Stateless line limiter

 -- drafter.lua -- stateless approach

local drafter = {}

function drafter.line(startX, startY, endX, endY, maxLength)
    local deltaX, deltaY = endX - startX, endY - startY
    local requestedLength = math.sqrt(deltaX * deltaX + deltaY * deltaY)
    if requestedLength > maxLength then
        local ratio = maxLength / requestedLength
        endX, endY = startX + deltaX * ratio, startY + deltaY * ratio
    end
    display.newLine(startX, startY, endX, endY)
end

return drafter