Stateful line limiter

 -- drafter.lua -- stateful approach

local drafter = {}

drafter.maxLength = 0

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

return drafter