#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""This stimulus class defines a field of dots with an update rule that
determines how they change on every call to the .draw() method.
"""
# Part of the PsychoPy library
# Copyright (C) 2002-2018 Jonathan Peirce (C) 2019-2024 Open Science Tools Ltd.
# Distributed under the terms of the GNU General Public License (GPL).
# Bugfix by Andrew Schofield.
# Replaces out of bounds but still live dots at opposite edge of aperture
# instead of randomly within the field. This stops the concentration of dots at
# one side of field when lifetime is long.
# Update the dot direction immediately for 'walk' as otherwise when the
# coherence varies some signal dots will inherit the random directions of
# previous walking dots.
# Provide a visible wrapper function to refresh all the dot locations so that
# the whole field can be more easily refreshed between trials.
# Ensure setting pyglet.options['debug_gl'] to False is done prior to any
# other calls to pyglet or pyglet submodules, otherwise it may not get picked
# up by the pyglet GL engine and have no effect.
# Shaders will work but require OpenGL2.0 drivers AND PyOpenGL3.0+
import pyglet
pyglet.options['debug_gl'] = False
import ctypes
GL = pyglet.gl
import psychopy # so we can get the __path__
from psychopy import logging
# tools must only be imported *after* event or MovieStim breaks on win32
# (JWP has no idea why!)
from psychopy.tools.attributetools import attributeSetter, setAttribute
from psychopy.tools.arraytools import val2array
from psychopy.visual.basevisual import (BaseVisualStim, ColorMixin,
ContainerMixin, WindowMixin)
from psychopy.layout import Size
import numpy as np
# some constants
_piOver2 = np.pi / 2.
_piOver180 = np.pi / 180.
_2pi = 2 * np.pi
[docs]class DotStim(BaseVisualStim, ColorMixin, ContainerMixin):
"""This stimulus class defines a field of dots with an update rule that
determines how they change on every call to the .draw() method. This is
a lazy-imported class, therefore import using full path
`from psychopy.visual.dot import DotStim` when inheriting from it.
This single class can be used to generate a wide variety of dot motion
types. For a review of possible types and their pros and cons see Scase,
Braddick & Raymond (1996). All six possible motions they describe can be
generated with appropriate choices of the `signalDots` (which determines
whether signal dots are the 'same' or 'different' on each frame),
`noiseDots` (which determines the locations of the noise dots on each frame)
and the `dotLife` (which determines for how many frames the dot will
continue before being regenerated).
The default settings (as of v1.70.00) is for the noise dots to have
identical velocity but random direction and signal dots remain the 'same'
(once a signal dot, always a signal dot).
For further detail about the different configurations see :ref:`dots` in the
Builder Components section of the documentation.
If further customisation is required, then the DotStim should be subclassed
and its _update_dotsXY and _newDotsXY methods overridden.
The maximum number of dots that can be drawn is limited by system
performance.
Attributes
----------
fieldShape : str
*'sqr'* or 'circle'. Defines the envelope used to present the dots. If
changed while drawing, dots outside new envelope will be respawned.
dotSize : float
Dot size specified in pixels (overridden if `element` is specified).
:ref:`operations <attrib-operations>` are supported.
dotLife : int
Number of frames each dot lives for (-1=infinite). Dot lives are
initiated randomly from a uniform distribution from 0 to dotLife. If
changed while drawing, the lives of all dots will be randomly initiated
again.
signalDots : str
If 'same' then the signal and noise dots are constant. If 'different'
then the choice of which is signal and which is noise gets randomised on
each frame. This corresponds to Scase et al's (1996) categories of RDK.
noiseDots : str
Determines the behaviour of the noise dots, taken directly from Scase et
al's (1996) categories. For 'position', noise dots take a random
position every frame. For 'direction' noise dots follow a random, but
constant direction. For 'walk' noise dots vary their direction every
frame, but keep a constant speed.
element : object
This can be any object that has a ``.draw()`` method and a
``.setPos([x,y])`` method (e.g. a GratingStim, TextStim...)!! DotStim
assumes that the element uses pixels as units. ``None`` defaults to
dots.
fieldPos : array_like
Specifying the location of the centre of the stimulus using a
:ref:`x,y-pair <attrib-xy>`. See e.g. :class:`.ShapeStim` for more
documentation/examples on how to set position.
