1 #include "gesturedetector.h"
2 #define _USE_MATH_DEFINES
4 #include <sigc++/bind_return.h>
5 #include "touchscreen.h"
12 GestureDetector::GestureDetector(Touchscreen &ts):
18 touchscreen.signal_button_press.connect(sigc::bind_return(sigc::mem_fun(this, &GestureDetector::touch_down), false));
19 touchscreen.signal_button_release.connect(sigc::bind_return(sigc::mem_fun(this, &GestureDetector::touch_up), false));
20 touchscreen.signal_axis_motion.connect(sigc::bind_return(sigc::mem_fun(this, &GestureDetector::touch_move), false));
21 Graphics::Window &window = touchscreen.get_window();
22 window.signal_resize.connect(sigc::mem_fun(this, &GestureDetector::window_resized));
23 window_resized(window.get_width(), window.get_height());
26 string GestureDetector::get_button_name(unsigned btn) const
30 else if(btn==GESTURE_TAP_2)
31 return "Two-finger tap";
32 else if(btn==GESTURE_TAP_3)
33 return "Three-finger tap";
34 else if(btn==GESTURE_DRAG)
36 else if(btn==GESTURE_DRAG_2)
37 return "Two-finger drag";
38 else if(btn==GESTURE_DRAG_3)
39 return "Three-finger drag";
40 else if(btn==GESTURE_PINCH)
42 else if(btn==GESTURE_ROTATE)
45 return Device::get_button_name(btn);
48 string GestureDetector::get_axis_name(unsigned axis) const
59 return Device::get_axis_name(axis);
62 void GestureDetector::touch_down(unsigned btn)
67 TouchPoint &p = points[btn];
73 p.threshold_exceeded = false;
75 if(current_gesture==GESTURE_NONE && !invalid_gesture)
78 pending_tap = GESTURE_TAP;
80 pending_tap = GESTURE_TAP_2;
82 pending_tap = GESTURE_TAP_3;
86 void GestureDetector::touch_up(unsigned btn)
91 TouchPoint &p = points[btn];
96 if(btn<gesture_points(current_gesture))
99 if(current_gesture==GESTURE_NONE)
101 // New gesture can't start until all points have been released.
102 invalid_gesture = false;
103 for(unsigned i=0; (i<MAX_POINTS && !invalid_gesture); ++i)
104 invalid_gesture = points[i].down;
106 if(!invalid_gesture && pending_tap!=GESTURE_NONE)
108 set_gesture_location(gesture_points(pending_tap));
109 set_button_state(pending_tap, true, true);
110 set_button_state(pending_tap, false, true);
112 pending_tap = GESTURE_NONE;
117 void GestureDetector::touch_move(unsigned axis, float value, float)
119 if(axis>=MAX_POINTS*2)
122 unsigned i = axis>>1;
123 TouchPoint &p = points[i];
124 // Track relative position when pressed, absolute when not.
126 p.y = (p.down ? value-p.down_y : value);
128 p.x = (p.down ? value-p.down_x : value);
132 if(p.x*p.x/threshold_x_sq+p.y*p.y/threshold_y_sq>=1)
134 p.threshold_exceeded = true;
135 pending_tap = GESTURE_NONE;
138 if(current_gesture==GESTURE_NONE && !invalid_gesture)
140 else if(i<gesture_points(current_gesture))
145 void GestureDetector::start_gesture()
147 TouchPoint &p = points[0];
151 /* All held points need to have moved more than the threshold to start the
153 bool threshold_exceeded = true;
154 for(unsigned i=0; (i<MAX_POINTS && threshold_exceeded); ++i)
155 if(points[i].down && !points[i].threshold_exceeded)
156 threshold_exceeded = false;
157 if(!threshold_exceeded)
160 invalid_gesture = false;
163 bool same_direction = true;
164 for(unsigned i=0; (same_direction && i<2); ++i)
165 for(unsigned j=i+1; (same_direction && j<3); ++j)
167 TouchPoint &pi = points[i];
168 TouchPoint &pj = points[j];
169 same_direction = ((pi.x*pj.x+pi.y*pj.y)>2*abs(pi.x*pj.y-pi.y*pj.x));
173 current_gesture = GESTURE_DRAG_3;
175 else if(points[1].down)
177 TouchPoint &p2 = points[1];
178 float ddx = p.down_x-p2.down_x;
179 float ddy = p.down_y-p2.down_y;
180 float away = p.x*ddx+p.y*ddy;
181 float turn = p.y*ddx-p.x*ddy;
182 float away2 = -(p2.x*ddx+p2.y*ddy);
183 float turn2 = -(p2.y*ddx-p2.x*ddy);
184 if(away*away2>0 && abs(away)>abs(turn) && abs(away2)>abs(turn2))
185 /* If the points moved away from or towards each other without rotating
186 significantly, it's a pinch gesture. */
187 current_gesture = GESTURE_PINCH;
188 else if(turn*turn2>0 && abs(turn)>abs(away) && abs(turn2)>abs(away2))
189 /* If the points both turned in the same direction without significant
190 changes in distance, it's a rotate gesture. */
191 current_gesture = GESTURE_ROTATE;
192 else if((p.x*p2.x+p.y*p2.y)>2*abs(p.x*p2.y-p.y*p2.x))
193 // If both points moved in the same direction, it's a two-finger drag.
