input_common: touch: Rewrite touch driver to support multiple touch points

src/input_common/drivers/touch_screen.h

@@ -3,41 +3,65 @@
 
 #pragma once
 
+#include <optional>
+
 #include "input_common/input_engine.h"
 
 namespace InputCommon {
 
 /**
- * A button device factory representing a keyboard. It receives keyboard events and forward them
- * to all button devices it created.
+ * A touch device factory representing a touch screen. It receives touch events and forward them
+ * to all touch devices it created.
  */
 class TouchScreen final : public InputEngine {
 public:
     explicit TouchScreen(std::string input_engine_);
 
     /**
-     * Signals that mouse has moved.
-     * @param x the x-coordinate of the cursor
-     * @param y the y-coordinate of the cursor
-     * @param center_x the x-coordinate of the middle of the screen
-     * @param center_y the y-coordinate of the middle of the screen
+     * Signals that touch has moved and marks this touch point as active
+     * @param x new horizontal position
+     * @param y new vertical position
+     * @param finger_id of the touch point to be updated
      */
-    void TouchMoved(float x, float y, std::size_t finger);
+    void TouchMoved(float x, float y, std::size_t finger_id);
 
     /**
-     * Sets the status of all buttons bound with the key to pressed
-     * @param key_code the code of the key to press
+     * Signals and creates a new touch point with this finger id
+     * @param x starting horizontal position
+     * @param y starting vertical position
+     * @param finger_id to be assigned to the new touch point
      */
-    void TouchPressed(float x, float y, std::size_t finger);
+    void TouchPressed(float x, float y, std::size_t finger_id);
 
     /**
-     * Sets the status of all buttons bound with the key to released
-     * @param key_code the code of the key to release
+     * Signals and resets the touch point related to the this finger id
+     * @param finger_id to be released
      */
-    void TouchReleased(std::size_t finger);
+    void TouchReleased(std::size_t finger_id);
+
+    /// Resets the active flag for each touch point
+    void ClearActiveFlag();
+
+    /// Releases all touch that haven't been marked as active
+    void ReleaseInactiveTouch();
 
     /// Resets all inputs to their initial value
     void ReleaseAllTouch();
+
+private:
+    static constexpr std::size_t MAX_FINGER_COUNT = 16;
+
+    struct TouchStatus {
+        std::size_t finger_id{};
+        bool is_enabled{};
+        bool is_active{};
+    };
+
+    std::optional<std::size_t> GetIndexFromFingerId(std::size_t finger_id) const;
+
+    std::optional<std::size_t> GetNextFreeIndex() const;
+
+    std::array<TouchStatus, MAX_FINGER_COUNT> fingers{};
 };
 
 } // namespace InputCommon