:ref:`operations <attrib-operations>` are supported.
fieldSize : array_like
Specifying the size of the field of dots using a
:ref:`x,y-pair <attrib-xy>`. See e.g. :class:`.ShapeStim` for more
documentation/examples on how to set position.
:ref:`operations <attrib-operations>` are supported.
coherence : float
Change the coherence (%) of the DotStim. This will be rounded according
to the number of dots in the stimulus.
dir : float
Direction of the coherent dots in degrees. :ref:`operations
<attrib-operations>` are supported.
speed : float
Speed of the dots (in *units*/frame). :ref:`operations
<attrib-operations>` are supported.
"""
def __init__(self,
win,
units='',
nDots=1,
coherence=0.5,
fieldPos=(0.0, 0.0),
fieldSize=(1.0, 1.0),
fieldShape='sqr',
fieldAnchor="center",
dotSize=2.0,
dotLife=3,
dir=0.0,
speed=0.5,
rgb=None,
color=(1.0, 1.0, 1.0),
colorSpace='rgb',
opacity=None,
contrast=1.0,
depth=0,
element=None,
signalDots='same',
noiseDots='direction',
name=None,
autoLog=None):
"""
Parameters
----------
win : window.Window
Window this stimulus is associated with.
units : str
Units to use.
nDots : int
Number of dots to present in the field.
coherence : float
Proportion of dots which are coherent. This value can be set using
the `coherence` property after initialization.
fieldPos : array_like
(x,y) or [x,y] position of the field. This value can be set using
the `fieldPos` property after initialization.
fieldSize : array_like, int or float
(x,y) or [x,y] or single value (applied to both dimensions). Sizes
can be negative and can extend beyond the window. This value can be
set using the `fieldSize` property after initialization.
fieldShape : str
Defines the envelope used to present the dots. If changed while
drawing by setting the `fieldShape` property, dots outside new
envelope will be respawned., valid values are 'square', 'sqr' or
'circle'.
dotSize : array_like or float
Size of the dots. If given an array, the sizes of individual dots
will be set. The array must have length `nDots`. If a single value
is given, all dots will be set to the same size.
dotLife : int
Lifetime of a dot in frames. Dot lives are initiated randomly from a
uniform distribution from 0 to dotLife. If changed while drawing,
the lives of all dots will be randomly initiated again. A value of
-1 results in dots having an infinite lifetime. This value can be
set using the `dotLife` property after initialization.
dir : float
Direction of the coherent dots in degrees. At 0 degrees, coherent
dots will move from left to right. Increasing the angle will rotate
the direction counter-clockwise. This value can be set using the
`dir` property after initialization.
speed : float
Speed of the dots (in *units* per frame). This value can be set
using the `speed` property after initialization.
rgb : array_like, optional
Color of the dots in form (r, g, b) or [r, g, b]. **Deprecated**,
use `color` instead.
color : array_like or str
Color of the dots in form (r, g, b) or [r, g, b].
colorSpace : str
Colorspace to use.
opacity : float
Opacity of the dots from 0.0 to 1.0.
contrast : float
Contrast of the dots 0.0 to 1.0. This value is simply multiplied by
the `color` value.
depth : float
**Deprecated**, depth is now controlled simply by drawing order.
element : object
This can be any object that has a ``.draw()`` method and a
``.setPos([x,y])`` method (e.g. a GratingStim, TextStim...)!!
DotStim assumes that the element uses pixels as units.
``None`` defaults to dots.
signalDots : str
If 'same' then the signal and noise dots are constant. If different
then the choice of which is signal and which is noise gets
randomised on each frame. This corresponds to Scase et al's (1996)
categories of RDK. This value can be set using the `signalDots`
property after initialization.
noiseDots : str
Determines the behaviour of the noise dots, taken directly from
Scase et al's (1996) categories. For 'position', noise dots take a
random position every frame. For 'direction' noise dots follow a
random, but constant direction. For 'walk' noise dots vary their
direction every frame, but keep a constant speed. This value can be
set using the `noiseDots` property after initialization.
name : str, optional
Optional name to use for logging.
autoLog : bool
Enable automatic logging.
