Source code for psychopy.visual.grating

#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""Stimulus object for drawing arbitrary bitmaps that can repeat (cycle)
in either dimension. One of the main stimuli for PsychoPy.

# 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).

# 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

from psychopy.colors import Color

pyglet.options['debug_gl'] = False
import ctypes
GL =

import psychopy  # so we can get the __path__
from psychopy import logging

from import val2array
from import attributeSetter
from psychopy.visual.basevisual import (
    BaseVisualStim, DraggingMixin, ColorMixin, ContainerMixin, TextureMixin
import numpy

[docs]class GratingStim(BaseVisualStim, DraggingMixin, TextureMixin, ColorMixin, ContainerMixin): """Stimulus object for drawing arbitrary bitmaps that can repeat (cycle) in either dimension. This is a lazy-imported class, therefore import using full path `from psychopy.visual.grating import GratingStim` when inheriting from it. One of the main stimuli for PsychoPy. Formally `GratingStim` is just a texture behind an optional transparency mask (an 'alpha mask'). Both the texture and mask can be arbitrary bitmaps and their combination allows an enormous variety of stimuli to be drawn in realtime. A `GratingStim` can be rotated scaled and shifted in position, its texture can be drifted in X and/or Y and it can have a spatial frequency in X and/or Y (for an image file that simply draws multiple copies in the patch). Also since transparency can be controlled, two `GratingStim` objects can be combined (e.g. to form a plaid.) **Using GratingStim with images from disk (jpg, tif, png, ...)** Ideally texture images to be rendered should be square with 'power-of-2' dimensions e.g. 16 x 16, 128 x 128. Any image that is not will be up-scaled (with linear interpolation) to the nearest such texture by PsychoPy. The size of the stimulus should be specified in the normal way using the appropriate units (deg, pix, cm, ...). Be sure to get the aspect ratio the same as the image (if you don't want it stretched!). Parameters ---------- win : :class:`~psychopy.visual.Window` Window this shape is being drawn to. The stimulus instance will allocate its required resources using that Windows context. In many cases, a stimulus instance cannot be drawn on different windows unless those windows share the same OpenGL context, which permits resources to be shared between them. tex : str or None Texture to use for the primary carrier. Values may be one of `'sin'`, `'sin'`, `'sqr'`, `'saw'`, `'tri'`, or `None`. mask : str or None Optional mask to control the shape of the grating. Values may be one of `'circle'`, `'sin'`, `'sqr'`, `'saw'`, `'tri'`, or `None`. units : str Units to use when drawing. This will affect how parameters and attributes `pos`, `size` and `radius` are interpreted. anchor : str Anchor string to specify the origin of the stimulus. pos : array_like Initial position (`x`, `y`) of the shape on-screen relative to the origin located at the center of the window or buffer in `units`. This can be updated after initialization by setting the `pos` property. The default value is `(0.0, 0.0)` which results in no translation. size : array_like, float, int or None Width and height of the shape as `(w, h)` or `[w, h]`. If a single value is provided, the width and height will be set to the same specified value. If `None` is specified, the `size` will be set with values passed to `width` and `height`. sf : float Spatial frequency for the grating. Values are dependent on the units in use to draw the stimuli. ori : float Initial orientation of the shape in degrees about its origin. Positive values will rotate the shape clockwise, while negative values will rotate counterclockwise. The default value for `ori` is 0.0 degrees. phase : ArrayLike Initial phase of the grating along the vertical and horizontal dimension `(x, y)`. texRes : int Resolution of the texture. The higher the resolutions, the less aliasing