Game 2Unit 16 of 191 hr learning time
A Keep with Character
Compose the whole keep as one place. Let a room hold more than one torch — each floor cell lit by its nearest flame — and use that with per-room falloff to give every chamber its own character from one coherent toolset.
84% of Shadowkeep
We’ve given rooms moods one at a time. This unit pulls back and treats the whole keep as a single composition: three chambers that read as parts of one place, each lit to its own character, all from the same coherent set of tools. It’s the unit that turns “rooms with lighting” into “a keep you believe in”, and it closes the Mood and Light sub-arc.
The capability that makes it possible is a small but real upgrade: a room can have more than one torch.
What you’ll see by the end
The Hall, grandly lit now — three flames, their pools overlapping into a broad wash of light across the upper chamber, the statue and its banners standing in it, the thief and the Warden moving through it, the floor sinking to shadow toward the back. Walk to the Vault and it’s still a single flame in the black; the Gallery, two torches and a medium glow. One keep, one engine, three characters — and they feel like the same keep, lit by the same hand.
Many flames, nearest wins
Until now a room had one torch and find_torch looked for it. Now find_torches gathers every T in the room into a little list:
find_torches:
; ... scan the map; for each 'T', record (col, row) ...
; ... up to MAX_TORCHES, counting them in torch_count ...And a floor cell takes its light from whichever flame is closest — shade_for_cell measures the distance to each torch and keeps the smallest:
.sf_loop:
; distance from this cell to torch[i] ...
ld e, a ; this torch's distance
ld a, (min_dist)
cp e
jr c, .sf_keep ; already nearer
ld a, e
ld (min_dist), a ; new nearest
.sf_keep:
djnz .sf_loop
; ... then shift by the room's falloff and clamp, as before ...Two torches make two pools that overlap where they meet; three light a whole hall. The light stopped being one circle and became as many as the room has fires.
Character from a shared toolset
Now each room is composed with the same two dials — how many flames, and how fast they fade — turned to a different setting:
room_falloff:
defb 2 ; Hall — 3 sconces, broad: grand and bright
defb 1 ; Gallery — 2 torches, medium
defb 0 ; Vault — 1 flame on the altar, tight: a cryptThe Hall is generous and public — three sconces, soft falloff, light everywhere you’d gather. The Vault is private and fearful — one flame, sharp falloff, dark everywhere you’re not meant to linger. They’re opposites, and yet they’re plainly the same building, because they’re drawn with the same stone, the same dither ramp, the same flames. That coherence — variety within one clear hand — is what “character” means for a place. You’re no longer lighting rooms; you’re lighting a keep.
Milestone — light a keep, not a room
find_torch becomes find_torches: it gathers every T in a room into a short
list. shade_for_cell then measures a floor cell’s distance to each flame and keeps
the smallest, so two torches make two overlapping pools and three light a whole
hall. Paired with the per-room falloff from Unit 15, two dials — count of flames and
falloff — compose the grand Hall, the working Gallery and the crypt-dark Vault from
one shared toolset.
