Tile
In one sentence
A tile is an 8 by 8 block of pixels, and it is the brick backgrounds are built from. Each tile takes 16 bytes, because every pixel is two bits.
The detail
The background map does not store pixels. It stores tile numbers. Change the tile and every place that uses that number changes with it. That is why a repeated brick is cheap and a unique mural is expensive: the mural spends one tile per block and the brick spends one tile for the whole wall.
Sixteen bytes is two bits times 64 pixels. There is no compressed form the picture hardware understands. A Retroable background that looks like a photograph has been chopped into these blocks and reduced to four shades first.
Sprites use the same tile shapes. An 8 by 16 sprite is two tiles stacked. The map and the sprites are pointing at pictures in video RAM, not carrying the pixels themselves.
Worth keeping
- A tile is 8 × 8 pixels and 16 bytes
- The background map stores tile numbers, so one brick can fill a wall
- A unique picture spends a new tile for every block
Questions
Why do backgrounds repeat?
Because reusing a tile number is how the hardware fills the screen without storing every pixel.
Can a tile be 16 by 16?
Not as one tile. A 16 by 16 picture is four tiles.
Where do the pixels of a tile live?
In video RAM. The map only holds the number.
Related
Game Boy is a trademark of Nintendo. Retroable is independent and is not affiliated with Nintendo.