|
Routines |
| Prev: 9D0E | Up: Map | Next: 9D2F |
|
Used by the routine at UpdateBeams.
Clears the pixels of a beam, which is a row of bytes that all share the same pattern.
|
||||||||||||
| EraseBeam | 9D25 | LD A,C | Invert the pattern. | |||||||||
| 9D26 | CPL | |||||||||||
| 9D27 | LD C,A | |||||||||||
| EraseBeam_Loop | 9D28 | LD A,C | Fetch the inverted pattern. | |||||||||
| 9D29 | AND (HL) | Clear the pixels. | ||||||||||
| 9D2A | LD (HL),A | |||||||||||
| 9D2B | INC L | Move on to the next byte of the row. | ||||||||||
| 9D2C | DJNZ EraseBeam_Loop | Loop back to EraseBeam_Loop for each byte. | ||||||||||
| 9D2E | RET | Return. | ||||||||||
| Prev: 9D0E | Up: Map | Next: 9D2F |