API Documentation for: 1.0.0
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BlurFilter Class

Extends Filter
Defined in: BlurFilter:43
Module: EaselJS

Applies a box blur to DisplayObjects in context 2D and a Gaussian blur in webgl. Note that this filter is fairly intensive, particularly if the quality is set higher than 1.

Example

This example creates a red circle, and then applies a 5 pixel blur to it. It uses the getBounds method to account for the spread that the blur causes.

 var shape = new createjs.Shape().set({x:100,y:100});
 shape.graphics.beginFill("#ff0000").drawCircle(0,0,50);

 var blurFilter = new createjs.BlurFilter(5, 5, 1);
 shape.filters = [blurFilter];
 var bounds = blurFilter.getBounds();

 shape.cache(-50+bounds.x, -50+bounds.y, 100+bounds.width, 100+bounds.height);

See Filter for an more information on applying filters.

Constructor

BlurFilter

(
  • [blurX=0]
  • [blurY=0]
  • [quality=1]
)

Defined in BlurFilter:43

Parameters:

  • [blurX=0] Number optional

    The horizontal blur radius in pixels.

  • [blurY=0] Number optional

    The vertical blur radius in pixels.

  • [quality=1] Number optional

    The number of blur iterations.

Methods

_applyFilter

(
  • imageData
)
Boolean

Inherited from Filter: _applyFilter:180

Parameters:

  • imageData ImageData

    Target ImageData instance.

Returns:

_getTable

(
  • spread
)
Array

Defined in _getTable:177

Internal lookup function to create gaussian distribution.

Parameters:

  • spread Number

    How many steps in the curve.

Returns:

Array:

An array with Math.ceil(spread*2) entries with appropriately distributed weights.

_updateShader

()

Defined in _updateShader:199

Internal update function to create shader properties.

applyFilter

(
  • ctx
  • x
  • y
  • width
  • height
  • [targetCtx]
  • [targetX]
  • [targetY]
)
Boolean

Inherited from Filter: applyFilter:131

Applies the filter to the specified context.

Parameters:

  • ctx CanvasRenderingContext2D

    The 2D context to use as the source.

  • x Number

    The x position to use for the source rect.

  • y Number

    The y position to use for the source rect.

  • width Number

    The width to use for the source rect.

  • height Number

    The height to use for the source rect.

  • [targetCtx] CanvasRenderingContext2D optional

    The 2D context to draw the result to. Defaults to the context passed to ctx.

  • [targetX] Number optional

    The x position to draw the result to. Defaults to the value passed to x.

  • [targetY] Number optional

    The y position to draw the result to. Defaults to the value passed to y.

Returns:

Boolean:

If the filter was applied successfully.

clone

() Filter

Inherited from Filter: clone:170

Returns a clone of this Filter instance.

Returns:

Filter:

A clone of the current Filter instance.

getBounds

(
  • [rect]
)
Rectangle

Inherited from Filter: getBounds:111

Provides padding values for this filter. That is, how much the filter will extend the visual bounds of an object it is applied to.

Parameters:

  • [rect] Rectangle optional

    If specified, the provided Rectangle instance will be expanded by the padding amounts and returned.

Returns:

Rectangle:

If a rect param was provided, it is returned. If not, either a new rectangle with the padding values, or null if no padding is required for this filter.

shaderParamSetup

(
  • gl
  • stage
  • shaderProgram
)

Inherited from Filter: shaderParamSetup:121

Assign any unique uniforms or other setup functionality here.

Parameters:

  • gl WebGLContext

    The context associated with the stage performing the render.

  • stage StageGL

    The stage instance that will be rendering.

  • shaderProgram ShaderProgram

    The compiled shader that is going to be used to perform the render.

toString

() String

Inherited from Filter: toString:161

Returns a string representation of this object.

Returns:

String:

a string representation of the instance.

Properties

_multiPass

Filter private

Inherited from Filter: _multiPass:79

Another filter that is required to act as part of this filter and created and managed under the hood.

Default: null

blurX

Number

Defined in blurX:72

Horizontal blur radius in pixels

Default: 0

blurY

Number

Defined in blurY:82

Vertical blur radius in pixels

Default: 0

FRAG_SHADER

String readonly

Inherited from Filter: FRAG_SHADER:98

Pre-processed template shader code. It will be parsed before being fed in into the shader compiler. This should be based upon StageGL.SHADER_FRAGMENT_BODY_REGULAR

MUL_TABLE

Array protected static

Defined in MUL_TABLE:231

Array of multiply values for blur calculations.

quality

Number

Defined in quality:92

Number of blur iterations. For example, a value of 1 will produce a rough blur. A value of 2 will produce a smoother blur, but take twice as long to run.

Default: 1

SHG_TABLE

Array protected static

Defined in SHG_TABLE:240

Array of shift values for blur calculations.

usesContext

Boolean

Inherited from Filter: usesContext:71

A flag stating that this filter uses a context draw mode and cannot be batched into imageData processing.

Default: false

VTX_SHADER

String readonly

Inherited from Filter: VTX_SHADER:88

Pre-processed template shader code. It will be parsed before being fed in into the shader compiler. This should be based upon StageGL.SHADER_VERTEX_BODY_REGULAR