Routines
Prev: C3C1 Up: Map Next: C5BE
C433: Handle enemy lateral movement (2/2)
Used by the routine at C2E7.
Handle movement to the right for CATERPILLAR and FOOT MAN
C433 LD HL,($A1B4) Set HL to the tile address under entity
C436 LD DE,$0040 Set HL point to tile in front-upper of entity
C439 AND A
C43A SBC HL,DE
C43C INC HL
C43D INC HL
C43E CALL $CDF5 Check if tile is wall
C441 JP Z,$C4C6 Jump if tile is wall and change direction
C444 LD DE,$0020 Set HL point to tile in front-lower of entity
C447 ADD HL,DE
C448 CALL $CDF5 Check if tile is wall
C44B JP Z,$C4C6 Jump if tile is wall and change direction
C44E LD A,(IX+$09) Jump forward if enemy is FOOT MAN
C451 OR A
C452 JP Z,$C463
C455 LD A,(IX+$00) Computes new x-position based on speed
C458 ADD A,(IX+$10)
C45B CP $E8 Jump to handle collision with right border if x-position greater than 232
C45D JP NC,$C4F9
C460 JP $C46E Jump to continue the movement
check collision with border for FOOT MAN
C463 LD A,(IX+$00) Computes new x-position based on speed
C466 ADD A,(IX+$10)
C469 CP $F8 Jump to handle collision with right border if x-position greater than 248
C46B JP NC,$C4F9
no collision, continue movement
C46E LD (IX+$00),A Set the new x-position
C471 LD (IX+$02),$00 Set direction to right
C475 LD A,(IX+$03) Return if FOOT MAN jumping
C478 OR A
C479 RET NZ
C47A LD A,(IX+$06) Return if FOOT MAN falling
C47D OR A
C47E RET NZ
C47F LD A,(IX+$09) Jump forward if enemy is not FOOT MAN
C482 OR A
C483 JP NZ,$C4AE
C486 LD HL,($A1B4) Set HL to the address of the tile buffer in front of FOOT MAN
C489 LD DE,$001E
C48C AND A
C48D SBC HL,DE
C48F LD A,(HL) if tile type is $0F then jump to handle jump of FOOT MAN
C490 CP $0F
C492 JP Z,$C673
C495 CP $0E if tile type is $0E then jump to handle force crouch of FOOT MAN - Not used in Rex (Side B)
C497 JP Z,$C5BF
C49A CP $10 if tile type is $10 then jump to handle random crouch of FOOT MAN
C49C CALL Z,$C598
C49F CP $11 if tile type is $10 then jump to handle random jump of FOOT MAN
C4A1 CALL Z,$C5A7
C4A4 CP $15 if tile type is $10 then jump to handle random telporting of FOOT MAN
C4A6 CALL Z,$C5B4
C4A9 CP $16 if tile type is $10 then jump to handle forced telporting of FOOT MAN
C4AB CALL Z,$C5BA
check the next tile under the foots of enemy
C4AE LD HL,($A1B4) Set HL to the next tile under foots
C4B1 INC HL
C4B2 INC HL
C4B3 LD A,(HL) Return if tile is not background
C4B4 OR A
C4B5 RET NZ
C4B6 LD A,(IX+$09) Return if enemy is FOOT MAN
C4B9 AND $7F
C4BB OR A
C4BC RET Z
C4BD CP $08 Remnant code. No enemies with this type
C4BF RET Z
C4C0 CP $0C
C4C2 RET Z
C4C3 CP $0D
C4C5 RET Z
C4C6 LD A,(IX+$09) Return if FOOT MAN dying
C4C9 CP $07
C4CB RET Z
C4CC CP $06
C4CE RET Z
change direction of enemy
C4CF LD A,(IX+$02) change enemy direction
C4D2 XOR $01
C4D4 LD (IX+$02),A
special case for FOOT MAN dying
C4D7 LD A,(IX+$09) if FOOT MAN dying then generate explosion
C4DA CP $07
C4DC JP Z,$9807
C4DF CP $06
C4E1 JP Z,$9807
C4E4 CP $03 Remnant code for train of Rex (Side A). Nou used in game
C4E6 JP Z,$C4F4
C4E9 CP $04
C4EB JP Z,$C4F4
C4EE CP $05
C4F0 JP Z,$C4F4
C4F3 RET
Set enemy to not visible
C4F4 LD (IX+$0C),$00 Enemy not visible
C4F8 RET
Handle collision with room border
C4F9 LD A,(IX+$09) if enemy type is FOOT MAN then jump to make FOOT MAN invisible
C4FC OR A
C4FD JP Z,$C4F4
