- Opcode: 0x2D
- Short name: BGSCR
- Long name: Background Scroll
Memory layout
| 0x2D | B1 / B2 | L | X | Y | |——|———–|—–|—–|—–|
Arguments
- const Bit[4] B1: Bank to retrieve value for X, or zero if X is specified as a literal.
- const Bit[4] B2: Bank to retrieve value for Y, or zero if Y is specified as a literal.
- const UByte L: ID number of the layer to manipulate.
- const Short X: Speed of the scroll in the X direction; positive values indicate right-to-left scrolling.
- const Short Y: Speed of the scroll in the Y direction; positive values indicate bottom-to-top scrolling.
Description
Scrolls the background layer specified by L. This opcode will only scroll those extra layers above the standard background and foreground layers (0/1, respectively), and so should be an argument of 2 or greater. The X and Y speeds are signed; positive values scroll from right-to-left and bottom-to-top, whilst negative values scroll from left-to-right and top-to-bottom.