Step 1: many torches per room, each cell lit by its nearest flame
+79-42
| 1 | 1 | ; Shadowkeep — Unit 16: A Keep with Character | |
| 2 | 2 | ; Cumulative build; every step runs on its own. Narrative: the unit page. | |
| 3 | - | ; step-00 = Unit 15's end: each room one torch; now a room may hold many. | |
| 3 | + | ; step-01 lets a room hold many torches — each floor cell lit by its nearest flame. | |
| 4 | 4 | | |
| 5 | 5 | org 32768 | |
| 6 | 6 | | |
| ... | |||
| 11 | 11 | STATUE_ATTR equ %01001111 ; BRIGHT white on blue — pale stone (solid) | |
| 12 | 12 | BANNER_ATTR equ %01001011 ; BRIGHT magenta on blue — a hanging (solid) | |
| 13 | 13 | RUBBLE_ATTR equ %00001000 ; dim, like floor — walkable broken stone | |
| 14 | - | NO_TORCH equ $FF | |
| 15 | 14 | MAX_SHADE equ 4 | |
| 15 | + | MAX_TORCHES equ 4 | |
| 16 | 16 | THIEF equ %01001010 | |
| 17 | 17 | GOLD_ATTR equ %00000110 ; yellow ink, no BRIGHT -> walkable gold | |
| 18 | 18 | TOTAL_GOLD equ 6 | |
| ... | |||
| 154 | 154 | ; find_torch — scan the current room's map for 'T', remember where it is (or | |
| 155 | 155 | ; NO_TORCH if the room is unlit). | |
| 156 | 156 | ; ---------------------------------------------------------------------------- | |
| 157 | - | find_torch: | |
| 158 | - | ld a, NO_TORCH | |
| 159 | - | ld (torch_col), a | |
| 160 | - | ld (torch_row), a | |
| 157 | + | ; find_torches — collect every 'T' in the current room (up to MAX_TORCHES) into | |
| 158 | + | ; torch_list as (col, row) pairs; torch_count says how many. | |
| 159 | + | find_torches: | |
| 160 | + | xor a | |
| 161 | + | ld (torch_count), a | |
| 161 | 162 | call room_entry_addr | |
| 162 | 163 | ld a, (hl) | |
| 163 | 164 | inc hl | |
| 164 | 165 | ld h, (hl) | |
| 165 | 166 | ld l, a | |
| 166 | 167 | ld b, 0 | |
| 167 | - | .ft_row: | |
| 168 | + | .fr_row: | |
| 168 | 169 | ld c, 0 | |
| 169 | - | .ft_col: | |
| 170 | + | .fr_col: | |
| 170 | 171 | ld a, (hl) | |
| 171 | 172 | cp 'T' | |
| 172 | - | jr nz, .ft_skip | |
| 173 | - | ld a, c | |
| 174 | - | ld (torch_col), a | |
| 175 | - | ld a, b | |
| 176 | - | ld (torch_row), a | |
| 177 | - | .ft_skip: | |
| 173 | + | jr nz, .fr_skip | |
| 174 | + | ld a, (torch_count) | |
| 175 | + | cp MAX_TORCHES | |
| 176 | + | jr nc, .fr_skip | |
| 177 | + | push hl | |
| 178 | + | add a, a ; count * 2 | |
| 179 | + | ld e, a | |
| 180 | + | ld d, 0 | |
| 181 | + | ld hl, torch_list | |
| 182 | + | add hl, de | |
| 183 | + | ld (hl), c ; column | |
| 184 | + | inc hl | |
| 185 | + | ld (hl), b ; row | |
| 186 | + | pop hl | |
| 187 | + | ld a, (torch_count) | |
| 188 | + | inc a | |
| 189 | + | ld (torch_count), a | |
| 190 | + | .fr_skip: | |
| 178 | 191 | inc hl | |
| 179 | 192 | inc c | |
| 180 | 193 | ld a, c | |
| 181 | 194 | cp 32 | |
| 182 | - | jr nz, .ft_col | |
| 195 | + | jr nz, .fr_col | |
| 183 | 196 | inc b | |
| 184 | 197 | ld a, b | |
| 185 | 198 | cp 24 | |
| 186 | - | jr nz, .ft_row | |
| 199 | + | jr nz, .fr_row | |
| 187 | 200 | ret | |
| 188 | 201 | | |
| 189 | 202 | ; ---------------------------------------------------------------------------- | |
| ... | |||
