Game 1Unit 6 of 101 hr learning time
The Night Deepens
One dusk becomes a five-watch night: the run/watch state split, a win screen that deepens instead of ending, escalation as two data tables and a corner probe — and a small lie in the lives display, caught and fixed.
60% of The Long Night
Your redesigned dusk is a genuinely good fight now — and it’s over in a few minutes, once, with nowhere to go. The night you’ve built deserves a shape: this unit makes Gloaming’s single dusk the first of five watches. Hold a dusk and the night doesn’t end — it deepens: the square relights, the dark returns faster and hungrier, and your lives — this matters — carry. One run, five escalating fights, mounting stakes. That’s a game with an arc instead of an encounter.
Milestone 1 — a run of watches
The design question hiding in “the night continues” is precise: what resets per watch, and what persists per run? Lamps, pools, tendril, positions — per watch. Lives and the watch counter — per run. The code draws that line as two entry points: init_run (dusk to zero, lives to full) falling through into init_game (everything else), so a fresh night enters at the top and a held dusk re-enters halfway down.
And the state machine gets the module’s best structural trick for free. When you win a dusk, the game shows THE NIGHT IS HELD and waits — exactly as it always has. The only change is what SPACE means there: end_step checks whether you’re on a win or a loss, and a win now bumps dusk and re-enters init_game instead of returning to the title. The win screen has become an interstitial — the same screen, the same code, re-purposed as a breath between rounds. Only NIGHT FALLS still leads home.
Step 1: init_run / init_game, and the held screen becomes an interstitial
+29-7
| 40 | 40 | | |
| 41 | 41 | STATE_TITLE equ 0 | |
| 42 | 42 | STATE_PLAY equ 1 | |
| 43 | - | STATE_WIN equ 2 ; the night is held — the game is won | |
| 43 | + | STATE_WIN equ 2 ; a dusk held — the night deepens | |
| 44 | 44 | STATE_LOSE equ 3 ; night falls — the game is lost | |
| 45 | 45 | | |
| 46 | 46 | LOCK equ 25 ; input-lock frames after entering a screen | |
| ... | |||
| 111 | 111 | in a, (c) | |
| 112 | 112 | bit 0, a | |
| 113 | 113 | ret nz | |
| 114 | - | call init_game | |
| 114 | + | call init_run | |
| 115 | 115 | ld a, STATE_PLAY | |
| 116 | 116 | ld (game_state), a | |
| 117 | 117 | ret | |
| 118 | 118 | | |
| 119 | 119 | ; ---------------------------------------------------------------------------- | |
| 120 | - | ; end_step — WIN or LOSE: SPACE returns to the title. | |
| 120 | + | ; end_step — after the lock, SPACE moves on. A held dusk continues | |
| 121 | + | ; the run — the night deepens; only NIGHT FALLS returns to the title. | |
| 121 | 122 | ; ---------------------------------------------------------------------------- | |
| 122 | 123 | end_step: | |
| 123 | 124 | ld a, (input_lock) | |
| ... | |||
| 131 | 132 | in a, (c) | |
| 132 | 133 | bit 0, a | |
| 133 | 134 | ret nz | |
| 135 | + | ld a, (game_state) | |
| 136 | + | cp STATE_WIN | |
| 137 | + | jr z, .deeper | |
| 134 | 138 | call draw_title_screen | |
| 135 | 139 | call chime_dusk | |
| 136 | 140 | ld a, LOCK | |
| 137 | 141 | ld (input_lock), a | |
| 138 | 142 | ld a, STATE_TITLE | |
| 143 | + | ld (game_state), a | |
| 144 | + | ret | |
| 145 | + | .deeper: | |
| 146 | + | ; the dusk was held — the night is NOT over. Deepen and | |
| 147 | + | ; go again: the square relights, and the lives carry. | |
| 148 | + | ld hl, dusk | |
| 149 | + | inc (hl) | |
| 150 | + | call init_game | |
| 151 | + | ld a, STATE_PLAY | |
| 139 | 152 | ld (game_state), a | |
| 140 | 153 | ret | |
| 141 | 154 | | |
| ... | |||
| 170 | 183 | ret | |
| 171 | 184 | | |
| 172 | 185 | ; ---------------------------------------------------------------------------- | |
| 173 | - | ; init_game — everything a fresh night needs, gathered from what was | |
| 174 | - | ; the boot sequence. Beginning is a callable thing now. | |
| 186 | + | ; init_run / init_game — a run is a NIGHT now: dusk 0, full lives. | |
| 187 | + | ; Each held dusk re-enters init_game with dusk bumped — the square | |
| 188 | + | ; relights, the lives carry. What resets per RUN and what resets per | |
| 189 | + | ; WATCH is the whole design decision, drawn as two entry points. | |
| 175 | 190 | ; ---------------------------------------------------------------------------- | |
| 176 | - | init_game: | |
| 191 | + | init_run: | |
| 177 | 192 | xor a | |
| 178 | - | ld (lit_count), a | |
| 193 | + | ld (dusk), a | |
| 179 | 194 | ld a, LIVES | |
| 180 | 195 | ld (lives), a | |
| 196 | + | ; fall through into the per-dusk setup | |
| 197 | + | | |
| 198 | + | init_game: | |
| 199 | + | xor a | |
| 200 | + | ld (lit_count), a | |
| 181 | 201 | | |
| 182 | 202 | ; --- place the lamplighter --- | |
| 183 | 203 | ; His position is data. Everything that draws him reads it. | |
| ... | |||
| 1709 | 1729 | defb 16 | |
| 1710 | 1730 | player_timer: | |
| 1711 | 1731 | defb 0 | |
| 1732 | + | dusk: | |
| 1733 | + | defb 0 ; which watch of the night this is | |
| 1712 | 1734 | seek_col: | |
| 1713 | 1735 | defb 0 | |
| 1714 | 1736 | seek_row: |
The complete step 1 program
; The Long Night — Unit 6: The Night Deepens
; Cumulative build; every step runs on its own. Narrative: the unit page.
; Escalation as data — and the held screen becomes an interstitial.
org 32768
COBBLE equ %00000001 ; PAPER black (0), INK blue (1) — dark ground
GLOW equ %00000110 ; pool-warmed cobble: yellow INK on black —
; ground the light holds
DARK equ %01000001 ; the night made solid: blue INK on black,
; BRIGHT — impassable, unmistakably there
WALL equ %00001111 ; PAPER blue (1), INK white (7) — pale stone
WALL_BIT equ 3 ; the attribute bit that says "this is wall"
LAMP_ATTR equ %01000111 ; BRIGHT, PAPER black, INK white — his own light
LAMP_UNLIT equ %00000101 ; cold cyan INK on black PAPER — bit 3
; clear, so a lamp reads as floor
LAMP_LIT equ %01000110 ; BRIGHT yellow INK on black — a held flame
DRAUGHT_ATTR equ %01000101 ; the wisp: BRIGHT cyan on black — cold light
LIVES equ 3
LIFE_PIP equ %01010000 ; a life: BRIGHT red PAPER — a small ember
LIFE_BASE equ $5800 + 28 ; row 0, right of the ledge — three cells
DRAUGHT_SPEED equ 16 ; frames between the wisp's steps
DRAUGHT_COL0 equ 28 ; the corner the dark enters from
DRAUGHT_ROW0 equ 4
PIP_UNLIT equ %00101000 ; a cold pip: cyan PAPER, a solid block
PIP_LIT equ %01110000 ; a warm pip: BRIGHT yellow PAPER
PIP_BASE equ $5800 + 12 ; row 0, column 12 — the HUD ledge,
; eight cells, centred over the square
NUM_LAMPS equ 8
MSG_ATTR equ %01000111 ; message text: bright white on black
MSG_ROW equ 11
LOSE_COL equ 10 ; centres the eleven characters
WIN_COL equ 7 ; centres the seventeen characters
FONT equ $3C00 ; the ROM font, addressed so that
; ASCII x 8 lands on the right glyph
STATE_TITLE equ 0
STATE_PLAY equ 1
STATE_WIN equ 2 ; a dusk held — the night deepens
STATE_LOSE equ 3 ; night falls — the game is lost
LOCK equ 25 ; input-lock frames after entering a screen
SPEAKER equ %00010000 ; port $FE bit 4 — the beeper's one bit
TITLE_COL equ 12 ; GLOAMING, centred
PROMPT_COL equ 10 ; PRESS SPACE, centred
TITLE_ROW equ 8
PROMPT_ROW equ 14
CONT_ROW equ 16 ; "PRESS SPACE" under a win/lose line
START_COL equ 15 ; where the lamplighter begins
START_ROW equ 11
PLAYER_REPEAT equ 6 ; frames between steps while a key is held
GATHER equ 120 ; frames the dark gathers before its first step
WREST equ 48 ; frames it rests at home after a withdrawal —
; the snuff window holds even when home is close
KEYS_OP equ $DFFE ; half-row P O I U Y — bits 1 and 0
KEYS_Q equ $FBFE ; half-row Q W E R T — bit 0 is Q
KEYS_A equ $FDFE ; half-row A S D F G — bit 0 is A
KEYS_SPACE equ $7FFE ; half-row SPACE SYM M N B — bit 0
start:
; --- the border goes black — the night beyond the square ---
; Port $FE bits 0-2 set the BORDER colour. A = 0 = black.
