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Routines |
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Used by the routine at ANIMATE_AND_MOVE.
Reached when a step would make the object's box meet another record's (FIND_OBSTACLE), IX being the one it meets. Anything but a door (kind 1 in the low nibble of +12, the eleven-byte records of the object table) goes to OBJECTS_MEET. A door stops anyone but the knight, like a wall. For him: The key. If the door's +14 holds a thing's number, the thing in the place in use must be that one, or it is LOCKED (message 2). With the place empty, IX becomes nought and the test reads byte 19 of the ROM, $FF, which is no thing's number, so it is LOCKED. Eight things open doors (numbers 1 to 8; 21 doors need one). The way. The door's +17 has the direction bits (KNIGHT_CONTROLS) of the way through it, and he must be going that way this pass: x or y for a doorway, up or down for a hole (twelve doors). Walking into a door any other way is stopped as by a wall. Going down happens by gravity alone, as he stands over the hole; going up needs a jump. Room 61. The only way out of room 61 also needs the thing of kind 11 to be lying in the room (bit 1 of IY+$11) -- measured: without it he stands on the hole; with it he drops to room 60. Where he arrives. For a doorway along y he must be wholly within the door's width; he arrives as far along x from the door's +15 as he was from the door's corner, at y = +18 (less his depth if he walked down y). For one along x, within its depth; as far along y from +18, at x = +15 (less his width if he walked down x). For a hole his x and y are carried across relative to the door (+15 and +18) and his top is set to +16 (plus his height going up; that case never ran in the build's sessions). Through a doorway his height must lie wholly within the door's, and carries across relative to +16. The room behind. Every thing among the first 163 records of the object table whose record puts it in the room he is going to is tested against where he would arrive, its box made from the table's position and its template's sizes; if one is there, it is BLOCKED (message 1) and he stays. A thing with bit 4 of its +12 -- in the table, only the trolls -- does not count (measured, by moving thing 1 into room 30 where the door from room 29 lands him: BLOCKED; with bit 4 set he went through).
Then the room changes (Krumlinde's RTN_Trigger_Room_Change): the room number is the door's +13, the knight's record is moved to where he arrives, the things' places are saved (SAVE_OBJECT_POSITIONS), and the new room is entered (ROOMST), which goes back to the main loop.
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| BUMPED | F7C4 | LD A,(IX+OBJ_KIND) | Not a door: meet it | |||||||
| F7C7 | AND $0F | |||||||||
| F7C9 | CP $01 | |||||||||
| F7CB | JP NZ,OBJECTS_MEET | |||||||||
| F7CE | SET 7,(IY+STEP_AXES-V) | A door was met this pass | ||||||||
| F7D2 | LD A,(THIS_RECORD) | Only the knight goes through; for anything else it is a wall (MEET_DECOY) | ||||||||
| F7D5 | CP $07 | |||||||||
| F7D7 | JP NZ,BLOCKED_MOVE | |||||||||
| F7DA | LD A,(IX+OBJ_STATE) | No key needed | ||||||||
| F7DD | AND A | |||||||||
| F7DE | JR Z,DOOR_WAY | |||||||||
| F7E0 | PUSH HL | The thing in the place in use (nought, the ROM, if none) | ||||||||
| F7E1 | PUSH DE | |||||||||
| F7E2 | PUSH IX | |||||||||
| F7E4 | LD L,(IY+SELECTED-V) | |||||||||
| F7E7 | LD H,$FF | |||||||||
| F7E9 | LD E,(HL) | |||||||||
| F7EA | INC HL | |||||||||
| F7EB | LD D,(HL) | |||||||||
| F7EC | PUSH DE | |||||||||
