reverse status bars (again)

[Monolit]

I know this topic came out a couple of times already in the past, but uhm, I've ran search few times and have yet to find a solution to my problem regarding reverse status bars.

So I want my health status bar to fill in reverse, i.e. the bigger amount of health missing - the bigger health status bar is (starting from right to left).

If I understand correctly neither default wow API or oUF allows us to do that with some simple method, so I need to make a PostUpdateHealth hook and change this by my own, but I struggle with that one ...

Setting the new value is easy, but I can't reanchor the texture itself
my PostUpdateHealth function looks like this:

lib.PostUpdateHealth = function(s, unit, min, max)
    if unit=='player' or unit=='target' then
        s:SetValue(max-min)
        s.t = s:GetStatusBarTexture()
        s.t:SetPoint('TOPRIGHT', s, 'TOPLEFT', 0, 0)
    end 
end

and hp bar function:

lib.gen_hpbar = function(f)
    local s = CreateFrame("StatusBar", nil, f)
    s:SetStatusBarTexture(cfg.statusbar_texture)
    fixStatusbar(s)
    s:SetHeight(f.height)
    s:SetWidth(f.width)
    s:SetPoint("TOPLEFT",0,0)
    s:SetAlpha(0.65)
    s:SetOrientation("HORIZONTAL") 
    local h = CreateFrame("Frame", nil, s)
    h:SetFrameLevel(0)
    h:SetPoint("TOPLEFT",-4,4)
    h:SetPoint("BOTTOMRIGHT",4,-4)
    lib.gen_backdrop(h)
    local b = s:CreateTexture(nil, "BACKGROUND")
    b:SetTexture(cfg.statusbar_texture)
    b:SetAllPoints(s)
    s.PostUpdate = lib.PostUpdateHealth 
    f.Health = s
    f.Health.bg = b
  end

So basically I get bar with the right value, but it's placed at default position, i.e. anchored to right and filling up towards left. Any help or some kind of clues would be appreciated!