1 files changed, 143 insertions, 0 deletions
diff --git a/src/input/input_touch_wheel.cpp b/src/input/input_touch_wheel.cpp
new file mode 100644
index 00000000..7670e342
--- /dev/null
+++ b/src/input/input_touch_wheel.cpp
@@ -0,0 +1,143 @@
+/*
+ * Copyright 2024 jacqueline <me@jacqueline.id.au>
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+#include "input_touch_wheel.hpp"
+#include <stdint.h>
+
+#include <cstdint>
+#include <variant>
+
+#include "event_queue.hpp"
+#include "hal/lv_hal_indev.h"
+
+#include "haptics.hpp"
+#include "input_device.hpp"
+#include "input_trigger.hpp"
+#include "nvs.hpp"
+#include "property.hpp"
+#include "touchwheel.hpp"
+#include "ui_events.hpp"
+
+namespace input {
+
+TouchWheel::TouchWheel(drivers::NvsStorage& nvs, drivers::TouchWheel& wheel)
+    : nvs_(nvs),
+      wheel_(wheel),
+      sensitivity_(static_cast<int>(nvs.ScrollSensitivity()),
+                   [&](const lua::LuaValue& val) {
+                     if (!std::holds_alternative<int>(val)) {
+                       return false;
+                     }
+                     int int_val = std::get<int>(val);
+                     if (int_val < 0 || int_val > UINT8_MAX) {
+                       return false;
+                     }
+                     nvs.ScrollSensitivity(int_val);
+                     threshold_ = calculateThreshold(int_val);
+                     return true;
+                   }),
+      is_scrolling_(false),
+      threshold_(calculateThreshold(nvs.ScrollSensitivity())),
+      is_first_read_(true),
+      last_angle_(0) {}
+
+auto TouchWheel::read(lv_indev_data_t* data) -> void {
+  wheel_.Update();
+  auto wheel_data = wheel_.GetTouchWheelData();
+  int8_t ticks = calculateTicks(wheel_data);
+
+  if (!wheel_data.is_wheel_touched) {
+    // User has released the wheel.
+    is_scrolling_ = false;
+    data->enc_diff = 0;
+  } else if (ticks != 0) {
+    // User is touching the wheel, and has just passed the sensitivity
+    // threshold for a scroll tick.
+    is_scrolling_ = true;
+    data->enc_diff = ticks;
+  } else {
+    // User is touching the wheel, but hasn't moved.
+    data->enc_diff = 0;
+  }
+
+  if (!is_scrolling_ && wheel_data.is_button_touched) {
+    data->state = LV_INDEV_STATE_PRESSED;
+  } else {
+    data->state = LV_INDEV_STATE_RELEASED;
+  }
+
+  // If the user is touching the wheel but not scrolling, then they may be
+  // clicking on one of the wheel's cardinal directions.
+  bool pressing = wheel_data.is_wheel_touched && !is_scrolling_;
+
+  switch (up_.update(pressing && drivers::TouchWheel::isAngleWithin(
+                                     wheel_data.wheel_position, 0, 32))) {
+    case Trigger::State::kLongPress:
+      data->enc_diff = INT16_MIN;
+      break;
+    default:
+      break;
+  }
+  switch (right_.update(pressing && drivers::TouchWheel::isAngleWithin(
+                                        wheel_data.wheel_position, 192, 32))) {
+    default:
+      break;
+  }
+  switch (down_.update(pressing && drivers::TouchWheel::isAngleWithin(
+                                       wheel_data.wheel_position, 128, 32))) {
+    case Trigger::State::kLongPress:
+      data->enc_diff = INT16_MAX;
+      break;
+    default:
+      break;
+  }
+  switch (left_.update(pressing && drivers::TouchWheel::isAngleWithin(
+                                       wheel_data.wheel_position, 64, 32))) {
+    case Trigger::State::kLongPress:
+      events::Ui().Dispatch(ui::internal::BackPressed{});
+      break;
+    default:
+      break;
+  }
+}
+
+auto TouchWheel::sensitivity() -> lua::Property& {
+  return sensitivity_;
+}
+
+auto TouchWheel::calculateTicks(const drivers::TouchWheelData& data) -> int8_t {
+  if (!data.is_wheel_touched) {
+    is_first_read_ = true;
+    return 0;
+  }
+
+  uint8_t new_angle = data.wheel_position;
+  if (is_first_read_) {
+    is_first_read_ = false;
+    last_angle_ = new_angle;
+    return 0;
+  }
+
+  int delta = 128 - last_angle_;
+  uint8_t rotated_angle = new_angle + delta;
+  if (rotated_angle < 128 - threshold_) {
+    last_angle_ = new_angle;
+    return 1;
+  } else if (rotated_angle > 128 + threshold_) {
+    last_angle_ = new_angle;
+    return -1;
+  } else {
+    return 0;
+  }
+}
+
+auto TouchWheel::calculateThreshold(uint8_t sensitivity) -> uint8_t {
+  int tmax = 35;
+  int tmin = 5;
+  return (((255. - sensitivity) / 255.) * (tmax - tmin) + tmin);
+}
+
+}  // namespace input