BlendImage

Defined in: src/filters/BlendImage.ts:41

Image Blend filter class

Example

const filter = new filters.BlendColor({
 color: '#000',
 mode: 'multiply'
});

const filter = new BlendImage({
 image: fabricImageObject,
 mode: 'multiply'
});
object.filters.push(filter);
object.applyFilters();
canvas.renderAll();

Extends

BaseFilter<"BlendImage", BlendImageOwnProps>

Constructors

new BlendImage()

new BlendImage(options?): BlendImage

Defined in: src/filters/BaseFilter.ts:57

Constructor

Parameters

options?

object & Partial<BlendImageOwnProps> & Record<string, any> = {}

Options object

Returns

BlendImage

Inherited from

BaseFilter.constructor

Properties

alpha

alpha: number

Defined in: src/filters/BlendImage.ts:62

alpha value. represent the strength of the blend image operation. not implemented.

image

image: FabricImage

Defined in: src/filters/BlendImage.ts:45

Image to make the blend operation with.

mode

mode: TBlendImageMode

Defined in: src/filters/BlendImage.ts:56

Blend mode for the filter: either ‘multiply’ or ‘mask’. ‘multiply’ will multiply the values of each channel (R, G, B, and A) of the filter image by their corresponding values in the base image. ‘mask’ will only look at the alpha channel of the filter image, and apply those values to the base image’s alpha channel.

Default

defaults

static defaults: BlendImageOwnProps = blendImageDefaultValues

Defined in: src/filters/BlendImage.ts:66

Overrides

BaseFilter.defaults

type

static type: string = 'BlendImage'

Defined in: src/filters/BlendImage.ts:64

The class type. Used to identify which class this is. This is used for serialization purposes and internally it can be used to identify classes. As a developer you could use instance of Class but to avoid importing all the code and blocking tree shaking we try to avoid doing that.

Overrides

BaseFilter.type

uniformLocations

static uniformLocations: string[]

Defined in: src/filters/BlendImage.ts:68

Contains the uniform locations for the fragment shader. uStepW and uStepH are handled by the BaseFilter, each filter class needs to specify all the one that are needed

Overrides

BaseFilter.uniformLocations

Accessors

type

Get Signature

get type(): Name

Defined in: src/filters/BaseFilter.ts:31

Filter type

Default

Returns

Name

Inherited from

BaseFilter.type

Methods

_setupFrameBuffer()

_setupFrameBuffer(options): void

Defined in: src/filters/BaseFilter.ts:205

Parameters

options

TWebGLPipelineState

Returns

void

Inherited from

BaseFilter._setupFrameBuffer

_swapTextures()

_swapTextures(options): void

Defined in: src/filters/BaseFilter.ts:232

Parameters

options

TWebGLPipelineState

Returns

void

Inherited from

BaseFilter._swapTextures

applyTo()

applyTo(options): void

Defined in: src/filters/BaseFilter.ts:265

Apply this filter to the input image data provided.

Determines whether to use WebGL or Canvas2D based on the options.webgl flag.

Parameters

options

TWebGLPipelineState | T2DPipelineState

Returns

void

Inherited from

BaseFilter.applyTo

applyTo2d()

applyTo2d(options): void

Defined in: src/filters/BlendImage.ts:122

Apply the Blend operation to a Uint8ClampedArray representing the pixels of an image.

Parameters

options

T2DPipelineState

Returns

void

Overrides

BaseFilter.applyTo2d

applyToWebGL()

applyToWebGL(options): void

Defined in: src/filters/BlendImage.ts:82

Apply this filter using webgl.

Parameters

options

TWebGLPipelineState

Returns

void

Overrides

BaseFilter.applyToWebGL

bindAdditionalTexture()

bindAdditionalTexture(gl, texture, textureUnit): void

Defined in: src/filters/BaseFilter.ts:334

Parameters

gl

WebGLRenderingContext

texture

WebGLTexture

textureUnit

number

Returns

void

Inherited from

BaseFilter.bindAdditionalTexture

calculateMatrix()

calculateMatrix(): number[]

Defined in: src/filters/BlendImage.ts:100

Calculate a transformMatrix to adapt the image to blend over

Returns

number[]

createHelpLayer()

createHelpLayer(options): void

Defined in: src/filters/BaseFilter.ts:370

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.

