# GratingStim

## visual GratingStim

Grating Stimulus.

## Constructor

#### new GratingStim(options)

Source:
  - visual/GratingStim.js, line 35

##### 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

### Extends

- VisualStim

### Methods

#### (protected) _estimateBoundingBox()

Source:
  - visual/GratingStim.js, line 482

Estimate the bounding box.

#### (protected) _getDisplaySize() → {Array.<number>}

Source:
  - visual/GratingStim.js, line 459

Get the size of the display image, which is either that of the GratingStim or that of the image it contains.

##### Returns:

the size of the displayed image

Type
  Array.<number>

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

Source:
  - visual/GratingStim.js, line 506

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.

##### Returns:

Pixi.Mesh object that represents shader and later added to the scene.

Type
  Pixi.Mesh

#### (protected) _updateIfNeeded()

Source:
  - visual/GratingStim.js, line 641

Update the stimulus, if necessary.

#### setBlendmode(blendMode, logopt)

Source:
  - visual/GratingStim.js, line 607

Set blend mode of the grating stimulus.

##### Parameters:

Name | Type | Attributes | Default | Description
--- | --- | --- | --- | ---
`blendMode` | String |  | `avg` | blend mode, can be one of the following: ["avg", "add", "mul", "screen"].
`log` | boolean | <optional> | `false` | whether or not to log

#### setColor(colorVal, logopt)

Source:
  - visual/GratingStim.js, line 567

Set foreground color value for the grating stimulus.

##### Parameters:

Name | Type | Attributes | Default | Description
--- | --- | --- | --- | ---
`colorVal` | Color |  | `white` | color value, can be String like "red" or "#ff0000" or Number like 0xff0000.
`log` | boolean | <optional> | `false` | whether of not to log

#### setColorSpace(colorSpaceVal, logopt)

Source:
  - visual/GratingStim.js, line 550

Set color space value for the grating stimulus.

##### Parameters:

Name | Type | Attributes | Default | Description
--- | --- | --- | --- | ---
`colorSpaceVal` | String |  | `RGB` | color space value
`log` | boolean | <optional> | `false` | whether of not to log

#### setInterpolate(interpolate, logopt)

Source:
  - visual/GratingStim.js, line 628

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

##### Parameters:

Name | Type | Attributes | Default | Description
--- | --- | --- | --- | ---
`interpolate` | boolean |  | `false` | interpolate or not.
`log` | boolean | <optional> | `false` | whether or not to log

#### setMask(mask, logopt)

Source:
  - visual/GratingStim.js, line 405

Setter for the mask attribute.

##### Parameters:

Name | Type | Attributes | Default | Description
--- | --- | --- | --- | ---
`mask` | HTMLImageElement | string |  |  | the name of the mask resource or HTMLImageElement corresponding to the mask
`log` | boolean | <optional> | `false` | whether of not to log

#### setOpacity(opacityopt, logopt)

Source:
  - visual/GratingStim.js, line 581

Determines how visible the stimulus is relative to background.

##### Parameters:

Name | Type | Attributes | Default | Description
--- | --- | --- | --- | ---
`opacity` | number | <optional> | `1` | opacity - The value should be a single float ranging 1.0 (opaque) to 0.0 (transparent).
`log` | boolean | <optional> | `false` | whether of not to log

#### setPhase(phase, logopt)

Source:
  - visual/GratingStim.js, line 537

Set phase value for the function.

##### Parameters:

Name | Type | Attributes | Default | Description
--- | --- | --- | --- | ---
`phase` | number |  |  | phase value
`log` | boolean | <optional> | `false` | whether of not to log

#### setSF(sf, logopt)

Source:
  - visual/GratingStim.js, line 594

Set spatial frequency value for the function.

##### Parameters:

Name | Type | Attributes | Default | Description
--- | --- | --- | --- | ---
`sf` | number |  |  | spatial frequency value
`log` | boolean | <optional> | `false` | whether or not to log

#### setTex(tex, logopt)

Source:
  - visual/GratingStim.js, line 343

Setter for the tex attribute.

##### Parameters:

Name | Type | Attributes | Default | Description
--- | --- | --- | --- | ---
`tex` | HTMLImageElement | string |  |  | the name of built in shader function or name of the image resource or HTMLImageElement corresponding to the image
`log` | boolean | <optional> | `false` | whether of not to log