Update pinch gesture logic

src/lib/gesture/pinch_gesture.cpp

@@ -45,7 +45,7 @@ namespace comfortable_swipe::gesture
         const char* pinch_out4
     ):
         comfortable_swipe::gesture::xdo_gesture(),
-        threshold_squared(threshold),
+        threshold(threshold),
         commands(new const char*[4]{pinch_in3, pinch_in4, pinch_out3, pinch_out4})
     { }
 
@@ -60,7 +60,7 @@ namespace comfortable_swipe::gesture
     /**
      * Hook on begin of pinch gesture.
      */
-    void pinch_gesture::begin()
+    inline void pinch_gesture::begin()
     {
         this->previous_gesture = swipe_gesture::FRESH;
         this->previous_radius = this->radius;
@@ -69,10 +69,13 @@ namespace comfortable_swipe::gesture
     /**
      * Hook on update of swipe gesture.
      */
-    void swipe_gesture::update()
+    inline void pinch_gesture::update()
     {
         float delta_radius = this->radius - this->previous_radius;
         this->previous_radius = this->radius;
+
+        // TODO: use a different epsilon threshold
+        const float EPSILON = this->threshold;
         if (this->delta_radius > EPSILON)
         {
             // TODO: pinch out
@@ -86,9 +89,60 @@ namespace comfortable_swipe::gesture
     /**
      * Hook on end of swipe gesture.
      */
-    void pinch_gesture::end()
+    inline void pinch_gesture::end()
     { }
 
+    /**
+     * Parses an output line and dispatches pinch begin/update/end upon match.
+     * Uses GESTURE_BEGIN_REGEX_PATTERN for begin,
+     *      GESTURE_UPDATE_REGEX_PATTERN for update,
+     *      GESTURE_END_REGEX_PATTERN for end.
+     *
+     * @param  line the output line from libinput debug-events
+     * @return      true if line matches this gesture
+     */
+    inline bool pinch_gesture::parse_line(const char * line)
+    {
+        // pre-compile regex patterns
+        static const std::regex gesture_swipe_begin(pinch_gesture::GESTURE_BEGIN_REGEX_PATTERN);
+        static const std::regex gesture_swipe_update(pinch_gesture::GESTURE_UPDATE_REGEX_PATTERN);
+        static const std::regex gesture_swipe_end(pinch_gesture::GESTURE_END_REGEX_PATTERN);
+        std::cmatch matches;
+        if (this->flag_pinching)
+        {
+            // currently pinching
+            if (std::regex_match(line, matches, gesture_swipe_update) != 0)
+            {
+                // update pinch
+                this->fingers = std::stoi(matches[1]);
+                this->radius = std::stof(matches[2]);
+                this->update();
+                return true;
+            }
+            else if (std::regex_match(line, matches, gesture_swipe_end) != 0)
+            {
+                // end pinch
+                this->flag_pinching = false;
+                this->fingers = std::stoi(matches[1]);
+                this->end();
+                return true;
+            }
+        }
+        else /* !flag_swiping */
+        {
+            // not swiping, check if swipe will begin
+            if (std::regex_match(line, matches, gesture_swipe_begin) != 0)
+            {
+                // begin swipe
+                this->flag_pinching = true;
+                this->fingers = std::stoi(matches[1]);
+                this->begin();
+                return true;
+            }
+        }
+        return false;
+    }
+
     /* STATICS DEFINITIONS */
     const int pinch_gesture::MSK_THREE_FINGERS = 0;
     const int pinch_gesture::MSK_FOUR_FINGERS = 1;

src/lib/gesture/pinch_gesture.h

@@ -42,7 +42,7 @@ namespace comfortable_swipe::gesture
         );
 
         ~pinch_gesture();
-        float radius, omega;
+        float radius;
 
         inline void begin() override;
         inline void update() override;
@@ -52,8 +52,9 @@ namespace comfortable_swipe::gesture
     protected:
         // current location
         float previous_radius; 
-        float threshold_squared;
+        float threshold;
         int previous_gesture;
+        bool flag_pinching;
         const char ** commands;
 
     public:

src/lib/gesture/pinch_gesture.regex.cpp

@@ -60,8 +60,8 @@ namespace comfortable_swipe::gesture
     // matches signed decimal numbers (eg. "6.02" "-1.1")
     #define CF_NUMBER_REGEX "-?\\d+(?:\\.\\d+)"
 
-    // matches and extracts a space-prefixed signed fraction (eg. "-3.00/ 5.12")
-    #define CF_NUMBER_DIVISION "\\s*(" CF_NUMBER_REGEX ")/\\s*(" CF_NUMBER_REGEX ")"
+    // matches a space-prefixed signed fraction (eg. "-3.00/ 5.12")
+    #define CF_NUMBER_DIVISION "\\s*" CF_NUMBER_REGEX "/\\s*" CF_NUMBER_REGEX
 
     /**
      * Regex pattern for the libinput entry for during a pinch.
@@ -81,7 +81,7 @@ namespace comfortable_swipe::gesture
         "\\s+" CF_NUMBER_DIVISION                           // speed (dx/dy)
         "\\s+\\(" CF_NUMBER_DIVISION "\\s+unaccelerated\\)" // unaccelerated speed (udx/udy)
         "\\s+(" CF_NUMBER_REGEX ")"                         // radius
-        " @\\s+(" CF_NUMBER_REGEX ")"                       // angular velocity (omega)
+        " @\\s+" CF_NUMBER_REGEX ""                         // angular velocity (omega)
         "\\s*$"                                             // end of string
     ;