Missing detail about sprite fetch step 2 #4
Description
Hi, I've been relying heavily on this doc for implementing the PPU in my emulator. Thanks!
In https://hacktix.github.io/GBEDG/ppu/#sprite-fetching it says
Fetch Tile Data (Low): Same as the corresponding Background Fetcher step, however, Sprites always use 8000-addressing-mode, so this step is not affected by any LCDC bits.
The corresponding background fetcher step says
Using the Tile Number from the previous step the fetcher now fetches the first byte of tile data (with an offset of
2 * ((LY + SCY) mod 8))and stores it
For the sprite fetch I had to do 2 * ((LY + SCY - Sprite.Y) mod 8)) to get this to work correctly. Otherwise sprites get rendered incorrectly when Sprite.Y % 8 != 0. Is this correct? I didn't see any other part where Sprite.Y was taken into account (except the comparison in the OAM scan stage)