ld a, 0
out ($FE), a
ld a, STATE_TITLE
ld (game_state), a
call draw_title_screen
im 1
ei
call chime_dusk ; after EI — the rests need the interrupt
main_loop:
halt
; the dispatch: each state names what a frame means — the
; title listens for a beginning, PLAY beats the game forward,
; WIN and LOSE hold the screen exactly as it stands
ld a, (game_state)
cp STATE_TITLE
jr z, .do_title
cp STATE_PLAY
jr z, .do_play
call end_step ; WIN or LOSE — wait for a key, then title
jr main_loop
.do_title:
call title_step
jr main_loop
.do_play:
call play_step
jr main_loop
; ----------------------------------------------------------------------------
; title_step — SPACE starts a fresh game.
; ----------------------------------------------------------------------------
title_step:
ld a, (input_lock)
or a
jr z, .tready
dec a
ld (input_lock), a
ret
.tready:
ld bc, KEYS_SPACE
in a, (c)
bit 0, a
ret nz
call init_run
ld a, STATE_PLAY
ld (game_state), a
ret
; ----------------------------------------------------------------------------
; end_step — after the lock, SPACE moves on. A held dusk continues
; the run — the night deepens; only NIGHT FALLS returns to the title.
; ----------------------------------------------------------------------------
end_step:
ld a, (input_lock)
or a
jr z, .eready
dec a
ld (input_lock), a
ret
.eready:
ld bc, KEYS_SPACE
in a, (c)
bit 0, a
ret nz
ld a, (game_state)
cp STATE_WIN
jr z, .deeper
call draw_title_screen
call chime_dusk
ld a, LOCK
ld (input_lock), a
ld a, STATE_TITLE
ld (game_state), a
ret
.deeper:
; the dusk was held — the night is NOT over. Deepen and
; go again: the square relights, and the lives carry.
ld hl, dusk
inc (hl)
call init_game
ld a, STATE_PLAY
ld (game_state), a
ret
; play_step — one beat of the game: ask the keyboard.
play_step:
call player_step
; contact can end the game mid-frame — if it did, stop here
ld a, (game_state)
cp STATE_PLAY
ret nz
call draught_step
ld a, (game_state)
cp STATE_PLAY
ret nz
; the win check, at the only beat the count can have changed
ld a, (lit_count)
cp NUM_LAMPS
ret nz
; the night is held — the lives you kept are the score
ld a, (lives)
ld hl, best_lives
cp (hl)
jr c, .nobest
ld (hl), a
.nobest:
call draw_win_screen
call fanfare_held
ld a, LOCK
ld (input_lock), a
ld a, STATE_WIN
ld (game_state), a
ret
; ----------------------------------------------------------------------------
; init_run / init_game — a run is a NIGHT now: dusk 0, full lives.
; Each held dusk re-enters init_game with dusk bumped — the square
; relights, the lives carry. What resets per RUN and what resets per
; WATCH is the whole design decision, drawn as two entry points.
; ----------------------------------------------------------------------------
init_run:
xor a
ld (dusk), a
ld a, LIVES
ld (lives), a
; fall through into the per-dusk setup
init_game:
xor a
ld (lit_count), a
; --- place the lamplighter ---
; His position is data. Everything that draws him reads it.
ld a, START_COL
ld (lamp_col), a
ld a, START_ROW
ld (lamp_row), a
; --- and, in the far corner, something else ---
ld a, DRAUGHT_COL0
ld (draught_col), a
ld (draught_home_col), a ; and remember where home is —
ld a, DRAUGHT_ROW0
ld (draught_row), a
ld (draught_home_row), a ; the withdraw will need it
; the dark gathers before its first step — a beat to read
; the square before the hunt begins
ld a, GATHER
ld (draught_timer), a
xor a
ld (player_timer), a
ld (tendril_len), a
ld (tendril_head), a
ld (draught_mode), a
ld (lit_qcount), a
; --- wipe the canvas ---
; The bitmap ($4000-$57FF) is the pixel layer; whatever was on
; screen before us still lives there. Zero it so only our
; attribute colours show.
call clear_bitmap
; --- texture the ground ---
; Blit the cobble stipple into every cell's bitmap, rows 1-23.
; The attributes will colour these pixels in a moment.
call fill_ground
; --- wash in the cobbles ---
; Seed the first attribute cell, point DE one cell ahead, and
; let LDIR cascade the byte through all 768 cells.
ld hl, $5800
ld de, $5801
ld (hl), COBBLE
ld bc, 767
ldir
call warm_walls
call paint_buildings
; --- brick the walls ---
; Now that the wall cells are painted, fill_walls can read the
; map back and lay brick wherever the wall bit is set.
call fill_walls
call draw_pips
call draw_lives
call draw_lamps
; save what he is about to stand on, BEFORE the first draw
call save_under
call draw_lamp
call save_draught
call draw_draught
ret
; ----------------------------------------------------------------------------
; warm_walls — the square's edge, one attribute write per cell; the
; colour is no longer a constant but the wall_ramp entry for how many
; lamps are lit. Same painting loop as ever — only where C comes from
; has changed.
; ----------------------------------------------------------------------------
warm_walls:
ld a, (lit_count)
ld e, a
ld d, 0
ld hl, wall_ramp
add hl, de
ld c, (hl) ; the byte every wall cell gets
; the top wall: row 1 is 32 cells in a row from $5820
; (row 0 is kept back — it becomes the HUD later)
ld hl, $5820
ld b, 32
.wt:
ld (hl), c
inc hl
djnz .wt
; the bottom wall: row 23, 32 cells from $5AE0
ld hl, $5AE0
ld b, 32
.wb:
ld (hl), c
inc hl
djnz .wb
; the side walls: column 0 and column 31 of rows 1-23.
; Write the row's first cell, hop 31 cells to its last,
; then step a full row (32) down — 23 times.
ld hl, $5820
ld b, 23
.ws:
ld (hl), c
push hl
ld de, 31
add hl, de
ld (hl), c
pop hl
ld de, 32
add hl, de
djnz .ws
ret
; ----------------------------------------------------------------------------
; The beeper. One bit on port $FE: set it, wait, clear it, wait — a
; square wave by hand. C is the half-period (pitch: bigger is lower),
; B the number of cycles (duration). DI while it sounds: the 50 Hz
; interrupt would stretch random half-periods and buzz the tone.
; ----------------------------------------------------------------------------
beep:
di
.bcyc:
ld a, SPEAKER
out ($FE), a
ld a, c
.bd1:
dec a
jr nz, .bd1
xor a
out ($FE), a
ld a, c
.bd2:
dec a
jr nz, .bd2
djnz .bcyc
ei
ret
blip_lit: ; a rising third — the lamp catches
ld b, $17 ; C6
ld c, $67
call beep
ld b, $28 ; E6
ld c, $51
jp beep
chime_dusk: ; two cold tolls, then the motif far off
ld b, $84 ; A4
ld c, $F7
call beep
ld b, 10
call rest
ld b, $84 ; A4
ld c, $F7
call beep
ld b, 13
call rest
ld b, $92 ; E5
ld c, $A4
call beep
ld b, 4
call rest
ld b, $9D ; C5
ld c, $CF
jp beep
; rest — B frames of silence. Musical time rides the heartbeat: the
; gaps between notes are counted in HALTs, not busy-loops.
rest:
halt
djnz rest
ret
fanfare_held: ; THE NIGHT IS HELD — a rising run
ld b, $83 ; C5
ld c, $CF
call beep
ld b, 3
call rest
ld b, $A5 ; E5
ld c, $A4
call beep
ld b, 3
call rest
ld b, $C4 ; G5
ld c, $8A
call beep
ld b, 3
call rest
ld b, $FF ; C6, held — B only counts to 255,
ld c, $67
call beep
ld b, $FF ; so hold it by sounding it twice
ld c, $67
jp beep
sting_nightfall: ; NIGHT FALLS — two steps down, then dark
ld b, $53 ; E5
ld c, $A4
call beep
ld b, 4
call rest
ld b, $49 ; D5
ld c, $B8
call beep
ld b, 4
call rest
ld b, $DC ; A4, long — the night settles on it
ld c, $F7
jp beep
; ----------------------------------------------------------------------------
; Screens.
