Alien 8: Templates: what a room can place

The 37 kinds of thing a room record can place: the templates the builder (BUILD_ROOM) makes object records from, after the backgrounds and the $FF that ends them. A room gives a group header -- bits 3-7 a template number, an index into OBJECT_TABLE, and bits 0-2 how many copies less one -- then a position byte for each copy: U = 72 + 16 times bits 0-2, V = 72 + 16 times bits 3-5, and Z the floor plus 12 times bits 6-7, so a room is an 8 by 8 grid of cells, four levels high. The count at +1 of the record, not the data, ends the build: a group can be cut short by it.

A template is a list of five-byte parts ended by a zero: the graphic, the half-sizes in U and V, the height (Z is an object's base, not its middle) and the flags, which go to +0 and +4 to +7 of a record, the position to +1 to +3 and the room to +8. Most have one part; 7 have two at the same place: the creatures that walk on a separate lower half, and the chambers' sockets with the sparkle over them. The graphic decides everything else, its update routine and its sprite (see every graphic).

Two pages of templates

A header can name 32 templates, and the game has more. The table at OBJECT_TABLE is 40 words: header number 31 is not a template but moves the builder's TEMPLATES_AT on 64 bytes, to the words from number 32 on, for the rest of the room, and the byte after it is skipped. So templates 33 to 39 are header numbers 1 to 7 after a 31; they are listed here by their place in the table. Words 0, 31 and 32 are zero: a header number of 0 is the placement nudge, below, on either page, so neither page's word 0 is ever read, and 31 is the switch. The rooms switch pages 12 times; the second page holds the remote-control buttons and pad, the things that break and the leapers.

The placement nudge

Header number 0 is not a template either: the byte after it becomes PLACE_NUDGE for the groups that follow (BUILD_ROOM): its bit 0 adds 8 to U, bit 1 adds 8 to V, and the rest of it is added to Z. The rooms set it 42 times, always to $00 or $30: 41 times $30, which lifts what follows by 48, four levels, so that a room can stack things eight levels high; the bits that move a thing half a cell are never used. Pentagram's builder has the same code with no jump to it (see Pentagram's templates); here it is live. The picture is the game's: a one-off room with four of template 1 at levels 0 to 3 of one cell, the nudge of $30, and the same four again, which land on top of the first.

The templates

Each is drawn here by the game, on its own near the middle of an empty room (cell 3, 3, on the floor), from a one-off room record the game builds and draws its first turn of, in SkoolKit's simulator; a thing that moves has had one turn, and one that the rooms always raise with the nudge is drawn on the floor all the same. Knight Lore's templates are the same idea with a sixth byte, an offset (see Knight Lore's templates).

1: A plain block -- OBJECT1

Graphic	Half U, V; height	Flags	Update routine
30	8, 8; 12	$10 (to be drawn)	DRAW_AT_L16_D9

812 copies in 91 rooms, 36 of them raised by the nudge: $02, $04, $05, $0A, $0C, $0D, $12, $14, $1C, $1D, $20, $23, $27, $28, $2F, $30, $31, $33, $34, $36, $37, $38, $39, $3B, $3F, $40, $41, $42, $43, $44, $45, $46, $48, $49, $4A, $4B, $4C, $4E, $4F, $54, $56, $57, $58, $59, $61, $62, $64, $65, $67, $6A, $6B, $6E, $74, $75, $77, $78, $7A, $7B, $82, $84, $86, $87, $8C, $8D, $93, $94, $95, $96, $98, $99, $9A, $9C, $A4, $A5, $A6, $A7, $AA, $AB, $B5, $B7, $B9, $BA, $C6, $C7, $C8, $C9, $D6, $D8, $E7, $F7, $F8.

2: A block with a raised round top that can be pushed -- OBJECT2

Graphic	Half U, V; height	Flags	Update routine
28	7, 7; 12	$14 (pushable, to be drawn)	PUSHABLE

32 copies in 19 rooms, 5 of them raised by the nudge: $0A, $1C, $28, $41, $44, $49, $4B, $61, $62, $6B, $7A, $8C, $96, $99, $9C, $AA, $B6, $BA, $C8.

