svg.filter.js

A plugin for svg.js adding filter functionality.

svg.filter.js is licensed under the terms of the MIT License.

- Examples
- Furthermore
- unfilter
- referencing the filter node
- Animating filter values
- Chaining Effects
- Effect Classes

Usage

$3

``sh
npm i @svgdotjs/svg.filter.js
`

$3

`sh
yarn add @svgdotjs/svg.filter.js
`

Include this plugin after including the svg.js library in your html document.

Here is how each filter effect on the example page is achieved.




Examples

- gaussian blur
- horizontal blur
- desaturate
- contrast
- sepiatone
- hue rotate 180
- luminance to alpha
- colorize
- posterize
- darken
- lighten
- invert
- gamma correct 1
- gamma correct 2
- drop shadow
- extrude

$3

`javascript
var image = draw.image('path/to/image.jpg').size(300, 300)
`

$3

`javascript
image.filterWith(function(add) {
add.gaussianBlur(30)
})
`

$3

`javascript
image.filterWith(function(add) {
add.gaussianBlur(30, 0)
})
`

$3

`javascript
image.filterWith(function(add) {
add.colorMatrix('saturate', 0)
})
`

$3

`javascript
image.filterWith(function(add) {
var amount = 1.5

add.componentTransfer({
type: 'linear',
slope: amount,
intercept: -(0.3 * amount) + 0.3
})
})
`

$3

`javascript
image.filterWith(function(add) {
add.colorMatrix('matrix', [ .343, .669, .119, 0, 0
, .249, .626, .130, 0, 0
, .172, .334, .111, 0, 0
, .000, .000, .000, 1, 0 ])
})
`

$3

`javascript
image.filterWith(function(add) {
add.colorMatrix('hueRotate', 180)
})
`

$3

`javascript
image.filterWith(function(add) {
add.colorMatrix('luminanceToAlpha')
})
`

$3

`javascript
image.filterWith(function(add) {
add.colorMatrix('matrix', [ 1.0, 0, 0, 0, 0
, 0, 0.2, 0, 0, 0
, 0, 0, 0.2, 0, 0
, 0, 0, 0, 1.0, 0 ])
})
`

$3

`javascript
image.filterWith(function(add) {
add.componentTransfer({
type: 'discrete',
tableValues: [0, 0.2, 0.4, 0.6, 0.8, 1]
})
})
`

$3

`javascript
image.filterWith(function(add) {
add.componentTransfer({
type: 'linear',
slope: 0.2
})
})
`

$3

`javascript
image.filterWith(function(add) {
add.componentTransfer({
type: 'linear',
slope: 1.5,
intercept: 0.2
})
})
`

$3

`javascript
image.filterWith(function(add) {
add.componentTransfer({
type: 'table'
tableValues: [1, 0]
})
})
`

$3

`javascript
image.filterWith(function(add) {
add.componentTransfer({
g: { type: 'gamma', amplitude: 1, exponent: 0.5 }
})
})
`

$3

`javascript
image.filterWith(function(add) {
add.componentTransfer({
g: { type: 'gamma', amplitude: 1, exponent: 0.5, offset: -0.1 }
})
})
`




$3

You will notice that all the effect descriptions have a drop shadow. Here is how this drop shadow can be achieved:

`javascript
var text = draw.text('SVG text with drop shadow').fill('#fff')

text.filterWith(function(add) {
var blur = add.offset(0, 1).in(add.$sourceAlpha).gaussianBlur(1)

add.blend(add.$source, blur)
})
`

This technique can be achieved on any other shape of course:

`javascript
var rect = draw.rect(100,100).fill('#f09').stroke({ width: 3, color: '#0f9' }).move(10,10)

rect.filterWith(function(add) {
var blur = add.offset(20, 20).in(add.$sourceAlpha).gaussianBlur(5)

add.blend(add.$source, blur)

this.size('200%','200%').move('-50%', '-50%')
})
`

If the drop shadow should get the colour of the shape so it appears like coloured glass:

`javascript
var rect = draw.rect(100,100).fill('#f09').stroke({ width: 3, color: '#0f9' }).move(10,10)

rect.filterWith(function(add) {
var blur = add.offset(20, 20).gaussianBlur(5)

add.blend(add.$source, blur)

this.size('200%','200%').move('-50%', '-50%')
})
`

$3


`javascript
image.filterWith(function(add){
var matrix = add.convolveMatrix([
1,0,0,0,0,0,
0,1,0,0,0,0,
0,0,1,0,0,0,
0,0,0,1,0,0,
0,0,0,0,1,0,
0,0,0,0,0,1
]).attr({
devisor: '2',
preserveAlpha: 'false'
}).in(add.$sourceAlpha)

//recolor it
var color = add.composite(add.flood('#ff2222'),matrix,'in');

//merge all of them toggether
add.merge(color,add.$source);
})
`




Furthermore

Some more features you should know about.

