File content as of revision 9:6205ef056c8a:

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/*
 * $Date$
 * $Revision$
 */

#include "tof_gestures.h"
#include "tof_gestures_TAP_1.h"

int tof_gestures_initTAP_1(int MinBackGroundDistance, Gesture_TAP_1_Data_t *data){
    int status=0;
    status |= (int)(RB_init(&(data->rangeList),TAP_1_BUFFER_SIZE));
    data->MinBackGroundDistance = MinBackGroundDistance;
    data->timestampLastDetectedTap = 0;
    data->nbOfDataToDecide = TAP_1_NB_OF_DATA_TO_DECIDE;
    data->meanBackground = 0;
    data->gestureCode = GESTURES_NULL;
    data->timestamp = 0;
    return status;
}

int tof_gestures_detectTAP_1(int32_t range_mm, Gesture_TAP_1_Data_t *data){
    int time = GET_TIME_STAMP();
    int madRange = 0;
    int dir;
    int delta_time = 0;
    int background_threshold = 0;

    // Default state
	if (data->gestureCode == GESTURES_NULL){
		// Calculate background distance (averaging)
		data->meanBackground = (data->rangeList.count==0) ? 0 : RB_mean(&(data->rangeList));
		background_threshold = (int)((1-TAP_1_BACKGROUND_VARIATION) * data->meanBackground);
		// Check current distance vs background distance
		if (range_mm < background_threshold){
			// big variation detected => hand entering in FoV
			data->gestureCode = GESTURES_HAND_ENTERING;
			RB_init(&(data->rangeList),TAP_1_BUFFER_SIZE);
			RB_push(&(data->rangeList), range_mm);
			data->timestamp = time;
			TOF_GESTURES_DEBUG(TAP_1,"(background_thd=%d, current=%d, hand_entering=1)", background_threshold, range_mm);
		}else{
    		// no variation => keep averaging background
			RB_push(&(data->rangeList), range_mm);
    		TOF_GESTURES_DEBUG(TAP_1,"(background_thd=%d, current=%d, hand_entering=0)", background_threshold, range_mm);
    	}


	// Hand entering
	} else if (data->gestureCode == GESTURES_HAND_ENTERING){
		// Push the range value in the buffer
		RB_push(&(data->rangeList), range_mm);

		// Try to detect a Tap gesture as soon as possible (4 data are enough for normal/fast gestures speed)
		if(data->rangeList.count == data->nbOfDataToDecide){
			// Calculate MAD
			madRange = RB_mad(&(data->rangeList));
			dir = RB_dir(&(data->rangeList));
			delta_time = time - data->timestampLastDetectedTap;
			// Try to detect a TAP
			//  MAD is higher than a threshold, ranging elements stored in the buffer are decreasing and last TAP has been
			//  detected more than 250 ms ago (too avoid 2 TAPS being reported in case of a slow tap)
			if((madRange > 12) && (dir<0) && (delta_time>250)){
				// Big negative range variation
				if ((data->meanBackground > data->MinBackGroundDistance)){
					// Background estimated just before hand entering is above the min distance of possible background => Skip TAP as this is a false one
					// Relax constraints to detect the next TAP which can come very soon
					RB_init(&(data->rangeList),16);
					data->meanBackground = range_mm;
					data->nbOfDataToDecide = 3;
				}else{
					// Estimated background is now in the gesture area so this was the hand => TAP
					data->timestampLastDetectedTap = time;
					//RB_trace(&(data->rangeList));
					RB_init(&(data->rangeList),16);
					data->nbOfDataToDecide = 4;
					data->gestureCode = GESTURES_SINGLE_TAP;
				//TOF_GESTURES_DEBUG(TAP_1,"(madRange=%d, delta_time=%d, dir=%d) => TAP", madRange, delta_time, dir);
				}
			}else{
				// No TAP detected
				RB_init(&(data->rangeList),16);
				data->nbOfDataToDecide = 4;
				data->gestureCode = GESTURES_NULL;
				//TOF_GESTURES_DEBUG(TAP_1,"(madRange=%d, delta_time=%d, dir=%d) => no TAP", madRange, delta_time, dir);
			}

			TOF_GESTURES_DEBUG(TAP_1,"(hand_entering=1, current=%d, decide=1, madRange=%d, dir=%d, delta_time=%d, meanBackground=%d, tap=%d)", range_mm, madRange, dir, delta_time, data->meanBackground, (int)(data->gestureCode == GESTURES_SINGLE_TAP));

		} else {
			// Wait for more data before deciding
			TOF_GESTURES_DEBUG(TAP_1,"(hand_entering=1, current=%d) wait", range_mm);
		}
	// Tap detected
	} else {
		// Reset gesture code state machine
		data->gestureCode = GESTURES_NULL;
	}

	 return data->gestureCode;
}