3: A block tapering to the bottom that can be pushed -- OBJECT3

Graphic	Half U, V; height	Flags	Update routine
29	7, 7; 12	$14 (pushable, to be drawn)	PUSHABLE_INVERTED

20 copies in 13 rooms, 4 of them raised by the nudge: $0A, $1C, $37, $41, $4B, $61, $62, $7A, $82, $8C, $99, $BA, $C8.

4: A plain block that bobs up and down -- OBJECT4

Graphic	Half U, V; height	Flags	Update routine
31	8, 8; 12	$14 (pushable, to be drawn)	BOBBER, in LIFT

15 copies in 9 rooms, 1 of them raised by the nudge: $1D, $36, $39, $4A, $54, $86, $B9, $C6, $E7.

5: A plain block that sinks while stood on -- OBJECT5

Graphic	Half U, V; height	Flags	Update routine
44	8, 8; 12	$10 (to be drawn)	DROPPING_BLOCK

19 copies in 9 rooms, 2 of them raised by the nudge: $12, $82, $95, $9C, $A4, $AB, $B5, $B9, $F7.

6: A plain block that collapses when landed on -- OBJECT6

Graphic	Half U, V; height	Flags	Update routine
45	8, 8; 12	$10 (to be drawn)	COLLAPSING_BLOCK

203 copies in 38 rooms, 32 of them raised by the nudge: $02, $12, $15, $1B, $20, $27, $2F, $31, $3B, $3E, $3F, $40, $43, $44, $45, $46, $48, $4C, $59, $64, $6E, $75, $7B, $82, $87, $94, $95, $9A, $9C, $A4, $A7, $AA, $B5, $B6, $B8, $C7, $F7, $F8.

7: A crown of spikes on a base, deadly -- OBJECT7

Graphic	Half U, V; height	Flags	Update routine
46	8, 8; 12	$10 (to be drawn)	SPIKES

175 copies in 36 rooms, 2 of them raised by the nudge: $03, $04, $0D, $12, $15, $1A, $1D, $20, $27, $39, $3E, $40, $4A, $4C, $4F, $54, $57, $59, $5B, $64, $75, $76, $77, $86, $87, $88, $8A, $93, $95, $9C, $A7, $B6, $B9, $C7, $C8, $E7.

8: A plain block that carries things forwards in V -- OBJECT8

Graphic	Half U, V; height	Flags	Update routine
68	8, 8; 12	$10 (to be drawn)	CONVEYOR_PLUS_V

47 copies in 8 rooms: $0D, $1A, $23, $54, $5B, $76, $C9, $F7.

9: A plain block that carries things forwards in U -- OBJECT9

Graphic	Half U, V; height	Flags	Update routine
69	8, 8; 12	$10 (to be drawn)	CONVEYOR_PLUS_U

26 copies in 8 rooms, 1 of them raised by the nudge: $0D, $3B, $40, $43, $48, $4A, $96, $F7.

10: A plain block that carries things back in V -- OBJECT10

Graphic	Half U, V; height	Flags	Update routine
70	8, 8; 12	$10 (to be drawn)	CONVEYOR_MINUS_V

30 copies in 7 rooms: $0D, $12, $1D, $23, $54, $5B, $76.

11: A plain block that carries things back in U -- OBJECT11

Graphic	Half U, V; height	Flags	Update routine
71	8, 8; 12	$10 (to be drawn)	CONVEYOR_MINUS_U

22 copies in 5 rooms: $03, $0D, $1A, $3B, $43.

12: A plain block that lifts -- OBJECT12

Graphic	Half U, V; height	Flags	Update routine
47	8, 8; 12	$14 (pushable, to be drawn)	LIFT

13 copies in 6 rooms: $23, $34, $43, $93, $A6, $D6.

13: A plain block that shuttles in U -- OBJECT13

Graphic	Half U, V; height	Flags	Update routine
66	8, 8; 12	$10 (to be drawn)	SHUTTLE_U

3 copies in 2 rooms, 1 of them raised by the nudge: $3C, $61.

14: A plain block that shuttles in V -- OBJECT14

Graphic	Half U, V; height	Flags	Update routine
67	8, 8; 12	$10 (to be drawn)	SHUTTLE_V

6 copies in 4 rooms, 1 of them raised by the nudge: $30, $4F, $61, $F7.