| F7ED | POP IX | |||||||||
| F7EF | CP (IX+OBJ_NUMBER) | Is it the key? | ||||||||
| F7F2 | POP IX | |||||||||
| F7F4 | POP DE | |||||||||
| F7F5 | POP HL | |||||||||
| F7F6 | JR Z,DOOR_WAY | |||||||||
| F7F8 | LD (IY+MESSAGE-V),$02 | No: LOCKED, and it is a wall | ||||||||
| F7FC | JP BLOCKED_MOVE | |||||||||
| DOOR_WAY | F7FF | LD A,(IX+OBJ_FRAME) | Krumlinde's RTN_Check_Door_Keys, though the key is already settled here. C = the way through the door | |||||||
| F802 | LD C,A | |||||||||
| F803 | AND (IY+ASKED_DIRECTION-V) | Is he going that way? This is AND (IY+ASKED_DIRECTION-V): Krumlinde has a DB and a label at its second byte, and reads the rest as AND (HL) and LD A,H | ||||||||
| F806 | JP Z,BLOCKED_MOVE | |||||||||
| F809 | LD A,(ROOM) | In room 61... | ||||||||
| F80C | CP $3D | |||||||||
| F80E | JR NZ,DOOR_ARRIVAL | |||||||||
| F810 | BIT 1,(IY+THINGS_NOTED-V) | ...only if the thing of kind 11 lies there | ||||||||
| F814 | JP Z,BLOCKED_MOVE | |||||||||
| DOOR_ARRIVAL | F817 | CALL WORKING_POSITION | B, D, H = where he is (before the step) | |||||||
| F81A | LD L,(IX+OBJ_COUNT) | L = the x he arrives at, E = the y (the door's +15 and +18) | ||||||||
| F81D | LD E,(IX+OBJ_COURSE) | |||||||||
| F820 | LD A,C | Is the way along y (neither x nor height)? | ||||||||
| F821 | AND $3C | |||||||||
| F823 | JR NZ,BUMPED_0 | |||||||||
| F825 | LD A,B | Along y: he must be wholly within the door's width | ||||||||
| F826 | SUB (IX+OBJ_X) | |||||||||
| F829 | JP C,BLOCKED_MOVE | |||||||||
| F82C | LD B,A | |||||||||
| F82D | ADD A,(IY+REPEATS+$01-V) | |||||||||
| F830 | SUB (IX+OBJ_LEN_X) | |||||||||
| F833 | JP NC,BLOCKED_MOVE | |||||||||
| F836 | LD A,L | x: as far along from +15 as he was from the door's corner | ||||||||
| F837 | ADD A,B | |||||||||
| F838 | LD B,A | |||||||||
| F839 | LD H,E | y: +18 when going up y... | ||||||||
| F83A | BIT 6,C | |||||||||
| F83C | JR NZ,BUMPED_2 | |||||||||
| F83E | LD A,E | ...or his depth less, going down y | ||||||||
| F83F | SUB (IY+REPEAT_FROM+$01-V) | |||||||||
| F842 | LD H,A | |||||||||
| F843 | JR BUMPED_2 | |||||||||
| BUMPED_0 | F845 | LD A,C | A hole (up or down)? | |||||||
| F846 | AND $30 | |||||||||
| F848 | JR Z,BUMPED_1 | |||||||||
| F84A | LD A,B | x: carried across relative to the door | ||||||||
| F84B | SUB (IX+OBJ_X) | |||||||||
| F84E | ADD A,L | |||||||||
| F84F | LD B,A | |||||||||
| F850 | LD A,H | And y | ||||||||
| F851 | SUB (IX+OBJ_Z) | |||||||||
| F854 | ADD A,E | |||||||||
| F855 | LD H,A | |||||||||
| F856 | LD A,(IX+OBJ_WEIGHT) | His top: the door's +16... | ||||||||
| F859 | BIT 4,C | ...when going down | ||||||||
| F85B | JR Z,BUMPED_3 | |||||||||
| F85D | ADD A,(IY+REPEAT_FROM-V) | Going up, plus his height (never ran in the build's sessions) | ||||||||
| F860 | JR BUMPED_3 | |||||||||
| BUMPED_1 | F862 | LD A,H | Along x: he must be wholly within the door's depth | |||||||
| F863 | SUB (IX+OBJ_Z) | |||||||||
| F866 | JP C,BLOCKED_MOVE | |||||||||
| F869 | LD H,A | |||||||||
| F86A | ADD A,(IY+REPEAT_FROM+$01-V) | |||||||||
| F86D | SUB (IX+OBJ_LEN_Z) | |||||||||
| F870 | JP NC,BLOCKED_MOVE | |||||||||
| F873 | LD A,H | (A wasted load: A is loaded again at once) | ||||||||
| F874 | LD A,E | y: as far along from +18 as he was from the door's corner | ||||||||
| F875 | ADD A,H | |||||||||
| F876 | LD H,A | |||||||||
| F877 | LD A,L | x: +15 when going up x... | ||||||||
| F878 | LD B,A | |||||||||
| F879 | BIT 3,C | ...or his width less, going down x | ||||||||
| F87B | JR NZ,BUMPED_2 | |||||||||
| F87D | SUB (IY+REPEATS+$01-V) | |||||||||