"""
# what local vars are defined (these are the init params) for use by
# __repr__
self._initParams = __builtins__['dir']()
self._initParams.remove('self')
super(DotStim, self).__init__(win, units=units, name=name,
autoLog=False) # set at end of init
self.nDots = nDots
# pos and size are ambiguous for dots so DotStim explicitly has
# fieldPos = pos, fieldSize=size and then dotSize as additional param
self.fieldPos = fieldPos # self.pos is also set here
self.fieldSize = val2array(fieldSize, False) # self.size is also set
if type(dotSize) in (tuple, list):
self.dotSize = np.array(dotSize)
else:
self.dotSize = dotSize
if self.win.useRetina:
self.dotSize *= 2 # double dot size to make up for 1/2-size pixels
self.fieldShape = fieldShape
self.__dict__['dir'] = dir
self.speed = speed
self.element = element
self.dotLife = dotLife
self.signalDots = signalDots
if rgb != None:
logging.warning("Use of rgb arguments to stimuli are deprecated."
" Please use color and colorSpace args instead")
self.colorSpace = 'rgba'
self.color = rgb
else:
self.colorSpace = colorSpace
self.color = color
self.opacity = opacity
self.contrast = float(contrast)
self.depth = depth
# initialise the dots themselves - give them all random dir and then
# fix the first n in the array to have the direction specified
self.coherence = coherence # using the attributeSetter
self.noiseDots = noiseDots
# initialise a random array of X,Y
self.vertices = self._verticesBase = self._dotsXY = self._newDotsXY(self.nDots)
# all dots have the same speed
self._dotsSpeed = np.ones(self.nDots, dtype=float) * self.speed
# abs() means we can ignore the -1 case (no life)
self._dotsLife = np.abs(dotLife) * np.random.rand(self.nDots)
# pre-allocate array for flagging dead dots
self._deadDots = np.zeros(self.nDots, dtype=bool)
# set directions (only used when self.noiseDots='direction')
self._dotsDir = np.random.rand(self.nDots) * _2pi
self._dotsDir[self._signalDots] = self.dir * _piOver180
self._update_dotsXY()
self.anchor = fieldAnchor
# set autoLog now that params have been initialised
wantLog = autoLog is None and self.win.autoLog
self.__dict__['autoLog'] = autoLog or wantLog
if self.autoLog:
logging.exp("Created %s = %s" % (self.name, str(self)))
def set(self, attrib, val, op='', log=None):
"""DEPRECATED: DotStim.set() is obsolete and may not be supported
in future versions of PsychoPy. Use the specific method for each
parameter instead (e.g. setFieldPos(), setCoherence()...).
"""
self._set(attrib, val, op, log=log)
@attributeSetter
def fieldShape(self, fieldShape):
"""*'sqr'* or 'circle'. Defines the envelope used to present the dots.
If changed while drawing, dots outside new envelope will be respawned.
"""
self.__dict__['fieldShape'] = fieldShape
@property
def anchor(self):
return WindowMixin.anchor.fget(self)
@anchor.setter
def anchor(self, value):
WindowMixin.anchor.fset(self, value)
def setAnchor(self, value, log=None):
setAttribute(self, 'anchor', value, log)
@property
def dotSize(self):
"""Float specified in pixels (overridden if `element` is specified).
:ref:`operations <attrib-operations>` are supported."""
if hasattr(self, "_dotSize"):
return getattr(self._dotSize, 'pix')[0]
@dotSize.setter
def dotSize(self, value):
self._dotSize = Size(value, units='pix', win=self.win)
@attributeSetter
def dotLife(self, dotLife):
"""Int. Number of frames each dot lives for (-1=infinite).
Dot lives are initiated randomly from a uniform distribution
from 0 to dotLife. If changed while drawing, the lives of all
dots will be randomly initiated again.
