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#!/usr/bin/env python
from typing import TypeVar, Tuple
from dataclasses import dataclass, field
import math
import ast
import json
from argaze import DataStructures
from argaze.AreaOfInterest import AOIFeatures
import numpy
import pandas
import cv2 as cv
@dataclass(frozen=True)
class GazePosition():
"""Define gaze position as a tuple of coordinates with precision."""
value: tuple[int | float] = field(default=(0, 0))
"""Position's value."""
precision: float = field(default=0., kw_only=True)
"""Position's precision represents the radius of a circle around \
this gaze position value where other same gaze position measurements could be."""
def __getitem__(self, axis: int) -> int | float:
"""Get position value along a particular axis."""
return self.value[axis]
def __iter__(self) -> iter:
"""Iterate over each position value axis."""
return iter(self.value)
def __len__(self) -> int:
"""Number of axis in position value."""
return len(self.value)
def __repr__(self):
"""String representation"""
return json.dumps(self, ensure_ascii = False, default=vars)
def __array__(self):
"""Cast as numpy array."""
return numpy.array(self.value)
@property
def valid(self) -> bool:
"""Is the precision not None?"""
return self.precision is not None
def overlap(self, gaze_position, both=False) -> float:
"""Does this gaze position overlap another gaze position considering its precision?
Set both to True to test if the other gaze position overlaps this one too."""
dist = (self.value[0] - gaze_position.value[0])**2 + (self.value[1] - gaze_position.value[1])**2
dist = numpy.sqrt(dist)
if both:
return dist < min(self.precision, gaze_position.precision)
else:
return dist < self.precision
def draw(self, frame, color=(0, 255, 255), draw_precision=True):
"""Draw gaze position point and precision circle."""
if self.valid:
int_value = (int(self.value[0]), int(self.value[1]))
# Draw point at position
cv.circle(frame, int_value, 2, color, -1)
# Draw precision circle
if self.precision > 0 and draw_precision:
cv.circle(frame, int_value, round(self.precision), color, 1)
class UnvalidGazePosition(GazePosition):
"""Unvalid gaze position."""
def __init__(self, message=None):
self.message = message
super().__init__((None, None), precision=None)
TimeStampedGazePositionsType = TypeVar('TimeStampedGazePositions', bound="TimeStampedGazePositions")
# Type definition for type annotation convenience
class TimeStampedGazePositions(DataStructures.TimeStampedBuffer):
"""Define timestamped buffer to store gaze positions."""
def __setitem__(self, key, value: GazePosition|dict):
"""Force GazePosition storage."""
# Convert dict into GazePosition
if type(value) == dict:
assert(set(['value', 'precision']).issubset(value.keys()))
if 'message' in value.keys():
value = UnvalidGazePosition(value['message'])
else:
value = GazePosition(value['value'], precision=value['precision'])
assert(type(value) == GazePosition or type(value) == UnvalidGazePosition)
super().__setitem__(key, value)
@classmethod
def from_json(self, json_filepath: str) -> TimeStampedGazePositionsType:
"""Create a TimeStampedGazePositionsType from .json file."""
with open(json_filepath, encoding='utf-8') as ts_buffer_file:
json_buffer = json.load(ts_buffer_file)
return TimeStampedGazePositions({ast.literal_eval(ts_str): json_buffer[ts_str] for ts_str in json_buffer})
GazeMovementType = TypeVar('GazeMovement', bound="GazeMovement")
# Type definition for type annotation convenience
@dataclass(frozen=True)
class GazeMovement():
"""Define abstract gaze movement class as a buffer of timestamped positions."""
positions: TimeStampedGazePositions
"""All timestamp gaze positions."""
duration: float = field(init=False)
"""Inferred duration from first and last timestamps."""
distance: float = field(init=False)
"""Inferred distance from first and last positions."""
