Class: GratingStim

visual.GratingStim(options)

new GratingStim(options)

Grating Stimulus.
Parameters:
Name Type Description
options Object
Properties
Name Type Attributes Default Description
name String the name used when logging messages from this stimulus
win Window the associated Window
tex String | HTMLImageElement <optional>
 "sin" the name of the predefined grating texture or image resource or the HTMLImageElement corresponding to the texture
mask String | HTMLImageElement <optional>
 the name of the mask resource or HTMLImageElement corresponding to the mask
units String <optional>
 "norm" the units of the stimulus (e.g. for size, position, vertices)
sf number <optional>
 1.0 spatial frequency of the function used in grating stimulus
phase number <optional>
 0.0 phase of the function used in grating stimulus, multiples of period of that function
pos Array.<number> <optional>
 [0, 0] the position of the center of the stimulus
ori number <optional>
 0.0 the orientation (in degrees)
size number <optional>
 the size of the rendered image (DEFAULT_STIM_SIZE_PX will be used if size is not specified)
color Color <optional>
 "white" Foreground color of the stimulus. Can be String like "red" or "#ff0000" or Number like 0xff0000.
opacity number <optional>
 1.0 Set the opacity of the stimulus. Determines how visible the stimulus is relative to background.
contrast number <optional>
 1.0 Set the contrast of the stimulus, i.e. scales how far the stimulus deviates from the middle grey. Ranges [-1, 1].
depth number <optional>
 0 the depth (i.e. the z order)
interpolate boolean <optional>
 false Whether to interpolate (linearly) the texture in the stimulus. Currently supports only image based gratings.
blendmode String <optional>
 "avg" blend mode of the stimulus, determines how the stimulus is blended with the background. Supported values: "avg", "add", "mul", "screen".
autoDraw boolean <optional>
 false whether or not the stimulus should be automatically drawn on every frame flip
autoLog boolean <optional>
 false whether or not to log
Source:

Extends

  • VisualStim

Members

(static) DEFAULT_STIM_SIZE_PX :Array

Default size of the Grating Stimuli in pixels.
Type:
  • Array
Default Value:
  • [256, 256]
Source:

