Game 2Unit 14 of 191 hr learning time
Furnishings
A lit room is still a bare room. Add the things light falls on — a statue, banners, a scatter of rubble — as tiles in the palette. Bright ones you walk around, dim ones you walk over, and the keep starts to feel inhabited.
74% of Shadowkeep
The keep has light and shadow now, but its rooms are empty — stone, pillars, floor, and nothing to look at. A place you believe in has things in it: an altar, a statue, banners on the wall, a heap of rubble where the ceiling came down. This unit furnishes the keep — and it needs almost no new code, because furniture is just more tiles in the palette, placed in the map like everything else.
There’s one idea worth naming, and the engine already handles it: the difference between furniture you walk around and furniture you walk over.
What you’ll see by the end
The same lit Hall as last unit, but inhabited: a statue stands in the torchlight, banners hang on the walls, broken stone litters the floor at the statue’s base. Walk up to the statue and you stop — it’s solid. Walk onto the rubble and you stride right over it, and it’s still there behind you. Two kinds of furniture, and the keep didn’t need a single new rule to tell them apart.
Blocking is just brightness
Remember how collision works: a cell is solid if it’s BRIGHT, walkable if it’s dim. That one rule, from way back, sorts the furniture for free:
STATUE_ATTR equ %01001111 ; BRIGHT white — solid: walk around it
BANNER_ATTR equ %01001011 ; BRIGHT magenta — solid: it's on the wall
RUBBLE_ATTR equ %00001000 ; dim (like floor) — walkable: walk over itA statue is a wall that happens to look like a statue. Rubble is a floor that happens to look like broken stone. wall_at never knew the difference and never needs to — it just reads the brightness, exactly as it did for stone walls and slate floor. It is the same rule that stops the Warden walking through a wall, doing double duty. The furniture sorts itself.
Furniture is glyphs in the map
Each piece is a palette entry — a glyph, a tile, an attribute — and you place it by typing its letter into the room, clear of the coins and the Wardens’ routes:
defb "B..............S...............B" ; banners flanking a statue
defb "#.............ooo.........G....#" ; rubble at its feet, a coin beyondS a statue, B a banner, o rubble. The Hall now reads as a shrine: a figure in the light, hangings to either side, the floor strewn where time has worked on the stone. None of it is special-cased; it’s the same draw_room, the same lookup_tile, three more rows in the palette.
Walked-over, and remembered
The rubble is the interesting one, because it’s non-blocking — the thief walks over it. And here the work you did earlier pays off twice. His save-and-restore carries the rubble beneath him just as it carried slate and lit shade, so he crosses it without smearing it. And because rubble is a glyph in the room’s state buffer, it persists: leave the Hall and come back, and the broken stone is exactly where it lay. Furniture is part of the keep’s memory, for free.
(One honesty: furniture is drawn flat — it isn’t dimmed by distance to the torch the way the floor is. A statue in the dark is as bright as one in the light. Lighting the furniture too is a fine exercise, and the next unit leans hard on shade; for now, objects keep their own look.)
Milestone — furnish the keep
No new engine: furniture is palette entries placed in the maps. A statue and banners
take a bright attribute, so collision already treats them as solid; rubble takes
the dim floor attribute, so it stays walkable. draw_room, lookup_tile,
collision and the state buffers are all unchanged — the diff is three palette lines
and some letters typed into the templates.
Step 1: statue, banner and rubble tiles — bright blocks, dim doesn't
+49-7
| 1 | 1 | ; Shadowkeep — Unit 14: Furnishings | |
| 2 | 2 | ; Cumulative build; every step runs on its own. Narrative: the unit page. | |
| 3 | - | ; step-00 = Unit 13's end: lit rooms, but bare — no decoration yet. | |
| 3 | + | ; step-01 dresses the rooms — a statue, banners, rubble — scenery that makes a place. | |
| 4 | 4 | | |
| 5 | 5 | org 32768 | |
| 6 | 6 | | |
| ... | |||
| 8 | 8 | FLOOR_ATTR equ %00001000 | |
| 9 | 9 | MARK_ATTR equ %00001111 | |
| 10 | 10 | TORCH_ATTR equ %01001110 ; BRIGHT, blue paper, yellow ink — a lit sconce | |
| 11 | + | STATUE_ATTR equ %01001111 ; BRIGHT white on blue — pale stone (solid) | |
| 12 | + | BANNER_ATTR equ %01001011 ; BRIGHT magenta on blue — a hanging (solid) | |
