MTLBlendOperation.subtract
Subtract a portion of the destination pixel values from a portion of the source.
Declaration
case subtractDiscussion
RGB = Source.rgb * SBF - Dest.rgb * DBF
A = Source.a * SBF - Dest.a * DBF
Subtract a portion of the destination pixel values from a portion of the source.
case subtractRGB = Source.rgb * SBF - Dest.rgb * DBF
A = Source.a * SBF - Dest.a * DBF