This time I'm trying to catch the minimum distance of the point toward any side of the rectangle.
local abs, min, max = math.abs, math.min, math.max
local function clamp(x, lower, upper)
return max(lower, min(upper, x))
end
local function getNearestPointInPerimeter(l,t,w,h, x,y)
local r, b = l+w, t+h
x, y = clamp(x, l, r), clamp(y, t, b)
local dl, dr, dt, db = abs(x-l), abs(x-r), abs(y-t), abs(y-b)
local m = min(dl, dr, dt, db)
if m == dt then return x, t end
if m == db then return x, b end
if m == dl then return l, y end
return r, y
end