| 13 | + | RUBBLE_ATTR equ %00001000 ; dim, like floor — walkable broken stone | |
| 11 | 14 | NO_TORCH equ $FF | |
| 12 | 15 | MAX_SHADE equ 4 | |
| 13 | 16 | THIEF equ %01001010 | |
| ... | |||
| 802 | 805 | defb %01111100 | |
| 803 | 806 | defb %00111000 | |
| 804 | 807 | defb %00010000 | |
| 808 | + | | |
| 809 | + | statue_tile: | |
| 810 | + | defb %00111100 | |
| 811 | + | defb %01111110 | |
| 812 | + | defb %00111100 | |
| 813 | + | defb %00011000 | |
| 814 | + | defb %00011000 | |
| 815 | + | defb %00111100 | |
| 816 | + | defb %01111110 | |
| 817 | + | defb %01111110 | |
| 818 | + | | |
| 819 | + | banner_tile: | |
| 820 | + | defb %01111110 | |
| 821 | + | defb %01111110 | |
| 822 | + | defb %01011010 | |
| 823 | + | defb %01011010 | |
| 824 | + | defb %01111110 | |
| 825 | + | defb %01111110 | |
| 826 | + | defb %00111100 | |
| 827 | + | defb %00011000 | |
| 828 | + | | |
| 829 | + | rubble_tile: | |
| 830 | + | defb %00000000 | |
| 831 | + | defb %01100000 | |
| 832 | + | defb %01100000 | |
| 833 | + | defb %00000110 | |
| 834 | + | defb %00000110 | |
| 835 | + | defb %00011000 | |
| 836 | + | defb %00011000 | |
| 837 | + | defb %00000000 | |
| 805 | 838 | | |
| 806 | 839 | ; ---------------------------------------------------------------------------- | |
| 807 | 840 | ; show_title — black screen, the keep's name and a prompt; wait for SPACE (and | |
| ... | |||
| 1034 | 1067 | defb 'T' | |
| 1035 | 1068 | defw torch_tile | |
| 1036 | 1069 | defb TORCH_ATTR | |
| 1070 | + | defb 'S' | |
| 1071 | + | defw statue_tile | |
| 1072 | + | defb STATUE_ATTR | |
| 1073 | + | defb 'B' | |
| 1074 | + | defw banner_tile | |
| 1075 | + | defb BANNER_ATTR | |
| 1076 | + | defb 'o' | |
| 1077 | + | defw rubble_tile | |
| 1078 | + | defb RUBBLE_ATTR | |
| 1037 | 1079 | | |
| 1038 | 1080 | ; ---------------------------------------------------------------------------- | |
| 1039 | 1081 | ; The keep: three rooms. Hall -east-> Gallery -north-> Vault, and back. | |
| ... | |||
| 1050 | 1092 | ; The Great Hall — four pillars, east door at row 11. | |
| 1051 | 1093 | room0_template: | |
| 1052 | 1094 | defb "###############T################" | |
| 1053 | - | defb "#..............................#" | |
| 1054 | 1095 | defb "#..............................#" | |
| 1055 | 1096 | defb "#..............................#" | |
| 1056 | 1097 | defb "#..............................#" | |
| 1057 | 1098 | defb "#..............................#" | |
| 1058 | - | defb "#.........................G....#" | |
| 1099 | + | defb "B..............S...............B" | |
| 1100 | + | defb "#.............ooo.........G....#" | |
| 1059 | 1101 | defb "#..............................#" | |
| 1060 | 1102 | defb "#........##..........##........#" | |
| 1061 | 1103 | defb "#........##..........##........#" | |
| ... | |||
| 1089 | 1131 | defb "#..............................#" | |
| 1090 | 1132 | defb "#..............................#" | |
| 1091 | 1133 | defb "........................G......#" | |
| 1092 | - | defb "#..............................#" | |
| 1093 | - | defb "#..............................#" | |
| 1094 | 1134 | defb "#..............................#" | |
| 1095 | 1135 | defb "#..............................#" | |
| 1096 | 1136 | defb "#..............................#" | |
| 1137 | + | defb "B..............................#" | |
| 1097 | 1138 | defb "#..............................#" | |
| 1098 | 1139 | defb "#..............................#" | |
| 1140 | + | defb "#........................ooo...#" | |
| 1099 | 1141 | defb "#..............................#" | |
| 1100 | 1142 | defb "#.......................G......#" | |
| 1101 | 1143 | defb "#..............................#" | |
| ... | |||
| 1115 | 1157 | defb "#..............................#" | |
| 1116 | 1158 | defb "#..............................#" | |
| 1117 | 1159 | defb "#..............................#" | |
| 1118 | - | defb "#.............####.............#" | |
| 1119 | - | defb "#.............####.............#" | |
| 1120 | 1160 | defb "#.............####.............#" | |
| 1161 | + | defb "B.............####.............#" | |
| 1162 | + | defb "#.............####.............B" | |
| 1121 | 1163 | defb "#.............####.............#" | |
| 1122 | 1164 | defb "#..............................#" | |
| 1123 | 1165 | defb "#..............................#" |
The complete program
; Shadowkeep — Unit 14: Furnishings
; Cumulative build; every step runs on its own. Narrative: the unit page.