$3

The unfilter method removes the filter attribute from the node:

`javascript
image.unfilter()
`

$3


its also posible to create a filter by using the new keyword
NOTE: when creating a filter this way, it can take an optional attr object
`javascript
var filter = new SVG.Filter();

// create the filters effects here
filter.offset(20, 20).gaussianBlur(5);
filter.blend(filter.$source, blur);
filter.size('200%','200%').move('-50%', '-50%')
`
then once you have created the filter you can use it one multiple elements
`javascript
var image = new SVG.Image();
var shape = new SVG.Rect(10, 10);

image.filterWith(filter);
shape.filterWith(filter);
`

$3

An internal reference to the filter node is made in the element:

`javascript
image.filterer()
`

This can also be very useful to reuse an existing filter on various elements:

`javascript
otherimage.filterWith(image.filterer())
`

$3

Every filter value can be animated as well:

`javascript
var hueRotate

image.filterWith(function(add) {
hueRotate = add.colorMatrix('hueRotate', 0)
})

hueRotate.animate(3000).attr('values', 360)
`

$3

Method chaining is a programing style where each function returns the object it belongs to, for an example look at JQuery.

it's possible to chain the effects on a filter when you are creating them, for example:
`javascript
image.filterWith(function(add){
add.flood('black',0.5).composite(add.$sourceAlpha,'in').offset(10).merge(add.$source)
})
`

this would create a basic shadow filter where the first input on the composite effect would be the flood effect, and the input on the offset effect would be the composite effect.

same with the merge effect, its first input would be the offset effect, and its second input would be add.$source

some effects like Merge, Blend, Composite, DisplacementMap have thier arguments changed when they are chained, for example
`javascript
image.filterWith(function(add){
add.flood('black',0.5).composite(add.$sourceAlpha,'in')
})
`
the composite effects first input is set to the flood effect and its second input becomes the first argument, this is the same for the merge, blend, composite, and displacmentMap effect.

for more details check out each effects doc below

Effect Classes

- Base Effect Class
- Blend
- ColorMatrix
- ComponentTransfer
- Composite
- ConvolveMatrix
- DiffuseLighting
- DisplacementMap
- Flood
- GaussianBlur
- Image
- Merge
- Morphology
- Offset
- SpecularLighting
- Tile
- Turbulence

$3

#### in(effect)
gets or sets the in attribute of the effect

- effect: this can be another effect or a string

if effect is not provided it will look for another effect on the same filter whose result is equal to this effects in attribute, else it will return the value of the in attribute
`javascript
image.filterWith(function(add){
var offset = add.offset(10)

//create the blur effect and then set its input
var blur = add.gaussianBlur(3)

//set the input to an effect
blur.in(offset)

//this will return the offset effect
var input = blur.in()

//set the input to a string
blur.in('another-result-as-a-string')

//this will return a string since there is no other effect which has a matching result attribute
var input2 = blur.in()
})
`

#### in2(effect)
gets or sets the in2 attribute of the effect

this function works the same as the in method.

it's only on effects (Blend, Composite, and DisplacementMap)

#### result(string)
gets or sets the result attribute of the effect

- string: if a string is provided it will set the value of the result attribute.

if no arguments are provided it will act as a getter and return the value of the result attribute

$3

W3 doc

`javascript
filter.blend(in1, in2, mode)
//or
new SVG.BlendEffect({in1, in2, mode})
`

- in1: an effect or the result of effect
- in2: same as in1
- mode: "normal | multiply | screen | darken | lighten" defaults to "normal"

chaining when this effect is called right after another effect, for example:
`javascript
filter.offset(10).blend(filter.$source)
`
the first input is set to the offset effect and the second input is set to filter.$source or what ever was passed as the first argument, and the second input becomes the mode

$3

W3 doc

`javascript
filter.colorMatrix(type, values);
//or
new SVG.ColorMatrixEffect({type, values});
`

- type: "matrix | saturate | hueRotate | luminanceToAlpha"
- values
- type="matrix": values would be a matrix the size of 4x5
- type="saturate": number (0 to 1)
- type="hueRotate": number (0 to 360) deg
- type="luminanceToAlpha": value not needed

