Instance Method

# convert(_:from:)

Converts the point from the specified layer’s coordinate system to the receiver’s coordinate system.

## Parameters

`p`

A point specifying a location in the coordinate system of `l`.

`l`

The layer with `p` in its coordinate system. The receiver and `l` and must share a common parent layer. This parameter may be `nil`.

## Return Value

The point converted to the receiver’s coordinate system.

## Discussion

If you specify `nil` for the `l` parameter, this method returns the original point subtracted from the layer's frame's origin.

Listing 1 shows code that creates two layers, `redLayer` and `yellowLayer`. `yellowLayer` is scaled so that it is half of its original size.

Figure 1 shows the two layers and an overlaid point (rendered as a blue cross) with a position of `(50.0, 50.0)` in the red layer's coordinate system.

Listing 2 show how you can find the coordinates of that point in the yellow layer's coordinate system.

### Mapping Between Coordinate and Time Spaces

`func convert(CGPoint, to: CALayer?) -> CGPoint`

Converts the point from the receiver’s coordinate system to the specified layer’s coordinate system.

`func convert(CGRect, from: CALayer?) -> CGRect`

Converts the rectangle from the specified layer’s coordinate system to the receiver’s coordinate system.

`func convert(CGRect, to: CALayer?) -> CGRect`

Converts the rectangle from the receiver’s coordinate system to the specified layer’s coordinate system.

`func convertTime(CFTimeInterval, from: CALayer?) -> CFTimeInterval`

Converts the time interval from the specified layer’s time space to the receiver’s time space.

`func convertTime(CFTimeInterval, to: CALayer?) -> CFTimeInterval`

Converts the time interval from the receiver’s time space to the specified layer’s time space

Beta Software

This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.