Improve Image Caching Strategy...

[datahead8888]

I was thinking it might be good if someone analyzed the image caching we have now and tried to find ways to improve it:

• Does the game need to idle waiting for all images to be loaded at the start, or could we design a more complex strategy that loads the game menu in one thread while another thread continually works to load images into the cache ahead of time?
• If images are not all loaded before the game is loaded (ie the user is really, really fast at starting the game), then it will go ahead and show a loading screen until the necessary data is loaded
• Is it loading all images now? Could we make a more advanced cache policy that loads based on what part of the game you are in? If it's loading all images, this may take up more memory than is needed. As we continue to add more art work, this may become more of a concern.

[Bugsbane]

I was thinking about this myself. It's not particularly fun sitting and watching a loading bar, the first time you open the game, and it would be a very rare person who could get all the way through to entering the first level before it finished.

If we're going to do it smart, then it's probably worth doing in stages too. Menu screen first. Then overworld. Then level 1 etc. Would be nice if this incorporated #212

[datahead8888]

The basic idea here is to start the game ASAP while having another thread (line of execution) on the processor working at getting stuff loaded in advance. We can never guarantee a player will never have to wait for image loading but can make it improbable (or minimized). The other goal is to reduce memory usage if not all the images have to be loaded at once.

I imagine we will want to add the logic from #212 to the image caching, but @Quintus will have to confirm because I have not yet worked with the caching system.