; ----------------------------------------------------------------------------
; draw_win_screen — lift the lamplighter off the board (restore his
; cell: the eighth lamp, lit, comes out of the buffer), then say it.
; draw_title_screen — sparse and suggestive: a black void, the name,
; the invitation. Everything else is left to the imagination, which
; is both the aesthetic and the budget.
draw_title_screen:
call clear_bitmap
ld hl, $5800
ld de, $5801
ld (hl), %00000000
ld bc, 767
ldir
ld hl, title_text
ld b, TITLE_ROW
ld c, TITLE_COL
call print_string
ld hl, prompt_text
ld b, PROMPT_ROW
ld c, PROMPT_COL
call print_string
; your best night — the lives you kept on your finest win,
; read in lamps (no digits). It survives the loop back to
; the title: the go-again hook.
ld hl, $5800 + 11 * 32 + 14
ld b, LIVES
ld a, (best_lives)
ld c, a
.tpip:
ld a, PIP_UNLIT
inc c
dec c
jr z, .tpcold
ld a, PIP_LIT
dec c
.tpcold:
ld (hl), a
inc hl
djnz .tpip
ret
draw_win_screen:
call restore_under
ld hl, win_text
ld b, MSG_ROW
ld c, WIN_COL
call print_string
ld hl, prompt_text
ld b, CONT_ROW
ld c, PROMPT_COL
call print_string
ret
; draw_lose_screen — the whole attribute table goes black: every lamp,
; every wall, every warm cell, gone in one LDIR. Then the words.
draw_lose_screen:
ld hl, $5800
ld de, $5801
ld (hl), %00000000
ld bc, 767
ldir
ld hl, lose_text
ld b, MSG_ROW
ld c, LOSE_COL
call print_string
ld hl, prompt_text
ld b, CONT_ROW
ld c, PROMPT_COL
call print_string
ret
; ----------------------------------------------------------------------------
; clear_bitmap — zero the pixel layer, $4000-$57FF, with the same
; seed-and-cascade LDIR idiom the cobble wash uses.
; ----------------------------------------------------------------------------
clear_bitmap:
ld hl, $4000
ld de, $4001
ld (hl), 0
ld bc, 6143
ldir
ret
; ----------------------------------------------------------------------------
; player_step — the keys become movement. Each direction key edits a
; TARGET position (tcol, trow) — a proposal, not yet a move — so it
; can be vetoed before it becomes real. Then the move commits: leave
; the old cell, take the new one, draw.
; ----------------------------------------------------------------------------
player_step:
; --- propose: the target starts where he stands ---
ld a, (lamp_col)
ld (tcol), a
ld a, (lamp_row)
ld (trow), a
; The held-key gate: the first press steps at once, then one
; step every PLAYER_REPEAT frames. Releasing every direction
; key re-arms the instant first step, so taps stay crisp.
ld bc, KEYS_OP
in a, (c)
cpl
and %00000011
ld e, a
ld bc, KEYS_Q
in a, (c)
cpl
and %00000001
or e
ld e, a
ld bc, KEYS_A
in a, (c)
cpl
and %00000001
or e
jr nz, .held
xor a
ld (player_timer), a
ret
.held:
ld a, (player_timer)
or a
jr z, .stepnow
dec a
ld (player_timer), a
ret
.stepnow:
ld a, PLAYER_REPEAT
ld (player_timer), a
ld bc, KEYS_OP
in a, (c)
bit 1, a ; O — a zero bit is a pressed key
jr z, .pleft
bit 0, a ; P, same half-row
jr z, .pright
ld bc, KEYS_Q
in a, (c)
bit 0, a ; Q
jr z, .pup
ld bc, KEYS_A
in a, (c)
bit 0, a ; A
jr z, .pdown
ret ; nothing held — nothing to do
.pleft:
ld hl, tcol
dec (hl)
jr .pmove
.pright:
ld hl, tcol
inc (hl)
jr .pmove
.pup:
ld hl, trow
dec (hl)
jr .pmove
.pdown:
ld hl, trow
inc (hl)
.pmove:
; The veto: ask the target cell's attribute whether it's wall.
; NZ means brick — the proposal dies here and he stays put.
ld a, (trow)
ld b, a
ld a, (tcol)
ld c, a
call wall_at
ret nz
; the solid night blocks too — you cannot walk into the dark
ld a, (hl)
cp DARK
ret z
; and the mirror rule: he cannot step onto the wisp either
ld a, (tcol)
ld hl, draught_col
cp (hl)
jr nz, .pcommit
ld a, (trow)
ld hl, draught_row
cp (hl)
jr nz, .pcommit
call lose_life ; walking into the cold costs the same
ret
.pcommit:
; --- commit: restore, step, save, draw — in that order ---
call restore_under
ld a, (tcol)
ld (lamp_col), a
ld a, (trow)
ld (lamp_row), a
call save_under
; light it where it lives: while he covers the lamp, its truth
; is the buffer — rewrite the saved attribute, and restore will
; paint the lamp back lit when he leaves
ld a, (under_lamp + 8)
cp LAMP_UNLIT
jr nz, .pdrawn
ld a, LAMP_LIT
ld (under_lamp + 8), a
; record the lighting order — the night bears its grudges
; oldest-first (lamp_col/lamp_row are the lamplighter's
; position, and he is standing on the lamp)
ld a, (lamp_col)
ld c, a
ld a, (lamp_row)
ld b, a
call lamp_index_at
call lit_push
call light_pip
call blip_lit
call warm_walls
call recompute_pools
.pdrawn:
call draw_lamp
ret
; ----------------------------------------------------------------------------
; fill_ground — the cobble stipple. Not decoration: the stipple is what
; makes ground-state changes visible later, when the game starts
; recolouring these pixels. Rows 1-23 (row 0 is the HUD).
; ----------------------------------------------------------------------------
fill_ground:
ld b, 1 ; rows 1-23 (row 0 is the HUD)
.fgr:
ld c, 0
.fgc:
ld de, cobble_tex
call blit_tex
inc c
ld a, c
cp 32
jr c, .fgc
inc b
ld a, b
cp 24
jr c, .fgr
ret
; fill_walls — brickwork. Driven by the wall attribute bit, so anything
; painted as wall — now or later in the game — gets its brick for free:
; the map itself decides where the brick goes.
fill_walls:
ld b, 1
.fwr:
ld c, 0
.fwc:
push bc
call attr_addr_cr
bit WALL_BIT, (hl)
pop bc
jr z, .fwn
ld de, brick_tex
call blit_tex
.fwn:
inc c
ld a, c
cp 32
jr c, .fwc
inc b
ld a, b
cp 24
jr c, .fwr
ret
; blit_tex — write the 8-byte texture at DE into cell (C, B)'s bitmap.
; scr_addr_cr finds the cell's first pixel row; INC H steps down the
; other seven, 256 bytes apart.
blit_tex:
push bc
call scr_addr_cr
ld b, 8
.bt:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .bt
pop bc
ret
cobble_tex:
defb %10000010
defb %00000000
defb %00001000
defb %00000000
defb %00100001
defb %00000000
defb %00010000
defb %00000000
mist_tex:
; the solid night — dense, swirling, unmistakably *there*
defb %01101100
defb %11011011
defb %00110110
defb %01101101
defb %11011010
defb %10110110
defb %01101011
defb %11010110
brick_tex:
; mortar courses with staggered verticals — dusk-lit stone
defb %00001000
defb %00001000
defb %00001000
defb %11111111
defb %10000000
defb %10000000
defb %10000000
defb %11111111
; ----------------------------------------------------------------------------
; recompute_pools — the lamps cast their light. Every glow cell dies
; back to bare cobble, then every LIT lamp warms its eight neighbours.
