A option to Mongos point. If you wish to eliminate the slope being visual consider a contrasting floor and use it as a first row. Set to the height of the curb. The eye will now be drawn to the level horizontal change of tile and the slope barely noticeable. Just a tile guys point of view.
photo #! floor sloping left to right.
Photo #2 sloping right to left
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Large tile used to surround the tub.
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