Keep all zoom levels of current page in memory

[Ecnassianer]

I use scale tags to create different content (with different jpegs) for different zoom levels. When I zoom it seems very much like the content from the zoom level is being loaded from somewhere. Because this doesn't go away when you zoom in and out repeatedly, the only place I can assume this is loading from is off the disk. This tells me that different zoom levels aren't being kept in memory. That makes me sad. Can all the zoom levels of the current page be kept in memory all the time? Maybe even the zoom levels of the next and previous pages too.

This made a lot of sense to me in pictures, so I drew some.

These are my pages arranged by zoom level and order in my book:


The way it works now, these are the pages that are kept in memory:


These are the images I really care about being kept in memory:

[Florian Nücke]

Great visualization

Hm. Well, I understand your point. But on the other hand, one of the original points of the scale levels was that you don't have to have the large stuff in memory unless you really need it (reducing bandwidth / increasing load speed). Plus that will be quite a mess to implement, I think (at least I've had no 'nice' idea, yet).

What I was planning on doing anyway, though, was to make the 'switching' nicer to look at (using a similar approach as with the page previews), so that the reloaded element doesn't 'blank out' while being reloaded. And if an element has been loaded once, it'll be available again rather quickly, as Flash has it's own disk cache. Do you think you could live with that?

[Ecnassianer]

Using the currently loaded content scaled to fit the new zoom level while the correct content for the zoom level is loading sounds like a great solution. It's not so much the load times that bother me as the content going away and coming back. Just having a delay on the quality of the content sounds much better (and seems fair for the people who want to keep their memory usage down by unloading scaled content).