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My application is similar to a very simple CAD program. The user can create and modify a database of several thousand, simple 3D objects (e.g. cubes and spheres). Each object has a position, orientation, and size. I anticipate having these objects serialized in the database.

I want to render objects in the database in 3D views. The 3D views could be the entire database or a particular query (e.g. objects of a certain size). The views should always reflect the current state of the database as objects are added/removed.

So my question is: how can I have the render loop efficiently access the database? These are the options I can think of:

  1. Give render loop direct access to database. Deserialize objects and render at each loop. This seems inefficient, but maybe not as bad as I fear.
  2. Give render loop direct access to database, but try to store data in such a way that it does not need to be serialized.
  3. Create another data structure that always mirrors the database, but is more easily rendered.
murrdpirate
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In general, it doesn't seem wise to bind one of the potentially slowest parts of an app (disk-based DB access) to one that's performance sensitive (3D rendering).

I would consider either a Repository-style abstraction where you keep both an in-memory representation of the data and the DB store, flushing to the latter when the user is done editing; or, if the size of the data is manageable, an in-memory store such as Redis or memcached.

All that said, I would only consider the above if you're actually running into performance or data consistency problems with a simpler setup.

Dan1701
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  • This is a great answer. By using a repository pattern the interfaces can stay the same, but the repository can choose to use any type of caching solution without needing to change code in the renderer. – The Muffin Man Dec 29 '16 at 00:36
  • I'm sorry, I forgot to mention I was planning to use an in-memory database, via SQLite. My concern was that since SQLite can't store general objects (just byte arrays), I'd have to deserialize them every loop. Do you think that's a concern I should try to avoid? – murrdpirate Dec 30 '16 at 01:53