---
title: "init(screenSize:layer:label:)"
framework: metal
role: symbol
role_heading: Initializer
path: "metal/mtlrasterizationratemapdescriptor/init(screensize:layer:label:)"
---

# init(screenSize:layer:label:)

A convenience initializer that creates a rate map descriptor with a single rate layer.

## Declaration

```swift
convenience init(screenSize: MTLSize, layer: MTLRasterizationRateLayerDescriptor, label: String? = nil)
```

## Parameters

- `screenSize`: The logical size, in pixels, of the viewport coordinate system.
- `layer`: A descriptor for the rate layer to create.
- `label`: A string that identifies the resulting rate map.

## Return Value

Return Value A descriptor object whose screenSize and label properties are set to the provided values. Layer 0 in the rate map is set to the provided layer descriptor.

## See Also

### Creating rate map descriptors

- [init(screenSize:label:)](metal/mtlrasterizationratemapdescriptor/init(screensize:label:).md)
- [init(screenSize:layers:label:)](metal/mtlrasterizationratemapdescriptor/init(screensize:layers:label:).md)