; Derived, not tracked: called after any light or snuff, it rebuilds
; the whole layer from lamp truth, so the pools can never drift.
; ----------------------------------------------------------------------------
recompute_pools:
; the discipline: both movers OFF the screen first, so the
; recolour reads and writes true ground — never a sprite,
; and never into a buffer that would restore stale colour
call restore_under
call restore_draught
ld hl, $5820 ; rows 1-23 (row 0 is the HUD)
ld bc, 736
.rp1:
ld a, (hl)
cp GLOW
jr nz, .rp1n
ld (hl), COBBLE
.rp1n:
inc hl
dec bc
ld a, b
or c
jr nz, .rp1
ld hl, lamp_data
.rp2:
ld a, (hl)
cp $FF
jr z, .rpdone
ld c, a
inc hl
ld b, (hl)
inc hl
push hl
push bc
call attr_addr_cr
ld a, (hl)
pop bc
cp LAMP_LIT
jr nz, .rp2n
call glow_ring
.rp2n:
pop hl
jr .rp2
.rpdone:
; ...and back on, their buffers re-photographing ground
; that now includes the glow
call save_under
call save_draught
call draw_lamp
call draw_draught
ret
; glow_ring — warm the eight cells around lamp (C = col, B = row) where
; they are bare cobble. Pools never take walls, posts, or the dark.
glow_ring:
ld hl, ring_offsets
ld e, 8
.gr:
push hl
push de
push bc
ld a, (hl)
add a, c
ld c, a
inc hl
ld a, (hl)
add a, b
ld b, a
call attr_addr_cr
ld a, (hl)
cp COBBLE
jr nz, .grn
ld (hl), GLOW
.grn:
pop bc
pop de
pop hl
inc hl
inc hl
dec e
jr nz, .gr
ret
ring_offsets:
defb -1, -1, 0, -1, 1, -1
defb -1, 0, 1, 0
defb -1, 1, 0, 1, 1, 1
; ----------------------------------------------------------------------------
; lamp_index_at — which lamp_data entry sits at (C = col, B = row)?
; Returns the index in A ($FF if none — callers only ask about cells
; they know hold a lamp).
; ----------------------------------------------------------------------------
lamp_index_at:
ld hl, lamp_data
ld e, 0
.lia:
ld a, (hl)
cp $FF
ret z
cp c
jr nz, .lian
inc hl
ld a, (hl)
dec hl
cp b
jr nz, .lian
ld a, e
ret
.lian:
inc hl
inc hl
inc e
jr .lia
; lit_push — append lamp index (A) to the lit-order queue.
lit_push:
ld e, a
ld a, (lit_qcount)
ld d, a
inc a
ld (lit_qcount), a
ld a, d
ld hl, lit_queue
add a, l
ld l, a
jr nc, .lp
inc h
.lp:
ld (hl), e
ret
; lit_remove — take lamp index (A) out of the lit-order queue,
; closing the gap.
lit_remove:
ld e, a
ld hl, lit_queue
ld a, (lit_qcount)
ld d, a
or a
ret z
.lr:
ld a, (hl)
cp e
jr z, .lrfound
inc hl
dec d
jr nz, .lr
ret
.lrfound:
dec d
jr z, .lrlast
.lrshift:
inc hl
ld a, (hl)
dec hl
ld (hl), a
inc hl
dec d
jr nz, .lrshift
.lrlast:
ld a, (lit_qcount)
dec a
ld (lit_qcount), a
ret
; ----------------------------------------------------------------------------
; draught_step — the hunt bears grudges. The wisp steps toward the
; OLDEST grievance: the head of the lit-order queue, or, with
; nothing lit, the lamplighter's own flame. Still no walls.
; ----------------------------------------------------------------------------
draught_step:
ld a, (draught_timer)
dec a
ld (draught_timer), a
ret nz
ld a, DRAUGHT_SPEED
ld (draught_timer), a
; withdrawing? after a snuff the night carries its prize
; home before hunting again — behaviour is a MODE now, and
; the mode decides what this beat means
ld a, (draught_mode)
or a
jr z, .hunt
ld a, (draught_home_col)
ld hl, draught_col
cp (hl)
jr nz, .whome
ld a, (draught_home_row)
ld hl, draught_row
cp (hl)
jr nz, .whome
xor a ; home — rest, then the hunt resumes
ld (draught_mode), a
ld a, WREST
ld (draught_timer), a
ret
.whome:
ld a, (draught_home_col)
ld (seek_col), a
ld a, (draught_home_row)
ld (seek_row), a
jp .chase
.hunt:
; the oldest flame is the night's grievance — it reclaims
; the ground it lost first. With nothing lit, it hunts the
; lamplighter's own flame: light your first lamp and the
; hunt turns away from you.
ld a, (lit_qcount)
or a
jr nz, .oldest
ld a, (lamp_col)
ld (seek_col), a
ld a, (lamp_row)
ld (seek_row), a
jr .chase
.oldest:
ld a, (lit_queue)
add a, a
ld e, a
ld d, 0
ld hl, lamp_data
add hl, de
ld a, (hl)
ld (seek_col), a
inc hl
ld a, (hl)
ld (seek_row), a
.chase:
; step one cell along the axis with the greater distance
; (ties go sideways) — the night is 4-connected, like the
; lamplighter
ld a, (draught_col)
ld (dtcol), a
ld a, (draught_row)
ld (dtrow), a
ld a, (seek_col)
ld hl, draught_col
sub (hl)
jp p, .absc
neg
.absc:
ld d, a ; D = |dc|
ld a, (seek_row)
ld hl, draught_row
sub (hl)
jp p, .absr
neg
.absr:
cp d ; |dr| vs |dc|
jr z, .tie
jr c, .horiz
jr .vert
.tie:
ld a, d
or a
ret z ; already on the light
jr .horiz
.horiz:
ld a, (seek_col)
ld hl, draught_col
cp (hl)
jr c, .hleft
ld a, (hl)
inc a
ld (dtcol), a
jr .contact
.hleft:
ld a, (hl)
dec a
ld (dtcol), a
jr .contact
.vert:
ld a, (seek_row)
ld hl, draught_row
cp (hl)
jr c, .vup
ld a, (hl)
inc a
ld (dtrow), a
jr .contact
.vup:
ld a, (hl)
dec a
ld (dtrow), a
.contact:
; never step ONTO the lamplighter: adjacent is as close as
; the night comes. Two movers, two buffers — and one cell
; can only ever be under one of them.
ld a, (dtcol)
ld hl, lamp_col
cp (hl)
jr nz, .dmove
ld a, (dtrow)
ld hl, lamp_row
cp (hl)
jr nz, .dmove
call lose_life ; the touch, priced
ret
.dmove:
call restore_draught
; the tendril: night pools where the wisp has walked. Ground
; and spilt light are both taken; posts and stone are not.
ld a, (draught_col)
ld c, a
ld a, (draught_row)
ld b, a
push bc
call attr_addr_cr
pop bc
ld a, (hl)
cp DARK
jr z, .retake
cp COBBLE
jr z, .take
cp GLOW
jr nz, .notake
.take:
ld (hl), DARK
ld de, mist_tex
call blit_tex
.retake:
call tendril_push
.notake:
ld a, (dtcol)
ld (draught_col), a
ld a, (dtrow)
ld (draught_row), a
call save_draught
; the snuff: while the wisp covers a lit lamp, the lamp's
; truth is ITS buffer — the same saved-under rule that lights
; lamps beneath the lamplighter, run by the villain. Rewrite
; the saved attribute to cold, and the wisp's own restore
; will leave the lamp out as it moves on.
ld a, (under_draught + 8)
cp LAMP_LIT
jr nz, .nosnuff
ld a, LAMP_UNLIT
ld (under_draught + 8), a
; the grievance is settled — off the lit-order queue
ld a, (draught_col)
ld c, a
ld a, (draught_row)
ld b, a
call lamp_index_at
call lit_remove
call unlight_pip
call warm_walls
call recompute_pools
ld a, 1 ; the prize is taken — withdraw
ld (draught_mode), a
.nosnuff:
call draw_draught
ret
; ----------------------------------------------------------------------------
; tendril_push — record darkened cell (C = col, B = row) in the tendril
; ring. When the ring is full the oldest cell releases back to bare
; cobble first — the night cannot hold ground beyond its reach, so the
; tendril can never permanently wall the square off.
