Routines
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50780: Update Task Three Helpers
Used by the routine at Update_Task_Three_Entities.
Update Task Three Helpers for the current Thing Upstairs task.
Update_Task_Three_Helpers 50780 LD IX,36627 Point IX at the first Slimies entity (StateData_Complex_03).
50784 LD DE,14 Each entity record is 0014 bytes long, then load that length into DE.
50787 LD B,4 Load B with 4 as a loop counter.
Scan each upstairs helper: skip inactive / low slots, then randomly wander, climb, or drop a room.
Update_Task_Three_Helpers_Scan 50789 PUSH BC Stash BC on the stack.
50790 LD A,(IX+1) Load A with the current entity's flags byte 1.
50793 AND %11100000 Keep only the top bits 224 of the flag/coordinate in A.
50795 JR NZ,Update_Task_Three_Helpers_AdvanceSlot If the result was non-zero, jump to Update_Task_Three_Helpers_AdvanceSlot.
50797 LD A,(IX+6) Load A with the current entity's y-extent.
50800 CP 34 Is the current entity's y-extent less than 34? If so, jump to Update_Task_Three_Helpers_AdvanceSlot.
50802 JR C,Update_Task_Three_Helpers_AdvanceSlot
50804 BIT 7,(IX+0) Is bit 7 of the current entity's entity type set? If not, call Update_Task_Three_Helpers_MaybeSetFlagBit2.
50808 CALL Z,Update_Task_Three_Helpers_MaybeSetFlagBit2
50811 LD A,21 Load A with 21.
50813 CALL PseudoRandom Call PseudoRandom to pick a pseudo-random value.
50816 OR A Is 21 zero? If so, jump to Update_Task_Three_Helpers_ClearTypeBit7.
50817 JR Z,Update_Task_Three_Helpers_ClearTypeBit7
50819 CP 6 Is 21 less than 6? If so, jump to Update_Task_Three_Helpers_TryMoveLeft.
50821 JR C,Update_Task_Three_Helpers_TryMoveLeft
50823 CP 11 Is 21 less than 11? If so, jump to Update_Task_Three_Helpers_TryMoveRight.
50825 JR C,Update_Task_Three_Helpers_TryMoveRight
50827 CP 16 Is 21 less than 16? If so, jump to Update_Task_Three_Helpers_MoveRoomDown.
50829 JR C,Update_Task_Three_Helpers_MoveRoomDown
50831 LD A,(IX+4) Load A with the current entity's room index.
50834 CP 5 Is the current entity's room index equal to 5? If so, jump to Update_Task_Three_Helpers_AdvanceSlot.
50836 JR Z,Update_Task_Three_Helpers_AdvanceSlot
50838 INC (IX+5) Move this entity one character down.
50841 INC (IX+6)
50844 INC (IX+4) Advance this entity into the next room.
50847 JR Update_Task_Three_Helpers_AdvanceSlot Jump to Update_Task_Three_Helpers_AdvanceSlot to advance to the next helper entity.
Move this helper up one room (unless already in room 1).
Update_Task_Three_Helpers_MoveRoomDown 50849 LD A,(IX+4) Load A with the current entity's room index.
50852 CP 1 Is the current entity's room index equal to 1? If so, jump to Update_Task_Three_Helpers_AdvanceSlot.
50854 JR Z,Update_Task_Three_Helpers_AdvanceSlot
50856 DEC (IX+5) Move this entity one character up.
50859 DEC (IX+6)
50862 DEC (IX+4) Move this entity back one room.
50865 JR Update_Task_Three_Helpers_AdvanceSlot Jump to Update_Task_Three_Helpers_AdvanceSlot to advance to the next helper entity.
Try a left wander step, respecting the high-X and low-X bounds.
Update_Task_Three_Helpers_TryMoveLeft 50867 LD A,(IX+7) Load A with the current entity's x-coordinate.
50870 CP 224 Is the current entity's x-coordinate less than 224? If so, jump to Update_Task_Three_Helpers_LeftBoundCheck.