| 193 | 206 | ; ---------------------------------------------------------------------------- | |
| 194 | 207 | shade_for_cell: | |
| 195 | 208 | push bc | |
| 196 | - | ld a, (torch_col) | |
| 197 | - | cp NO_TORCH | |
| 198 | - | jr z, .sf_dark | |
| 199 | 209 | ld a, b | |
| 200 | - | ld hl, torch_row | |
| 201 | - | sub (hl) | |
| 202 | - | jr nc, .sf_rpos | |
| 203 | - | neg | |
| 204 | - | .sf_rpos: | |
| 205 | - | ld d, a ; |row - torch_row| | |
| 210 | + | ld (cell_row), a | |
| 206 | 211 | ld a, c | |
| 207 | - | ld hl, torch_col | |
| 212 | + | ld (cell_col), a | |
| 213 | + | ld a, (torch_count) | |
| 214 | + | or a | |
| 215 | + | jr z, .sf_dark | |
| 216 | + | ld a, 255 | |
| 217 | + | ld (min_dist), a | |
| 218 | + | ld hl, torch_list | |
| 219 | + | ld a, (torch_count) | |
| 220 | + | ld b, a ; loop count | |
| 221 | + | .sf_loop: | |
| 222 | + | ld a, (cell_col) | |
| 223 | + | sub (hl) ; - torch col | |
| 224 | + | jr nc, .sf_dc | |
| 225 | + | neg | |
| 226 | + | .sf_dc: | |
| 227 | + | ld d, a ; |dc| | |
| 228 | + | inc hl ; -> torch row | |
| 229 | + | ld a, (cell_row) | |
| 208 | 230 | sub (hl) | |
| 209 | - | jr nc, .sf_cpos | |
| 231 | + | jr nc, .sf_dr | |
| 210 | 232 | neg | |
| 211 | - | .sf_cpos: | |
| 212 | - | cp d ; A = |dc|; max(|dc|, |dr|) | |
| 213 | - | jr nc, .sf_max | |
| 233 | + | .sf_dr: | |
| 234 | + | inc hl ; -> next torch pair | |
| 235 | + | cp d ; A = |dr|; take the larger | |
| 236 | + | jr nc, .sf_mx | |
| 214 | 237 | ld a, d | |
| 215 | - | .sf_max: | |
| 216 | - | ld e, a ; E = Chebyshev distance | |
| 217 | - | ld a, (current_room) ; shift it by THIS room's falloff | |
| 238 | + | .sf_mx: | |
| 239 | + | ld e, a ; this torch's distance | |
| 240 | + | ld a, (min_dist) | |
| 241 | + | cp e | |
| 242 | + | jr c, .sf_keep ; min already smaller | |
| 243 | + | ld a, e | |
| 244 | + | ld (min_dist), a | |
| 245 | + | .sf_keep: | |
| 246 | + | djnz .sf_loop | |
| 247 | + | | |
| 248 | + | ld a, (current_room) | |
| 218 | 249 | ld c, a | |
| 219 | 250 | ld b, 0 | |
| 220 | 251 | ld hl, room_falloff | |
| 221 | 252 | add hl, bc | |
| 222 | - | ld b, (hl) ; B = this room's falloff | |
| 223 | - | ld a, e | |
| 253 | + | ld b, (hl) | |
| 254 | + | ld a, (min_dist) | |
| 224 | 255 | inc b | |
| 225 | 256 | .sf_shift: | |
| 226 | 257 | dec b | |
| ... | |||
| 240 | 271 | ret | |
| 241 | 272 | | |
| 242 | 273 | draw_room: | |
| 243 | - | call find_torch | |
| 274 | + | call find_torches | |
| 244 | 275 | call room_entry_addr | |
| 245 | 276 | ld a, (hl) | |
| 246 | 277 | inc hl | |
| ... | |||
| 1122 | 1153 | defb "B..............S...............B" | |
| 1123 | 1154 | defb "#.............ooo.........G....#" | |
| 1124 | 1155 | defb "#..............................#" | |
| 1125 | - | defb "#........##..........##........#" | |
| 1156 | + | defb "T........##..........##........T" | |
| 1126 | 1157 | defb "#........##..........##........#" | |
| 1127 | 1158 | defb "#..............................#" | |
| 1128 | 1159 | defb "#..............................." | |
| ... | |||
| 1143 | 1174 | ; back to the Hall; north door (column 15) up to the Vault. | |