; step-01 dresses the rooms — a statue, banners, rubble — scenery that makes a place.
org 32768
WALL_ATTR equ %01001000
FLOOR_ATTR equ %00001000
MARK_ATTR equ %00001111
TORCH_ATTR equ %01001110 ; BRIGHT, blue paper, yellow ink — a lit sconce
STATUE_ATTR equ %01001111 ; BRIGHT white on blue — pale stone (solid)
BANNER_ATTR equ %01001011 ; BRIGHT magenta on blue — a hanging (solid)
RUBBLE_ATTR equ %00001000 ; dim, like floor — walkable broken stone
NO_TORCH equ $FF
MAX_SHADE equ 4
THIEF equ %01001010
GOLD_ATTR equ %00000110 ; yellow ink, no BRIGHT -> walkable gold
TOTAL_GOLD equ 6
WARDEN equ %01000101 ; BRIGHT cyan on black — the sentinel
WARDEN_COL0 equ 26 ; the Hall's gold column
WARDEN_ROW0 equ 11
WARDEN_SPEED equ 10 ; frames between patrol steps
WARDEN_GATHER equ 50 ; a beat before it begins to move
AXIS_HORIZ equ 0 ; the Warden varies its column (walks a row)
AXIS_VERT equ 1 ; the Warden varies its row (walks a column)
WALL_BIT equ 6
START_COL equ 15
START_ROW equ 11
NO_EXIT equ $FF
KEYS_OP equ $DFFE
KEYS_Q equ $FBFE
KEYS_A equ $FDFE
KEYS_SPACE equ $7FFE
start:
ld a, 0
out ($FE), a
im 1
; --- TITLE -> PLAY -> WIN -> TITLE ------------------------------------------
main_title:
call show_title ; returns (interrupts off) when SPACE pressed
call new_game ; reset the keep, place the gold, draw
ei
.game_loop:
halt
ld a, (won)
or a
jr nz, .won
call player_step
call warden_step ; every room has its Warden now
ld a, (caught)
or a
jr nz, .lost
call mark_step
jr .game_loop
.lost:
call show_lose ; "THE KEEP SLEEPS", the sting, wait for SPACE
jr main_title
.won:
call show_win ; "THE KEEP STANDS", flourish, wait for SPACE
jr main_title ; round again
; new_game — copy the room templates back into working state (so collected gold
; returns), reset the thief, the gold counter and the win flag, draw the keep.
new_game:
ld hl, room0_template
ld de, room0_state
ld bc, 768
ldir
ld hl, room1_template
ld de, room1_state
ld bc, 768
ldir
ld hl, room2_template
ld de, room2_state
ld bc, 768
ldir
xor a
ld (current_room), a
ld (won), a
ld (caught), a
ld a, TOTAL_GOLD
ld (gold_remaining), a
ld a, START_COL
ld (thief_col), a
ld a, START_ROW
ld (thief_row), a
call draw_room
call save_under
call draw_thief
call warden_enter ; this room's Warden, from the table
call save_warden
call draw_warden
ret
mark_step:
ld bc, KEYS_SPACE
in a, (c)
bit 0, a
ret nz
call cell_state_addr
ld (hl), '+'
ld hl, mark_tile
ld de, under_thief
ld bc, 8
ldir
ld a, MARK_ATTR
ld (under_thief + 8), a
ret
cell_state_addr:
call room_entry_addr
ld a, (hl)
inc hl
ld h, (hl)
ld l, a
push hl
ld a, (thief_row)
ld l, a
ld h, 0
add hl, hl
add hl, hl
add hl, hl
add hl, hl
add hl, hl
ld a, (thief_col)
ld e, a
ld d, 0
add hl, de
pop de
add hl, de
ret
room_entry_addr:
ld a, (current_room)
ld l, a
ld h, 0
ld d, h
ld e, l
add hl, hl
add hl, de
add hl, hl
ld de, rooms
add hl, de
ret
; ----------------------------------------------------------------------------
; find_torch — scan the current room's map for 'T', remember where it is (or
; NO_TORCH if the room is unlit).
; ----------------------------------------------------------------------------
find_torch:
ld a, NO_TORCH
ld (torch_col), a
ld (torch_row), a
call room_entry_addr
ld a, (hl)
inc hl
ld h, (hl)
ld l, a
ld b, 0
.ft_row:
ld c, 0
.ft_col:
ld a, (hl)
cp 'T'
jr nz, .ft_skip
ld a, c
ld (torch_col), a
ld a, b
ld (torch_row), a
.ft_skip:
inc hl
inc c
ld a, c
cp 32
jr nz, .ft_col
inc b
ld a, b
cp 24
jr nz, .ft_row
ret
; ----------------------------------------------------------------------------
; shade_for_cell — row in B, column in C. Returns a shade 0..4 in A: the
; Chebyshev distance to the torch, halved and clamped. Near the flame = 0
; (lightest); far away = 4 (darkest). No torch = darkest everywhere.