:ref:`operations <attrib-operations>` are supported.
"""
self.__dict__['dotLife'] = dotLife
self._dotsLife = abs(self.dotLife) * np.random.rand(self.nDots)
@attributeSetter
def signalDots(self, signalDots):
"""str - 'same' or *'different'*
If 'same' then the signal and noise dots are constant. If different
then the choice of which is signal and which is noise gets
randomised on each frame. This corresponds to Scase et al's (1996)
categories of RDK.
"""
self.__dict__['signalDots'] = signalDots
@attributeSetter
def noiseDots(self, noiseDots):
"""str - *'direction'*, 'position' or 'walk'
Determines the behaviour of the noise dots, taken directly from
Scase et al's (1996) categories. For 'position', noise dots take a
random position every frame. For 'direction' noise dots follow a
random, but constant direction. For 'walk' noise dots vary their
direction every frame, but keep a constant speed.
"""
self.__dict__['noiseDots'] = noiseDots
self.coherence = self.coherence # update using attributeSetter
@attributeSetter
def element(self, element):
"""*None* or a visual stimulus object
This can be any object that has a ``.draw()`` method and a
``.setPos([x,y])`` method (e.g. a GratingStim, TextStim...)!!
DotStim assumes that the element uses pixels as units.
``None`` defaults to dots.
See `ElementArrayStim` for a faster implementation of this idea.
"""
self.__dict__['element'] = element
@attributeSetter
def fieldPos(self, pos):
"""Specifying the location of the centre of the stimulus
using a :ref:`x,y-pair <attrib-xy>`.
See e.g. :class:`.ShapeStim` for more documentation / examples
on how to set position.
:ref:`operations <attrib-operations>` are supported.
"""
# Isn't there a way to use BaseVisualStim.pos.__doc__ as docstring
# here?
self.pos = pos # using BaseVisualStim. we'll store this as both
self.__dict__['fieldPos'] = self.pos
def setFieldPos(self, val, op='', log=None):
"""Usually you can use 'stim.attribute = value' syntax instead, but use
this method if you need to suppress the log message.
"""
setAttribute(self, 'fieldPos', val, log, op) # calls attributeSetter
def setPos(self, newPos=None, operation='', units=None, log=None):
"""Obsolete - users should use setFieldPos instead of setPos
"""
logging.error("User called DotStim.setPos(pos). "
"Use DotStim.SetFieldPos(pos) instead.")
def setFieldSize(self, val, op='', log=None):
"""Usually you can use 'stim.attribute = value' syntax instead, but use
this method if you need to suppress the log message.
"""
setAttribute(self, 'fieldSize', val, log, op) # calls attributeSetter
@attributeSetter
def fieldSize(self, size):
"""Specifying the size of the field of dots using a
:ref:`x,y-pair <attrib-xy>`. See e.g. :class:`.ShapeStim` for more
documentation/examples on how to set position.
:ref:`operations <attrib-operations>` are supported.
"""
# Isn't there a way to use BaseVisualStim.pos.__doc__ as docstring
# here?
self.size = size # using BaseVisualStim. we'll store this as both
self.__dict__['fieldSize'] = self.size
@attributeSetter
def coherence(self, coherence):
"""Scalar between 0 and 1.
Change the coherence (%) of the DotStim. This will be rounded according
to the number of dots in the stimulus.
:ref:`operations <attrib-operations>` are supported.
"""
if not 0 <= coherence <= 1:
raise ValueError('DotStim.coherence must be between 0 and 1')
_cohDots = coherence * self.nDots
self.__dict__['coherence'] = round(_cohDots) /self.nDots
self._signalDots = np.zeros(self.nDots, dtype=bool)
self._signalDots[0:int(self.coherence * self.nDots)] = True
# for 'direction' method we need to update the direction of the number
# of signal dots immediately, but for other methods it will be done
# during updateXY
# NB - AJS Actually you need to do this for 'walk' also
# otherwise would be signal dots adopt random directions when the become
# sinal dots in later trails
if self.noiseDots in ('direction', 'position', 'walk'):
self._dotsDir = np.random.rand(self.nDots) * _2pi
self._dotsDir[self._signalDots] = self.dir * _piOver180
def setFieldCoherence(self, val, op='', log=None):
"""Usually you can use 'stim.attribute = value' syntax instead, but use
this method if you need to suppress the log message.