| 1144 | 1175 | room1_template: | |
| 1145 | 1176 | defb "###############.################" | |
| 1146 | - | defb "#..............................#" | |
| 1147 | 1177 | defb "#..............................#" | |
| 1148 | 1178 | defb "#..............................#" | |
| 1149 | 1179 | defb "#..............................#" | |
| 1180 | + | defb "#..............................T" | |
| 1150 | 1181 | defb "#..............................#" | |
| 1151 | 1182 | defb "#..............................#" | |
| 1152 | 1183 | defb "#..............................#" | |
| ... | |||
| 1271 | 1302 | defb WARDEN_GATHER | |
| 1272 | 1303 | caught: | |
| 1273 | 1304 | defb 0 | |
| 1274 | - | torch_col: | |
| 1275 | - | defb NO_TORCH | |
| 1276 | - | torch_row: | |
| 1277 | - | defb NO_TORCH | |
| 1305 | + | torch_count: | |
| 1306 | + | defb 0 | |
| 1307 | + | cell_row: | |
| 1308 | + | defb 0 | |
| 1309 | + | cell_col: | |
| 1310 | + | defb 0 | |
| 1311 | + | min_dist: | |
| 1312 | + | defb 0 | |
| 1313 | + | torch_list: | |
| 1314 | + | defs MAX_TORCHES * 2 | |
| 1278 | 1315 | | |
| 1279 | 1316 | room0_state: | |
| 1280 | 1317 | defs 768 |
The complete program
; Shadowkeep — Unit 16: A Keep with Character
; Cumulative build; every step runs on its own. Narrative: the unit page.
; step-01 lets a room hold many torches — each floor cell lit by its nearest flame.
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
MAX_SHADE equ 4
MAX_TORCHES 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_torches — collect every 'T' in the current room (up to MAX_TORCHES) into
; torch_list as (col, row) pairs; torch_count says how many.
find_torches:
xor a
ld (torch_count), a
call room_entry_addr
ld a, (hl)
inc hl
ld h, (hl)
ld l, a
ld b, 0
.fr_row:
ld c, 0
.fr_col:
ld a, (hl)
cp 'T'
jr nz, .fr_skip
ld a, (torch_count)
cp MAX_TORCHES
jr nc, .fr_skip
push hl
add a, a ; count * 2
ld e, a
ld d, 0
ld hl, torch_list
add hl, de
ld (hl), c ; column
inc hl
ld (hl), b ; row
pop hl
ld a, (torch_count)
inc a
ld (torch_count), a
.fr_skip:
inc hl
inc c
ld a, c
cp 32
jr nz, .fr_col
inc b
ld a, b
cp 24
jr nz, .fr_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:
push bc
ld a, b
ld (cell_row), a
ld a, c
ld (cell_col), a
ld a, (torch_count)
or a
jr z, .sf_dark
ld a, 255
ld (min_dist), a
ld hl, torch_list
ld a, (torch_count)
ld b, a ; loop count
.sf_loop:
ld a, (cell_col)
sub (hl) ; - torch col
jr nc, .sf_dc
neg
.sf_dc:
ld d, a ; |dc|
inc hl ; -> torch row
ld a, (cell_row)
sub (hl)
jr nc, .sf_dr
neg
.sf_dr:
inc hl ; -> next torch pair
cp d ; A = |dr|; take the larger
jr nc, .sf_mx
ld a, d
.sf_mx:
ld e, a ; this torch's distance
ld a, (min_dist)
cp e
jr c, .sf_keep ; min already smaller
ld a, e
ld (min_dist), a
.sf_keep:
djnz .sf_loop
ld a, (current_room)
ld c, a
ld b, 0
ld hl, room_falloff
add hl, bc
ld b, (hl)
ld a, (min_dist)
inc b
.sf_shift:
dec b
jr z, .sf_clamp
srl a
jr .sf_shift
.sf_clamp:
cp MAX_SHADE + 1
jr c, .sf_done
ld a, MAX_SHADE
.sf_done:
pop bc
ret
.sf_dark:
ld a, MAX_SHADE
pop bc
ret
draw_room:
call find_torches
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
; One byte of mood per room: how slowly its light fades.