; ----------------------------------------------------------------------------
shade_for_cell:
ld a, (torch_col)
cp NO_TORCH
jr z, .sf_dark
ld a, b
ld hl, torch_row
sub (hl)
jr nc, .sf_rpos
neg
.sf_rpos:
ld d, a ; |row - torch_row|
ld a, c
ld hl, torch_col
sub (hl)
jr nc, .sf_cpos
neg
.sf_cpos:
cp d ; A = |dc|; max(|dc|, |dr|)
jr nc, .sf_max
ld a, d
.sf_max:
srl a ; distance / 2
cp MAX_SHADE + 1
jr c, .sf_done
ld a, MAX_SHADE
.sf_done:
ret
.sf_dark:
ld a, MAX_SHADE
ret
draw_room:
call find_torch
call room_entry_addr
ld a, (hl)
inc hl
ld h, (hl)
ld l, a
ld (map_ptr), hl
ld b, 0
.room_row:
ld c, 0
.room_col:
ld hl, (map_ptr)
ld a, (hl)
cp '.'
jr nz, .not_floor
call shade_for_cell
add a, a
ld e, a
ld d, 0
ld hl, shade_tiles
add hl, de
ld e, (hl)
inc hl
ld d, (hl)
ld (tile_ptr), de
ld a, FLOOR_ATTR
ld (tile_attr), a
call draw_tile
jr .cell_done
.not_floor:
call lookup_tile
call draw_tile
.cell_done:
ld hl, (map_ptr)
inc hl
ld (map_ptr), hl
inc c
ld a, c
cp 32
jr nz, .room_col
inc b
ld a, b
cp 24
jr nz, .room_row
ret
lookup_tile:
ld hl, palette
.scan:
cp (hl)
jr z, .found
inc hl
inc hl
inc hl
inc hl
jr .scan
.found:
inc hl
ld e, (hl)
inc hl
ld d, (hl)
ld (tile_ptr), de
inc hl
ld a, (hl)
ld (tile_attr), a
ret
draw_tile:
push bc
call attr_addr_cr
ld a, (tile_attr)
ld (hl), a
call scr_addr_cr
ld de, (tile_ptr)
ld b, 8
.tile_row:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .tile_row
pop bc
ret
player_step:
ld a, (thief_col)
ld (tcol), a
ld a, (thief_row)
ld (trow), a
ld bc, KEYS_OP
in a, (c)
bit 1, a
jr z, .left
bit 0, a
jr z, .right
ld bc, KEYS_Q
in a, (c)
bit 0, a
jr z, .up
ld bc, KEYS_A
in a, (c)
bit 0, a
jr z, .down
ret
.left:
ld hl, tcol
dec (hl)
jr .move
.right:
ld hl, tcol
inc (hl)
jr .move
.up:
ld hl, trow
dec (hl)
jr .move
.down:
ld hl, trow
inc (hl)
.move:
ld a, (trow)
ld b, a
ld a, (tcol)
ld c, a
call wall_at
ret nz
call restore_under
ld a, (tcol)
ld (thief_col), a
ld a, (trow)
ld (thief_row), a
call collect_gold ; the new cell might be gold — lift it first
call save_under
call draw_thief
call check_exit
ret
wall_at:
call attr_addr_cr
bit WALL_BIT, (hl)
ret
check_exit:
ld a, (thief_col)
or a
jr z, .west
cp 31
jr z, .east
ld a, (thief_row)
or a
jr z, .north
cp 23
jr z, .south
ret
.east:
call room_entry_addr
ld de, 4
add hl, de
ld a, (hl)
cp NO_EXIT
ret z
ld (current_room), a
ld a, 1
ld (thief_col), a
jr .enter
.west:
call room_entry_addr
ld de, 5
add hl, de
ld a, (hl)
cp NO_EXIT
ret z
ld (current_room), a
ld a, 30
ld (thief_col), a
jr .enter
.north:
call room_entry_addr
inc hl
inc hl
ld a, (hl)
cp NO_EXIT
ret z
ld (current_room), a
ld a, 22
ld (thief_row), a
jr .enter
.south:
call room_entry_addr
inc hl
inc hl
inc hl
ld a, (hl)
cp NO_EXIT
ret z
ld (current_room), a
ld a, 1
ld (thief_row), a
.enter:
call draw_room
call save_under
call draw_thief
call warden_enter ; this room's Warden, clear of the entry cell
call save_warden
call draw_warden
ret
pos_bc:
ld a, (thief_row)
ld b, a
ld a, (thief_col)
ld c, a
ret
save_under:
call pos_bc
call scr_addr_cr
ld de, under_thief
ld b, 8
.save_row:
ld a, (hl)
ld (de), a
inc de
inc h
djnz .save_row
call pos_bc
call attr_addr_cr
ld a, (hl)
ld (under_thief + 8), a
ret
restore_under:
call pos_bc
call scr_addr_cr
ld de, under_thief
ld b, 8
.restore_row:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .restore_row
call pos_bc
call attr_addr_cr
ld a, (under_thief + 8)
ld (hl), a
ret
draw_thief:
call pos_bc
call attr_addr_cr
ld (hl), THIEF
call pos_bc
call scr_addr_cr
ld de, thief
ld b, 8
.thief_row:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .thief_row
ret
; ----------------------------------------------------------------------------
; The Warden — something shares the keep. A second mover, drawn exactly like the
; thief: a private under-buffer and its own save / draw, a spectral hooded
; sentinel. First we simply give it a body (it neither moves nor harms yet).
