Design issue: camera

I let my GUI system control the view port, and make the camera and object that can, if the programmer desires, be manipulated by the physics engine. I have a seperate lens class with a bunch of standard stock lenses to hand my field of view issues.

It's simple -- the two cameras are not the same thing. You maintain a camera object in the simulation component, and use it's position and orientation (and perhaps other properties) to configure the visualization component's camera.

Good point and something I should have thought of :) Thanks.

When developing my cameras for my game Rock Paper Scissors, I implemented a camera base which contained the basic functions like forward, right, up vectors, orientation, position and the projection properties etc. I then derived a camera that worked with yaw, pitch and roll angles which provides the implementation (updating all the matrices is based on a dirty flag system, which I feel quite proud of).
Separately, I have camera controllers which reference the camera - and this provides great flexibility. They can be easily switched as well, like for the developer camera where you can move around, the normal camera and the chasing camera effects during the game.

With this, the camera properties and the controllers would be part of your state and the camera state (CameraBase in my example) would be used by the Visualisation component to render from that point.

Hope that helps,

theres one camera per instance of your black box. this is your main camera
that the gamer sees and renders the world. if you have extra cameras on top of
this notably used for dukenukem cameras then youll need a camera per rendertarget, its basicly camera per rendertarget. all these cams simply have
up,right,forwards and position, thats it.
then your game world can have cameras that swap between each other depending on
which one is active at the time, these cameras could index one of the duke nukem cams or the main blackbox cam. these cameras can have all the fancy stuff
in em, like movement etc.
in 2 sections, just like you wanted.
its all straight c object systems.