Parameters

options

T2DPipelineState

Returns

void

Inherited from

BaseFilter.createHelpLayer

createProgram()

createProgram(gl, fragmentSource, vertexSource): object

Defined in: src/filters/BaseFilter.ts:83

Compile this filter’s shader program.

Parameters

gl

WebGLRenderingContext

The GL canvas context to use for shader compilation.

fragmentSource

string = ...

fragmentShader source for compilation

vertexSource

string = ...

vertexShader source for compilation

Returns

object

attributeLocations

attributeLocations: TWebGLAttributeLocationMap

program

program: WebGLProgram

uniformLocations

uniformLocations: TWebGLUniformLocationMap

Inherited from

BaseFilter.createProgram

createTexture()

createTexture(backend, image): null | WebGLTexture

Defined in: src/filters/BlendImage.ts:90

Parameters

backend

WebGLFilterBackend

image

FabricImage

Returns

null | WebGLTexture

getAttributeLocations()

getAttributeLocations(gl, program): TWebGLAttributeLocationMap

Defined in: src/filters/BaseFilter.ts:153

Return a map of attribute names to WebGLAttributeLocation objects.

Parameters

gl

WebGLRenderingContext

The canvas context used to compile the shader program.

program

WebGLProgram

The shader program from which to take attribute locations.

Returns

TWebGLAttributeLocationMap

A map of attribute names to attribute locations.

Inherited from

BaseFilter.getAttributeLocations

getCacheKey()

getCacheKey(): string

Defined in: src/filters/BlendImage.ts:70

Returns a string that represent the current selected shader code for the filter. Used to force recompilation when parameters change or to retrieve the shader from cache

Returns

string

Overrides

BaseFilter.getCacheKey

getFragmentSource()

getFragmentSource(): string

Defined in: src/filters/BlendImage.ts:74

Returns

string

Overrides

BaseFilter.getFragmentSource

getUniformLocations()

getUniformLocations(gl, program): TWebGLUniformLocationMap

Defined in: src/filters/BaseFilter.ts:169

Return a map of uniform names to WebGLUniformLocation objects.

Parameters

gl

WebGLRenderingContext

The canvas context used to compile the shader program.

program

WebGLProgram

The shader program from which to take uniform locations.

Returns

TWebGLUniformLocationMap

A map of uniform names to uniform locations.

Inherited from

BaseFilter.getUniformLocations

getVertexSource()

getVertexSource(): string

Defined in: src/filters/BlendImage.ts:78

Returns

string

Overrides

BaseFilter.getVertexSource

isNeutralState()

isNeutralState(options?): boolean

Defined in: src/filters/BaseFilter.ts:248

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

options?

any

Returns

boolean

Inherited from

BaseFilter.isNeutralState

retrieveShader()

retrieveShader(options): TWebGLProgramCacheItem

Defined in: src/filters/BaseFilter.ts:295

Retrieves the cached shader.

Parameters

options

TWebGLPipelineState

Returns

TWebGLProgramCacheItem

the compiled program shader

Inherited from

BaseFilter.retrieveShader

sendAttributeData()

sendAttributeData(gl, attributeLocations, aPositionData): void

Defined in: src/filters/BaseFilter.ts:192

Send attribute data from this filter to its shader program on the GPU.

Parameters

gl

WebGLRenderingContext

The canvas context used to compile the shader program.

attributeLocations

Record<string, number>

A map of shader attribute names to their locations.

aPositionData

Float32Array

Returns

void

Inherited from

BaseFilter.sendAttributeData

sendUniformData()

sendUniformData(gl, uniformLocations): void

Defined in: src/filters/BlendImage.ts:179

Send data from this filter to its shader program’s uniforms.

Parameters

gl

WebGLRenderingContext

The GL canvas context used to compile this filter’s shader.

uniformLocations

TWebGLUniformLocationMap

A map of string uniform names to WebGLUniformLocation objects

Returns

void

Overrides

BaseFilter.sendUniformData

toJSON()

toJSON(): object & BlendImageOwnProps

Defined in: src/filters/BaseFilter.ts:407

Returns a JSON representation of an instance

Returns

object & BlendImageOwnProps

JSON

Inherited from

BaseFilter.toJSON

toObject()

toObject(): object & BlendImageOwnProps

Defined in: src/filters/BlendImage.ts:194

Returns object representation of an instance TODO: Handle the possibility of missing image better. As of now a BlendImage filter without image can’t be used with fromObject