local tex =  Texture(32, 32, ETF_A8R8G8B8)

ffi.cdef("typedef struct { uint8_t r, g, b, a; } rgba_pixel;")
local size = 32*32
local img = ffi.new("rgba_pixel[?]", size)
for i = 0, size-1 do
    img[i].r = math.random(255)
    img[i].g = math.random(255)
    img[i].b = math.random(255)
    img[i].a = math.random(255)
end

tex:SetData(img)-- ????

local rect = Rect(0, 0, 32*8, 32*8)

hook.Add("PostDrawMenu", "draw_texture_noise", function()
    graphics.Set2DFlags()
    rect.x, rect.y = mouse.GetPos()
    graphics.DrawTexture(tex, rect, nil, nil, true)
end)