SVGMaskElement: maskUnits property
The read-only maskUnits
property of the SVGMaskElement
interface reflects the maskUnits
attribute of a <mask>
element which defines the coordinate system to use for the mask of the element.
Value
An SVGAnimatedEnumeration
representing the coordinate system. The possible values are defined in the SVGUnitTypes
interface:
0
(SVG_UNIT_TYPE_UNKNOWN
)-
The type is not one of the predefined types.
1
(SVG_UNIT_TYPE_USERSPACEONUSE
)-
Corresponds to a value of
userSpaceOnUse
for themaskUnits
attribute and means that all coordinates inside the element refer to the user coordinate system as defined when the mask was created. It is the default value. 2
(SVG_UNIT_TYPE_OBJECTBOUNDINGBOX
)-
Corresponds to a value of
objectBoundingBox
for the attribute and means that all coordinates inside the element are relative to the bounding box of the element the mask is applied to. It means that the origin of the coordinate system is the top left corner of the object bounding box and the width and height of the object bounding box are considered to have a length of 1 unit value.
Examples
html
<div>
<svg
viewBox="0 0 100 100"
height="200"
width="200"
xmlns="http://www.w3.org/2000/svg">
<mask
id="mask1"
maskUnits="userSpaceOnUse"
x="20%"
y="20%"
width="60%"
height="60%">
<rect fill="black" x="0" y="0" width="100%" height="100%" />
<circle fill="white" cx="50" cy="50" r="35" />
</mask>
<mask
id="mask2"
maskUnits="objectBoundingBox"
x="20%"
y="20%"
width="60%"
height="60%">
<rect fill="black" x="0" y="0" width="100%" height="100%" />
<circle fill="white" cx="50" cy="50" r="35" />
<animate
attributeName="maskUnits"
values="objectBoundingBox;userSpaceOnUse"
dur="1s"
repeatCount="indefinite" />
</mask>
<!-- Some reference rect to materialized the mask -->
<rect id="r1" x="0" y="0" width="45" height="45" />
<rect id="r2" x="0" y="55" width="45" height="45" />
<rect id="r3" x="55" y="55" width="45" height="45" />
<rect id="r4" x="55" y="0" width="45" height="45" />
<!-- The first 3 rect are masked with useSpaceOnUse units -->
<use mask="url(#mask1)" xlink:href="#r1" fill="blue" />
<use mask="url(#mask1)" xlink:href="#r2" fill="green" />
<use mask="url(#mask1)" xlink:href="#r3" fill="yellow" />
<!-- The last rect is masked with objectBoundingBox units -->
<use mask="url(#mask2)" xlink:href="#r4" fill="lightblue" />
</svg>
</div>
<pre id="log"></pre>
js
const unitType = ["unknown", "userSpaceOnUse", "objectBoundingBox"];
const mask = document.getElementById("mask2");
const log = document.getElementById("log");
function displayLog() {
const baseValue = unitType[mask.maskUnits.baseVal];
const animValue = unitType[mask.maskUnits.animVal];
log.textContent = `The top-right 'maskUnits.baseVal' coord system : ${baseValue}\n`;
log.textContent += `The top-right 'maskUnits.animVal' coord system : ${animValue}`;
requestAnimationFrame(displayLog);
}
displayLog();
Specifications
Specification |
---|
CSS Masking Module Level 1 # dom-svgmaskelement-maskunits |
Browser compatibility
BCD tables only load in the browser