room_falloff:
defb 2 ; Hall — broad, soft pool
defb 1 ; Gallery — medium
defb 0 ; Vault — tight pool, deep dark
; 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 "T........##..........##........T"
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 "#..............................T"
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 "################################"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#..............................#"
defb "#.............#T##.............#"
defb "#.............####.............#"
defb "#.............####.............#"
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_count:
defb 0
cell_row:
defb 0
cell_col:
defb 0
min_dist:
defb 0
torch_list:
defs MAX_TORCHES * 2
room0_state:
defs 768
room1_state:
defs 768
room2_state:
defs 768
end start
Walk the whole keep, end to end: the Hall opens out under its three flames, the Gallery settles to a working glow, the Vault closes in to its one cold light. Three rooms, one place — the two stills above are its grandest and its darkest, drawn by the same hand.
Try this: add a flame, take one away
Drop another T into a room’s map and watch a new pool bloom and overlap the others; delete one and watch a corner fall dark. You’re lighting by placing fires — the most physical way there is. Mind MAX_TORCHES; raise it if you want a room ablaze. (Keep them clear of a Warden’s route, or you light the danger and not the gold.)
Try this: a colonnade of light
Line a long room’s wall with a row of evenly-spaced sconces, falloff 1 or 2. The overlapping pools merge into a continuous band of light down the room — a lit gallery, a cathedral nave. Repetition of one element is its own kind of grandeur.
Try this: ruin the character
Give the Vault three torches and a falloff of 2. It floods with light and instantly stops being a crypt — it’s just another bright room. A useful failure: it shows that the Vault’s character was never the altar or the stone, it was the restraint. Put it back, and notice how much the darkness was doing.
When it’s wrong, see why
- Only one torch lights a room.
find_torchesis stopping at the firstT, orshade_for_cellisn’t looping overtorch_count. EveryTshould be collected and every one measured. - The machine slows to a crawl entering a room. Many torches × 768 cells is real work; it’s a one-time cost on entry, but keep
MAX_TORCHESmodest (a handful) so the redraw stays a flick, not a freeze. - A room is all dark with torches present.
torch_countcame back zero — the map’sTs aren’t being found, ormin_distisn’t being reset to a large value before the loop. - Two pools don’t overlap / one wins everywhere. The nearest test is backwards. Keep the smaller distance: update
min_distonly when the new distance is less. - Garbage after adding torches.
torch_listoverflowed — you placed more thanMAX_TORCHESand the count guard is missing. Thecp MAX_TORCHES/jr nccheck protects the list.
Before and after
You started with rooms that each held a single mood and finished with a whole keep composed as one place — the Hall grand under three sconces, the Vault a crypt with one cold flame, the Gallery somewhere between, and all three plainly the same building. The upgrade was small: a room gathers every torch it holds, and each cell takes its light from the nearest. With that and the falloff byte, two dials compose grand, working and fearful rooms from one shared toolset. You stopped lighting rooms and started lighting a keep — the difference between a set of screens and somewhere you believe in.
What you’ve learnt
- Light is as many pools as there are flames. Collect every torch; light each cell from the nearest. Pools overlap into the shape of the room’s fires.
- Character is variety within one hand. Two dials — count of flames and falloff — compose grand, working, and fearful rooms that still read as one building.
- Restraint is a feature. The Vault’s darkness, not its altar, is its character. Over-light it and it vanishes.
- A keep is a composition. You stopped lighting rooms and started lighting a place — the difference between a set of screens and somewhere to be.
What’s next
The keep looks like somewhere now — lit, furnished, composed — and it plays. But it’s near-silent: the coins chime, the win and the loss sound, and otherwise the stone is mute. A place you believe in has ambient sound — footsteps on stone, the creak of a door. The next sub-arc, The Keep’s Voice, gives it that. We begin in Unit 17, “Footsteps and Doors,” building on the beeper you rang the dusk bells with — turned now to stone and hinges — so the keep is heard as well as seen.