def __post_init__(self):
start_position_ts, start_position = self.positions.first
end_position_ts, end_position = self.positions.last
# Update frozen duration attribute
object.__setattr__(self, 'duration', end_position_ts - start_position_ts)
_, start_position = self.positions.first
_, end_position = self.positions.last
distance = numpy.linalg.norm( numpy.array(start_position.value) - numpy.array(end_position.value))
# Update frozen distance attribute
object.__setattr__(self, 'distance', distance)
def __str__(self) -> str:
"""String display"""
output = f'{type(self)}:\n\tduration={self.duration}\n\tsize={len(self.positions)}'
for ts, position in self.positions.items():
output += f'\n\t{ts}:\n\t\tvalue={position.value},\n\t\taccurracy={position.precision}'
return output
class Fixation(GazeMovement):
"""Define abstract fixation as gaze movement."""
def __post_init__(self):
super().__post_init__()
class Saccade(GazeMovement):
"""Define abstract saccade as gaze movement."""
def __post_init__(self):
super().__post_init__()
TimeStampedGazeMovementsType = TypeVar('TimeStampedGazeMovements', bound="TimeStampedGazeMovements")
# Type definition for type annotation convenience
class TimeStampedGazeMovements(DataStructures.TimeStampedBuffer):
"""Define timestamped buffer to store gaze movements."""
def __setitem__(self, key, value: GazeMovement):
"""Force value to be or inherit from GazeMovement."""
assert(isinstance(value, GazeMovement) or type(value).__bases__[0] == Fixation or type(value).__bases__[0] == Saccade)
super().__setitem__(key, value)
def __str__(self):
output = ''
for ts, item in self.items():
output += f'\n{item}'
return output
GazeStatusType = TypeVar('GazeStatus', bound="GazeStatus")
# Type definition for type annotation convenience
@dataclass(frozen=True)
class GazeStatus(GazePosition):
"""Define gaze status as a gaze position belonging to an identified and indexed gaze movement."""
movement_type: str = field(kw_only=True)
"""GazeMovement type to which gaze position belongs."""
movement_index: int = field(kw_only=True)
"""GazeMovement index to which gaze positon belongs."""
@classmethod
def from_position(cls, gaze_position: GazePosition, movement_type: str, movement_index: int) -> GazeStatusType:
"""Initialize from a gaze position instance."""
return cls(gaze_position.value, precision=gaze_position.precision, movement_type=movement_type, movement_index=movement_index)
TimeStampedGazeStatusType = TypeVar('TimeStampedGazeStatus', bound="TimeStampedGazeStatus")
# Type definition for type annotation convenience
class TimeStampedGazeStatus(DataStructures.TimeStampedBuffer):
"""Define timestamped buffer to store gaze status."""
def __setitem__(self, key, value: GazeStatus):
super().__setitem__(key, value)
class GazeMovementIdentifier():
"""Abstract class to define what should provide a gaze movement identifier."""
def identify(self, ts, gaze_position, terminate=False) -> GazeMovementType:
"""Identify gaze movement from successive timestamped gaze positions.
The optional *terminate* argument allows to notify identification algorithm that given gaze position will be the last one.
"""
raise NotImplementedError('identify() method not implemented')
def browse(self, ts_gaze_positions: TimeStampedGazePositions) -> Tuple[TimeStampedGazeMovementsType, TimeStampedGazeMovementsType, TimeStampedGazeStatusType]:
"""Identify fixations and saccades browsing timestamped gaze positions."""
assert(type(ts_gaze_positions) == TimeStampedGazePositions)
ts_fixations = TimeStampedGazeMovements()
ts_saccades = TimeStampedGazeMovements()
ts_status = TimeStampedGazeStatus()
# Get last ts to terminate identification on last gaze position
last_ts, _ = ts_gaze_positions.last
# Iterate on gaze positions
for ts, gaze_position in ts_gaze_positions.items():
gaze_movement = self.identify(ts, gaze_position, terminate=(ts == last_ts))
if isinstance(gaze_movement, Fixation):
start_ts, start_position = gaze_movement.positions.first
ts_fixations[start_ts] = gaze_movement
for ts, position in gaze_movement.positions.items():
ts_status[ts] = GazeStatus.from_position(position, 'Fixation', len(ts_fixations))
elif isinstance(gaze_movement, Saccade):
start_ts, start_position = gaze_movement.positions.first
ts_saccades[start_ts] = gaze_movement
for ts, position in gaze_movement.positions.items():
ts_status[ts] = GazeStatus.from_position(position, 'Saccade', len(ts_saccades))
else:
continue
return ts_fixations, ts_saccades, ts_status
|