(static) SHADERS :Object

An object that keeps shaders source code and default uniform values for them. Shader source code is later used for construction of shader programs to create respective visual stimuli.
Type:
  • Object
Properties:
Name Type Description
imageShader Object Renders provided image with applied effects (coloring, phase, frequency).
Properties
Name Type Description
shader String shader source code for the image based grating stimuli.
uniforms Object default uniforms for the image based shader.
Properties
Name Type Default Description
uFreq float 1.0 how much times image repeated within grating stimuli.
uPhase float 0.0 offset of the image along X axis.
uAlpha float 1.0 value of the alpha channel.
sin Object Creates 2d sine wave image as if 1d sine graph was extended across Z axis and observed from above. https://en.wikipedia.org/wiki/Sine_wave
Properties
Name Type Description
shader String shader source code for the sine wave stimuli
uniforms Object default uniforms for sine wave shader
Properties
Name Type Default Description
uFreq float 1.0 frequency of sine wave.
uPhase float 0.0 phase of sine wave.
uAlpha float 1.0 value of the alpha channel.
sqr Object Creates 2d square wave image as if 1d square graph was extended across Z axis and observed from above. https://en.wikipedia.org/wiki/Square_wave
Properties
Name Type Description
shader String shader source code for the square wave stimuli
uniforms Object default uniforms for square wave shader
Properties
Name Type Default Description
uFreq float 1.0 frequency of square wave.
uPhase float 0.0 phase of square wave.
uAlpha float 1.0 value of the alpha channel.
saw Object Creates 2d sawtooth wave image as if 1d sawtooth graph was extended across Z axis and observed from above. https://en.wikipedia.org/wiki/Sawtooth_wave
Properties
Name Type Description
shader String shader source code for the sawtooth wave stimuli
uniforms Object default uniforms for sawtooth wave shader
Properties
Name Type Default Description
uFreq float 1.0 frequency of sawtooth wave.
uPhase float 0.0 phase of sawtooth wave.
uAlpha float 1.0 value of the alpha channel.
tri Object Creates 2d triangle wave image as if 1d triangle graph was extended across Z axis and observed from above. https://en.wikipedia.org/wiki/Triangle_wave
Properties
Name Type Description
shader String shader source code for the triangle wave stimuli
uniforms Object default uniforms for triangle wave shader
Properties
Name Type Default Description
uFreq float 1.0 frequency of triangle wave.
uPhase float 0.0 phase of triangle wave.
uPeriod float 1.0 period of triangle wave.
uAlpha float 1.0 value of the alpha channel.
sinXsin Object Creates an image of two 2d sine waves multiplied with each other. https://en.wikipedia.org/wiki/Sine_wave
Properties
Name Type Description
shader String shader source code for the two multiplied sine waves stimuli
uniforms Object default uniforms for shader
Properties
Name Type Default Description
uFreq float 1.0 frequency of sine wave (both of them).
uPhase float 0.0 phase of sine wave (both of them).
uAlpha float 1.0 value of the alpha channel.
sqrXsqr Object Creates an image of two 2d square waves multiplied with each other. https://en.wikipedia.org/wiki/Square_wave
Properties
Name Type Description
shader String shader source code for the two multiplied sine waves stimuli
uniforms Object default uniforms for shader
Properties
Name Type Default Description
uFreq float 1.0 frequency of sine wave (both of them).
uPhase float 0.0 phase of sine wave (both of them).
uAlpha float 1.0 value of the alpha channel.
circle Object Creates a filled circle shape with sharp edges.
Properties
Name Type Description
shader String shader source code for filled circle.
uniforms Object default uniforms for shader.
Properties
Name Type Default Description
uRadius float 1.0 Radius of the circle. Ranges [0.0, 1.0], where 0.0 is circle so tiny it results in empty stim and 1.0 is circle that spans from edge to edge of the stim.
uAlpha float 1.0 value of the alpha channel.
gauss Object Creates a 2d Gaussian image as if 1d Gaussian graph was rotated arount Y axis and observed from above. https://en.wikipedia.org/wiki/Gaussian_function
Properties
Name Type Description
shader String shader source code for Gaussian shader
uniforms Object default uniforms for shader
Properties
Name Type Default Description
uA float 1.0 A constant for gaussian formula (see link).
uB float 0.0 B constant for gaussian formula (see link).
uC float 0.16 C constant for gaussian formula (see link).
uAlpha float 1.0 value of the alpha channel.
cross Object Creates a filled cross shape with sharp edges.
Properties
Name Type Description
shader String shader source code for cross shader
uniforms Object default uniforms for shader
Properties
Name Type Default Description
uThickness float 0.2 Thickness of the cross. Ranges [0.0, 1.0], where 0.0 thickness makes a cross so thin it becomes invisible and results in an empty stim and 1.0 makes it so thick it fills the entire stim.
uAlpha float 1.0 value of the alpha channel.
radRamp Object Creates 2d radial ramp image.
Properties
Name Type Description
shader String shader source code for radial ramp shader
uniforms Object default uniforms for shader
Properties
Name Type Default Description
uSqueeze float 1.0 coefficient that helps to modify size of the ramp. Ranges [0.0, Infinity], where 0.0 results in ramp being so large it fills the entire stim and Infinity makes it so tiny it's invisible.
uAlpha float 1.0 value of the alpha channel.
raisedCos Object Creates 2d raised-cosine image as if 1d raised-cosine graph was rotated around Y axis and observed from above. https://en.wikipedia.org/wiki/Raised-cosine_filter
Properties
Name Type Description
shader String shader source code for raised-cosine shader
uniforms Object default uniforms for shader
Properties
Name Type Default Description
uBeta float 0.25 roll-off factor (see link).
uPeriod float 0.625 reciprocal of the symbol-rate (see link).
uAlpha float 1.0 value of the alpha channel.
Source:

setBlendmode

Set blend mode of the grating stimulus.
Source:

setColor

Set foreground color value for the grating stimulus.
Source:

setColorSpace

Set color space value for the grating stimulus.
Source:

setInterpolate

Whether to interpolate (linearly) the texture in the stimulus.
Source:

setMask

Setter for the mask attribute.
Source:

setOpacity

Determines how visible the stimulus is relative to background.
Source:

setPhase

Set phase value for the function.
Source:

setSF

Set spatial frequency value for the function.
Source:

setTex

Setter for the tex attribute.
Source:

Methods

(protected) _estimateBoundingBox()

Estimate the bounding box.
Source:

(protected) _getPixiMeshFromPredefinedShaders(shaderName, uniforms) → {Pixi.Mesh}

Generate PIXI.Mesh object based on provided shader function name and uniforms.
Parameters:
Name Type Description
shaderName String name of the shader. Must be one of the SHADERS
uniforms Object a set of uniforms to supply to the shader. Mixed together with default uniform values.
Source:
Returns:
Pixi.Mesh object that represents shader and later added to the scene.
Type
Pixi.Mesh