"""
setAttribute(self, 'coherence', val, log, op) # calls attributeSetter
@attributeSetter
def dir(self, dir):
"""float (degrees). direction of the coherent dots. :ref:`operations
<attrib-operations>` are supported.
"""
# check which dots are signal before setting new dir
signalDots = self._dotsDir == (self.dir * _piOver180)
self.__dict__['dir'] = dir
# dots currently moving in the signal direction also need to update
# their direction
self._dotsDir[signalDots] = self.dir * _piOver180
def setDir(self, val, op='', log=None):
"""Usually you can use 'stim.attribute = value' syntax instead, but use
this method if you need to suppress the log message.
"""
setAttribute(self, 'dir', val, log, op)
@attributeSetter
def speed(self, speed):
"""float. speed of the dots (in *units*/frame). :ref:`operations
<attrib-operations>` are supported.
"""
self.__dict__['speed'] = speed
def setSpeed(self, val, op='', log=None):
"""Usually you can use 'stim.attribute = value' syntax instead, but use
this method if you need to suppress the log message.
"""
setAttribute(self, 'speed', val, log, op)
def draw(self, win=None):
"""Draw the stimulus in its relevant window. You must call this method
after every MyWin.flip() if you want the stimulus to appear on that
frame and then update the screen again.
Parameters
----------
win : window.Window, optional
Window to draw dots to. If `None`, dots will be drawn to the parent
window.
"""
if win is None:
win = self.win
self._selectWindow(win)
self._update_dotsXY()
GL.glPushMatrix() # push before drawing, pop after
# draw the dots
if self.element is None:
win.setScale('pix')
GL.glPointSize(self.dotSize)
# load Null textures into multitexteureARB - they modulate with
# glColor
GL.glActiveTexture(GL.GL_TEXTURE0)
GL.glEnable(GL.GL_TEXTURE_2D)
GL.glBindTexture(GL.GL_TEXTURE_2D, 0)
GL.glActiveTexture(GL.GL_TEXTURE1)
GL.glEnable(GL.GL_TEXTURE_2D)
GL.glBindTexture(GL.GL_TEXTURE_2D, 0)
CPCD = ctypes.POINTER(ctypes.c_double)
GL.glVertexPointer(2, GL.GL_DOUBLE, 0,
self.verticesPix.ctypes.data_as(CPCD))
GL.glColor4f(*self._foreColor.render('rgba1'))
GL.glEnableClientState(GL.GL_VERTEX_ARRAY)
GL.glDrawArrays(GL.GL_POINTS, 0, self.nDots)
GL.glDisableClientState(GL.GL_VERTEX_ARRAY)
else:
# we don't want to do the screen scaling twice so for each dot
# subtract the screen centre
initialDepth = self.element.depth
for pointN in range(0, self.nDots):
_p = self.verticesPix[pointN, :] + self.fieldPos
self.element.setPos(_p)
self.element.draw()
# reset depth before going to next frame
self.element.setDepth(initialDepth)
GL.glPopMatrix()
def _newDotsXY(self, nDots):
"""Returns a uniform spread of dots, according to the `fieldShape` and
`fieldSize`.
Parameters
----------
nDots : int
Number of dots to sample.
Returns
-------
ndarray
Nx2 array of X and Y positions of dots.
