buffer??

Ok here is my question, when you play a game, there is a drop of a bitmap in front of a camera untill the entire stage or map is loaded, then the drop is removed so you can play the stage. (this is so you dont see the state loading) How do you make it so that the 2D image waites untill the 3D state is loaded?? then remove it??

main_loop()
{
if (waiting_until_everything_has_loaded)
{
draw textured polygon
load stuff
}
else
{
do_game_loop()
}

}

btw instead of bitmap u meant texture