50872 JR C,Update_Task_Three_Helpers_LeftBoundCheck
50874 CP 228 Is the current entity's x-coordinate less than 228? If so, jump to Update_Task_Three_Helpers_AdvanceSlot.
50876 JR C,Update_Task_Three_Helpers_AdvanceSlot
50878 JR Update_Task_Three_Helpers_DecX Jump to Update_Task_Three_Helpers_DecX to decrease the helper's x-coordinate.
Left-bound check: below 67 step right instead of left.
Update_Task_Three_Helpers_LeftBoundCheck 50880 CP 67 Is the current entity's x-coordinate less than 67? If so, jump to Update_Task_Three_Helpers_IncX.
50882 JR C,Update_Task_Three_Helpers_IncX
Nudge the helper one character left.
Update_Task_Three_Helpers_DecX 50884 DEC (IX+7) Move this entity one character left.
50887 DEC (IX+8)
50890 JR Update_Task_Three_Helpers_AdvanceSlot Jump to Update_Task_Three_Helpers_AdvanceSlot to advance to the next helper entity.
Try a right wander step, respecting the high-X and mid-X bounds.
Update_Task_Three_Helpers_TryMoveRight 50892 LD A,(IX+7) Load A with the current entity's x-coordinate.
50895 CP 224 Is the current entity's x-coordinate less than 224? If so, jump to Update_Task_Three_Helpers_RightBoundCheck.
50897 JR C,Update_Task_Three_Helpers_RightBoundCheck
50899 CP 251 Is the current entity's x-coordinate less than 251? If not, jump to Update_Task_Three_Helpers_AdvanceSlot.
50901 JR NC,Update_Task_Three_Helpers_AdvanceSlot
50903 JR Update_Task_Three_Helpers_IncX Jump to Update_Task_Three_Helpers_IncX to increase the helper's x-coordinate.
Right-bound check: at or beyond 187 step left instead of right.
Update_Task_Three_Helpers_RightBoundCheck 50905 CP 187 Is the current entity's x-coordinate less than 187? If not, jump to Update_Task_Three_Helpers_DecX.
50907 JR NC,Update_Task_Three_Helpers_DecX
Nudge the helper one character right.
Update_Task_Three_Helpers_IncX 50909 INC (IX+7) Move this entity one character right.
50912 INC (IX+8)
Advance to the next helper slot and loop until all 4 are done.
Update_Task_Three_Helpers_AdvanceSlot 50915 ADD IX,DE Advance IX to the next entity record.
50917 POP BC Restore BC from the stack.
50918 DEC B Step the loop counter in B back by one.
50919 JP NZ,Update_Task_Three_Helpers_Scan If the result was non-zero, jump to Update_Task_Three_Helpers_Scan.
50922 RET Return.
Clear type bit 7 (end the 'loose' pose) and advance.
Update_Task_Three_Helpers_ClearTypeBit7 50923 RES 7,(IX+0) Reset bit 7 of the current entity's entity type.
50927 JR Update_Task_Three_Helpers_AdvanceSlot Jump to Update_Task_Three_Helpers_AdvanceSlot to advance to the next helper entity.
When X is below 224, clear type bit 7 and raise SlimyLoose on TaskThreeFlags.
Update_Task_Three_Helpers_MaybeSetFlagBit2 50929 LD A,(IX+7) Load A with the current entity's x-coordinate.
50932 CP 224 Is the current entity's x-coordinate less than 224? If not, jump to Update_Task_Three_Helpers_MaybeSetTypeBit7.
50934 JR NC,Update_Task_Three_Helpers_MaybeSetTypeBit7
50936 RES 7,(IX+0) Reset bit 7 of the current entity's entity type.
50940 LD HL,29366 Point HL at the task-three flags (TaskThreeFlags).
50943 SET 2,(HL) Set SlimyLoose (bit 2 of TaskThreeFlags. 55559 skips that line while set).
50945 RET Return.
Rarely set type bit 7 so this helper can enter the SlimyLoose path.
Update_Task_Three_Helpers_MaybeSetTypeBit7 50946 LD A,10 Load A with 10.
50948 CALL PseudoRandom Call PseudoRandom to pick a pseudo-random value.
50951 OR A Is the random result in A zero? If not, return.
50952 RET NZ
50953 SET 7,(IX+0) Set bit 7 of the current entity's entity type.
50957 RET Return.
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