I tried to search different solutions but also due to the lack of knowledge in camera handling I found none fitting my needs.
The situation is the following.
I have a 2d game structured in rectangular rooms and I want the camera to always have the whole room visible in the screen despite the screen resolution and the room bounds.
Edit: Sorry for really bad painting, this is what I'd like to achieve somehow.
The camera viewport is where, inside the screen, the game will flow. everything else will be static, like a GUI frame with general informations and commands.