artifacts will be visible. However, this comes at the expense of higher video memory use. Power-of-two values are recommended (e.g. 256, 512, 1024, etc.) color : array_like, str, :class:`~psychopy.colors.Color` or None Sets both the initial `lineColor` and `fillColor` of the shape. colorSpace : str Sets the colorspace, changing how values passed to `lineColor` and `fillColor` are interpreted. contrast : float Contrast level of the shape (0.0 to 1.0). This value is used to modulate the contrast of colors passed to `lineColor` and `fillColor`. opacity : float Opacity of the shape. A value of 1.0 indicates fully opaque and 0.0 is fully transparent (therefore invisible). Values between 1.0 and 0.0 will result in colors being blended with objects in the background. This value affects the fill (`fillColor`) and outline (`lineColor`) colors of the shape. depth : int Depth layer to draw the shape when `autoDraw` is enabled. *DEPRECATED* rgbPedestal : ArrayLike Pedestal color `(r, g, b)`, presently unused. interpolate : bool Enable smoothing (anti-aliasing) when drawing shape outlines. This produces a smoother (less-pixelated) outline of the shape. draggable : bool Can this stimulus be dragged by a mouse click? lineRGB, fillRGB: ArrayLike, :class:`~psychopy.colors.Color` or None *Deprecated*. Please use `lineColor` and `fillColor`. These arguments may be removed in a future version. name : str Optional name of the stimuli for logging. autoLog : bool Enable auto-logging of events associated with this stimuli. Useful for debugging and to track timing when used in conjunction with `autoDraw`. autoDraw : bool Enable auto drawing. When `True`, the stimulus will be drawn every frame without the need to explicitly call the :py:meth:`~psychopy.visual.shape.ShapeStim.draw()` method. Examples -------- Creating a circular grating with a sinusoidal pattern:: myGrat = GratingStim(tex='sin', mask='circle') Create a 'Gabor':: myGabor = GratingStim(tex='sin', mask='gauss') """ def __init__(self, win, tex="sin", mask="none", units=None, anchor="center", pos=(0.0, 0.0), size=None, sf=None, ori=0.0, phase=(0.0, 0.0), texRes=128, rgb=None, dkl=None, lms=None, color=(1.0, 1.0, 1.0), colorSpace='rgb', contrast=1.0, opacity=None, depth=0, rgbPedestal=(0.0, 0.0, 0.0), interpolate=False, draggable=False, blendmode='avg', name=None, autoLog=None, autoDraw=False, maskParams=None): """ """ # Empty docstring. All doc is in attributes # what local vars are defined (these are the init params) for use by # __repr__ self._initParams = dir() for unecess in ['self', 'rgb', 'dkl', 'lms']: self._initParams.remove(unecess) # initialise parent class super(GratingStim, self).__init__(win, units=units, name=name, autoLog=False) self.draggable = draggable # UGLY HACK: Some parameters depend on each other for processing. # They are set "superficially" here. # TO DO: postpone calls to _createTexture, setColor and # _calcCyclesPerStim whin initiating stimulus self.__dict__['contrast'] = 1 self.__dict__['size'] = 1 self.__dict__['sf'] = 1 self.__dict__['tex'] = tex self.__dict__['maskParams'] = maskParams # initialise textures and masks for stimulus self._texID = GL.GLuint() GL.glGenTextures(1, ctypes.byref(self._texID)) self._maskID = GL.GLuint() GL.glGenTextures(1, ctypes.byref(self._maskID)) self.__dict__['texRes'] = texRes # must be power of 2 self.interpolate = interpolate self._needTextureUpdate = True # NB Pedestal isn't currently being used during rendering - this is a # place-holder self.rgbPedestal = val2array(rgbPedestal, False, length=3) # No need to invoke decorator for color updating. It is done just # below. self.colorSpace = colorSpace self.color = color if rgb is not None: logging.warning("Use of rgb arguments to stimuli are deprecated." " Please use color and colorSpace args instead") self.color = Color(rgb, 'rgb') elif dkl is not None: logging.warning("Use of dkl arguments to stimuli are deprecated." " Please use color and colorSpace args instead") self.color = Color(dkl, 'dkl') elif