Class: BaseFilter

fabric.Image.filters.BaseFilter

new BaseFilter()

Root filter class from which all filter classes inherit from
Source:

Members

type

Filter type
Default Value:
  • BaseFilter
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Methods

applyTo(options)

Apply this filter to the input image data provided. Determines whether to use WebGL or Canvas2D based on the options.webgl flag.
Parameters:
Name Type Description
options Object
Properties
Name Type Description
passes Number The number of filters remaining to be executed
webgl Boolean Whether to use webgl to render the filter.
sourceTexture WebGLTexture The texture setup as the source to be filtered.
targetTexture WebGLTexture The texture where filtered output should be drawn.
context WebGLRenderingContext The GL context used for rendering.
programCache Object A map of compiled shader programs, keyed by filter type.
Source:

applyToWebGL(options)

Apply this filter using webgl.
Parameters:
Name Type Description
options Object
Properties
Name Type Description
passes Number The number of filters remaining to be executed
webgl Boolean Whether to use webgl to render the filter.
originalTexture WebGLTexture The texture of the original input image.
sourceTexture WebGLTexture The texture setup as the source to be filtered.
targetTexture WebGLTexture The texture where filtered output should be drawn.
context WebGLRenderingContext The GL context used for rendering.
programCache Object A map of compiled shader programs, keyed by filter type.
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createHelpLayer()

If needed by a 2d filter, this functions can create an helper canvas to be used remember that options.targetCanvas is available for use till end of chain.
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createProgram(gl, fragmentSource, vertexSource)

Compile this filter's shader program.
Parameters:
Name Type Description
gl WebGLRenderingContext The GL canvas context to use for shader compilation.
fragmentSource String fragmentShader source for compilation
vertexSource String vertexShader source for compilation
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getAttributeLocations(gl, program) → {Object}

Return a map of attribute names to WebGLAttributeLocation objects.
Parameters:
Name Type Description
gl WebGLRenderingContext The canvas context used to compile the shader program.
program WebGLShaderProgram The shader program from which to take attribute locations.
Source:
Returns:
A map of attribute names to attribute locations.
Type
Object

getUniformLocations(gl, program) → {Object}

Return a map of uniform names to WebGLUniformLocation objects. Intended to be overridden by subclasses.
Parameters:
Name Type Description
gl WebGLRenderingContext The canvas context used to compile the shader program.
program WebGLShaderProgram The shader program from which to take uniform locations.
Source:
Returns:
A map of uniform names to uniform locations.
Type
Object

initialize(optionsopt)

Constructor
Parameters:
Name Type Attributes Description
options Object <optional>
 Options object
Source:

isNeutralState(options)

Generic isNeutral implementation for one parameter based filters. Used only in image applyFilters to discard filters that will not have an effect on the image Other filters may need their own version ( ColorMatrix, HueRotation, gamma, ComposedFilter )
Parameters:
Name Type Description
options Object
Source:

retrieveShader(options)

Retrieves the cached shader.
Parameters:
Name Type Description
options Object
Properties
Name Type Description
context WebGLRenderingContext The GL context used for rendering.
programCache Object A map of compiled shader programs, keyed by filter type.
Source:

sendAttributeData(gl, attributeLocations)

Send attribute data from this filter to its shader program on the GPU.
Parameters:
Name Type Description
gl WebGLRenderingContext The canvas context used to compile the shader program.
attributeLocations Object A map of shader attribute names to their locations.
Source:

sendUniformData(gl, uniformLocations)

Send uniform data from this filter to its shader program on the GPU. Intended to be overridden by subclasses.
Parameters:
Name Type Description
gl WebGLRenderingContext The canvas context used to compile the shader program.
uniformLocations Object A map of shader uniform names to their locations.
Source:

setOptions(optionsopt)

Sets filter's properties from options
Parameters:
Name Type Attributes Description
options Object <optional>
 Options object
Source:

toJSON() → {Object}

Returns a JSON representation of an instance
Source:
Returns:
JSON
Type
Object

toObject() → {Object}

Returns object representation of an instance
Source:
Returns:
Object representation of an instance
Type
Object