; ----------------------------------------------------------------------------
wpos_bc:
ld a, (warden_row)
ld b, a
ld a, (warden_col)
ld c, a
ret
save_warden:
call wpos_bc
call scr_addr_cr
ld de, under_warden
ld b, 8
.svw_row:
ld a, (hl)
ld (de), a
inc de
inc h
djnz .svw_row
call wpos_bc
call attr_addr_cr
ld a, (hl)
ld (under_warden + 8), a
ret
draw_warden:
call wpos_bc
call attr_addr_cr
ld (hl), WARDEN
call wpos_bc
call scr_addr_cr
ld de, warden_glyph
ld b, 8
.drw_row:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .drw_row
ret
; A spectral hooded sentinel: a cowl with dark eye-slits over a robe that frays
; at the hem. Cold, faceless, unmistakably a figure.
warden_glyph:
defb %00111100
defb %01111110
defb %01100110
defb %01111110
defb %00111100
defb %01111110
defb %01111110
defb %01011010
restore_warden:
call wpos_bc
call scr_addr_cr
ld de, under_warden
ld b, 8
.rsw_row:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .rsw_row
call wpos_bc
call attr_addr_cr
ld a, (under_warden + 8)
ld (hl), a
ret
; warden_step — the patrol. Walks its column one cell every WARDEN_SPEED frames,
; after a WARDEN_GATHER beat, reversing at walls. Deterministic: a route you learn
; and time. It reads the thief's cell as a wall (his attribute has WALL_BIT set),
; so it turns aside at him for now — the catch is Unit 11.
warden_step:
ld a, (warden_timer)
dec a
ld (warden_timer), a
ret nz
ld a, WARDEN_SPEED
ld (warden_timer), a
; propose the next cell along the patrol axis, in the current dir
ld a, (warden_axis)
or a
jr nz, .ws_vert
.ws_horiz:
ld a, (warden_row)
ld b, a ; B = row (fixed)
ld a, (warden_dir)
ld hl, warden_col
add a, (hl)
ld c, a ; C = next col
jr .ws_have
.ws_vert:
ld a, (warden_col)
ld c, a ; C = col (fixed)
ld a, (warden_dir)
ld hl, warden_row
add a, (hl)
ld b, a ; B = next row
.ws_have:
ld a, b ; the thief there? caught — check BEFORE
ld hl, thief_row ; wall_at, because his own cell reads as wall
cp (hl)
jr nz, .ws_wall
ld a, c
ld hl, thief_col
cp (hl)
jr nz, .ws_wall
ld a, 1
ld (caught), a
ret
.ws_wall:
push bc
call wall_at
pop bc
jr z, .ws_commit ; floor ahead — step onto it
ld a, (warden_dir) ; wall ahead — reverse, wait a beat
neg
ld (warden_dir), a
ret
.ws_commit:
push bc ; keep the proposed (row B, col C)
call restore_warden
pop bc
ld a, c
ld (warden_col), a
ld a, b
ld (warden_row), a
call save_warden ; photograph the new cell's ground
call draw_warden
ret
; ----------------------------------------------------------------------------
; warden_enter — instantiate the current room's Warden from warden_table: place
; it at the route-start (chosen clear of the entry cell), set its axis, and start
; its gather. Called on new_game and on every room change. A second mover is a
; table entry — like the torches and the gold.
; ----------------------------------------------------------------------------
warden_enter:
ld a, (current_room)
add a, a
add a, a ; * 4 bytes per table row
ld e, a
ld d, 0
ld hl, warden_table
add hl, de
ld a, (hl)
ld (warden_col), a
inc hl
ld a, (hl)
ld (warden_row), a
inc hl
ld a, (hl)
ld (warden_dir), a
inc hl
ld a, (hl)
ld (warden_axis), a
ld a, WARDEN_GATHER
ld (warden_timer), a
ret
; warden_table — one row per room: start col, start row, dir (+1/-1), axis.
; Each route crosses that room's gold and starts clear of the entry cell.
warden_table:
defb WARDEN_COL0, WARDEN_ROW0, -1, AXIS_VERT ; Hall — the gold's column
defb 24, 15, -1, AXIS_VERT ; Gallery — column 24, lower chamber
defb 15, 20, -1, AXIS_HORIZ ; Vault — row 20, between the coins
; ----------------------------------------------------------------------------
; The gold — the keep's goal. Step onto a coin and it lifts: the map cell turns
; to floor (gone for good), the cell repaints as plain floor (no lighting yet),
; a chime sounds, and the counter ticks down.