; ----------------------------------------------------------------------------
tendril_push:
ld a, (tendril_len)
ld hl, tendril_max
cp (hl)
jr c, .tgrow
; full: release the oldest cell (the slot head points at)
push bc
ld a, (tendril_head)
add a, a
ld e, a
ld d, 0
ld hl, tendril_buf
add hl, de
ld c, (hl)
inc hl
ld b, (hl)
; a newer ring entry may still claim this cell (the wisp
; re-walks its own trail) — then the night keeps it
call tendril_claimed
jr z, .treld
; if the wisp itself is crossing that cell, mend its saved
; ground instead of the screen
ld a, (draught_col)
cp c
jr nz, .trel
ld a, (draught_row)
cp b
jr nz, .trel
; mend the wisp's saved ground: stipple, and glow if a lit
; lamp still pools this cell — the light heals behind the dark
push bc
ld hl, cobble_tex
ld de, under_draught
ld bc, 8
ldir
pop bc
call pooled_at
ld a, COBBLE
jr nz, .tsetu
ld a, GLOW
.tsetu:
ld (under_draught + 8), a
jr .treld
.trel:
push bc
call attr_addr_cr
pop bc
ld a, (hl)
cp DARK
jr nz, .treld
push hl
call pooled_at
pop hl
ld a, COBBLE
jr nz, .tset
ld a, GLOW
.tset:
ld (hl), a
ld de, cobble_tex
call blit_tex
.treld:
pop bc
jr .tstore
.tgrow:
inc a
ld (tendril_len), a
.tstore:
ld a, (tendril_head)
add a, a
ld e, a
ld d, 0
ld hl, tendril_buf
add hl, de
ld (hl), c
inc hl
ld (hl), b
ld a, (tendril_head)
inc a
ld hl, tendril_max
cp (hl)
jr c, .tadv
xor a
.tadv:
ld (tendril_head), a
ret
; paint_buildings — walk the rectangle table: each entry is col, row,
; width, height; $FF ends the list. Every cell inside a rectangle gets
; the WALL attribute — and because fill_walls textures by the wall bit,
; the brickwork arrives without another line of drawing code.
paint_buildings:
ld hl, bldg_data
.pb:
ld a, (hl)
cp $FF
ret z
ld c, a ; col
inc hl
ld b, (hl) ; row
inc hl
ld d, (hl) ; width
inc hl
ld e, (hl) ; height
inc hl
push hl
.pbrow:
push bc
push de
.pbcol:
push bc
push de
call attr_addr_cr
ld (hl), WALL
pop de
pop bc
inc c
dec d
jr nz, .pbcol
pop de
pop bc
inc b
dec e
jr nz, .pbrow
pop hl
jr .pb
bldg_data:
defb 5, 5, 4, 3
defb 23, 5, 4, 3
defb $FF
; ----------------------------------------------------------------------------
; tendril_claimed — does any ring slot other than head hold (C, B)?
; Z set if claimed. Only called with the ring full, so every slot holds
; a real cell.
; ----------------------------------------------------------------------------
tendril_claimed:
ld hl, tendril_buf
ld e, 0
.tc:
ld a, (tendril_head)
cp e
jr z, .tcn ; the slot being released — skip
ld a, (hl)
cp c
jr nz, .tcn
inc hl
ld a, (hl)
dec hl
cp b
jr nz, .tcn
xor a ; Z — a newer claim holds it
ret
.tcn:
inc hl
inc hl
inc e
ld a, (tendril_max)
cp e
jr nz, .tc
or a ; NZ (max is never 0) — free
ret
; ----------------------------------------------------------------------------
; pooled_at — is cell (C, B) within one cell of a LIT lamp? Z if so.
; The light heals: released tendril ground inside a live pool returns
; to glow, not bare cobble.
; ----------------------------------------------------------------------------
pooled_at:
ld hl, lamp_data
.pa:
ld a, (hl)
cp $FF
jr z, .pano
ld e, a ; lamp col
inc hl
ld d, (hl) ; lamp row
inc hl
ld a, e
sub c
jp p, .pac
neg
.pac:
cp 2
jr nc, .pa
ld a, d
sub b
jp p, .par
neg
.par:
cp 2
jr nc, .pa
push hl
push bc
ld c, e
ld b, d
call attr_addr_cr
ld a, (hl)
pop bc
pop hl
cp LAMP_LIT
jr nz, .pa
xor a ; Z — pooled by a lit lamp
ret
.pano:
or 1 ; NZ — bare ground
ret
; ----------------------------------------------------------------------------
; lose_life — the price of the touch: one ember out, and either a
; fresh start or the fall of night.
; ----------------------------------------------------------------------------
lose_life:
ld a, (lives)
dec a
ld (lives), a
ld e, a
ld d, 0
ld hl, LIFE_BASE
add hl, de
ld (hl), COBBLE ; the ember at the new count goes out
ld a, (lives)
or a
jr z, .gone
; a life left: the lamplighter returns to the start cell
call restore_under
ld a, START_COL
ld (lamp_col), a
ld a, START_ROW
ld (lamp_row), a
call save_under
call draw_lamp
; the taking costs the night its reach — the wisp recoils to
; the far corner, so every life buys a whole fresh chase
; (leaving it beside the respawn made a catch strip every
; life in seconds once the draught learnt to hunt)
call restore_draught
ld a, (draught_home_col)
ld (draught_col), a
ld a, (draught_home_row)
ld (draught_row), a
ld a, DRAUGHT_SPEED
ld (draught_timer), a
xor a ; already home — hunt on arrival
ld (draught_mode), a
call save_draught
call draw_draught
ret
.gone:
call draw_lose_screen
call sting_nightfall
ld a, LOCK
ld (input_lock), a
ld a, STATE_LOSE
ld (game_state), a
ret
; ----------------------------------------------------------------------------
; print_string / print_char — the machine's own letters. The Spectrum
; keeps its font in ROM: eight bytes per character, and FONT is chosen
; so that ASCII code x 8 + FONT is the glyph's address. Each character
; is drawn like any cell: attribute first, eight rows down the cell.
; ----------------------------------------------------------------------------
print_string:
.ps:
ld a, (hl)
cp $FF
ret z
push hl
push bc
call print_char
pop bc
pop hl
inc hl
inc c
jr .ps
print_char:
ld l, a
ld h, 0
add hl, hl
add hl, hl
add hl, hl
ld de, FONT
add hl, de
ex de, hl
push de
call attr_addr_cr
ld (hl), MSG_ATTR
call scr_addr_cr
pop de
ld b, 8
.pc:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .pc
ret
; ----------------------------------------------------------------------------
; light_pip / unlight_pip / draw_pips / draw_lives.
; ----------------------------------------------------------------------------
; light_pip — warm the next pip along and count the lamp. lit_count is
; the index of the pip to light AND the number of lamps lit so far —
; read it for the address, then step it.
light_pip:
ld a, (lit_count)
ld e, a
ld d, 0
inc a
ld (lit_count), a
ld hl, PIP_BASE
add hl, de
ld (hl), PIP_LIT
ret
; unlight_pip — light_pip's mirror: step the count back and cool the
; pip at the new count. The tally can go DOWN now.
unlight_pip:
ld a, (lit_count)
dec a
ld (lit_count), a
ld e, a
ld d, 0
ld hl, PIP_BASE
add hl, de
ld (hl), PIP_UNLIT
ret
; draw_pips — the tally row: one cell per lamp on the HUD ledge, all
; cold to start. A pip is pure attribute — no glyph, just a block of
; PAPER — so the row costs eight bytes of screen and no bitmap at all.
draw_pips:
ld hl, PIP_BASE
ld b, NUM_LAMPS
ld a, PIP_UNLIT
.dp:
ld (hl), a
inc hl
djnz .dp
ret
; draw_lives — three embers on the ledge's right shoulder.
draw_lives:
ld hl, LIFE_BASE
ld b, LIVES
ld a, LIFE_PIP
.dlv:
ld (hl), a
inc hl
djnz .dlv
ret
; ----------------------------------------------------------------------------
; draw_lamps — walk the position table: col, row pairs, $FF to finish.
; Placement is data; the drawing code neither knows nor cares how many
; lamps the town has tonight.