| F880 | LD B,A | |||||||||
| BUMPED_2 | F881 | LD A,D | Through a doorway: his top must be below the door's top... | |||||||
| F882 | SUB (IX+OBJ_TOP) | |||||||||
| F885 | JP NC,BLOCKED_MOVE | |||||||||
| F888 | LD D,A | ...and his feet not below the door's foot | ||||||||
| F889 | SUB (IY+REPEAT_FROM-V) | |||||||||
| F88C | ADD A,(IX+OBJ_HEIGHT) | |||||||||
| F88F | JP NC,BLOCKED_MOVE | |||||||||
| F892 | LD A,(IX+OBJ_WEIGHT) | His top: as far below +16 as it was below the door's top | ||||||||
| F895 | ADD A,D | |||||||||
| BUMPED_3 | F896 | LD D,A | D = his top on arrival | |||||||
| F897 | CALL WORKING_SIZES | C, E, L = his sizes; keep all six in the other set | ||||||||
| F89A | EXX | |||||||||
| F89B | LD C,(IX+OBJ_DIRECTION) | C = the room behind the door (+13) | ||||||||
| ARRIVAL_CHECK | F89E | LD HL,$A91F | HL five bytes before the object table, so that each step of five and the byte read after it moves on one six-byte record; keep the door's record | |||||||
| F8A1 | PUSH IX | |||||||||
| BUMPED_4 | F8A3 | LD DE,$0005 | Next record: E = its room, A = its type | |||||||
| F8A6 | ADD HL,DE | |||||||||
| F8A7 | LD E,(HL) | |||||||||
| F8A8 | INC HL | |||||||||
| F8A9 | LD A,(HL) | |||||||||
| F8AA | CP $46 | The first eleven-byte record ends the things: none is in the way | ||||||||
| F8AC | JR NC,GO_THROUGH_DOOR | |||||||||
| F8AE | LD A,E | A thing in another room: next | ||||||||
| F8AF | CP C | |||||||||
| F8B0 | JR NZ,BUMPED_4 | |||||||||
| F8B2 | PUSH HL | Make a record of it at IY+$4B: its +12 byte and its place (x, top, y) go to +5 to +8 (+5 and +6 are PRINT_X and PRINT_Y; whatever prints next sets them again) | ||||||||
| F8B3 | PUSH BC | |||||||||
| F8B4 | LD A,(HL) | |||||||||
| F8B5 | INC HL | |||||||||
| F8B6 | LD DE,$FFD0 | |||||||||
| F8B9 | LD BC,$0004 | |||||||||
| F8BC | LDIR | |||||||||
| F8BE | PUSH DE | Its template (TEMPLATES): the sizes, at byte 6 | ||||||||
| F8BF | LD HL,$B72F | |||||||||
| F8C2 | LD DE,$000B | |||||||||
| F8C5 | INC A | |||||||||
| BUMPED_5 | F8C6 | ADD HL,DE | ||||||||
| F8C7 | DEC A | |||||||||
| F8C8 | JR NZ,BUMPED_5 | |||||||||
| F8CA | POP DE | To +9 to +11 | ||||||||
| F8CB | LD BC,$0003 | |||||||||
| F8CE | LDIR | |||||||||
| F8D0 | LD IX,ARRIVAL_BOX | Would he arrive in its box? (the box test in TEST_ONE_RECORD, with his arrival in the other set) | ||||||||
| F8D4 | EXX | |||||||||
| F8D5 | CALL BOX_OVERLAP | |||||||||
| F8D8 | EXX | |||||||||
| F8D9 | POP BC | No: next thing | ||||||||
| F8DA | POP HL | |||||||||
| F8DB | JR NC,BUMPED_4 | |||||||||
| F8DD | BIT 4,(IX+OBJ_SPRITE+$01) | A thing with bit 4 of +12 does not count | ||||||||
| F8E1 | JR NZ,BUMPED_4 | |||||||||
| F8E3 | LD (IY+MESSAGE-V),$01 | Anything else: BLOCKED, and it is a wall | ||||||||
| F8E7 | POP IX | |||||||||
| F8E9 | JP BLOCKED_MOVE | |||||||||
| GO_THROUGH_DOOR | F8EC | LD (IY+ROOM-V),C | Krumlinde's RTN_Trigger_Room_Change. The room is the one behind the door | |||||||
| F8EF | POP AF | Drop the scan's IX, and the two words the main loop left (MAIN_LOOP): ROOMST goes back into the loop itself | ||||||||
| F8F0 | EXX | |||||||||
| F8F1 | POP AF | |||||||||
| F8F2 | POP AF | |||||||||
| F8F3 | LD IX,(WORK_RECORD) | Move the knight to where he arrives | ||||||||
| F8F7 | CALL ISO_MOVE | |||||||||
| F8FA | LD A,(WORK_BEHAVIOUR) | With the state he had | ||||||||
| F8FD | LD (IX+OBJ_STATE),A | |||||||||
| F900 | CALL SAVE_OBJECT_POSITIONS | Save where the things of the room are (SAVE_OBJECT_POSITIONS) | ||||||||
| F903 | JP ROOMST | And enter the new one | ||||||||
| Prev: F7BA | Up: Map | Next: F906 |