; ----------------------------------------------------------------------------
collect_gold:
call cell_state_addr ; HL -> map cell at the thief's position
ld a, (hl)
cp 'G'
ret nz
ld (hl), '.' ; the gold is taken — floor from now on
call pos_bc ; B = row, C = col
call draw_floor_cell ; repaint the cell as plain floor
call sfx_pickup
ld hl, gold_remaining
dec (hl)
ld a, (hl)
or a
call z, win ; the last coin — the keep stands
ret
; draw_floor_cell — paint the floor tile at (row B, col C). Lighting (Unit 13)
; will replace this with a shade chosen by distance from the nearest torch.
draw_floor_cell:
call shade_for_cell
add a, a
ld e, a
ld d, 0
ld hl, shade_tiles
add hl, de
ld e, (hl)
inc hl
ld d, (hl)
ld (tile_ptr), de
ld a, FLOOR_ATTR
ld (tile_attr), a
call draw_tile
ret
; ----------------------------------------------------------------------------
; beep — the one tone primitive (the tiny game's blip, reused). B = cycles,
; C = the delay between speaker toggles (the pitch; larger C = lower).
; ----------------------------------------------------------------------------
beep:
.bp_cycle:
ld a, %00010000
out ($FE), a
ld e, c
.bp_hi:
dec e
jr nz, .bp_hi
xor a
out ($FE), a
ld e, c
.bp_lo:
dec e
jr nz, .bp_lo
djnz .bp_cycle
ret
; sfx_pickup — a bright two-blip chime: the sound of gold.
sfx_pickup:
ld b, 8
ld c, 20
call beep
ld b, 8
ld c, 14
call beep
ret
gold_tile:
defb %00000000
defb %00111100
defb %01111110
defb %01111110
defb %01111110
defb %01111110
defb %00111100
defb %00000000
; The shade ramp: lightest (lit) to darkest (deep shadow), all blue/black dither.
shade_tiles:
defw shade0_tile
defw shade1_tile
defw shade2_tile
defw shade3_tile
defw shade4_tile
shade0_tile: ; lit — nearly all blue
defb %00000000
defb %00100010
defb %00000000
defb %00000000
defb %00000000
defb %10001000
defb %00000000
defb %00000000
shade1_tile:
defb %00100010
defb %00000000
defb %10001000
defb %00000000
defb %00100010
defb %00000000
defb %10001000
defb %00000000
shade2_tile: ; the half-and-half slate from Unit 2
defb %10101010
defb %01010101
defb %10101010
defb %01010101
defb %10101010
defb %01010101
defb %10101010
defb %01010101
shade3_tile:
defb %10101010
defb %11111111
defb %01010101
defb %11111111
defb %10101010
defb %11111111
defb %01010101
defb %11111111
shade4_tile: ; deep shadow — nearly all black
defb %11111111
defb %11101110
defb %11111111
defb %10111011
defb %11111111
defb %11101110
defb %11111111
defb %10111011
torch_tile: ; a flame in its sconce
defb %00010000
defb %00111000
defb %00111000
defb %01111100
defb %01111100
defb %01111100
defb %00111000
defb %00010000
statue_tile:
defb %00111100
defb %01111110
defb %00111100
defb %00011000
defb %00011000
defb %00111100
defb %01111110
defb %01111110
banner_tile:
defb %01111110
defb %01111110
defb %01011010
defb %01011010
defb %01111110
defb %01111110
defb %00111100
defb %00011000
rubble_tile:
defb %00000000
defb %01100000
defb %01100000
defb %00000110
defb %00000110
defb %00011000
defb %00011000
defb %00000000
; ----------------------------------------------------------------------------
; show_title — black screen, the keep's name and a prompt; wait for SPACE (and
; release). Silent for now — the composed theme arrives in Unit 18. Words use the
; ROM's own 8x8 font at $3D00.
; ----------------------------------------------------------------------------
show_title:
di
call clear_screen
ld hl, str_title
ld b, 8
ld c, 11
call print_string
ld hl, str_prompt
ld b, 16
ld c, 6
call print_string
.tt_wait:
ld bc, KEYS_SPACE
in a, (c)
bit 0, a
jr nz, .tt_wait
.tt_rel:
ld bc, KEYS_SPACE
in a, (c)
bit 0, a
jr z, .tt_rel
ret
; show_win — the keep is cleared. Black screen, the words, the flourish, then
; wait for SPACE (and release) to return to the title.
show_win:
di
call clear_screen
ld hl, str_won
ld b, 9
ld c, 8
call print_string
ld hl, str_again
ld b, 15
ld c, 5
call print_string
call sfx_win
.sw_wait:
ld bc, KEYS_SPACE
in a, (c)
bit 0, a
jr nz, .sw_wait
.sw_rel:
ld bc, KEYS_SPACE
in a, (c)
bit 0, a
jr z, .sw_rel
ret
; win — the last coin is gone. Flourish, and raise the flag the loop watches.
win:
ld a, 1
ld (won), a
call sfx_win
ret
; sfx_win — an ascending flourish: a low note climbing in steps to a high one.
