Immediate mode is simply a way of designing your API so that there's no creation, destruction, callbacks, etc. It's a convenience to the programmer, because the

Immediate mode is simply a way of designing your API so that there's no creation, destruction, callbacks, etc. It's a convenience to the programmer, because they can explicitly express what they want to happen at a given moment, and the application state is known at any given time. It's a general concept that can be applied to any code you write, and it most certainly doesn't forbid you from keeping track of dirty regions between frames, that would be ridiculous.