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sourceAtop

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

Declaration

static var sourceAtop: GraphicsContext.BlendMode { get }

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