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Routines |
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Handles a portcullis that is not moving. Nothing happens while another portcullis in the room is moving. A portcullis that is on the floor of the room, or no more than 1F above it, starts to rise on one frame in thirty-two. One that is higher than that starts to come down: at once for the first four times that a portcullis comes down, and after that on one frame in thirty-two.
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Start the portcullis rising or lowering when it is time.
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| HandlePortcullis | C65E | CALL SetPixelAdjustments_Legs | Set the pixel adjustments of the bottom half of a guard. | |||||
| C661 | LD HL,$5BAF | Point HL at PortcullisMovingFlag. | ||||||
| C664 | LD A,(HL) | Fetch it. | ||||||
| C665 | AND A | Test it. | ||||||
| C666 | RET NZ | Return if a portcullis is moving. | ||||||
| C667 | LD A,($5BAE) | Fetch the Z coordinate of the floor of the room from FloorHeight. | ||||||
| C66A | CP (IX+$03) | Compare it with the Z coordinate of the portcullis. | ||||||
| C66D | JR Z,StartPortcullisRising | Jump to StartPortcullisRising if the portcullis is on the floor. | ||||||
| C66F | ADD A,$1F | Add 1F to the height. | ||||||
| C671 | CP (IX+$03) | Compare it with the Z coordinate of the portcullis. | ||||||
| C674 | JR NC,StartPortcullisRising | Jump to StartPortcullisRising if the portcullis is no more than 1F above the floor of the room. | ||||||
| C676 | LD A,($5BB0) | Fetch the number of times that a portcullis has come down from PortcullisLowerCount. | ||||||
| C679 | CP $04 | Jump to HandlePortcullis_Lower if it is fewer, to set off at once. | ||||||
| C67B | JR C,HandlePortcullis_Lower | |||||||
| C67D | LD A,($5BA5) | Fetch the second random seed from RandomSeed2. | ||||||
| C680 | AND %00011111 | Keep the lowest five bits. | ||||||
| C682 | RET NZ | Return unless it is the time to set off. | ||||||
| C683 | OR %10000000 | Set A to a large number, so that it stays above four. | ||||||
| HandlePortcullis_Lower | C685 | INC A | Add one to the number of times that a portcullis has come down. | |||||
| C686 | LD ($5BB0),A | Store it at PortcullisLowerCount. | ||||||
| C689 | SET 0,(IX+$00) | Change the graphic of the portcullis to the moving one. | ||||||
| C68D | LD (IX+$0B),$FF | Set the speed in Z to move it down. | ||||||
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This entry point is used by the routine at StartPortcullisRising.
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| HandlePortcullis_Flag | C691 | INC (HL) | Flag that a portcullis is moving. | |||||
| Prev: C64E | Up: Map | Next: C692 |