From 598786409491a119ba761eca53c5eb2d94a4d9e8 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 19 Sep 2016 23:30:14 +0300
Subject: [PATCH] Refactor GestureDetector logic

Active_points only ever had the one or two bottom bits set and always
matched current gesture.  It's simpler to just use the number of points
for the gesture.
---
 source/input/gesturedetector.cpp | 83 ++++++++++++++++++--------------
 source/input/gesturedetector.h   |  5 +-
 2 files changed, 50 insertions(+), 38 deletions(-)

diff --git a/source/input/gesturedetector.cpp b/source/input/gesturedetector.cpp
index 145262a..26968c0 100644
--- a/source/input/gesturedetector.cpp
+++ b/source/input/gesturedetector.cpp
@@ -12,7 +12,6 @@ namespace Input {
 GestureDetector::GestureDetector(Touchscreen &ts):
 	touchscreen(ts),
 	current_gesture(GESTURE_NONE),
-	active_points(0),
 	pending_tap(GESTURE_NONE),
 	invalid_gesture(false)
 {
@@ -90,7 +89,7 @@ void GestureDetector::touch_up(unsigned btn)
 	p.y += p.down_y;
 	p.down = false;
 
-	if(active_points&(1<<btn))
+	if(btn<gesture_points(current_gesture))
 		end_gesture();
 
 	if(current_gesture==GESTURE_NONE)
@@ -102,8 +101,7 @@ void GestureDetector::touch_up(unsigned btn)
 
 		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_gesture_location(gesture_points(pending_tap));
 			set_button_state(pending_tap, true, true);
 			set_button_state(pending_tap, false, true);
 
@@ -135,7 +133,7 @@ void GestureDetector::touch_move(unsigned axis, float value, float)
 
 		if(current_gesture==GESTURE_NONE && !invalid_gesture)
 			start_gesture();
-		else if(active_points&(1<<i))
+		else if(i<gesture_points(current_gesture))
 			update_progress();
 	}
 }
@@ -175,20 +173,13 @@ void GestureDetector::start_gesture()
 		else if((p.x*p2.x+p.y*p2.y)>2*abs(p.x*p2.y-p.y*p2.x))
 			// If both points moved in the same direction, it's a two-finger drag.
 			current_gesture = GESTURE_DRAG_2;
-
-		if(current_gesture!=GESTURE_NONE)
-			active_points = 3;
 	}
 	else
-	{
 		current_gesture = GESTURE_DRAG;
-		active_points = 1;
-	}
-
 
 	if(current_gesture!=GESTURE_NONE)
 	{
-		set_gesture_location(active_points);
+		set_gesture_location(gesture_points(current_gesture));
 		update_progress();
 		set_button_state(current_gesture, true, true);
 	}
@@ -196,40 +187,41 @@ void GestureDetector::start_gesture()
 		invalid_gesture = true;
 }
 
-void GestureDetector::set_gesture_location(unsigned mask)
+void GestureDetector::set_gesture_location(unsigned n_points)
 {
 	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;
-		}
+	for(unsigned i=0; i<n_points; ++i)
+	{
+		x += points[i].down_x;
+		y += points[i].down_y;
+	}
 
-	set_axis_value(0, x/count, true);
-	set_axis_value(1, y/count, true);
+	set_axis_value(0, x/n_points, true);
+	set_axis_value(1, y/n_points, true);
 }
 
-void GestureDetector::update_progress()
+void GestureDetector::set_gesture_delta(unsigned n_points)
 {
-	TouchPoint &p = points[0];
-
-	if(current_gesture==GESTURE_DRAG)
-	{
-		set_axis_value(2, p.x, true);
-		set_axis_value(3, p.y, true);
-	}
-	else if(current_gesture==GESTURE_DRAG_2)
+	float x = 0;
+	float y = 0;
+	for(unsigned i=0; i<n_points; ++i)
 	{
-		TouchPoint &p2 = points[1];
-		set_axis_value(2, (p.x+p2.x)/2, true);
-		set_axis_value(3, (p.y+p2.y)/2, true);
+		x += points[i].x;
+		y += points[i].y;
 	}
+
+	set_axis_value(2, x/n_points, true);
+	set_axis_value(3, y/n_points, true);
+}
+
+void GestureDetector::update_progress()
+{
+	if(current_gesture>=GESTURE_DRAG && current_gesture<=GESTURE_DRAG_2)
+		set_gesture_delta(gesture_points(current_gesture));
 	else if(current_gesture==GESTURE_PINCH || current_gesture==GESTURE_ROTATE)
 	{
+		TouchPoint &p = points[0];
 		TouchPoint &p2 = points[1];
 		/* Pinch progress is the ratio between the current distance of the points
 		and their distance when they were pressed. */
@@ -255,7 +247,6 @@ void GestureDetector::end_gesture()
 	set_button_state(current_gesture, false, true);
 	set_axis_value(2, 0, false);
 	current_gesture = GESTURE_NONE;
-	active_points = 0;
 	pending_tap = GESTURE_NONE;
 }
 
@@ -275,5 +266,23 @@ GestureDetector::TouchPoint::TouchPoint():
 	threshold_exceeded(false)
 { }
 
+
+unsigned gesture_points(Gesture gesture)
+{
+	switch(gesture)
+	{
+	case GESTURE_NONE: return 0;
+	case GESTURE_TAP: return 1;
+	case GESTURE_TAP_2: return 2;
+	case GESTURE_TAP_3: return 3;
+	case GESTURE_DRAG: return 1;
+	case GESTURE_DRAG_2: return 2;
+	case GESTURE_DRAG_3: return 3;
+	case GESTURE_PINCH: return 2;
+	case GESTURE_ROTATE: return 2;
+	default: throw invalid_argument("gesture_points");
+	}
+}
+
 } // namespace Input
 } // namespace Msp
diff --git a/source/input/gesturedetector.h b/source/input/gesturedetector.h
index a6186fd..f39fdce 100644
--- a/source/input/gesturedetector.h
+++ b/source/input/gesturedetector.h
@@ -48,7 +48,6 @@ private:
 	Touchscreen &touchscreen;
 	TouchPoint points[MAX_POINTS];
 	Gesture current_gesture;
-	unsigned active_points;
 	Gesture pending_tap;
 	bool invalid_gesture;
 	float threshold_x_sq;
@@ -66,11 +65,15 @@ private:
 	void touch_move(unsigned, float, float);
 	void start_gesture();
 	void set_gesture_location(unsigned);
+	void set_gesture_delta(unsigned);
 	void update_progress();
 	void end_gesture();
 	void window_resized(unsigned, unsigned);
 };
 
+
+unsigned gesture_points(Gesture);
+
 } // namespace Input
 } // namespace Msp
 
-- 
2.43.0