15: A pyramid, deadly -- OBJECT15

Graphic	Half U, V; height	Flags	Update routine
72	8, 8; 12	$10 (to be drawn)	STILL_DEADLY

232 copies in 30 rooms, 7 of them raised by the nudge: $04, $14, $23, $24, $2F, $30, $33, $34, $36, $38, $3B, $43, $45, $46, $48, $54, $56, $61, $6B, $77, $78, $7D, $86, $98, $A4, $AB, $B8, $D6, $D7, $E7.

16: A crackle of sparks that chases him (the sparkle's sprites) -- OBJECT16

Graphic	Half U, V; height	Flags	Update routine
76	8, 8; 12	$10 (to be drawn)	SPARK_CHASER

6 copies in 6 rooms: $20, $3C, $57, $78, $9C, $A7.

17: A bug-eyed creature that wanders, on a lower half -- OBJECT17

Graphic	Half U, V; height	Flags	Update routine
94	7, 7; 12	$10 (to be drawn)	WANDERER
11	7, 7; 12	$10 (to be drawn)	LOWER_HALF

6 copies in 6 rooms, 1 of them raised by the nudge: $2F, $67, $89, $8A, $AB, $F8.

18: A bug-eyed creature that paces to and fro, on a lower half -- OBJECT18

Graphic	Half U, V; height	Flags	Update routine
86	7, 7; 12	$10 (to be drawn)	PACER
11	7, 7; 12	$10 (to be drawn)	LOWER_HALF

1 copy in 1 room: $A6.

19: A bug-eyed creature, the other view, that paces to and fro, on a lower half; mirrored -- OBJECT19

Graphic	Half U, V; height	Flags	Update routine
87	7, 7; 12	$50 (to be drawn, mirrored)	PACER
11	7, 7; 12	$50 (to be drawn, mirrored)	LOWER_HALF

2 copies in 2 rooms: $7B, $82.

20: A spiked dome that drops from the ceiling -- OBJECT20

Graphic	Half U, V; height	Flags	Update routine
73	8, 8; 12	$14 (pushable, to be drawn)	CEILING_DROP

25 copies in 4 rooms, 24 of them raised by the nudge: $0C, $1C, $58, $84.

21: A frozen spaceman: a cryonaut -- OBJECT21

Graphic	Half U, V; height	Flags	Update routine
74	8, 8; 24	$10 (to be drawn)	CRYONAUT

81 copies in 20 rooms: $0C, $1D, $28, $41, $4B, $4F, $65, $6E, $7A, $84, $8C, $8D, $94, $96, $99, $A5, $B6, $BA, $D6, $F8.

22: A frozen spaceman: a cryonaut; mirrored -- OBJECT22

Graphic	Half U, V; height	Flags	Update routine
74	8, 8; 24	$50 (to be drawn, mirrored)	CRYONAUT

51 copies in 13 rooms: $0A, $0C, $31, $41, $62, $65, $7A, $8C, $96, $A5, $AA, $B6, $D6.

23: Three cylinders on a plate, deadly -- OBJECT23

Graphic	Half U, V; height	Flags	Update routine
75	8, 8; 12	$14 (pushable, to be drawn)	STILL_DEADLY

168 copies in 27 rooms, 4 of them raised by the nudge: $04, $0B, $0C, $13, $1B, $31, $36, $37, $41, $42, $4B, $61, $62, $67, $6E, $7B, $8D, $94, $96, $99, $9A, $A5, $B5, $BA, $C6, $C8, $F8.

24: A domed socket on a plinth, for the valve of graphic 96 (a drum) -- OBJECT24

Graphic	Half U, V; height	Flags	Update routine
112	8, 8; 12	$10 (to be drawn)	SOCKET
108	8, 8; 12	$12 (out of collisions, to be drawn)	SOCKET_SPARKLE

6 copies in 6 rooms, 3 of them raised by the nudge: $0C, $28, $7A, $99, $A5, $B6.

25: A domed socket on a plinth, for the valve of graphic 97 (a cube) -- OBJECT25

Graphic	Half U, V; height	Flags	Update routine
113	8, 8; 12	$10 (to be drawn)	SOCKET
109	8, 8; 12	$12 (out of collisions, to be drawn)	SOCKET_SPARKLE

6 copies in 6 rooms, 3 of them raised by the nudge: $41, $62, $6E, $96, $AA, $D6.

