API Documentation for: 0.8.2
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BlurFilter Class

Extends Filter
Defined in: BlurFilter:43
Module: EaselJS

Applies a box blur to DisplayObjects. Note that this filter is fairly CPU 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:177

Parameters:

  • imageData ImageData

    Target ImageData instance.

Returns:

_createWebGLRenderer

() protected

Attempt to creates a WebGLContextRenderer for fast, efficient filter rendering. Used during filter initialization. If it cannot be done, or this.useGL is set to false, then the filter is rendered normally using a Context2D.

_getFragmentShader Get fragment shader code in GLSL. Filters are responsible for their own fragment shaders.

() String protected

Returns:

_getVertexShader Get vertex shader in GLSL code. This sets the positions of each point on the context in 3D space.

() String protected

Returns:

_initBuffers

(
  • ctx
)
protected

Inherited from Filter: _initBuffers:213

Setup the buffers and camera for the object. In this case, just create a rectangle that occupies the full stage.

Parameters:

_initShaders

(
  • ctx
)
protected

Inherited from Filter: _initShaders:156

Setup the shaders for WebGL rendering. Each filter is responsible for its own fragment shader.

Parameters:

_initUniforms

(
  • ctx
)
protected

Inherited from Filter but overwritten in _initUniforms:248

Setup the uniforms for the fragment shader. Each filter is responsible for its own fragment shader uniforms, as they are responsible for their own fragment shaders.

Parameters:

applyFilter

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

Inherited from Filter but overwritten in applyFilter:99

Applies the filter to the specified context. Filter only works with WebGL - use subclass applyFilter for individual filters.

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

() BlurFilter

Inherited from Filter but overwritten in clone:340

Returns a clone of this object.

Returns:

getBounds

() Rectangle

Inherited from Filter but overwritten in getBounds:88

Returns a rectangle with values indicating the margins required to draw the filter or null. For example, a filter that will extend the drawing area 4 pixels to the left, and 7 pixels to the right (but no pixels up or down) would return a rectangle with (x=-4, y=0, width=11, height=0).

Returns:

Rectangle:

a rectangle object indicating the margins required to draw the filter or null if the filter does not effect bounds.

initialize

() protected

Inherited from Filter but overwritten in initialize:80

Initialization method.

shaderParamSetup

(
  • gl
  • stage
  • shaderProgram
)

Inherited from Filter: shaderParamSetup:118

Assign any unique uniforms or other setup functionality here.

Parameters:

  • gl WebGLContext

    The context associated with the stage performing the render.

  • stage SpriteStage

    The stage instance that will be rendering.

  • shaderProgram ShaderProgram

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

toString

() String

Inherited from Filter but overwritten in toString:114

Returns a string representation of this object.

Returns:

String:

a string representation of the instance.

Properties

blurX

Number

Defined in blurX:82

Horizontal blur radius in pixels

Default: 0

blurX

Number

Defined in blurX:77

Horizontal blur radius in pixels

Default: 0

blurY

Number

Defined in blurY:90

Vertical blur radius in pixels

Default: 0

blurY

Number

Defined in blurY:85

Vertical blur radius in pixels

Default: 0

FRAG_SHADER

String

Inherited from Filter: FRAG_SHADER:81

Pre-processing shader code, will be parsed before being fed in. This should be based upon SpriteStage.SHADER_FRAGMENT_BODY_REGULAR

MUL_TABLE

Array protected static

Defined in MUL_TABLE:117

Array of multiply values for blur calculations.

quality

Number

Defined in quality:98

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

quality

Number

Defined in quality:93

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:126

Array of shift values for blur calculations.

VTX_SHADER

String

Inherited from Filter: VTX_SHADER:71

Pre-processing shader code, will be parsed before being fed in. This should be based upon SpriteStage.SHADER_VERTEX_BODY_REGULAR