Set Locals

-- From app.lua
function _M.setLocals()
    local locals = {_W = _W, _H = _H, _L = _L, _R = _R, _T = _T, _B = _B, _CX = _CX, _CY = _CY, _SW = _SW, _SH = _SH}
    local i = 1
    repeat
        local k, v = debug.getlocal(2, i)
        if k then
            if v == nil then
                if not locals[k] then
                    print('No value for a local variable: ' .. k)
                else
                    debug.setlocal(2, i, locals[k])
                end
            end
            i = i + 1
        end
    until nil == k
end


-- Use in your scene.lua
local app = require('app')
local _W, _H, _CX, _CY
app.setLocals() -- fills values for _W, _H, _CX and _CY