---
title: sourceAtop
framework: swiftui
role: symbol
role_heading: Type Property
path: swiftui/graphicscontext/blendmode-swift.struct/sourceatop
---

# sourceAtop

A mode that you use to paint the opaque parts of the source image onto the opaque parts of the background.

## Declaration

```swift
static var sourceAtop: GraphicsContext.BlendMode { get }
```

## Discussion

Discussion This mode implements the equation R = S*Da + D*(1 - Sa) where R is the composite image. S is the source image. D is the background. Sa is the source image’s alpha value. Da is the source background’s alpha value.

## See Also

### Accessing Porter-Duff modes

- [clear](swiftui/graphicscontext/blendmode-swift.struct/clear.md)
- [copy](swiftui/graphicscontext/blendmode-swift.struct/copy.md)
- [sourceIn](swiftui/graphicscontext/blendmode-swift.struct/sourcein.md)
- [sourceOut](swiftui/graphicscontext/blendmode-swift.struct/sourceout.md)
- [destinationOver](swiftui/graphicscontext/blendmode-swift.struct/destinationover.md)
- [destinationIn](swiftui/graphicscontext/blendmode-swift.struct/destinationin.md)
- [destinationOut](swiftui/graphicscontext/blendmode-swift.struct/destinationout.md)
- [destinationAtop](swiftui/graphicscontext/blendmode-swift.struct/destinationatop.md)
- [xor](swiftui/graphicscontext/blendmode-swift.struct/xor.md)