---
title: sourceRegion
framework: metal
role: symbol
role_heading: Instance Property
path: metal/mtl4copysparsetexturemappingoperation/sourceregion
---

# sourceRegion

The region in the source texture, in tiles.

## Declaration

```swift
var sourceRegion: MTLRegion
```

## Discussion

Discussion The tiles remain mapped in the source texture. When sourceLevel is equal to the source texture’s firstMipmapInTail, set origin.y to 0 and size.height to 1.