How are the sprite sheets for bullet sprites laid out?

[The Martian]

Could someone please explain the layout of the bullet sprite images?


How does this animate and how big is each frame?

What part is the bullet and what part is the trail that follows it?

[Nord]

Each bullet is a chain of a squares of 3x3 pixels, from left to right. For example, when you shoot stright right side, bullet sprite will be turned like that in pixels: ...9,10,11,6,7,8,3,4,5,0,1,2.

[The Martian]

It was chains like this that were throwing me off as there are dots before the larger blocks and I thought it was an animation loop of some kind:


But after watching it closely ingame I see what you are describing:


Thank you for the help.