; ----------------------------------------------------------------------------
draw_lamps:
ld hl, lamp_data
.next:
ld a, (hl)
cp $FF
ret z
ld c, a
inc hl
ld b, (hl)
inc hl
push hl
call draw_lantern
pop hl
jr .next
; draw_lantern — an unlit lamp into cell (C, B): cold cyan attribute,
; then the lantern glyph down the cell like any texture.
draw_lantern:
call attr_addr_cr
ld (hl), LAMP_UNLIT
call scr_addr_cr
ld de, lantern
ld b, 8
.dlt:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .dlt
ret
; ----------------------------------------------------------------------------
; scr_addr_cr — HL = bitmap address of cell (C, B)'s first pixel row.
; The row's top two bits pick the third of the screen (H), its bottom
; three become L's top bits, and the column fills L's low five.
; ----------------------------------------------------------------------------
scr_addr_cr:
ld a, b
and %00011000 ; the third (row bits 4-3) ...
or %01000000 ; ... under the screen base $40xx
ld h, a
ld a, b
and %00000111 ; the char row within the third ...
rrca ; ... rotated into bits 7-5
rrca
rrca
or c ; the column in bits 4-0
ld l, a
ret
; attr_addr_cr — HL = attribute address of cell (C, B):
; $5800 + row*32 + col, the row shifted up five times.
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
; wall_at — is cell (C, B) wall? The answer is already on the screen:
; every wall cell's attribute has WALL_BIT set, so one bit-test of
; attribute memory is the whole collision system. NZ = wall.
wall_at:
call attr_addr_cr
bit WALL_BIT, (hl)
ret
; ----------------------------------------------------------------------------
; The lamplighter's save / restore / draw.
; ----------------------------------------------------------------------------
; pos_bc — the lamplighter's cell into (C, B), read fresh from the data.
pos_bc:
ld a, (lamp_row)
ld b, a
ld a, (lamp_col)
ld c, a
ret
; save_under — copy the nine bytes of his cell into the buffer: eight
; bitmap rows, then the attribute. Runs as he ARRIVES, before the
; draw — so the buffer always holds true ground, never him.
save_under:
call pos_bc
call scr_addr_cr
ld de, under_lamp
ld b, 8
.su:
ld a, (hl)
ld (de), a
inc de
inc h
djnz .su
call pos_bc
call attr_addr_cr
ld a, (hl)
ld (under_lamp + 8), a
ret
; restore_under — the same nine bytes back the other way: the ground
; returns exactly as it was. Runs as he LEAVES, while the position
; still points at the old cell.
restore_under:
call pos_bc
call scr_addr_cr
ld de, under_lamp
ld b, 8
.ru:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .ru
call pos_bc
call attr_addr_cr
ld a, (under_lamp + 8)
ld (hl), a
ret
draw_lamp:
; his colour first: the cell's attribute becomes his own —
; bright white on the black, his own light about him
call pos_bc
call attr_addr_cr
ld (hl), LAMP_ATTR
; then his shape, eight bytes down the cell like any texture
call pos_bc
call scr_addr_cr
ld de, lamplighter
ld b, 8
.dl:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .dl
ret
; ----------------------------------------------------------------------------
; The draught's save / restore / draw — the lamplighter's engine, twice.
; Same loops, same nine-byte contract, its own buffer and its own
; position: two movers can share a world but never a buffer.
; ----------------------------------------------------------------------------
dpos_bc:
ld a, (draught_row)
ld b, a
ld a, (draught_col)
ld c, a
ret
save_draught:
call dpos_bc
call scr_addr_cr
ld de, under_draught
ld b, 8
.sd:
ld a, (hl)
ld (de), a
inc de
inc h
djnz .sd
call dpos_bc
call attr_addr_cr
ld a, (hl)
ld (under_draught + 8), a
ret
restore_draught:
call dpos_bc
call scr_addr_cr
ld de, under_draught
ld b, 8
.rd:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .rd
call dpos_bc
call attr_addr_cr
ld a, (under_draught + 8)
ld (hl), a
ret
draw_draught:
call dpos_bc
call attr_addr_cr
ld (hl), DRAUGHT_ATTR
call dpos_bc
call scr_addr_cr
ld de, draught_glyph
ld b, 8
.dd:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .dd
ret
; ----------------------------------------------------------------------------
; Data.
; ----------------------------------------------------------------------------
game_state:
defb STATE_TITLE
input_lock:
defb 0
wall_ramp:
; The square warms in the game's own vocabulary: the stone
; stays dusk-blue; the lamplight catches the mortar first
; (ink white -> yellow), then the whole face glows BRIGHT.
; Never magenta — warmth is yellow here, not red-shifted blue.
defb %00001111 ; dusk stone, white mortar
defb %00001111
defb %00001111
defb %00001110 ; the mortar warms — yellow ink
defb %00001110
defb %00001110
defb %01001110 ; the stone catches the glow — BRIGHT
defb %01001110
defb %01110000 ; all eight lit: the square aglow —
; warm yellow stone, only at the win
lamp_data:
defb 4, 3
defb 27, 3
defb 9, 7
defb 22, 7
defb 6, 15
defb 25, 15
defb 13, 20
defb 18, 20
defb $FF
lamp_col:
defb START_COL
lamp_row:
defb START_ROW
tcol:
defb 0
trow:
defb 0
lit_count:
defb 0
lives:
defb LIVES
best_lives:
defb 0 ; lives kept on the finest win — never reset
draught_col:
defb 28
draught_row:
defb 4
draught_home_col:
defb 28
draught_home_row:
defb 4
draught_mode:
defb 0 ; 0 = hunting, 1 = withdrawing home
draught_timer:
defb 16
player_timer:
defb 0
dusk:
defb 0 ; which watch of the night this is
seek_col:
defb 0
seek_row:
defb 0
lit_queue:
defb 0, 0, 0, 0, 0, 0, 0, 0
lit_qcount:
defb 0
tendril_head:
defb 0
tendril_len:
defb 0
tendril_max:
defb 6 ; the night's reach — six cells of held ground
tendril_buf:
defb 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
defb 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
dtcol:
defb 0
dtrow:
defb 0
under_lamp:
defb 0, 0, 0, 0, 0, 0, 0, 0, 0
under_draught:
defb 0, 0, 0, 0, 0, 0, 0, 0, 0
lamplighter:
defb %00111100
defb %00111100
defb %00011000
defb %01111110
defb %00011000
defb %00011000
defb %00100100
defb %01000010
lantern:
defb %00011000
defb %00100100
defb %01111110
defb %01111110
defb %01011010
defb %01111110
defb %01111110
defb %00111100
draught_glyph:
defb %00000000
defb %00111100
defb %01111110
defb %11111111
defb %11111111
defb %01111110
defb %00111100
defb %00000000
title_text:
defb "GLOAMING"
defb $FF
prompt_text:
defb "PRESS SPACE"
defb $FF
win_text:
defb "THE NIGHT IS HELD"
defb $FF
lose_text:
defb "NIGHT FALLS"
defb $FF
end start
Milestone 2 — escalation as data
What actually deepens? Two numbers per watch: the wisp’s pace and the tendril’s reach. They live in two five-byte tables, and init_game reads the current watch’s entry from each — code that never changes, difficulty that’s pure data. The pace table runs 16, 13, 11, 9, 9; the reach table 3, 6, 9, 13, 18. Both rows are playtest scar tissue, and their comments say so. Watch 1 is gentle on purpose — the hunt must be readable before it’s a threat, and the tendril opens at three cells, because the first tuning front-loaded the reach and a practised player lost at watch 2: the opening should teach the mechanic, and the deep watches punish with it. At the other end, the final pace is 9, not 8 — 8 was play-tested to be the human wall, and the last watch should be the climax, not the ceiling.
There’s a third escalation, and it’s free: the dark probes from a new quarter each watch. Home comes from a four-entry corner table indexed by the watch — NE, SE, SW, NW — so watch 2 feels different before a single number of it has landed, because the threat is suddenly coming from behind you.
