Reorders the channels of the top 8-bit, 4-channel, premultiplied image, and blends the image into a bottom premultiplied, RGBA8888 image.
SDKs
- iOS 7.0+
- macOS 10.9+
- Mac Catalyst 13.0+Beta
- tvOS 9.0+
- watchOS 2.0+
Framework
- Accelerate
Declaration
func vImagePremultipliedAlphaBlendWithPermute_RGBA8888(_ srcTop: UnsafeParameters
srcTopA pointer to a vImage buffer structure that contains data for the top source image.
srcBottomA pointer to a vImage buffer structure that contains data for the bottom source image.
destA pointer to a vImage buffer data structure. You're responsible for filling out the
height,width, androwfields of this structure, and for allocating a data buffer of the appropriate size. On return, the data buffer this structure points to contains the destination image data. When you no longer need the data buffer, you must deallocate the memory.Bytes permuteMapValues that can be used to switch the channel order of the source top image.
makeDestAlphaOpaqueA Boolean value that sets destination alpha to
0xwhen true.FF flagsThe options to use when performing the compositing. If you plan to perform your own tiling or use multithreading, pass
kv.Image Do Not Tile
Return Value
kv; otherwise, one of the error codes described in Data Types and Constants.
Discussion
The permuteMap parameter changes the order of the src channels:
permutespecifies which channel inMap[0] srcXXXX8888 will be used as A.Top permutespecifies which channel inMap[1] srcXXXX8888 will be used as R.Top permutespecifies which channel inMap[2] srcXXXX8888 will be used as G.Top permutespecifies which channel inMap[3] srcXXXX8888 will be used as B.Top