SFML vertex arrays and sprite sheets
We are nearly ready to implement the scrolling background. We just need to learn about SFML vertex arrays and sprite sheets.
What is a sprite sheet?
A sprite sheet is a set of images, either frames of animation, or totally individual graphics contained in one image file. Take a closer look at this sprite sheet, which contains four separate images that will be used to draw the background in our Zombie Arena game:
SFML allows us to load a sprite sheet as a regular texture, in the same way we have done for every texture in this book so far. When we load multiple images as a single texture, the GPU can handle it much more efficiently.
Tip
Actually, a modern PC could handle these four textures without using a sprite sheet. It is worth learning these techniques, however, as our games are going to start getting progressively more demanding on our hardware.
What we need to do when we draw an image from the sprite...