Step 2: dusk_table, dusk_lentab, corner_tab — the deepening, in fourteen bytes of data
+64-11
| 21 | 21 | LIVES equ 3 | |
| 22 | 22 | LIFE_PIP equ %01010000 ; a life: BRIGHT red PAPER — a small ember | |
| 23 | 23 | LIFE_BASE equ $5800 + 28 ; row 0, right of the ledge — three cells | |
| 24 | - | DRAUGHT_SPEED equ 16 ; frames between the wisp's steps | |
| 25 | - | DRAUGHT_COL0 equ 28 ; the corner the dark enters from | |
| 26 | - | DRAUGHT_ROW0 equ 4 | |
| 24 | + | NUM_DUSKS equ 5 ; five watches of night — the tables | |
| 25 | + | ; below give each watch its teeth | |
| 27 | 26 | | |
| 28 | 27 | PIP_UNLIT equ %00101000 ; a cold pip: cyan PAPER, a solid block | |
| 29 | 28 | PIP_LIT equ %01110000 ; a warm pip: BRIGHT yellow PAPER | |
| ... | |||
| 205 | 204 | ld (lamp_col), a | |
| 206 | 205 | ld a, START_ROW | |
| 207 | 206 | ld (lamp_row), a | |
| 208 | - | ; --- and, in the far corner, something else --- | |
| 209 | - | ld a, DRAUGHT_COL0 | |
| 207 | + | ; the dark probes from a new quarter each watch — | |
| 208 | + | ; a lesson the square teaches by ITSELF: watch 2 already | |
| 209 | + | ; feels different before anything else has changed | |
| 210 | + | ld a, (dusk) | |
| 211 | + | and 3 | |
| 212 | + | add a, a | |
| 213 | + | ld e, a | |
| 214 | + | ld d, 0 | |
| 215 | + | ld hl, corner_tab | |
| 216 | + | add hl, de | |
| 217 | + | ld a, (hl) | |
| 210 | 218 | ld (draught_col), a | |
| 211 | - | ld (draught_home_col), a ; and remember where home is — | |
| 212 | - | ld a, DRAUGHT_ROW0 | |
| 219 | + | ld (draught_home_col), a | |
| 220 | + | inc hl | |
| 221 | + | ld a, (hl) | |
| 213 | 222 | ld (draught_row), a | |
| 214 | - | ld (draught_home_row), a ; the withdraw will need it | |
| 215 | - | ; the dark gathers before its first step — a beat to read | |
| 223 | + | ld (draught_home_row), a | |
| 224 | + | ; the night deepens: the wisp's pace comes from the dusk | |
| 225 | + | ; table, deeper dusks holding the last entry | |
| 226 | + | ld a, (dusk) | |
| 227 | + | cp NUM_DUSKS | |
| 228 | + | jr c, .dpace | |
| 229 | + | ld a, NUM_DUSKS - 1 | |
| 230 | + | .dpace: | |
| 231 | + | ld e, a | |
| 232 | + | ld d, 0 | |
| 233 | + | ld hl, dusk_table | |
| 234 | + | add hl, de | |
| 235 | + | ld a, (hl) | |
| 236 | + | ld (dusk_speed), a | |
| 237 | + | ; ...but it gathers before the first step — a beat to read | |
| 216 | 238 | ; the square before the hunt begins | |
| 217 | 239 | ld a, GATHER | |
| 218 | 240 | ld (draught_timer), a | |
| 241 | + | ; the tendril reaches further as the night deepens | |
| 242 | + | ld hl, dusk_lentab | |
| 243 | + | add hl, de | |
| 244 | + | ld a, (hl) | |
| 245 | + | ld (tendril_max), a | |
| 219 | 246 | xor a | |
| 220 | 247 | ld (player_timer), a | |
| 221 | 248 | ld (tendril_len), a | |
| ... | |||
| 903 | 930 | dec a | |
| 904 | 931 | ld (draught_timer), a | |
| 905 | 932 | ret nz | |
| 906 | - | ld a, DRAUGHT_SPEED | |
| 933 | + | ld a, (dusk_speed) | |
| 907 | 934 | ld (draught_timer), a | |
| 908 | 935 | | |
| 909 | 936 | ; withdrawing? after a snuff the night carries its prize | |
| ... | |||
| 1222 | 1249 | defb 5, 5, 4, 3 | |
| 1223 | 1250 | defb 23, 5, 4, 3 | |
| 1224 | 1251 | defb $FF | |
| 1252 | + | | |
| 1253 | + | corner_tab: | |
| 1254 | + | ; where the dark enters, per watch (NE, SE, SW, NW) | |
| 1255 | + | defb 28, 4 | |
| 1256 | + | defb 28, 19 | |
| 1257 | + | defb 3, 19 | |
| 1258 | + | defb 3, 4 | |
| 1225 | 1259 | | |
| 1226 | 1260 | ; ---------------------------------------------------------------------------- | |
| 1227 | 1261 | ; tendril_claimed — does any ring slot other than head hold (C, B)? | |
| ... | |||
| 1333 | 1367 | ld (draught_col), a | |
| 1334 | 1368 | ld a, (draught_home_row) | |
| 1335 | 1369 | ld (draught_row), a | |
| 1336 | - | ld a, DRAUGHT_SPEED | |
| 1370 | + | ld a, (dusk_speed) | |
| 1337 | 1371 | ld (draught_timer), a | |
| 1338 | 1372 | xor a ; already home — hunt on arrival | |
| 1339 | 1373 | ld (draught_mode), a | |
| ... | |||
| 1671 | 1705 | defb STATE_TITLE | |
| 1672 | 1706 | input_lock: | |
| 1673 | 1707 | defb 0 | |
| 1708 | + | | |
| 1709 | + | dusk_table: | |
| 1710 | + | ; the wisp's pace per dusk (frames between steps) — the | |
| 1711 | + | ; night deepens as data, not code. Dusk 1 is gentle on | |
| 1712 | + | ; purpose: the hunt must be readable before it's a threat. | |
| 1713 | + | ; The final watch is pace 9, not 8 — playtested: 8 is the | |
| 1714 | + | ; human wall, 9 is beatable. The last watch should be the | |
| 1715 | + | ; climax, not the ceiling. | |
| 1716 | + | defb 16, 13, 11, 9, 9 | |
| 1717 | + | | |
| 1718 | + | dusk_lentab: | |
| 1719 | + | ; the tendril's reach per watch (cells of night held) — | |
| 1720 | + | ; the second axis of the deepening. Front-loading reach | |
| 1721 | + | ; made watch 1 brutal (playtested: a practised player lost | |
| 1722 | + | ; at watch 2) — the opening teaches the mechanic, the deep | |
| 1723 | + | ; watches punish with it. | |
| 1724 | + | defb 3, 6, 9, 13, 18 | |
| 1674 | 1725 | | |
| 1675 | 1726 | wall_ramp: | |
| 1676 | 1727 | ; The square warms in the game's own vocabulary: the stone | |
| ... | |||
| 1731 | 1782 | defb 0 | |
| 1732 | 1783 | dusk: | |
| 1733 | 1784 | defb 0 ; which watch of the night this is | |
| 1785 | + | dusk_speed: | |
| 1786 | + | defb 16 | |
| 1734 | 1787 | seek_col: | |
| 1735 | 1788 | defb 0 | |
| 1736 | 1789 | seek_row: |
The complete step 2 program
; The Long Night — Unit 6: The Night Deepens
; Cumulative build; every step runs on its own. Narrative: the unit page.
; Escalation as data — and the held screen becomes an interstitial.