$3

W3 doc

`javascript
filter.componentTransfer(components);
// or
filter.componentTransfer(function (add) { add.funcA({ type... }) });
//or
new SVG.ComponentTransferEffect();
`

- components: an object which is set for all chanels or r, g, b, a properties for each chanel
`javascript
type: "identity | table | discrete | linear | gamma",

//type="table"
tableValues: "0 0.5 2 1", //number separated by spaces

//type="linear"
slope: 1, //number
intercept: 3,//number

//type="gamma"
amplitude: 0, //number
exponent: 0, //number
offset: 0 //number
}
`

$3

W3 doc

`javascript
filter.composite(in1, in2, operator);
//or
new SVG.CompositeEffect({in1, in2, operator});
`

- in1: an effect or the result of an effect
- in2: same as in1
- operator: "over | in | out | atop | xor | arithmetic" defaults to "over"

chaining when this effect is called right after another effect, for example:
`javascript
filter.flood('black',0.5).composite(filter.$sourceAlpha,'in')
`
the first input is set to the flood effect and the second input is set to filter.$sourceAlpha or what ever was passed as the first argument.

also the second argument becomes the operator

$3

W3 doc

`javascript
filter.convolveMatrix(matrix);
//or
new SVG.ConvolveMatrixEffect({matrix});
`

- matrix: a square matrix of numbers that will be applied to the image
- exmaple:
`javascript
[
1,0,0,
0,1,0,
0,0,1
]
`

$3

W3 doc

`javascript
filter.diffuseLighting(surfaceScale, lightingColor, diffuseConstant, kernelUnitLength);
//or
new SVG.DiffuseLightingEffect({surfaceScale, lightingColor, diffuseConstant, kernelUnitLength});
`

very complicated, just check out the W3 doc

$3

W3 doc

`javascript
filter.displacementMap(in1, in2, scale, xChannelSelector, yChannelSelector);
//or
new SVG.DisplacementMapEffect({in1, in2, scale, xChannelSelector, yChannelSelector});
`

very complicated, just check out the W3 doc

chaining when this effect is called right after another effect, for example:
`javascript
filter.offset(20,50).displacementMap(filter.$source,2)
`
the first input is set to the offset effect and the second input is set to filter.$source or what ever was passed as the first argument.

also the second argument becomes the scale, and the third argument is the xChannelSelector and so on

$3

W3 doc

`javascript
filter.flood(color,opacity);
//or
new SVG.FloodEffect(color,opacity);
`

- color: a named or hex color in string format
- opacity: number form 0 to 1

$3

W3 doc

`javascript
filter.gaussianBlur(x, y);
//or
new SVG.GaussianBlurEffect({x, y});
`

- x: blur on the X
- y: blur on the y, will default to the x if not provided

$3

W3 doc

`javascript
filter.image(src);
//or
new SVG.ImageEffect({src});
`

$3

W3 doc

`javascript
filter.merge();
//or
new SVG.MergeEffect();
`

- Array: an Array of effects or effect results filter.merge([effectOne,"result-two",another_effect])
- chaining you can also chain the merge effect filter.offset(10).merge(anotherEffect) which will result in a merge effect with its first input set to the offset effect and its second input set to anotherEffect

$3

W3 doc

`javascript
filter.morphology(operator, radius);
//or
new SVG.MorphologyEffect({operator, radius});
`

- operator: "erode | dilate"
- radius: a single number or a string of two numbers separated by a space
- the first number is the X
- the second number is the Y, if no second number was provided it will default to the first number

$3

W3 doc

`javascript
filter.offset(x, y);
//or
new SVG.OffsetEffect({x, y});
`

- x: move on the X
- y: move on the y, will default to the x if not provided

$3

W3 doc

`javascript
filter.specularLighting(surfaceScale, lightingColor, diffuseConstant, specularExponent, kernelUnitLength);
//or
new SVG.SpecularLightingEffect(surfaceScale, lightingColor, diffuseConstant, specularExponent, kernelUnitLength);
`

very complicated, just check out the W3 doc

$3

W3 doc

`javascript
filter.tile();
//or
new SVG.TileEffect();
`

no arguments, but if you want to find out what it does check out the W3 doc

$3

W3 doc

`javascript
filter.turbulence(baseFrequency, numOctaves, seed, stitchTiles, type);
//or
new SVG.TurbulenceEffect({baseFrequency, numOctaves, seed, stitchTiles, type});
``

very complicated, just check out the W3 doc