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Routines |
Prev: 28101 | Up: Map |
The address of this uninterruptible subcommand routine is placed into bytes 111 and 112 of a catapult pellet's buffer by the routine at 27932. It controls the pellet from the beginning of its vertical flight to the end, including any collision with a shield.
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28102 | CALL 25108 | Update the SRB for the pellet's current location | |||||||
28105 | LD B,A | B=pellet's animatory state | |||||||
28106 | LD A,D | A=pellet's y-coordinate | |||||||
28107 | CP 152 | Has the pellet hit the ceiling of the top floor? | |||||||
28109 | JP Z,27940 | Terminate the pellet if so | |||||||
28112 | DEC D | Up a level | |||||||
28113 | LD L,113 | Byte 113 of the pellet's buffer holds the distance left to travel | |||||||
28115 | DEC (HL) | Has the pellet finished travelling? | |||||||
28116 | JP Z,27940 | Jump if so | |||||||
28119 | LD A,B | A=pellet's animatory state | |||||||
28120 | CALL 25008 | Update the pellet's location and update the SRB | |||||||
This entry point is used by the routine at 27932 to check whether a pellet fired from a staircase has hit a shield.
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28123 | LD L,97 | Byte 97 holds the pellet's y-coordinate | |||||||
28125 | LD D,(HL) | Pick this up in D | |||||||
28126 | INC D | D=y-coordinate of the pellet's potential target | |||||||
28127 | INC L | Byte 98 holds the pellet's x-coordinate | |||||||
28128 | LD E,(HL) | Pick this up in E | |||||||
28129 | INC E | E=x-coordinate of the pellet's potential target | |||||||
This entry point is used by the routine at 63270 with DE holding the coordinates of ERIC's hand (and H=172).
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28130 | SET 7,E | E=128 + x-coordinate of the potential target | |||||||
28132 | PUSH HL | ||||||||
28133 | CALL 28143 | Has the pellet (or ERIC's hand) hit a shield? | |||||||
28136 | POP HL | ||||||||
28137 | RET NC | Return if not | |||||||
28138 | LD L,113 | If it was a pellet that hit the shield, this sets its remaining distance to travel to 1, so it will be terminated the next time this routine is called | |||||||
28140 | LD (HL),1 | ||||||||
28142 | RET |
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