points[0].x));
+
+    gesture.detection_count = last_gesture.detection_count;
+
+    if (last_update_timestamp > timestamp) {
+        timestamp = last_tap_timestamp;
+    }
+
+    time_difference = static_cast<f32>(timestamp - last_update_timestamp) / (1000 * 1000 * 1000);
+}
+
+bool GestureHandler::NeedsUpdate() {
+    if (force_update) {
+        force_update = false;
+        return true;
+    }
+
+    // Update if coordinates change
+    for (size_t id = 0; id < MaxPoints; id++) {
+        if (gesture.points[id] != last_gesture.points[id]) {
+            return true;
+        }
+    }
+
+    // Update on press and hold event after 0.5 seconds
+    if (last_gesture_state.type == GestureType::Touch && last_gesture_state.point_count == 1 &&
+        time_difference > PressDelay) {
+        return enable_press_and_tap;
+    }
+
+    return false;
+}
+
+void GestureHandler::UpdateGestureState(GestureState& next_state, s64 timestamp) {
+    last_update_timestamp = timestamp;
+
+    GestureType type = GestureType::Idle;
+    GestureAttribute attributes{};
+
+    // Reset next state to default
+    next_state.sampling_number = last_gesture_state.sampling_number + 1;
+    next_state.delta = {};
+    next_state.vel_x = 0;
+    next_state.vel_y = 0;
+    next_state.direction = GestureDirection::None;
+    next_state.rotation_angle = 0;
+    next_state.scale = 0;
+
+    if (gesture.active_points > 0) {
+        if (last_gesture.active_points == 0) {
+            NewGesture(type, attributes);
+        } else {
+            UpdateExistingGesture(next_state, type);
+        }
+    } else {
+        EndGesture(next_state, type, attributes);
+    }
+
+    // Apply attributes
+    next_state.detection_count = gesture.detection_count;
+    next_state.type = type;
+    next_state.attributes = attributes;
+    next_state.pos = gesture.mid_point;
+    next_state.point_count = static_cast<s32>(gesture.active_points);
+    next_state.points = gesture.points;
+    last_gesture = gesture;
+    last_gesture_state = next_state;
+}
+
+void GestureHandler::NewGesture(GestureType& type, GestureAttribute& attributes) {
+    gesture.detection_count++;
+    type = GestureType::Touch;
+
+    // New touch after cancel is not considered new
+    if (last_gesture_state.type != GestureType::Cancel) {
+        attributes.is_new_touch.Assign(1);
+        enable_press_and_tap = true;
+    }
+}
+
+void GestureHandler::UpdateExistingGesture(GestureState& next_state, GestureType& type) {
+    // Promote to pan type if touch moved
+    for (size_t id = 0; id < MaxPoints; id++) {
+        if (gesture.points[id] != last_gesture.points[id]) {
+            type = GestureType::Pan;
+            break;
+        }
+    }
+
+    // Number of fingers changed cancel the last event and clear data
+    if (gesture.active_points != last_gesture.active_points) {
+        type = GestureType::Cancel;
+        enable_press_and_tap = false;
+        gesture.active_points = 0;
+        gesture.mid_point = {};
+        gesture.points.fill({});
+        return;
+    }
+
+    // Calculate extra parameters of panning
+    if (type == GestureType::Pan) {
+        UpdatePanEvent(next_state, type);
+        return;
+    }
+
+    // Promote to press type
+    if (last_gesture_state.type == GestureType::Touch) {
+        type = GestureType::Press;
+    }
+}
+
+void GestureHandler::EndGesture(GestureState& next_state, GestureType& type,
+                                GestureAttribute& attributes) {
+    if (last_gesture.active_points != 0) {
+        switch (last_gesture_state.type) {
+        case GestureType::Touch:
+            if (enable_press_and_tap) {
+                SetTapEvent(type, attributes);
+                return;
+            }
+            type = GestureType::Cancel;
+            force_update = true;
+            break;
+        case GestureType::Press:
+        case GestureType::Tap:
+        case GestureType::Swipe:
+        case GestureType::Pinch:
+        case GestureType::Rotate:
+            type = GestureType::Complete;
+            force_update = true;
+            break;
+        case GestureType::Pan:
+            EndPanEvent(next_state, type);
+            break;
+        default:
+            break;
+        }
+        return;
+    }
+    if (last_gesture_state.type == GestureType::Complete ||
+        last_gesture_state.type == GestureType::Cancel) {
+        gesture.detection_count++;
+    }
+}
+
+void GestureHandler::SetTapEvent(GestureType& type, GestureAttribute& attributes) {
+    type = GestureType::Tap;
+    gesture = last_gesture;
+    force_update = true;
+    f32 tap_time_difference =
+        static_cast<f32>(last_update_timestamp - last_tap_timestamp) / (1000 * 1000 * 1000);
+    last_tap_timestamp = last_update_timestamp;
+    if (tap_time_difference < DoubleTapDelay) {
+        attributes.is_double_tap.Assign(1);
+    }
+}
+
+void GestureHandler::UpdatePanEvent(GestureState& next_state, GestureType& type) {
+    next_state.delta = gesture.mid_point - last_gesture_state.pos;
+    next_state.vel_x = static_cast<f32>(next_state.delta.x) / time_difference;
+    next_state.vel_y = static_cast<f32>(next_state.delta.y) / time_difference;
+    last_pan_time_difference = time_difference;
+
+    // Promote to pinch type
+    if (std::abs(gesture.average_distance - last_gesture.average_distance) > PinchThreshold) {
+        type = GestureType::Pinch;
+        next_state.scale = gesture.average_distance / last_gesture.average_distance;
+    }
+
+    const f32 angle_between_two_lines = std::atan((gesture.angle - last_gesture.angle) /
+                                                  (1 + (gesture.angle * last_gesture.angle)));
+    // Promote to rotate type
+    if (std::abs(angle_between_two_lines) > AngleThreshold) {
+        type = GestureType::Rotate;
+        next_state.scale = 0;
+        next_state.rotation_angle = angle_between_two_lines * 180.0f / Common::PI;
+    }
+}
+
+void GestureHandler::EndPanEvent(GestureState& next_state, GestureType& type) {
+    next_state.vel_x =
+        static_cast<f32>(last_gesture_state.delta.x) / (last_pan_time_difference + time_difference);
+    next_state.vel_y =
+        static_cast<f32>(last_gesture_state.delta.y) / (last_pan_time_difference + time_difference);
+    const f32 curr_vel =
+        std::sqrt((next_state.vel_x * next_state.vel_x) + (next_state.vel_y * next_state.vel_y));
+
+    // Set swipe event with parameters
+    if (curr_vel > SwipeThreshold) {
+        SetSwipeEvent(next_state, type);
+        return;
+    }
+
+    // End panning without swipe
+    type = GestureType::Complete;
+    next_state.vel_x = 0;
+    next_state.vel_y = 0;
+    force_update = true;
+}
+
+void GestureHandler::SetSwipeEvent(GestureState& next_state, GestureType& type) {
+    type = GestureType::Swipe;
+    gesture = last_gesture;
+    force_update = true;
+    next_state.delta = last_gesture_state.delta;
+
+    if (std::abs(next_state.delta.x) > std::abs(next_state.delta.y)) {
+        if (next_state.delta.x > 0) {
+            next_state.direction = GestureDirection::Right;
+            return;
+        }
+        next_state.direction = GestureDirection::Left;
+        return;
+    }
+    if (next_state.delta.y > 0) {
+        next_state.direction = GestureDirection::Down;
+        return;
+    }
+    next_state.direction = GestureDirection::Up;
+}
+
+} // namespace Service::HID