sfx_win:
ld c, 60
.swf_loop:
ld b, 12
push bc
call beep
pop bc
ld a, c
sub 8
ld c, a
cp 16
jr nc, .swf_loop
ret
; clear_screen — fill bitmap and attributes with zero: a black screen.
clear_screen:
ld hl, $4000
ld (hl), 0
ld de, $4001
ld bc, 6911
ldir
ret
; print_string — HL -> zero-terminated text, B = row, C = col.
print_string:
.ps_loop:
ld a, (hl)
or a
ret z
push hl
call print_char
pop hl
inc hl
inc c
jr .ps_loop
; print_char — A = character (32..127), B = row, C = col. Copies the ROM font
; glyph at $3D00 + (char-32)*8 to the screen, bright white.
print_char:
push bc
sub 32
ld l, a
ld h, 0
add hl, hl
add hl, hl
add hl, hl
ld de, $3D00
add hl, de
push hl
call scr_addr_cr
pop de
ld b, 8
.pc_row:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .pc_row
pop bc
call attr_addr_cr
ld (hl), %01000111
ret
str_title:
defb "SHADOWKEEP", 0
str_prompt:
defb "PRESS SPACE TO ENTER", 0
str_won:
defb "THE KEEP STANDS", 0
str_again:
defb "PRESS SPACE TO RETURN", 0
; ----------------------------------------------------------------------------
; show_lose — the mirror of show_win. Black screen, the words, the freezing
; sting, then wait for SPACE (and release) to return to the title.
; ----------------------------------------------------------------------------
show_lose:
di
call clear_screen
ld hl, str_lost
ld b, 9
ld c, 8
call print_string
ld hl, str_again
ld b, 15
ld c, 5
call print_string
call sfx_caught
.slo_wait:
ld bc, KEYS_SPACE
in a, (c)
bit 0, a
jr nz, .slo_wait
.slo_rel:
ld bc, KEYS_SPACE
in a, (c)
bit 0, a
jr z, .slo_rel
ret
; sfx_caught — the plunge into stasis: a quick fall, then a deep, long toll as
; the stone closes over you. The opposite of the win flourish.
sfx_caught:
ld c, 16
.sca_fall:
ld b, 5
push bc
call beep
pop bc
ld a, c
add a, 7
ld c, a
cp 100
jr c, .sca_fall
ld b, 60
ld c, 130
call beep
ret
str_lost:
defb "THE KEEP SLEEPS", 0
scr_addr_cr:
ld a, b
and %00011000
or %01000000
ld h, a
ld a, b
and %00000111
rrca
rrca
rrca
or c
ld l, a
ret
attr_addr_cr:
ld a, b
ld l, a
ld h, 0
add hl, hl
add hl, hl
add hl, hl
add hl, hl
add hl, hl
ld de, $5800
add hl, de
ld a, c
ld e, a
ld d, 0
add hl, de
ret
palette:
defb '.'
defw floor_tile
defb FLOOR_ATTR
defb '#'
defw wall_tile
defb WALL_ATTR
defb '+'
defw mark_tile
defb MARK_ATTR
defb 'G'
defw gold_tile
defb GOLD_ATTR
defb 'T'
defw torch_tile
defb TORCH_ATTR
defb 'S'
defw statue_tile
defb STATUE_ATTR
defb 'B'
defw banner_tile
defb BANNER_ATTR
defb 'o'
defw rubble_tile
defb RUBBLE_ATTR
; ----------------------------------------------------------------------------
; The keep: three rooms. Hall -east-> Gallery -north-> Vault, and back.
; entry: map ptr, North, South, East, West
; ----------------------------------------------------------------------------
rooms:
defw room0_state
defb NO_EXIT, NO_EXIT, 1, NO_EXIT ; Hall: east -> Gallery
defw room1_state
defb 2, NO_EXIT, NO_EXIT, 0 ; Gallery: north -> Vault, west -> Hall
defw room2_state
defb NO_EXIT, 1, NO_EXIT, NO_EXIT ; Vault: south -> Gallery
; The Great Hall — four pillars, east door at row 11.
room0_template:
defb "###############T################"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "B..............S...............B"
defb "#.............ooo.........G....#"
defb "#..............................#"
defb "#........##..........##........#"
defb "#........##..........##........#"
defb "#..............................#"
defb "#..............................."
defb "#..............................#"
defb "#..............................#"
defb "#........##..........##........#"
defb "#........##..........##........#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#.........................G....#"
defb "#..............................#"
defb "#..............................#"
defb "################################"
; The Gallery — a dividing wall with one gap (column 15). West door (row 11)
; back to the Hall; north door (column 15) up to the Vault.
room1_template:
defb "###############.################"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "###############.################"
defb "#..............................#"
defb "#..............................#"
defb "........................G......#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "B..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#........................ooo...#"
defb "#..............................#"
defb "#.......................G......#"
defb "#..............................#"
defb "#..............................#"
defb "###############T################"
; The Vault — a great altar of stone in the middle, south door (column 15)
; down to the Gallery.
