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Routines |
| Prev: 55616 | Up: Map | Next: 55818 |
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Evaluates objects in data sets at 31744 and store state of any DOORS, CREATURES or OBJECTS.
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| 55628 | LD A,(60080) | Room number | ||
| 55631 | CP 0 | |||
| 55633 | JP Z,50870 | If it's zero, it means that room's all set up, so jump to the main game cycle | ||
| 55636 | LD A,0 | |||
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Start preparing the room items that will need dealing with:
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| 55638 | LD (60343),A | Set the creatures in the room to zero | ||
| 55641 | LD HL,(56046) | Pointer to start of the room data sets at 31744 | ||
| 55644 | LD DE,16 | Skip pointer past first data set, which deals with the room/viewport setup | ||
| 55647 | ADD HL,DE | |||
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Check each data set in the room item list at 31744 in turn:
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| 55648 | LD A,(HL) | Get first byte of data set | ||
| 55649 | CP 255 | Check for end-of-data marker | ||
| 55651 | JP Z,55818 | If found, skip copying routine | ||
| 55654 | LD DE,16 | |||
| 55657 | CP 0 | If first data byte <> 0, there's some data to copy for this set | ||
| 55659 | JR NZ,55664 | |||
| 55661 | ADD HL,DE | First data byte is zero, so skip to next data set and keep checking data sets | ||
| 55662 | JR 55648 | |||
| 55664 | LD BC,16 | 16 bytes to copy | ||
| 55667 | LD DE,60227 | Start of buffer (destination) | ||
| 55670 | LDIR | |||
| 55672 | LD (60094),HL | Store data pointer ready at the start of the next data bank | ||
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Check what the item in the data set is:
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| 55675 | LD A,(60227) | Get first byte of data set which indicates the item type | ||
| 55678 | CP 2 | Door | ||
| 55680 | JR Z,55692 | |||
| 55682 | CP 4 | Interactable object | ||
| 55684 | JR Z,55706 | |||
| 55686 | CP 3 | Creature | ||
| 55688 | JR Z,55765 | |||
| 55690 | JR 55648 | If not one of these three items, no extra processing needed at this point, so jump back and continue copying data sets | ||
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DOOR
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| 55692 | LD HL,(60228) | Address pointer to door connector data set in the table at 26512 | ||
| 55695 | INC HL | Move to 3rd byte of data set | ||
| 55696 | INC HL | |||
| 55697 | LD A,(60238) | This is the door properties byte | ||
| 55700 | LD (HL),A | Store in the 3rd byte of the room connector data set | ||
| 55701 | LD HL,(60094) | Retrieve address pointer to current data set at 31744 | ||
| 55704 | JR 55648 | ...and continue to check data sets | ||
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INTERACTABLE OBJECT
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| 55706 | LD HL,(60228) | Address pointer to object data set in the table at 29551 | ||
| 55709 | LD A,(60087) | Get room number... | ||
| 55712 | LD (HL),A | Store in object set as the room number for this item (first byte of set) | ||
| 55713 | INC HL | Move to the next item data byte... | ||
| 55714 | LD (60228),HL | ...And store the address pointer to this object's set | ||
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Calculate item's vertical & horizontal co-ordinates (in relation to the room viewport's position) and store in the object's data set (in the table at 29551)
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| 55717 | LD HL,(60152) | Horizontal position of current screen viewport in 4-pixel/half-character steps - to be used as a calculation offset for the item's position | ||
| 55720 | EX DE,HL | Swap into DE | ||
| 55721 | LD HL,(60231) | Item graphic's horizontal position in room - H register contains value in 4-pixel/half-character steps (L = pixel fraction/overflow) | ||
| 55724 | SCF | Clear/reset the carry flag (set, then toggle) | ||
| 55725 | CCF | |||
| 55726 | SBC HL,DE | Subtract the offset to get the item's room position | ||
| 55728 | LD A,H | Get the high byte (contains the object's adjusted horizontal position in 4-pixel steps) | ||
| 55729 | LD HL,(60228) | |||
| 55732 | LD (HL),A | Store as the 2nd byte of the object's data set at 29551 | ||
| 55733 | INC HL | Move address pointer to next byte (which stores the item's vertical pixel position) | ||
| 55734 | LD (60228),HL | Store the address pointer | ||
| 55737 | LD HL,(60150) | Get vertical room pixel position | ||
| 55740 | EX DE,HL | Swap into DE | ||
| 55741 | LD HL,(60233) | Item graphic's vertical position in room - H register contains value in pixels (L = pixel fraction/overflow) | ||
| 55744 | SCF | Clear/reset the carry flag (set, then toggle) | ||
| 55745 | CCF | |||
| 55746 | SBC HL,DE | Subtract the offset to get the item's room position in pixels | ||
| 55748 | LD A,H | Get the high byte (contains the adjusted vertical pixel position) | ||
| 55749 | LD HL,(60228) | Retrieve the address pointer to the 3rd byte of the object's data set at 29551 | ||
| 55752 | LD (HL),A | Store the item's vertical room position | ||
| 55753 | INC HL | Move along to the next byte of the object's data set | ||
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Store item properties byte:
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| 55754 | LD A,(60238) | Get item properties byte | ||
| 55757 | AND 239 | Reset bit 4 (if set, indicates item carried by servant). In most cases it's unlikely for Maroc to be able to switch room while the servant spell is active however |
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| 55759 | LD (HL),A | Store in item data set | ||
| 55760 | LD HL,(60094) | Restore pointer to data set at 31744 | ||
| 55763 | JR 55648 | Continue to copy data sets | ||
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CREATURE
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| 55765 | LD B,0 | The B register will hold a value indicating the type and number of creatures in the room | ||
| 55767 | LD A,(60238) | Creature properties byte | ||
| 55770 | AND 224 | Check if any of the top 3 bits are set: Bit 6/7 = creature materializing Bit 5 = creature disintegrating |
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| 55772 | JR NZ,55805 | If any of these are set, the creature isn't considered present, so don't add this creature's value | ||
| 55774 | LD A,(60230) | Creature type | ||
| 55777 | CP 8 | Byte value < 8, it's a warlock (no action to take as they're not 'stored') | ||
| 55779 | JR C,55805 | |||
| 55781 | CP 8 | |||
| 55783 | JR NZ,55787 | |||
| 55785 | LD B,64 | Byte value = 8, it's a guardian of chaos (set value = 64, these creatures are stored in bits 6 & 7) | ||
| 55787 | CP 9 | |||
| 55789 | JR NZ,55793 | |||
| 55791 | LD B,16 | Byte value = 9, it's a goblin warrior (set value = 16, these creatures are stored in bits 4 & 5) | ||
| 55793 | CP 10 | |||
| 55795 | JR NZ,55799 | |||
| 55797 | LD B,4 | Byte value = 10 it's a goblin missile thrower (set value = 4, these creatures are stored in bits 2 & 3) | ||
| 55799 | CP 11 | |||
| 55801 | JR NZ,55805 | |||
| 55803 | LD B,1 | Byte value = 11, it's a wraith (set value = 1, these creatures are stored in bits 0 & 1) | ||
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Add this creature's value (in B register) to the creature data byte for this room.
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| 55805 | LD A,(60343) | Creature data byte for room | ||
| 55808 | ADD A,B | Add the creature type value | ||
| 55809 | LD (60343),A | ...and re-store | ||
| 55812 | LD HL,(60094) | Retrieve address pointer to the next data set (at 31744) | ||
| 55815 | JP 55648 | |||
| Prev: 55616 | Up: Map | Next: 55818 |