Finding a normal (perpendicular) vector on a 2d plane

There are plenty of times when we need a normal vector in game dev and graphics programming (or if we are simply just learning vector math). It is relatively simple for you to find a normal (perpendicular) vector on a 2D plane. Swap the vector components and negate one, i.e. if the vector components are (u, v) swap it (-v, u) or (v, -u). Negating the first component will make the normal vector counter clock wise to the initial vector. Negating the 2nd term will make the normal clockwise to the initial vector.

Normal Vector Illustration

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