scroll.h

Structures

struct DisplayScrollWork

The wavy background's work: two pages of BG1 to BG3 scroll offsets for each of the 160 scanlines, and the sine wave that bends them on each axis.

Field	Declared as
`rows`	`struct BgScroll rows[2][160][3]`	per page and scanline: BG3, BG2, BG1
`page`	`u8 page`	the page the HBlank DMA shows; the other is built
`mode`	`u8 mode`	set at the start; not read by name
`frame`	`u16 frame`	frames built so far, added to BG3's y for the wave's phase
`unkf04`	`u8 unkf04[4]`	not named by TBS code
`freqX`	`s32 freqX`	phase per frame and per BG3 row, 16.16 wave table entries
`freqY`	`s32 freqY`	phase per frame and per BG3 row, 16.16 wave table entries
`stepX`	`s32 stepX`	16.16 wave table entries a scanline, 256 a cycle
`stepY`	`s32 stepY`	16.16 wave table entries a scanline, 256 a cycle
`ampX`	`s32 ampX`	16.16 scale on the sine entry, which is then divided by 256
`ampY`	`s32 ampY`	16.16 scale on the sine entry, which is then divided by 256