in
The in
attribute identifies input for the given filter primitive.
The value can be either one of the six keywords defined below, or a string which matches a previous result
attribute value within the same <filter>
element. If no value is provided and this is the first filter primitive, then this filter primitive will use SourceGraphic
as its input. If no value is provided and this is a subsequent filter primitive, then this filter primitive will use the result from the previous filter primitive as its input.
If the value for result
appears multiple times within a given <filter>
element, then a reference to that result will use the closest preceding filter primitive with the given value for attribute result
.
You can use this attribute with the following SVG elements:
Usage notes
Value |
SourceGraphic | SourceAlpha |
BackgroundImage | BackgroundAlpha |
FillPaint | StrokePaint |
<filter-primitive-reference>
|
---|---|
Default value |
SourceGraphic for first filter primitive, otherwise result
of previous filter primitive
|
Animatable | Yes |
SourceGraphic
-
This keyword represents the graphics elements that were the original input into the
<filter>
element. SourceAlpha
-
This keyword represents the graphics elements that were the original input into the
<filter>
element.SourceAlpha
has all of the same rules asSourceGraphic
except that only the alpha channel is used. BackgroundImage
-
This keyword represents an image snapshot of the SVG document under the filter region at the time that the
<filter>
element was invoked. BackgroundAlpha
-
Same as
BackgroundImage
except only the alpha channel is used. FillPaint
-
This keyword represents the value of the
fill
property on the target element for the filter effect. In many cases, theFillPaint
is opaque everywhere, but that might not be the case if a shape is painted with a gradient or pattern which itself includes transparent or semi-transparent parts. StrokePaint
-
This keyword represents the value of the
stroke
property on the target element for the filter effect. In many cases, theStrokePaint
is opaque everywhere, but that might not be the case if a shape is painted with a gradient or pattern which itself includes transparent or semi-transparent parts. <filter-primitive-reference>
-
This value is an assigned name for the filter primitive in the form of a
<custom-ident>
. If supplied, then graphics that result from processing this filter primitive can be referenced by an in attribute on a subsequent filter primitive within the same filter element. If no value is provided, the output will only be available for re-use as the implicit input into the next filter primitive if that filter primitive provides no value for its in attribute.
Workaround for BackgroundImage
BackgroundImage
is not supported as a filter source in modern browsers (see the feComposite compatibility table). We therefore need to import one of the images to blend inside the filter itself, using an <feImage>
element.
Note:
Firefox Bug 455986 means that feImage
cannot load partial images, including circles, rectangles, paths or other fragments defined in the document. So that this example works on more browsers, a full external image of the logo is loaded.
HTML
<div style="width: 420px; height: 220px;">
<svg
style="width:200px; height:200px; display: inline;"
xmlns="http://www.w3.org/2000/svg"
xmlns:xlink="http://www.w3.org/1999/xlink">
<defs>
<filter id="backgroundMultiply">
<!-- This will not work. -->
<feBlend in="BackgroundImage" in2="SourceGraphic" mode="multiply" />
</filter>
</defs>
<image
href="mdn_logo_only_color.png"
x="10%"
y="10%"
width="80%"
height="80%" />
<circle
cx="50%"
cy="40%"
r="40%"
fill="#c00"
style="filter:url(#backgroundMultiply);" />
</svg>
<svg
style="width:200px; height:200px; display: inline;"
xmlns="http://www.w3.org/2000/svg"
xmlns:xlink="http://www.w3.org/1999/xlink">
<defs>
<filter id="imageMultiply">
<!-- This is a workaround. -->
<feImage
href="mdn_logo_only_color.png"
x="10%"
y="10%"
width="80%"
height="80%" />
<feBlend in2="SourceGraphic" mode="multiply" />
</filter>
</defs>
<circle
cx="50%"
cy="40%"
r="40%"
fill="#c00"
style="filter:url(#imageMultiply);" />
</svg>
</div>
Result
Specifications
Specification |
---|
Filter Effects Module Level 1 # element-attrdef-filter-primitive-in |