<!--
{
  "availability" : [
    "iOS: 13.0.0 -",
    "iPadOS: 13.0.0 -",
    "macCatalyst: 13.4.0 -",
    "macOS: 10.15.4 -",
    "tvOS: 16.0.0 -",
    "visionOS: 1.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "Metal",
  "identifier" : "/documentation/Metal/MTLRasterizationRateMap/physicalCoordinates(screenCoordinates:layer:)",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Method",
  "symbol" : {
    "kind" : "Instance Method",
    "modules" : [
      "Metal"
    ],
    "preciseIdentifier" : "c:objc(pl)MTLRasterizationRateMap(im)mapScreenToPhysicalCoordinates:forLayer:"
  },
  "title" : "physicalCoordinates(screenCoordinates:layer:)"
}
-->

# physicalCoordinates(screenCoordinates:layer:)

Converts a point in logical viewport coordinates to the corresponding physical coordinates in a render layer.

```
func physicalCoordinates(screenCoordinates: MTLCoordinate2D, layer layerIndex: Int) -> MTLCoordinate2D
```

## Parameters

`screenCoordinates`

A point in viewport coordinates.

`layerIndex`

The index of the rate map to use.

## Return Value

A point in the layer’s physical coordinate system corresponding to the source point.

## Discussion

The returned coordinates are always less than or equal to the input coordinates because the rasterization rate never exceeds 1:1 in any region.

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)