lms is not None: logging.warning("Use of lms arguments to stimuli are deprecated." " Please use color and colorSpace args instead") self.color = Color(lms, 'lms') # set other parameters self.ori = float(ori) self.phase = val2array(phase, False) self._origSize = None # updated if an image texture is loaded self._requestedSize = size self.size = size self.sf = val2array(sf) self.pos = val2array(pos, False, False) self.depth = depth self.anchor = anchor # self.tex = tex self.mask = mask self.contrast = float(contrast) self.opacity = opacity self.autoLog = autoLog self.autoDraw = autoDraw self.blendmode = blendmode # fix scaling to window coords self._calcCyclesPerStim() # generate a displaylist ID self._listID = GL.glGenLists(1) # JRG: doing self._updateList() here means MRO issues for RadialStim, # which inherits from GratingStim but has its own _updateList code. # So don't want to do the update here (= ALSO the init of RadialStim). # Could potentially define a BaseGrating class without # updateListShaders code, and have GratingStim and RadialStim # inherit from it and add their own _updateList stuff. # Seems unnecessary. Instead, simply defer the update to the # first .draw(), should be fast: # self._updateList() # ie refresh display list self._needUpdate = True # set autoLog now that params have been initialised wantLog = autoLog is None and self.__dict__['autoLog'] = autoLog or wantLog if self.autoLog: logging.exp("Created {} = {}".format(, self)) @attributeSetter def sf(self, value): """Spatial frequency of the grating texture. Should be a :ref:`x,y-pair <attrib-xy>` or :ref:`scalar <attrib-scalar>` or None. If `units` == 'deg' or 'cm' units are in cycles per deg or cm as appropriate. If `units` == 'norm' then sf units are in cycles per stimulus (and so SF scales with stimulus size). If texture is an image loaded from a file then sf=None defaults to 1/stimSize to give one cycle of the image. """ # Recode phase to numpy array if value is None: # Set the sf to default (e.g. to the 1.0/size of the loaded image if (self.units in ('pix', 'pixels') or self._origSize is not None and self.units in ('deg', 'cm')): value = 1.0 / self.size # default to one cycle else: value = numpy.array([1.0, 1.0]) else: value = val2array(value) # Set value and update stuff self.__dict__['sf'] = value self._calcCyclesPerStim() self._needUpdate = True @attributeSetter def phase(self, value): """Phase of the stimulus in each dimension of the texture. Should be an :ref:`x,y-pair <attrib-xy>` or :ref:`scalar <attrib-scalar>` **NB** phase has modulus 1 (rather than 360 or 2*pi) This is a little unconventional but has the nice effect that setting phase=t*n drifts a stimulus at *n* Hz. """ # Recode phase to numpy array value = val2array(value) self.__dict__['phase'] = value self._needUpdate = True @attributeSetter def tex(self, value): """Texture to used on the stimulus as a grating (aka carrier). This can be one of various options: + **'sin'**,'sqr', 'saw', 'tri', None (resets to default) + the name of an image file (most formats supported) + a numpy array (1xN or NxN) ranging -1:1 If specifying your own texture using an image or numpy array you should ensure that the image has square power-of-two dimensions (e.g. 256 x 256). If not then PsychoPy will up-sample your stimulus to the next larger power of two. """ self._createTexture( value, id=self._texID, pixFormat=GL.GL_RGB, stim=self, res=self.texRes, maskParams=self.maskParams) self.__dict__['tex'] = value self._needTextureUpdate = False @attributeSetter def blendmode(self, value): """The OpenGL mode in which the stimulus is draw Can the 'avg' or 'add'. Average (avg) places the new stimulus over the old one with a transparency given by its opacity. Opaque stimuli will hide other stimuli transparent stimuli won't. Add performs the arithmetic sum of the new stimulus and the ones already present. """ self.__dict__['blendmode'] = value self._needUpdate = True
