Convolute

fabric.Image.filters. Convolute

new Convolute()

Source:
See:
Adapted from html5rocks article
Examples

Sharpen filter

var filter = new fabric.Image.filters.Convolute({
  matrix: [ 0, -1,  0,
           -1,  5, -1,
            0, -1,  0 ]
});
object.filters.push(filter);
object.applyFilters();
canvas.renderAll();

Blur filter

var filter = new fabric.Image.filters.Convolute({
  matrix: [ 1/9, 1/9, 1/9,
            1/9, 1/9, 1/9,
            1/9, 1/9, 1/9 ]
});
object.filters.push(filter);
object.applyFilters();
canvas.renderAll();

Emboss filter

var filter = new fabric.Image.filters.Convolute({
  matrix: [ 1,   1,  1,
            1, 0.7, -1,
           -1,  -1, -1 ]
});
object.filters.push(filter);
object.applyFilters();
canvas.renderAll();

Emboss filter with opaqueness

var filter = new fabric.Image.filters.Convolute({
  opaque: true,
  matrix: [ 1,   1,  1,
            1, 0.7, -1,
           -1,  -1, -1 ]
});
object.filters.push(filter);
object.applyFilters();
canvas.renderAll();

Extends

Members

fragmentSource

Source:
Fragment source for the brightness program

type

Source:
Overrides:
Default Value:
  • Convolute
Filter type

Methods

applyTo(options)

Source:
Inherited From:
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.

applyTo2d(options)

Source:
Apply the Brightness operation to a Uint8ClampedArray representing the pixels of an image.
Parameters:
Name Type Description
options Object
Properties
Name Type Description
imageData ImageData The Uint8ClampedArray to be filtered.

applyToWebGL(options)

Source:
Inherited From:
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.

createHelpLayer()

Source:
Inherited From:
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.

createProgram(gl, fragmentSource, vertexSource)

Source:
Inherited From:
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

getAttributeLocations(gl, program) → {Object}

Source:
Inherited From:
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.
Returns:
A map of attribute names to attribute locations.
Type
Object

getUniformLocations(gl, program)

Source:
Overrides:
Return WebGL uniform locations for this filter's shader.
Parameters:
Name Type Description
gl WebGLRenderingContext The GL canvas context used to compile this filter's shader.
program WebGLShaderProgram This filter's compiled shader program.

initialize(optionsopt)

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

isNeutralState(options)

Source:
Inherited From:
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

retrieveShader(options)

Source:
Overrides:
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.

sendAttributeData(gl, attributeLocations)

Source:
Inherited From:
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.

sendUniformData(gl, uniformLocations)

Source:
Overrides:
Send data from this filter to its shader program's uniforms.
Parameters:
Name Type Description
gl WebGLRenderingContext The GL canvas context used to compile this filter's shader.
uniformLocations Object A map of string uniform names to WebGLUniformLocation objects

setOptions(optionsopt)

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

toJSON() → {Object}

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

toObject() → {Object}

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