Scan Path Without Flow

scan_path_no_flow.py

'''
(*)~----------------------------------------------------------------------------------
 Pupil - eye tracking platform
 Copyright (C) 2012-2016  Pupil Labs

 Distributed under the terms of the GNU Lesser General Public License (LGPL v3.0).
 License details are in the file license.txt, distributed as part of this software.
----------------------------------------------------------------------------------~(*)
'''

from plugin import Plugin
from pyglui import ui

class Scan_Path_No_Flow(Plugin):
    """docstring
    using this plugin will extend the recent_gaze_positions by x extra dots from previous frames.
    lock recent gaze points onto pixels.
    """

    def __init__(self, g_pool,timeframe=.5):
        super(Scan_Path_No_Flow, self).__init__(g_pool)
        #let the plugin work after most other plugins.
        self.order = .6
        self.menu = None

        #user settings
        self.timeframe = timeframe

        self.prev_frame_idx = -1
        self.past_gaze_positions = []


    def update(self,frame,events):
        updated_past_gaze = []
        succeeding_frame = frame.index-self.prev_frame_idx == 1
        same_frame = frame.index == self.prev_frame_idx

        if same_frame:
            # paused
            # re-use last result
            events['gaze_positions'][:] = self.past_gaze_positions[:]    
        else:
            # trim gaze that is too old
            if events['gaze_positions']:
                now = events['gaze_positions'][0]['timestamp']
                cutoff = now-self.timeframe
                updated_past_gaze = [g for g in self.past_gaze_positions if g['timestamp']>cutoff]

                #inject the scan path gaze points into recent_gaze_positions
                events['gaze_positions'][:] = updated_past_gaze + events['gaze_positions']
                events['gaze_positions'].sort(key=lambda x: x['timestamp']) #this may be redundant...

                self.past_gaze_positions = events['gaze_positions']


    def init_gui(self):
        # initialize the menu
        self.menu = ui.Scrolling_Menu('Scan Path No Flow')
        self.g_pool.gui.append(self.menu)
        self.menu.append(ui.Button('Close',self.unset_alive))
        # max is set to 100000 seconds which is about 27 hours
        self.menu.append(ui.Slider('timeframe',self,min=0,step=0.5,max=100000,label="duration in sec"))

    def deinit_gui(self):
        if self.menu:
            self.g_pool.gui.remove(self.menu)
            self.menu = None

    def unset_alive(self):
        self.alive = False

    def get_init_dict(self):
        return {'timeframe':self.timeframe}

    def cleanup(self):
        """ called when the plugin gets terminated.
        This happens either voluntarily or forced.
        if you have a GUI or glfw window destroy it here.
        """
        self.deinit_gui()