194 current_gesture = GESTURE_DRAG_2;
197 current_gesture = GESTURE_DRAG;
199 if(current_gesture!=GESTURE_NONE)
201 set_gesture_location(gesture_points(current_gesture));
203 set_button_state(current_gesture, true, true);
206 invalid_gesture = true;
209 void GestureDetector::set_gesture_location(unsigned n_points)
213 for(unsigned i=0; i<n_points; ++i)
215 x += points[i].down_x;
216 y += points[i].down_y;
219 set_axis_value(0, x/n_points, true);
220 set_axis_value(1, y/n_points, true);
223 void GestureDetector::set_gesture_delta(unsigned n_points)
227 for(unsigned i=0; i<n_points; ++i)
233 set_axis_value(2, x/n_points, true);
234 set_axis_value(3, y/n_points, true);
237 void GestureDetector::update_progress()
239 if(current_gesture>=GESTURE_DRAG && current_gesture<=GESTURE_DRAG_3)
240 set_gesture_delta(gesture_points(current_gesture));
241 else if(current_gesture==GESTURE_PINCH || current_gesture==GESTURE_ROTATE)
243 TouchPoint &p = points[0];
244 TouchPoint &p2 = points[1];
245 /* Pinch progress is the ratio between the current distance of the points
246 and their distance when they were pressed. */
247 float ddx = p.down_x-p2.down_x;
248 float ddy = p.down_y-p2.down_y;
249 float dx = ddx+p.x-p2.x;
250 float dy = ddy+p.y-p2.y;
251 if(current_gesture==GESTURE_PINCH)
253 set_axis_value(2, sqrt(dx*dx+dy*dy)/sqrt(ddx*ddx+ddy*ddy)-1, true);
254 set_axis_value(3, 0, true);
256 else if(current_gesture==GESTURE_ROTATE)
258 set_axis_value(2, atan2(dy*ddx-dx*ddy, dx*ddx+dy*ddy)/M_PI/2, true);
259 set_axis_value(3, 0, true);
264 void GestureDetector::end_gesture()
266 set_button_state(current_gesture, false, true);
267 set_axis_value(2, 0, false);
268 current_gesture = GESTURE_NONE;
269 pending_tap = GESTURE_NONE;
272 void GestureDetector::window_resized(unsigned w, unsigned h)
274 threshold_x_sq = 2500.0/(w*w);
275 threshold_y_sq = 2500.0/(h*h);
279 GestureDetector::TouchPoint::TouchPoint():
285 threshold_exceeded(false)
289 unsigned gesture_points(Gesture gesture)
293 case GESTURE_NONE: return 0;
294 case GESTURE_TAP: return 1;
295 case GESTURE_TAP_2: return 2;
296 case GESTURE_TAP_3: return 3;
297 case GESTURE_DRAG: return 1;
298 case GESTURE_DRAG_2: return 2;
299 case GESTURE_DRAG_3: return 3;
300 case GESTURE_PINCH: return 2;
301 case GESTURE_ROTATE: return 2;
302 default: throw invalid_argument("gesture_points");