rectifier output smoothing, Vout with V0/I0/P0=konst.

Hi,

I have given a simple full-wave bridge rectifier with parallel smoothing 
capacitor at the output and parallel load.
I know the typical waveform of the voltage over the capacitor, i.e. 
following the voltage peaks of the rectified sine and then decreasing 
very little until it meets the next rectified sine peak.
My question is how a forced constant V,I,P over the load, respectively, 
impacts this waveform. I found these three waveforms shown in the 
attachment, but I am not sure how to match with constant V/I/P.

I would be very thankful for any help.
Greetings, Artur