26: A domed socket on a plinth, for the valve of graphic 98 (a point) -- OBJECT26

Graphic	Half U, V; height	Flags	Update routine
114	8, 8; 12	$10 (to be drawn)	SOCKET
110	8, 8; 12	$12 (out of collisions, to be drawn)	SOCKET_SPARKLE

6 copies in 6 rooms, 2 of them raised by the nudge: $1D, $31, $4B, $84, $8D, $94.

27: A domed socket on a plinth, for the valve of graphic 99 (a ball) -- OBJECT27

Graphic	Half U, V; height	Flags	Update routine
115	8, 8; 12	$10 (to be drawn)	SOCKET
111	8, 8; 12	$12 (out of collisions, to be drawn)	SOCKET_SPARKLE

6 copies in 6 rooms, 4 of them raised by the nudge: $0A, $4F, $65, $8C, $BA, $F8.

28: A clockwork mouse -- OBJECT28

Graphic	Half U, V; height	Flags	Update routine
116	7, 7; 12	$10 (to be drawn)	CLOCKWORK_MOUSE

9 copies in 7 rooms, 1 of them raised by the nudge: $3F, $42, $45, $4D, $72, $A9, $D8.

29: A domed column of rings that homes in on him -- OBJECT29

Graphic	Half U, V; height	Flags	Update routine
120	6, 6; 12	$10 (to be drawn)	SLOW_CHASER

2 copies in 2 rooms: $5E, $D8.

30: A little domed robot with feelers: a remote-controlled robot -- OBJECT30

Graphic	Half U, V; height	Flags	Update routine
124	7, 7; 12	$10 (to be drawn)	REMOTE_ROBOT

9 copies in 8 rooms: $0B, $44, $56, $6A, $6B, $74, $8B, $D9.

33 (page 2, number 1): A box with an arrow on its lid: a remote-control button -- OBJECT33

Graphic	Half U, V; height	Flags	Update routine
122	8, 8; 12	$10 (to be drawn)	REMOTE_BUTTON

8 copies in 8 rooms: $0B, $44, $56, $6A, $6B, $74, $8B, $D9.

34 (page 2, number 2): A box with an arrow on its lid: a remote-control button; mirrored -- OBJECT34

Graphic	Half U, V; height	Flags	Update routine
122	8, 8; 12	$50 (to be drawn, mirrored)	REMOTE_BUTTON

8 copies in 8 rooms: $0B, $44, $56, $6A, $6B, $74, $8B, $D9.

35 (page 2, number 3): A box with an arrow on its lid, the other way: a remote-control button -- OBJECT35

Graphic	Half U, V; height	Flags	Update routine
123	8, 8; 12	$10 (to be drawn)	REMOTE_BUTTON

8 copies in 8 rooms: $0B, $44, $56, $6A, $6B, $74, $8B, $D9.

36 (page 2, number 4): A box with an arrow on its lid, the other way: a remote-control button; mirrored -- OBJECT36

Graphic	Half U, V; height	Flags	Update routine
123	8, 8; 12	$50 (to be drawn, mirrored)	REMOTE_BUTTON

8 copies in 8 rooms: $0B, $44, $56, $6A, $6B, $74, $8B, $D9.

37 (page 2, number 5): A plain block: the remote-control pad -- OBJECT37

Graphic	Half U, V; height	Flags	Update routine
128	8, 8; 12	$10 (to be drawn)	REMOTE_PAD

8 copies in 8 rooms: $0B, $44, $56, $6A, $6B, $74, $8B, $D9.

38 (page 2, number 6): A round thing with prongs that breaks when moved -- OBJECT38

Graphic	Half U, V; height	Flags	Update routine
129	7, 7; 12	$14 (pushable, to be drawn)	FRAGILE

102 copies in 7 rooms: $44, $56, $6A, $72, $74, $8B, $D9.

39 (page 2, number 7): A spiky ball that leaps -- OBJECT39

Graphic	Half U, V; height	Flags	Update routine
130	8, 8; 12	$10 (to be drawn)	LEAPER

26 copies in 3 rooms: $97, $A9, $B7.