Routines
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52961: Update Plant Pots
Used by the routines at Update_Berk_ReadControls and Update_Ghosts.
Spawn a plant shoot into the first free collectible-eye slot when a pot germinates. IX addresses the pot; free slots are sought from StateData_Complex_07 onwards.
Input
IX Address of the plant-pot complex state data
C Vertical offset applied when placing the shoot above the pot
Stash DE (caller-preserved) while the free eye slot is found.
Update_Plant_Pots 52961 PUSH DE Stash DE on the stack.
52962 LD IY,36683 Point IY at the first collectible-eye slot (StateData_Complex_07).
52966 LD DE,14 Each entity record is 0014 bytes long, then load that length into DE.
Find the first free collectible-eye slot.
Update_Plant_Pots_FindFreeSlot 52969 LD A,(IY+0) Fetch this eye slot's entity type, then is the slot empty (type 0)?.
52972 OR A
52973 JR Z,Update_Plant_Pots_PlaceShoot If so, plant the shoot here at Update_Plant_Pots_PlaceShoot.
52975 ADD IY,DE Otherwise advance IY to the next entity record.
52977 JR Update_Plant_Pots_FindFreeSlot Keep scanning at Update_Plant_Pots_FindFreeSlot.
Place the shoot in that slot, matching the pot's room and position.
Update_Plant_Pots_PlaceShoot 52979 LD (IY+0),14 Mark the free slot as a plant shoot (type 14).
52983 LD A,(IX+5) Load the pot's y-coordinate.
52986 SUB C Raise the shoot by the caller's offset in C.
52987 LD (IY+5),A Write that as the shoot's y-coordinate.
52990 ADD A,2 Make the shoot two characters tall.
52992 LD (IY+6),A Write the shoot's y-extent.
52995 LD A,(IX+7) Fetch the pot's x-coordinate.
52998 LD (IY+7),A Place the shoot on the same x.
53001 ADD A,2 Make the shoot two characters wide.
53003 LD (IY+8),A Write the shoot's x-extent.
53006 LD A,(IX+4) Fetch the pot's room index.
53009 LD (IY+4),A Keep the shoot in the same room as the pot.
53012 LD (IY+10),27 Set the shoot's graphic layout to GraphicLayout_CollectibleEyeballFrame2.
53016 LD (IY+11),161
53020 POP DE Restore DE from the stack.
53021 RET Return.
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