C500 JP $C4CF if not change enemy direction
Handle movement to the left for CATERPILLAR and FOOT MAN
C503 LD HL,($A1B4) Set HL to the tile address under entity
C506 LD DE,$0040 Set HL to the tile address in front-upper of enemy
C509 AND A
C50A SBC HL,DE
C50C DEC HL
C50D CALL $CDF5 Check if tile type is wall
C510 JP Z,$C588 Jump if it's a wall
C513 LD DE,$0020 Increment address to tile in front-lower of enemy
C516 ADD HL,DE
C517 CALL $CDF5 Check if tile type is wall
C51A JP Z,$C588 Jump if it's a wall and change direction
C51D LD A,(IX+$00) Computes new x-position based on speed
C520 SUB (IX+$10)
C523 CP $E8 if x-position is less than 24 then jump and handle left collision with room border
C525 JP NC,$C4F9
no collision, continue moving
C528 LD (IX+$00),A Set the new x-position
C52B LD (IX+$02),$01 Continue in the same direction
C52F LD A,(IX+$03) Return if jumping
C532 OR A
C533 RET NZ
C534 LD A,(IX+$06) Return if falling
C537 OR A
C538 RET NZ
C539 LD A,(IX+$09) Check enemy type
C53C OR A Jump forward if enemy type is not FOOT MAN
C53D JP NZ,$C568
handle special behavior of FOOT MAN
C540 LD HL,($A1B4) Set HL to the tile address under FOOT MAN
C543 LD DE,$0021 Check tile type where is FOOT MAN
C546 AND A
C547 SBC HL,DE
C549 LD A,(HL) if tile type is $0F then jump to handle jump of FOOT MAN
C54A CP $0F
C54C JP Z,$C66E
C54F CP $0E if tile type is $0E then jump to handle force crouch of FOOT MAN - Not used in Rex (Side B)
C551 JP Z,$C5BF
C554 CP $10 if tile type is $10 then jump to handle random crouch of FOOT MAN
C556 CALL Z,$C598
C559 CP $11 if tile type is $10 then jump to handle random jump of FOOT MAN
C55B CALL Z,$C5A7
C55E CP $15 if tile type is $10 then jump to handle random telporting of FOOT MAN
C560 CALL Z,$C5B4
C563 CP $16 if tile type is $10 then jump to handle forced telporting of FOOT MAN
C565 CALL Z,$C5BA
check for space under the feet in next tile
C568 LD HL,($A1B4) Return if next tile under a feet is not space
C56B DEC HL
C56C LD A,(HL)
C56D OR A
C56E RET NZ
C56F LD A,(IX+$09) Check enemy type
C572 AND $7F Return if FOOT MAN
C574 OR A
C575 RET Z
C576 CP $03 Remant code for train of Rex (Side A)
C578 RET Z
C579 CP $04
C57B RET Z
C57C CP $05
C57E RET Z
C57F CP $08 Remnant code. No enemies with this type
C581 RET Z
C582 CP $0C
C584 RET Z
C585 CP $0D
C587 RET Z
change direction
C588 LD A,(IX+$09) Return if FOOT MAN dying
C58B CP $06
C58D RET Z
C58E CP $07
C590 RET Z
C591 LD (IX+$02),$00 Change enemy direction
C595 JP $C4D7 Jump to handle special case for FOOT MAN dying
Handle random crouch for FOOT MAN
C598 PUSH AF Save AF
C599 CALL $A51D Set A a pseudo random nummber
C59C CP $80 is less than 128?
C59E JP C,$C5BE Jump to crouch FOOT MAN if so
C5A1 LD (IX+$11),$04 Reset state change counter
C5A5 POP AF Restore AF
C5A6 RET
Handle random jump for FOOT MAN
C5A7 CALL $A51D Set A a pseudo random nummber
C5AA CP $80 is less than 128?
C5AC JP C,$C66E Jump to make FOOT MAN jump
C5AF LD (IX+$11),$04 Reset state change counter
C5B3 RET
Handle random teleporting out of the room for FOOT MAN
C5B4 CALL $A51D Set A a pseudo random nummber
C5B7 CP $80 is less than 128?
C5B9 RET C Return if so
Handle forced teleporting out of the room for FOOT MAN
C5BA CALL $9EF1 Configure teleporting out of the room
C5BD RET
Prev: C3C1 Up: Map Next: C5BE