No reason why you can't transmap it.  I don't know how you'd do it "properly", with all the correct physical characteristics of a real glass shader but you could certainly get something reasonable with a well thought out map.  As a thought, maybe have you glass shader plugged into the white parts of the map and leave the black part "empty".  I guess it'd get more tricky if you wanted the pieces of glass to be at different directions, as they often are in real broken glass.

I haven't ever tried it meself but (I think) the idea is sound enough.  

Coppula eam se non posit acceptera jocularum.

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