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Routines |
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Used by the routine at StartCrystalObject.
Looks for a free slot among the nine enemy slots. If there is not one, it looks for an object with bit 7 of its flags set among the first eight.
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| FindFreeEnemySlot | 97BD | LD B,$09 | Set a counter for nine slots. | |||||
| 97BF | LD IX,$9974 | Use the first enemy slot. | ||||||
| 97C3 | LD DE,$0018 | Set the length of a slot. | ||||||
| FindFreeEnemySlot_Loop | 97C6 | LD A,(IX+$00) | Fetch the type of the object in the slot. | |||||
| 97C9 | INC A | Increment it. | ||||||
| 97CA | RET Z | Return if the slot is free. | ||||||
| 97CB | ADD IX,DE | Move on to the next slot. | ||||||
| 97CD | DJNZ FindFreeEnemySlot_Loop | Decrease the counter by one and loop back to FindFreeEnemySlot_Loop until none remain. | ||||||
| 97CF | LD IX,$9974 | Use the first enemy slot. | ||||||
| 97D3 | LD B,$08 | Set a counter for eight slots. | ||||||
| FindFreeEnemySlot_Flags | 97D5 | BIT 7,(IX+$10) | Test bit 7 of the flags of the object. | |||||
| 97D9 | RET Z | Return if it is clear. | ||||||
| 97DA | ADD IX,DE | Move on to the next slot. | ||||||
| 97DC | DJNZ FindFreeEnemySlot_Flags | Decrease the counter by one and loop back to FindFreeEnemySlot_Flags until none remain. | ||||||
| 97DE | RET | Return. | ||||||
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