Contents

destinationAtop

A mode that you use to paint the source image under the background, while erasing any of the background not matched by opaque pixels from the source image.

Declaration

static var destinationAtop: GraphicsContext.BlendMode { get }

Discussion

This mode implements the equation R = S*(1 - Da) + D*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