local ass_mt = {}ass_mt.__index = ass_mtlocal c = 0.551915024494 -- circle approximation local function ass_new()    return setmetatable({ scale = 4, text = "" }, ass_mt)end function ass_mt.new_event(ass)    -- osd_libass.c adds an event per line    if #ass.text > 0 then        ass.text = ass.text .. "\n"    endend function ass_mt.draw_start(ass)    ass.text = string.format("%s{\\p%d}", ass.text, ass.scale)end function ass_mt.draw_stop(ass)    ass.text = ass.text .. "{\\p0}"end function ass_mt.coord(ass, x, y)    local scale = 2 ^ (ass.scale - 1)    local ix = math.ceil(x * scale)    local iy = math.ceil(y * scale)    ass.text = string.format("%s %d %d", ass.text, ix, iy)end function ass_mt.append(ass, s)    ass.text = ass.text .. send function ass_mt.merge(ass1, ass2)    ass1.text = ass1.text .. ass2.textend function ass_mt.pos(ass, x, y)    ass:append(string.format("{\\pos(%f,%f)}", x, y))end function ass_mt.an(ass, an)    ass:append(string.format("{\\an%d}", an))end function ass_mt.move_to(ass, x, y)    ass:append(" m")    ass:coord(x, y)end function ass_mt.line_to(ass, x, y)    ass:append(" l")    ass:coord(x, y)end function ass_mt.bezier_curve(ass, x1, y1, x2, y2, x3, y3)    ass:append(" b")    ass:coord(x1, y1)    ass:coord(x2, y2)    ass:coord(x3, y3)end  function ass_mt.rect_ccw(ass, x0, y0, x1, y1)    ass:move_to(x0, y0)    ass:line_to(x0, y1)    ass:line_to(x1, y1)    ass:line_to(x1, y0)end function ass_mt.rect_cw(ass, x0, y0, x1, y1)    ass:move_to(x0, y0)    ass:line_to(x1, y0)    ass:line_to(x1, y1)    ass:line_to(x0, y1)end function ass_mt.hexagon_cw(ass, x0, y0, x1, y1, r1, r2)    if r2 == nil then        r2 = r1    end    ass:move_to(x0 + r1, y0)    if x0 ~= x1 then        ass:line_to(x1 - r2, y0)    end    ass:line_to(x1, y0 + r2)    if x0 ~= x1 then        ass:line_to(x1 - r2, y1)    end    ass:line_to(x0 + r1, y1)    ass:line_to(x0, y0 + r1)end function ass_mt.hexagon_ccw(ass, x0, y0, x1, y1, r1, r2)    if r2 == nil then        r2 = r1    end    ass:move_to(x0 + r1, y0)    ass:line_to(x0, y0 + r1)    ass:line_to(x0 + r1, y1)    if x0 ~= x1 then        ass:line_to(x1 - r2, y1)    end    ass:line_to(x1, y0 + r2)    if x0 ~= x1 then        ass:line_to(x1 - r2, y0)    endend function ass_mt.round_rect_cw(ass, x0, y0, x1, y1, r1, r2)    if r2 == nil then        r2 = r1    end    local c1 = c * r1 -- circle approximation    local c2 = c * r2 -- circle approximation    ass:move_to(x0 + r1, y0)    ass:line_to(x1 - r2, y0) -- top line    if r2 > 0 then        ass:bezier_curve(x1 - r2 + c2, y0, x1, y0 + r2 - c2, x1, y0 + r2) -- top right corner    end    ass:line_to(x1, y1 - r2) -- right line    if r2 > 0 then        ass:bezier_curve(x1, y1 - r2 + c2, x1 - r2 + c2, y1, x1 - r2, y1) -- bottom right corner    end    ass:line_to(x0 + r1, y1) -- bottom line    if r1 > 0 then        ass:bezier_curve(x0 + r1 - c1, y1, x0, y1 - r1 + c1, x0, y1 - r1) -- bottom left corner    end    ass:line_to(x0, y0 + r1) -- left line    if r1 > 0 then        ass:bezier_curve(x0, y0 + r1 - c1, x0 + r1 - c1, y0, x0 + r1, y0) -- top left corner    endend function ass_mt.round_rect_ccw(ass, x0, y0, x1, y1, r1, r2)    if r2 == nil then        r2 = r1    end    local c1 = c * r1 -- circle approximation    local c2 = c * r2 -- circle approximation    ass:move_to(x0 + r1, y0)    if r1 > 0 then        ass:bezier_curve(x0 + r1 - c1, y0, x0, y0 + r1 - c1, x0, y0 + r1) -- top left corner    end    ass:line_to(x0, y1 - r1) -- left line    if r1 > 0 then        ass:bezier_curve(x0, y1 - r1 + c1, x0 + r1 - c1, y1, x0 + r1, y1) -- bottom left corner    end    ass:line_to(x1 - r2, y1) -- bottom line    if r2 > 0 then        ass:bezier_curve(x1 - r2 + c2, y1, x1, y1 - r2 + c2, x1, y1 - r2) -- bottom right corner    end    ass:line_to(x1, y0 + r2) -- right line    if r2 > 0 then        ass:bezier_curve(x1, y0 + r2 - c2, x1 - r2 + c2, y0, x1 - r2, y0) -- top right corner    endend return {ass_new = ass_new}