Which layer is the target layer?

How can I determine which layer among those in the ->layersDescriptor structures corresponds to the target layer?

In photoshop cc x64 pc

-- all the read channel numbers seem to be unique

-- all channels have ->target=1

(edit after more work with layersDescriptor)

the information presented has a lot of errors and omissions, such that it's impossible

in principal to display layers the same way as photoshop does.  Invisible "pass through"

layers are listed as visible.  Layers with "stroke" special effects are indistinguishable

from normal layers.