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Routines |
Prev: 30291 | Up: Map | Next: 30380 |
Used by the routines at 30380, 30804 and 31254. Returns with the carry flag set if there is a wall, closed door or closed window blocking the path of the mouse, frog or pellet
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30292 | PUSH HL | |||
30293 | LD HL,32756 | 32756 contains the doors flags | ||
30296 | LD A,E | A=x-coordinate of the point in front of the mouse/frog/pellet | ||
30297 | CP 190 | 190=x-coordinate of the far wall of the girls' skool | ||
30299 | JR NC,30335 | Jump if the mouse/frog/pellet is facing this wall | ||
30301 | LD A,D | A=y-coordinate of the mouse/frog/pellet | ||
30302 | CP 5 | Is the mouse/frog/pellet on the top floor (or just below it)? | ||
30304 | JR NC,30338 | Jump if not | ||
The mouse/frog/pellet is on the top floor.
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30306 | LD A,E | A=x-coordinate of the point in front of the mouse/frog/pellet | ||
30307 | CP 159 | 159=x-coordinate of the left wall of the girls' skool | ||
30309 | JR Z,30335 | Jump if the mouse/frog/pellet is facing this wall | ||
30311 | LD D,1 | Set bit 0: left study door | ||
30313 | CP 72 | 72=x-coordinate of the left study door | ||
30315 | JR Z,30331 | Jump if the mouse/frog/pellet is facing this door | ||
30317 | INC D | Set bit 1: right study door | ||
30318 | CP 84 | 84=x-coordinate of the right study door | ||
30320 | JR Z,30331 | Jump if the mouse/frog/pellet is facing this door | ||
30322 | LD D,64 | Set bit 6: top-floor window | ||
30324 | CP 92 | 92=x-coordinate of the top-floor window | ||
30326 | JR Z,30331 | Jump if the mouse/frog/pellet is facing this window | ||
30328 | AND A | Clear the carry flag: no obstacles ahead | ||
30329 | POP HL | Restore the character number of the mouse/frog/pellet to H | ||
30330 | RET | Return with the carry flag reset | ||
30331 | LD A,D | A holds the identifier of the door or window in front of the mouse/frog/pellet | ||
30332 | AND (HL) | Is this door/window open? | ||
30333 | JR NZ,30329 | Jump if so | ||
30335 | SCF | Set the carry flag: no admittance | ||
30336 | POP HL | Restore the character number of the mouse/frog/pellet to H | ||
30337 | RET | Return with the carry flag set | ||
30338 | CP 12 | |||
30340 | LD A,E | |||
30341 | JR NC,30366 | Jump if the mouse/frog/pellet is on the bottom floor (or just above it) | ||
The mouse/frog/pellet is on the middle floor.
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30343 | CP 159 | 159=x-coordinate of the left wall of the girls' skool | ||
30345 | JR Z,30335 | Jump if the mouse/frog/pellet is facing this wall | ||
30347 | CP 62 | 62=x-coordinate of the far wall of the Science Lab storeroom | ||
30349 | JR Z,30335 | Jump if the mouse/frog/pellet is facing this wall | ||
30351 | CP 53 | 53=x-coordinate of the Science Lab storeroom door | ||
30353 | LD D,4 | Set bit 2: Science Lab storeroom door | ||
30355 | JR Z,30331 | Jump if the mouse/frog/pellet is facing this door | ||
30357 | LD D,128 | Set bit 7: middle-floor window | ||
30359 | CP 94 | 94=x-coordinate of the middle-floor window | ||
30361 | JR Z,30331 | Jump if the mouse/frog/pellet is facing this window | ||
30363 | AND A | Clear the carry flag: no obstacles ahead | ||
30364 | POP HL | Restore the character number of the mouse/frog/pellet to H | ||
30365 | RET | Return with the carry flag reset | ||
The mouse/frog/pellet is on the bottom floor.
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30366 | LD D,8 | Set bit 3: boys' skool door | ||
30368 | CP 94 | 94=x-coordinate of the boys' skool door | ||
30370 | JR Z,30331 | Jump if mouse/frog/pellet is facing this door | ||
30372 | LD D,16 | Set bit 4: skool gate | ||
30374 | CP 133 | 133=x-coordinate of the skool gate | ||
30376 | JR Z,30331 | Jump if the mouse/frog/pellet is facing this | ||
30378 | JR 30363 | Otherwise it's all clear |
Prev: 30291 | Up: Map | Next: 30380 |