Knight Lore: Room structure

The castle

The castle is a grid of 16 by 16 squares, and a room's number is its square's row times 16 plus its column: leaving by the east side adds 1 and by the west side takes 1, north adds 16 and south takes 16 (screen_west to screen_south). 128 of the 256 squares are rooms. Below, every room is drawn by the game and put where the game's own projection places it -- east down to the right, north up to the right -- on its floor, so the castle can be seen whole. Click a room for its record, or see the whole castle at full size.

The markers show where things are, each read from the game's own tables: the four rooms a game can start in (start_locations, chosen by the menu's seed), the wizard's room, the rooms of the 32 places where a charm or an extra life lies (special_objs_tbl: the eight kinds are dealt round the places, four of each, from a different kind each game), and the rooms whose records build something that kills on touch or a portcullis, which kills what it falls on. A thing is counted as deadly when its handler sets the deadly flags (set_deadly_wipe_and_draw_flags or set_both_deadly_flags and their callers): the guards and the wizard, the ghosts, spikes, gargoyles, the spiked ball, fires, flames and the bouncing balls. Tick a box to show its layer.

Start rooms: $2F, $44, $8F, $B3.

The wizard and the cauldron: $88.

Charm places: $00, $04, $08, $0A, $0F, $22, $27, $38, $40, $42, $5E, $6D, $6F, $74, $7A, $87, $8D, $A8, $B4, $BA, $BB, $D0, $D2, $D6, $DF, $E8, $F0, $F3, $F6, $F9, $FD, $FF.

Guards and ghosts: $01, $09, $27, $2E, $37, $40, $58, $67, $6D, $78, $8C, $8E, $B7, $BB, $C7, $CF, $D1, $D3, $F3.

Spikes, fire, balls and gargoyles: $01, $03, $04, $08, $0A, $0C, $0E, $0F, $10, $12, $14, $18, $1D, $1F, $20, $21, $22, $24, $28, $2D, $2E, $30, $34, $38, $3F, $41, $42, $43, $45, $46, $48, $4F, $54, $67, $68, $6B, $6C, $6D, $6F, $74, $75, $76, $78, $79, $7A, $84, $85, $86, $87, $89, $8A, $8C, $8D, $93, $97, $98, $9B, $9F, $A3, $A8, $AA, $BA, $BF, $D0, $D1, $D2, $D3, $D6, $D7, $DF, $E0, $E2, $E3, $E7, $E8, $F0, $F1, $F7, $F9, $FE, $FF.

Portcullises: $09, $3F, $67, $87, $8C, $CF, $D3, $F1.

A room record

A room is a record of a few dozen bytes in location_tbl, and the records are packed end to end with no index: find_screen finds a room by walking them from the start. In order:

Byte	What
0	The room's number.
1	The record's length less one: the distance from this byte to the next record.
2	Bits 0-2 the ink the whole room is drawn in, always bright on black; bits 3-7 its size, an index into room_size_tbl.
3 ...	Its backgrounds, one byte each: indexes into background_type_tbl -- see the scenery.
$FF	The end of the backgrounds, if objects follow. A room with none just ends.
groups	A byte whose bits 3-7 are a template, an index into block_type_tbl (see the templates), and bits 0-2 the number of copies less one; then a position byte per copy.

A position byte is a cell of the room's floor and a level: bits 0-2 the x cell and bits 3-5 the y cell of an 8 by 8 grid, and bits 6-7 the level. next_fg_obj_sprite makes x = $48 + 16 times the x cell, y likewise, and z = the floor height + 12 times the level, then adds the template's offset.

The three sizes, as half-widths about the room's centre at 128, and the floor's height:

Size	Half x	Half y	Floor
0	64	64	$80
1	32	64	$80
2	64	32	$80

A room becomes object records from $5C08 up: the player's two, two for the room's charms, then everything the record names, background pieces first. That leaves 36 records, and six rooms need all 36.