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Routines |
| Prev: F8B5 | Up: Map | Next: F93A |
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Used by the routine at EDF7.
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| F8B9 | LD IX,$80A9 | Point IX at the movement table. | ||
| F8BD | LD A,$08 | Moving objects decrease endurance by 8. | ||
| F8BF | LD ($F26E),A | |||
| F8C2 | LD B,$0C | 0C entries to check. | ||
| F8C4 | PUSH BC | Remember the count in BC. | ||
| F8C5 | LD BC,$F8B5 | Point BC at the bounds table. (F8B5) | ||
| F8C8 | LD A,(IX+$00) | |||
| F8CB | CP $FF | |||
| F8CD | JR NZ,$F8D6 | Jump forward if it isn't. | ||
| F8CF | CALL $EF88 | Move to the next entry and return. | ||
| F8D2 | INC IX | |||
| F8D4 | JR $F936 | |||
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The lightning bolt is active.
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| F8D6 | CALL $EF35 | Update the position. | ||
| F8D9 | LD A,(IX+$00) | Get the current graphic ID. | ||
| F8DC | CALL $A8A0 | Put it in the sprite buffer. | ||
| F8DF | INC IX | Move to the next position in the table. | ||
| F8E1 | LD A,(IY+$05) | Get the player's x co-ordinate. | ||
| F8E4 | SUB (IX-$05) | Is it close enough to the lightning? | ||
| F8E7 | SUB $08 | |||
| F8E9 | CP $F0 | |||
| F8EB | JR C,$F8FA | Jump forward if it isn't. | ||
| F8ED | LD A,(IY+$0A) | Get the player's y co-ordinate. | ||
| F8F0 | SUB (IX-$04) | Is it close enough to the lightning? | ||
| F8F3 | SUB $08 | |||
| F8F5 | CP $F0 | |||
| F8F7 | CALL NC,$E33F | If it is, the player has hit the lightning, so decrease endurance. | ||
| F8FA | LD A,($F672) | Has the missile hit a boundary in X? | ||
| F8FD | OR A | |||
| F8FE | JR Z,$F918 | Jump forward if it hasn't. | ||
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If the missile hits a boundary, the usual logic for moving objects needs changing. Instead of reversing direction, move to the other end of the screen, and keep the existing direction.
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| F900 | LD A,(IX-$05) | If the position is F0 set it to 02. Otherwise, it must be 0, so set it to EE. | ||
| F903 | CP $F0 | |||
| F905 | JR Z,$F90B | |||
| F907 | LD A,$EE | |||
| F909 | JR $F90D | |||
| F90B | LD A,$02 | |||
| F90D | LD (IX-$05),A | Set the new x co-ordinate. | ||
| F910 | LD A,(IX-$03) | Restore the sign of the direction, that was changed in the previous call to EF35. | ||
| F913 | NEG | |||
| F915 | LD (IX-$03),A | |||
| F918 | LD A,($F673) | Has the missile hit a boundary in Y? | ||
| F91B | OR A | |||
| F91C | JR Z,$F936 | Jump forward if it hasn't. | ||
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Update the boundary logic as earlier.
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| F91E | LD A,(IX-$04) | If the position is 40 set it to AE. Otherwise it must be B0 so set it to 42. | ||
| F921 | CP $40 | |||
| F923 | JR NZ,$F929 | |||
| F925 | LD A,$AE | |||
| F927 | JR $F92B | |||
| F929 | LD A,$42 | |||
| F92B | LD (IX-$04),A | Set the new y co-ordinate. | ||
| F92E | LD A,(IX-$02) | Restore the sign of the direction, that was changed in the previous call to EF35. | ||
| F931 | NEG | |||
| F933 | LD (IX-$02),A | |||
| F936 | POP BC | Restore the count in BC. | ||
| F937 | DJNZ $F8C4 | Loop while there is more lightning to draw. | ||
| F939 | RET | Otherwise return. | ||
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