[docs] def setSF(self, value, operation='', log=None): """DEPRECATED. Use 'stim.parameter = value' syntax instead """ self._set('sf', value, operation, log=log)
[docs] def setPhase(self, value, operation='', log=None): """DEPRECATED. Use 'stim.parameter = value' syntax instead """ self._set('phase', value, operation, log=log)
[docs] def setTex(self, value, log=None): """DEPRECATED. Use 'stim.parameter = value' syntax instead """ self.tex = value
[docs] def setBlendmode(self, value, log=None): """DEPRECATED. Use 'stim.parameter = value' syntax instead """ self._set('blendmode', value, log=log)
[docs] 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 : `~psychopy.visual.Window` or `None` Window to draw the stimulus to. Context sharing must be enabled if any other window beside the one specified during creation of this stimulus is specified. """ if win is None: win = self._selectWindow(win) saveBlendMode = win.blendMode win.setBlendMode(self.blendmode, log=False) # do scaling GL.glPushMatrix() # push before the list, pop after win.setScale('pix') # the list just does the texture mapping GL.glColor4f(*self._foreColor.render('rgba1')) if self._needTextureUpdate: self.setTex(value=self.tex, log=False) if self._needUpdate: self._updateList() GL.glCallList(self._listID) # return the view to previous state GL.glPopMatrix() win.setBlendMode(saveBlendMode, log=False)
[docs] def _updateListShaders(self): """The user shouldn't need this method since it gets called after every call to .set() Basically it updates the OpenGL representation of your stimulus if some parameter of the stimulus changes. Call it if you change a property manually rather than using the .set() command """ self._needUpdate = False GL.glNewList(self._listID, GL.GL_COMPILE) # setup the shaderprogram _prog = GL.glUseProgram(_prog) # set the texture to be texture unit 0 GL.glUniform1i(GL.glGetUniformLocation(_prog, b"texture"), 0) # mask is texture unit 1 GL.glUniform1i(GL.glGetUniformLocation(_prog, b"mask"), 1) # mask GL.glActiveTexture(GL.GL_TEXTURE1) GL.glBindTexture(GL.GL_TEXTURE_2D, self._maskID) GL.glEnable(GL.GL_TEXTURE_2D) # implicitly disables 1D # main texture GL.glActiveTexture(GL.GL_TEXTURE0) GL.glBindTexture(GL.GL_TEXTURE_2D, self._texID) GL.glEnable(GL.GL_TEXTURE_2D) Ltex = (-self._cycles[0] / 2) - self.phase[0] + 0.5 Rtex = (+self._cycles[0] / 2) - self.phase[0] + 0.5 Ttex = (+self._cycles[1] / 2) - self.phase[1] + 0.5 Btex = (-self._cycles[1] / 2) - self.phase[1] + 0.5 Lmask = Bmask = 0.0 Tmask = Rmask = 1.0 # mask # access just once because it's slower than basic property vertsPix = self.verticesPix GL.glBegin(GL.GL_QUADS) # draw a 4 sided polygon # right bottom GL.glMultiTexCoord2f(GL.GL_TEXTURE0, Rtex, Btex) GL.glMultiTexCoord2f(GL.GL_TEXTURE1, Rmask, Bmask) GL.glVertex2f(vertsPix[0, 0], vertsPix[0, 1]) # left bottom GL.glMultiTexCoord2f(GL.GL_TEXTURE0, Ltex, Btex) GL.glMultiTexCoord2f(GL.GL_TEXTURE1, Lmask, Bmask) GL.glVertex2f(vertsPix[1, 0], vertsPix[1, 1]) # left top GL.glMultiTexCoord2f(GL.GL_TEXTURE0, Ltex, Ttex) GL.glMultiTexCoord2f(GL.GL_TEXTURE1, Lmask, Tmask) GL.glVertex2f(vertsPix[2, 0], vertsPix[2, 1]) # right top GL.glMultiTexCoord2f(GL.GL_TEXTURE0, Rtex, Ttex) GL.glMultiTexCoord2f(GL.GL_TEXTURE1, Rmask, Tmask) GL.glVertex2f(vertsPix[3, 0], vertsPix[3, 1]) GL.glEnd() # unbind the textures GL.glActiveTexture(GL.GL_TEXTURE1) GL.glBindTexture(GL.GL_TEXTURE_2D, 0) GL.glDisable(GL.GL_TEXTURE_2D) # implicitly disables 1D # main texture GL.glActiveTexture(GL.GL_TEXTURE0) GL.glBindTexture(GL.GL_TEXTURE_2D, 0) GL.glDisable(GL.GL_TEXTURE_2D) GL.glUseProgram(0) GL.glEndList()
def __del__(self): try: GL.glDeleteLists(self._listID, 1) except Exception: pass # probably we don't have a _listID property try: # remove textures from graphics card to prevent crash self.clearTextures() except Exception: pass def _calcCyclesPerStim(self): if self.units in ('norm', 'height'): # this is the only form of sf that is not size dependent self._cycles = self.sf else: self._cycles = self.sf * self.size

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