If I've understand you right, you want to have SFML a coordination system with a vertical y axis facing up and a horizontal x axis facing right, right?
I think we've had this 'request' a few times and SFML won't nativly support this, that's mostly because it's very easy to do the correction yourself, just negate the y axis and you're good to go.
(With a high enough abstraction level the physic part shouldn't even know anything about the graphics part, then you could easily swap the sign when updating the coordinates.
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