Examples
--------
Create a new array of dot positions::
dots = self._newDots(nDots)
"""
if self.fieldShape == 'circle':
length = np.sqrt(np.random.uniform(0, 1, (nDots,)))
angle = np.random.uniform(0., _2pi, (nDots,))
newDots = np.zeros((nDots, 2))
newDots[:, 0] = length * np.cos(angle)
newDots[:, 1] = length * np.sin(angle)
newDots *= self.fieldSize * .5
else:
newDots = np.random.uniform(-0.5, 0.5, size = (nDots, 2)) * self.fieldSize
return newDots
def refreshDots(self):
"""Callable user function to choose a new set of dots."""
self.vertices = self._verticesBase = self._dotsXY = self._newDotsXY(self.nDots)
# Don't allocate another array if the new number of dots is equal to
# the last.
if self.nDots != len(self._deadDots):
self._deadDots = np.zeros(self.nDots, dtype=bool)
def _update_dotsXY(self):
"""The user shouldn't call this - its gets done within draw().
"""
# Find dead dots, update positions, get new positions for
# dead and out-of-bounds
# renew dead dots
if self.dotLife > 0: # if less than zero ignore it
# decrement. Then dots to be reborn will be negative
self._dotsLife -= 1
self._deadDots[:] = (self._dotsLife <= 0)
self._dotsLife[self._deadDots] = self.dotLife
else:
self._deadDots[:] = False
# update XY based on speed and dir
# NB self._dotsDir is in radians, but self.dir is in degs
# update which are the noise/signal dots
if self.signalDots == 'different':
# **up to version 1.70.00 this was the other way around,
# not in keeping with Scase et al**
# noise and signal dots change identity constantly
np.random.shuffle(self._dotsDir)
# and then update _signalDots from that
self._signalDots = (self._dotsDir == (self.dir * _piOver180))
# update the locations of signal and noise; 0 radians=East!
reshape = np.reshape
if self.noiseDots == 'walk':
# noise dots are ~self._signalDots
sig = np.random.rand(np.sum(~self._signalDots))
self._dotsDir[~self._signalDots] = sig * _2pi
# then update all positions from dir*speed
cosDots = reshape(np.cos(self._dotsDir), (self.nDots,))
sinDots = reshape(np.sin(self._dotsDir), (self.nDots,))
self._verticesBase[:, 0] += self.speed * cosDots
self._verticesBase[:, 1] += self.speed * sinDots
elif self.noiseDots == 'direction':
# simply use the stored directions to update position
cosDots = reshape(np.cos(self._dotsDir), (self.nDots,))
sinDots = reshape(np.sin(self._dotsDir), (self.nDots,))
self._verticesBase[:, 0] += self.speed * cosDots
self._verticesBase[:, 1] += self.speed * sinDots
elif self.noiseDots == 'position':
# update signal dots
sd = self._signalDots
sdSum = self._signalDots.sum()
cosDots = reshape(np.cos(self._dotsDir[sd]), (sdSum,))
sinDots = reshape(np.sin(self._dotsDir[sd]), (sdSum,))
self._verticesBase[sd, 0] += self.speed * cosDots
self._verticesBase[sd, 1] += self.speed * sinDots
# update noise dots
self._deadDots[:] = self._deadDots + (~self._signalDots)
# handle boundaries of the field
if self.fieldShape in (None, 'square', 'sqr'):
out0 = (np.abs(self._verticesBase[:, 0]) > .5 * self.fieldSize[0])
out1 = (np.abs(self._verticesBase[:, 1]) > .5 * self.fieldSize[1])
outofbounds = out0 + out1
else:
# transform to a normalised circle (radius = 1 all around)
# then to polar coords to check
# the normalised XY position (where radius should be < 1)
normXY = self._verticesBase / .5 / self.fieldSize
# add out-of-bounds to those that need replacing
outofbounds = np.hypot(normXY[:, 0], normXY[:, 1]) > 1.
# update any dead dots
nDead = self._deadDots.sum()
if nDead:
self._verticesBase[self._deadDots, :] = self._newDotsXY(nDead)
# Reposition any dots that have gone out of bounds. Net effect is to
# place dot one step inside the boundary on the other side of the
# aperture.
nOutOfBounds = outofbounds.sum()
if nOutOfBounds:
self._verticesBase[outofbounds, :] = self._newDotsXY(nOutOfBounds)
self.vertices = self._verticesBase / self.fieldSize
# update the pixel XY coordinates in pixels (using _BaseVisual class)
self._updateVertices()
