From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 23 Nov 2015 17:57:11 +0000 (+0200)
Subject: Implement tap gestures
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgui.git;a=commitdiff_plain;h=1b33313502f837e2b0d02d3f2d129c85a8c66064

Implement tap gestures
---

diff --git a/source/input/gesturedetector.cpp b/source/input/gesturedetector.cpp
index aecfa81..98e3ff3 100644
--- a/source/input/gesturedetector.cpp
+++ b/source/input/gesturedetector.cpp
@@ -12,6 +12,7 @@ GestureDetector::GestureDetector(Touchscreen &ts):
 	touchscreen(ts),
 	current_gesture(GESTURE_NONE),
 	active_points(0),
+	pending_tap(GESTURE_NONE),
 	invalid_gesture(false)
 {
 	name = "Gesture";
@@ -62,6 +63,14 @@ void GestureDetector::touch_down(unsigned btn)
 	p.x = 0;
 	p.y = 0;
 	p.threshold_exceeded = false;
+
+	if(current_gesture==GESTURE_NONE && !invalid_gesture)
+	{
+		if(btn==0)
+			pending_tap = GESTURE_TAP;
+		else if(btn==1)
+			pending_tap = GESTURE_TAP_2;
+	}
 }
 
 void GestureDetector::touch_up(unsigned btn)
@@ -83,6 +92,16 @@ void GestureDetector::touch_up(unsigned btn)
 		invalid_gesture = false;
 		for(unsigned i=0; (i<MAX_POINTS && !invalid_gesture); ++i)
 			invalid_gesture = points[i].down;
+
+		if(!invalid_gesture && pending_tap!=GESTURE_NONE)
+		{
+			unsigned n_points = min<unsigned>((pending_tap-GESTURE_TAP)+1, MAX_POINTS);
+			set_gesture_location((1<<n_points)-1);
+			set_button_state(pending_tap, true, true);
+			set_button_state(pending_tap, false, true);
+
+			pending_tap = GESTURE_NONE;
+		}
 	}
 }
 
@@ -102,7 +121,10 @@ void GestureDetector::touch_move(unsigned axis, float value, float)
 	if(p.down)
 	{
 		if(p.x*p.x/threshold_x_sq+p.y*p.y/threshold_y_sq>=1)
+		{
 			p.threshold_exceeded = true;
+			pending_tap = GESTURE_NONE;
+		}
 
 		if(current_gesture==GESTURE_NONE && !invalid_gesture)
 			start_gesture();
@@ -148,28 +170,42 @@ void GestureDetector::start_gesture()
 			current_gesture = GESTURE_DRAG_2;
 
 		if(current_gesture!=GESTURE_NONE)
-		{
 			active_points = 3;
-			set_axis_value(0, (p.down_x+p2.down_x)/2, true);
-			set_axis_value(1, (p.down_y+p2.down_y)/2, true);
-		}
 	}
 	else
 	{
 		current_gesture = GESTURE_DRAG;
 		active_points = 1;
-		set_axis_value(0, p.down_x, true);
-		set_axis_value(1, p.down_y, true);
 	}
 
-	update_progress();
 
 	if(current_gesture!=GESTURE_NONE)
+	{
+		set_gesture_location(active_points);
+		update_progress();
 		set_button_state(current_gesture, true, true);
+	}
 	else
 		invalid_gesture = true;
 }
 
+void GestureDetector::set_gesture_location(unsigned mask)
+{
+	float x = 0;
+	float y = 0;
+	unsigned count = 0;
+	for(unsigned i=0; i<MAX_POINTS; ++i)
+		if(mask&(1<<i))
+		{
+			x += points[i].down_x;
+			y += points[i].down_y;
+			++count;
+		}
+
+	set_axis_value(0, x/count, true);
+	set_axis_value(1, y/count, true);
+}
+
 void GestureDetector::update_progress()
 {
 	TouchPoint &p = points[0];
@@ -213,6 +249,7 @@ void GestureDetector::end_gesture()
 	set_axis_value(2, 0, false);
 	current_gesture = GESTURE_NONE;
 	active_points = 0;
+	pending_tap = GESTURE_NONE;
 }
 
 void GestureDetector::window_resized(unsigned w, unsigned h)
diff --git a/source/input/gesturedetector.h b/source/input/gesturedetector.h
index ccccc88..a6186fd 100644
--- a/source/input/gesturedetector.h
+++ b/source/input/gesturedetector.h
@@ -11,6 +11,8 @@ class Touchscreen;
 enum Gesture
 {
 	GESTURE_NONE,
+	GESTURE_TAP,
+	GESTURE_TAP_2,
 	GESTURE_DRAG,
 	GESTURE_DRAG_2,
 	GESTURE_PINCH,
@@ -47,6 +49,7 @@ private:
 	TouchPoint points[MAX_POINTS];
 	Gesture current_gesture;
 	unsigned active_points;
+	Gesture pending_tap;
 	bool invalid_gesture;
 	float threshold_x_sq;
 	float threshold_y_sq;
@@ -62,6 +65,7 @@ private:
 	void touch_up(unsigned);
 	void touch_move(unsigned, float, float);
 	void start_gesture();
+	void set_gesture_location(unsigned);
 	void update_progress();
 	void end_gesture();
 	void window_resized(unsigned, unsigned);