I plan to use TextureAtlas in my open world 2d game.
I need to load textures dynamically (because there are thousands of them, so I cannot load all at once). I plan to load textures that are needed at specific moment in gameplay. Also for some reasons I cannot have many texture atlases per map location.
Generally, I must avoid situation that I read all textures (entire atlas), because RAM usage will be too large. How the TextureAtlas work? Is is possible to keep the atlas open during entire game, but read from the atlas (to the RAM) only chosen textures when needed without worrying about RAM usage?
Best regards.
You cannot load portions of a TextureAtlas. It is all or nothing. You will have to use multiple atlases and carefully plan what to put in each atlas such that you don’t have to load all of them simultaneously.
A Texture represents a single image loaded into GPU memory for use in OpenGL. A page of a TextureAtlas corresponds to a single Texture. Typically, you will have multiple TextureRegions on each page (Texture) of a TextureRegion. If you don’t, there’s no point in using TextureAtlas. The point of TextureAtlas is to avoid SpriteBatch having to flush vertex data and swap OpenGL textures for every sprite you draw. If you draw consecutive TextureRegions from the same Texture (or atlas page), they are batched together into a single mesh and OpenGL texture so it performs better.
Libgdx doesn’t support loading individual pages of a TextureAtlas though. That would make it too complicated to use. So, if you are doing a lot of loading and unloading, I recommend avoiding multipage atlases. Use AssetManager to very easily load and unload what you need.