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Routines |
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Used by the routine at NextStep.
Used when the ship is on the same row as a step of a segment. It sets bit 7 of the contact flags at ContactFlags. If the vertical speed is not negative it also sets bit 0 (clearing bit 7) and copies the flags into LastContactFlags. It carries on at NextStep_Column.
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| FlagFloorContact | 52857 | LD A,(23601) | The contact flags. | |
| 52860 | OR %10000000 | Set the bits of A that are set in 128. | ||
| 52862 | LD (23601),A | Update the contact flags. | ||
| 52865 | LD A,(52410) | The vertical scroll speed. | ||
| 52868 | BIT 7,A | Jump to NextStep_Column if bit 7 of A is set. | ||
| 52870 | JP NZ,NextStep_Column | |||
| 52873 | LD A,(23601) | The contact flags. | ||
| 52876 | XOR %10000001 | Flip the bits of A that are set in 129. | ||
| 52878 | LD (23601),A | Update the contact flags. | ||
| 52881 | LD (23602),A | Update the last contact flags. | ||
| 52884 | JP NextStep_Column | Jump to NextStep_Column. | ||
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