I asked a question yesterday about a problem I was having displaying a level in a C++ 2D GameBoy Advance game when the level is larger than the screen size. However, I may have been slightly too specific, and so I want to ask this more generally.
What is the simplest way to go about trying to display a scrolling level which is large (512x512 pixels) on a screen which is much smaller (240x160 pixels)?
A brief description of my code structure so far: I have a base class called Object which defines (x, y) position and a width and height, there is an Entity class which inherits from Object and adds velocity components, and a Character class which inherits from Entity and adds movement functions. My player is a Character object, and boxes I want the player to pick up are an array of Entity objects. Both the player and cubes array are members of the Level class, which also inherits from Object.
So far I have implemented a game which works very well when the level is the same size as the screen - all the objects' positions are stored relative to their position in the level. However, I am having serious trouble trying to work out how to display the objects in the correct place when the level is offset on the screen. I want the viewport to never extend out of the level, and if the viewport is not against the edge of the level, display the player in the middle of the screen.
Should I try to work it out using a couple of simple offset variables to move the background? If so, in what order should the offsets be calculated and applied? How would the offsets differently apply to the player and boxes? Or instead, should I try creating another Object as a member of the Level class for the viewport? How would I go about calculating the offsets using that?
Any advice provided wilil be greatly appreciated.
