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Routines |
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Used by the routine at MainLoop.
Shows the position of the program packet on the map of the sectors. The marker is drawn with XOR, so the old marker is removed by drawing it again. Nothing is done if the packet has not moved.
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| UpdatePacketMarker | 44589 | LD A,(38476) | Fetch the X cell where the marker was drawn last... | |
| 44592 | LD D,A | ...and keep it in D. | ||
| 44593 | LD A,(38477) | Fetch the Y cell... | ||
| 44596 | LD H,A | ...and keep it in H. | ||
| 44597 | LD A,(38478) | Fetch the flag that says whether there was a marker. | ||
| 44600 | AND A | Jump if there was not. | ||
| 44601 | JR Z,UpdatePacketMarker_Draw | |||
| 44603 | LD A,(38768) | Fetch the type of the packet. | ||
| 44606 | AND A | Jump to remove the old marker if there is no packet now. | ||
| 44607 | JR Z,UpdatePacketMarker_Remove | |||
| 44609 | LD A,(38770) | Fetch the X cell of the packet. | ||
| 44612 | CP D | Jump to remove the old marker if the packet has moved in the X direction. | ||
| 44613 | JR NZ,UpdatePacketMarker_Remove | |||
| 44615 | LD A,(38772) | Fetch the Y cell of the packet. | ||
| 44618 | CP H | Return if the packet has not moved. | ||
| 44619 | RET Z | |||
| UpdatePacketMarker_Remove | 44620 | CALL ToggleMarker | Remove the old marker using ToggleMarker. | |
| UpdatePacketMarker_Draw | 44623 | LD A,(38770) | Fetch the X cell of the packet... | |
| 44626 | LD (38476),A | ...and store it... | ||
| 44629 | LD D,A | ...and keep it in D. | ||
| 44630 | LD A,(38772) | Fetch the Y cell of the packet... | ||
| 44633 | LD (38477),A | ...and store it... | ||
| 44636 | LD H,A | ...and keep it in H. | ||
| 44637 | LD A,(38768) | Fetch the type of the packet. | ||
| 44640 | AND A | Store the flag that says whether there is a marker... | ||
| 44641 | LD (38478),A | |||
| 44644 | RET Z | ...and return if there is not. | ||
| 44645 | JR ToggleMarker | Jump to ToggleMarker. | ||
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