DOMPoint.fromPoint() - Web APIs 编辑

The static DOMPoint method fromPoint() creates and returns a new mutable DOMPoint object given a source point. The source point is specified as a DOMPointInit-compatible object, which includes both DOMPoint and DOMPointReadOnly.

You can also create a new DOMPoint object using the new DOMPoint() constructor.

Although this interface is based on DOMPointReadOnly, it is not read-only; the properties within may be changed at will.

Syntax

var point = DOMPoint.fromPoint(sourcePoint);

Properties

sourcePoint

A DOMPointInit-compliant object, which includes both DOMPoint and DOMPointReadOnly, from which to take the values of the new point's properties.

Return value

A new DOMPoint object whose coordinate and perspective values are identical to those in the source point. The point's properties are mutable and may be changed at any time.

Examples

Creating a mutable point from a read-only point

If you have a DOMPointReadOnly object, you can easily create a mutable copy of that point:

var mutablePoint = DOMPoint.fromPoint(readOnlyPoint);

Creating a 2D point

This sample creates a 2D point, specifying an inline object that includes the values to use for x and y. The z and w properties are allowed to keep their default values (0 and 1 respectively).

var center = DOMPoint.fromPoint({x: 75, y: -50, z: -55, w: 0.25});

Specifications

Browser compatibility

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