SPRITE_SHEET

In video games, a sprite sheet is a single image that contains multiple smaller images, called sprites.  To allow the game to draw these sprites to the screen more efficiently, the separate sprites are usually grouped together into a larger image. A game can have a single sprite sheet with every sprite on it, or sometimes it is smarter to break them up by scenes, characters, menus, overlays, etc.

Here is an example of a large outdoor sprite sheet that could be used to build a town, grassy fields, steep cliffs, rivers, waterfalls, and even a castle dungeon, all combined into a single image.

You can see how variety is created by drawing several different rocks, boxes, grass edges, bushes, benches, and more to make the scenery more interesting. Pieces of the sprite sheet can be mixed and matched like the 2 houses for example can create a whole town of houses, each with a different number of windows, chimneys, and doors. Some sprites on this sprite sheet are made to be animations such as the water tiles with the droplets or the waterfall splashes, and the 3 fountain sprites are actually just 1 fountain but with animated water.

This is an example of a large sprite sheet for a single character, with many variations of poses that will create the animations in the game. You can see walking, carrying, attacking with a sword, and climbing, with each action animated across 3 to 4 poses, and each row is a different direction with the character facing down, right, up, and left.

Studying the 2D sprite sheet of games you like is a great way to learn sprite drawing tips, sprite sheet efficiency, as well as sprite animation.

By putting all of these sprites together on a single sheet, the game can pull out specific parts of the sprite sheet to draw everything on the game screen. This method helps the game run more smoothly and saves memory by keeping all related images in one place.

PICO-8 Sprite Sheet

In PICO-8, a sprite sheet works in a similar way but with some specific limitations. PICO-8 has a fixed 128x128 pixel area where you can store all of your sprites, and each sprite is usually an 8x8 pixel area called a tile. You can fit up to 256 sprites on the sheet.

Like in other games, these sprites can be used for characters, items, backgrounds, or any visual element in the game. PICO-8 has built-in tools to help you edit and organize these sprites in its sprite editor, allowing you to easily design and manage the visuals for your game within this limited space.

The sprite sheet is split into 4 different tabs seen in the bottom right of the sprite editor and labeled as numbers 0, 1, 2, and 3. You should know that the data stored in tabs 2 and 3 (the bottom half of the sprite sheet) is shared with the bottom half of the map in the map editor.

This is an example of the exported sprite sheet of the demo game Jelpi by Zep. You can see that the game's sprites are only using the top half of the sprite sheet, while the bottom half looks strange. That's because the game uses the full map and we are able to see the data of the bottom half of the map expressed as colored pixels here in the bottom half of the sprite sheet.

So without using memory manipulation techniques, the default limitation forces you to choose to use the full sprite sheet but with less map space, or use the full map but with less sprites.

It is important to understand not only how to use the sprite sheet for drawing sprites, but also how to use it efficiently, how to balance variety of characters and scenery with animation frames, and how to make it easier to code your animations. You might be surprised how much life you can bring to your game with just 2 frames of animations instead of the 50 frames of one character in the example above.

(From the game Puzzles of the Paladin.)

Images in this Guide by NerdyTeachers is licensed under CC BY-SA 4.0