room2_template:
defb "###############T################"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#.............####.............#"
defb "B.............####.............#"
defb "#.............####.............B"
defb "#.............####.............#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#.........G.........G..........#"
defb "#..............................#"
defb "#..............................#"
defb "###############.################"
floor_tile:
defb %10101010
defb %01010101
defb %10101010
defb %01010101
defb %10101010
defb %01010101
defb %10101010
defb %01010101
wall_tile:
defb %00010001
defb %00000000
defb %01000100
defb %00000000
defb %00010001
defb %00000000
defb %01000100
defb %00000000
mark_tile:
defb %00000000
defb %00011000
defb %00011000
defb %01111110
defb %01111110
defb %00011000
defb %00011000
defb %00000000
thief:
defb %00011000
defb %00111100
defb %01111110
defb %01111110
defb %01111110
defb %01111110
defb %00111100
defb %00100100
current_room:
defb 0
thief_col:
defb START_COL
thief_row:
defb START_ROW
tcol:
defb 0
trow:
defb 0
map_ptr:
defw 0
tile_ptr:
defw 0
tile_attr:
defb 0
under_thief:
defb 0, 0, 0, 0, 0, 0, 0, 0, 0
gold_remaining:
defb TOTAL_GOLD
won:
defb 0
under_warden:
defb 0, 0, 0, 0, 0, 0, 0, 0, 0
warden_col:
defb WARDEN_COL0
warden_row:
defb WARDEN_ROW0
warden_dir:
defb -1
warden_axis:
defb AXIS_VERT
warden_timer:
defb WARDEN_GATHER
caught:
defb 0
torch_col:
defb NO_TORCH
torch_row:
defb NO_TORCH
room0_state:
defs 768
room1_state:
defs 768
room2_state:
defs 768
end start
Walk up to the statue and it turns you back; the rubble at its feet you stride right over, and it stays where it lay behind you. Two kinds of furniture, one collision rule:
Try this: furnish a room yourself
Open a room template and dress it. Put a statue at the end of the Gallery; line its walls with banners; pile rubble where a wall has failed. You’re set-dressing by typing letters — the fastest art tool there is. Keep the thief’s start, the doorways, the coins and the Wardens’ routes clear, and remember bright is solid.
Try this: rubble you can clear
Rubble is a glyph in the room’s state. Add a key that, when the thief stands on rubble, writes . over it — he’s cleared the debris, and it stays cleared because the state remembers. You’ve made the world not just furnished but changeable: the first step from scenery toward things the player acts on.
Try this: a new piece
Design one more: a well (a dark round hole — solid, you can’t cross it), or a rug (a coloured floor — walkable, just decoration). One tile, one palette line, one attribute (bright to block, dim to walk). See how few bytes a new piece of the world costs.
When it’s wrong, see why
- The thief walks through the statue. Its attribute isn’t bright —
wall_atonly blocks bright cells. Statues and banners must have bit 6 set. - The thief can’t cross the rubble. Its attribute is bright. Rubble must be dim (share
FLOOR_ATTR) to stay walkable. - The rubble vanishes when he walks over it. That’s a save/restore fault — but it shouldn’t happen, since rubble is in the state buffer and
restore_underlays back whatever was beneath him. Check you didn’t special-case the draw. - A glyph draws as blank or garbage. It isn’t in the palette, so
lookup_tilescans off the end. Every furniture letter (S,B,o) needs an entry. - A room is shifted. A furnished template row isn’t 32 characters any more — adding a letter means removing a
., not pushing the row longer. Count it.
Before and after
You started with rooms that were lit but bare and finished with a keep that looks inhabited — a statue in the torchlight, banners on the walls, rubble underfoot. None of it took new engine code: furniture is glyphs in the palette, and the brightness rule that already sorts wall from floor (and stops the Warden at a wall) sorts the solid statue from the walkable rubble for nothing. The walkable pieces ride the hero’s save/restore and live in the room’s state, so he crosses them cleanly and they persist. Set-dressing turned out to be design — letters typed into a map — not engineering.
What you’ve learnt
- Furniture is tiles. A statue, a banner, rubble — each a glyph, a pattern and a colour in the palette, placed by typing into the map.
- Blocking is brightness, again. The collision rule you already had sorts solid furniture from walkable furniture with no new code: bright blocks, dim doesn’t.
- Non-blocking scenery is free and persistent. Walkable decoration rides the hero’s save/restore and lives in the room’s state, so he crosses it cleanly and it remembers.
- Set-dressing is design, not engineering. Once the palette is rich enough, making a room feel inhabited is something you do in a text editor.
What’s next
The keep is lit and furnished — now to compose with it. In Unit 15, “Mood through Constraint,” we stop adding features and start using restraint: dark rooms with a single lit pool, sharp contrast between gloom and flame, the eye led by light. With only two colours a cell and a ramp of dither, the limit itself becomes the vocabulary — and a plain stone room becomes a place with a feeling. Atmosphere is as much what you withhold as what you add.