My shower curtain wraps inward on the shower a few inches and we try to make sure it is smoothed along the wall.
The problem I had with my corner shower was that water would run down the walls and hit the gap where the walls and tub came together. If the camper wasn't perfectly level it would then travel down the gap, behind the curtain, and down onto the floor. This had me stumped for little while, but I finally figured it out.
To solve, I took some tub and tile caulk and made a little dam at the corners that would direct the water back into the tub.
Since I did this I have never had another puddle on the floor unless the curtain wasn't completely closed and the shower accidentally sprayed out.