org 32768
COBBLE equ %00000001 ; PAPER black (0), INK blue (1) — dark ground
GLOW equ %00000110 ; pool-warmed cobble: yellow INK on black —
; ground the light holds
DARK equ %01000001 ; the night made solid: blue INK on black,
; BRIGHT — impassable, unmistakably there
WALL equ %00001111 ; PAPER blue (1), INK white (7) — pale stone
WALL_BIT equ 3 ; the attribute bit that says "this is wall"
LAMP_ATTR equ %01000111 ; BRIGHT, PAPER black, INK white — his own light
LAMP_UNLIT equ %00000101 ; cold cyan INK on black PAPER — bit 3
; clear, so a lamp reads as floor
LAMP_LIT equ %01000110 ; BRIGHT yellow INK on black — a held flame
DRAUGHT_ATTR equ %01000101 ; the wisp: BRIGHT cyan on black — cold light
LIVES equ 3
LIFE_PIP equ %01010000 ; a life: BRIGHT red PAPER — a small ember
LIFE_BASE equ $5800 + 28 ; row 0, right of the ledge — three cells
NUM_DUSKS equ 5 ; five watches of night — the tables
; below give each watch its teeth
PIP_UNLIT equ %00101000 ; a cold pip: cyan PAPER, a solid block
PIP_LIT equ %01110000 ; a warm pip: BRIGHT yellow PAPER
PIP_BASE equ $5800 + 12 ; row 0, column 12 — the HUD ledge,
; eight cells, centred over the square
NUM_LAMPS equ 8
MSG_ATTR equ %01000111 ; message text: bright white on black
MSG_ROW equ 11
LOSE_COL equ 10 ; centres the eleven characters
WIN_COL equ 7 ; centres the seventeen characters
FONT equ $3C00 ; the ROM font, addressed so that
; ASCII x 8 lands on the right glyph
STATE_TITLE equ 0
STATE_PLAY equ 1
STATE_WIN equ 2 ; a dusk held — the night deepens
STATE_LOSE equ 3 ; night falls — the game is lost
LOCK equ 25 ; input-lock frames after entering a screen
SPEAKER equ %00010000 ; port $FE bit 4 — the beeper's one bit
TITLE_COL equ 12 ; GLOAMING, centred
PROMPT_COL equ 10 ; PRESS SPACE, centred
TITLE_ROW equ 8
PROMPT_ROW equ 14
CONT_ROW equ 16 ; "PRESS SPACE" under a win/lose line
START_COL equ 15 ; where the lamplighter begins
START_ROW equ 11
PLAYER_REPEAT equ 6 ; frames between steps while a key is held
GATHER equ 120 ; frames the dark gathers before its first step
WREST equ 48 ; frames it rests at home after a withdrawal —
; the snuff window holds even when home is close
KEYS_OP equ $DFFE ; half-row P O I U Y — bits 1 and 0
KEYS_Q equ $FBFE ; half-row Q W E R T — bit 0 is Q
KEYS_A equ $FDFE ; half-row A S D F G — bit 0 is A
KEYS_SPACE equ $7FFE ; half-row SPACE SYM M N B — bit 0
start:
; --- the border goes black — the night beyond the square ---
; Port $FE bits 0-2 set the BORDER colour. A = 0 = black.
ld a, 0
out ($FE), a
ld a, STATE_TITLE
ld (game_state), a
call draw_title_screen
im 1
ei
call chime_dusk ; after EI — the rests need the interrupt
main_loop:
halt
; the dispatch: each state names what a frame means — the
; title listens for a beginning, PLAY beats the game forward,
; WIN and LOSE hold the screen exactly as it stands
ld a, (game_state)
cp STATE_TITLE
jr z, .do_title
cp STATE_PLAY
jr z, .do_play
call end_step ; WIN or LOSE — wait for a key, then title
jr main_loop
.do_title:
call title_step
jr main_loop
.do_play:
call play_step
jr main_loop
; ----------------------------------------------------------------------------
; title_step — SPACE starts a fresh game.
; ----------------------------------------------------------------------------
title_step:
ld a, (input_lock)
or a
jr z, .tready
dec a
ld (input_lock), a
ret
.tready:
ld bc, KEYS_SPACE
in a, (c)
bit 0, a
ret nz
call init_run
ld a, STATE_PLAY
ld (game_state), a
ret
; ----------------------------------------------------------------------------
; end_step — after the lock, SPACE moves on. A held dusk continues
; the run — the night deepens; only NIGHT FALLS returns to the title.
; ----------------------------------------------------------------------------
end_step:
ld a, (input_lock)
or a
jr z, .eready
dec a
ld (input_lock), a
ret
.eready:
ld bc, KEYS_SPACE
in a, (c)
bit 0, a
ret nz
ld a, (game_state)
cp STATE_WIN
jr z, .deeper
call draw_title_screen
call chime_dusk
ld a, LOCK
ld (input_lock), a
ld a, STATE_TITLE
ld (game_state), a
ret
.deeper:
; the dusk was held — the night is NOT over. Deepen and
; go again: the square relights, and the lives carry.
ld hl, dusk
inc (hl)
call init_game
ld a, STATE_PLAY
ld (game_state), a
ret
; play_step — one beat of the game: ask the keyboard.
play_step:
call player_step
; contact can end the game mid-frame — if it did, stop here
ld a, (game_state)
cp STATE_PLAY
ret nz
call draught_step
ld a, (game_state)
cp STATE_PLAY
ret nz
; the win check, at the only beat the count can have changed
ld a, (lit_count)
cp NUM_LAMPS
ret nz
; the night is held — the lives you kept are the score
ld a, (lives)
ld hl, best_lives
cp (hl)
jr c, .nobest
ld (hl), a
.nobest:
call draw_win_screen
call fanfare_held
ld a, LOCK
ld (input_lock), a
ld a, STATE_WIN
ld (game_state), a
ret
; ----------------------------------------------------------------------------
; init_run / init_game — a run is a NIGHT now: dusk 0, full lives.
; Each held dusk re-enters init_game with dusk bumped — the square
; relights, the lives carry. What resets per RUN and what resets per
; WATCH is the whole design decision, drawn as two entry points.
; ----------------------------------------------------------------------------
init_run:
xor a
ld (dusk), a
ld a, LIVES
ld (lives), a
; fall through into the per-dusk setup
init_game:
xor a
ld (lit_count), a
; --- place the lamplighter ---
; His position is data. Everything that draws him reads it.
ld a, START_COL
ld (lamp_col), a
ld a, START_ROW
ld (lamp_row), a
; the dark probes from a new quarter each watch —
; a lesson the square teaches by ITSELF: watch 2 already
; feels different before anything else has changed
ld a, (dusk)
and 3
add a, a
ld e, a
ld d, 0
ld hl, corner_tab
add hl, de
ld a, (hl)
ld (draught_col), a
ld (draught_home_col), a
inc hl
ld a, (hl)
ld (draught_row), a
ld (draught_home_row), a
; the night deepens: the wisp's pace comes from the dusk
; table, deeper dusks holding the last entry
ld a, (dusk)
cp NUM_DUSKS
jr c, .dpace
ld a, NUM_DUSKS - 1
.dpace:
ld e, a
ld d, 0
ld hl, dusk_table
add hl, de
ld a, (hl)
ld (dusk_speed), a
; ...but it gathers before the first step — a beat to read
; the square before the hunt begins
ld a, GATHER
ld (draught_timer), a
; the tendril reaches further as the night deepens
ld hl, dusk_lentab
add hl, de
ld a, (hl)
ld (tendril_max), a
xor a
ld (player_timer), a
ld (tendril_len), a
ld (tendril_head), a
ld (draught_mode), a
ld (lit_qcount), a
; --- wipe the canvas ---
; The bitmap ($4000-$57FF) is the pixel layer; whatever was on
; screen before us still lives there. Zero it so only our
; attribute colours show.
call clear_bitmap
; --- texture the ground ---
; Blit the cobble stipple into every cell's bitmap, rows 1-23.
; The attributes will colour these pixels in a moment.
call fill_ground
; --- wash in the cobbles ---
; Seed the first attribute cell, point DE one cell ahead, and
; let LDIR cascade the byte through all 768 cells.
ld hl, $5800
ld de, $5801
ld (hl), COBBLE
ld bc, 767
ldir
call warm_walls
call paint_buildings
; --- brick the walls ---
; Now that the wall cells are painted, fill_walls can read the
; map back and lay brick wherever the wall bit is set.
call fill_walls
call draw_pips
call draw_lives
call draw_lamps
; save what he is about to stand on, BEFORE the first draw
call save_under
call draw_lamp
call save_draught
call draw_draught
ret
; ----------------------------------------------------------------------------
; warm_walls — the square's edge, one attribute write per cell; the
; colour is no longer a constant but the wall_ramp entry for how many
; lamps are lit. Same painting loop as ever — only where C comes from
; has changed.
; ----------------------------------------------------------------------------
warm_walls:
ld a, (lit_count)
ld e, a
ld d, 0
ld hl, wall_ramp
add hl, de
ld c, (hl) ; the byte every wall cell gets
; the top wall: row 1 is 32 cells in a row from $5820
; (row 0 is kept back — it becomes the HUD later)
ld hl, $5820
ld b, 32
.wt:
ld (hl), c
inc hl
djnz .wt
; the bottom wall: row 23, 32 cells from $5AE0
ld hl, $5AE0
ld b, 32
.wb:
ld (hl), c
inc hl
djnz .wb
; the side walls: column 0 and column 31 of rows 1-23.
; Write the row's first cell, hop 31 cells to its last,
; then step a full row (32) down — 23 times.
ld hl, $5820
ld b, 23
.ws:
ld (hl), c
push hl
ld de, 31
add hl, de
ld (hl), c
pop hl
ld de, 32
add hl, de
djnz .ws
ret
; ----------------------------------------------------------------------------
; The beeper. One bit on port $FE: set it, wait, clear it, wait — a
; square wave by hand. C is the half-period (pitch: bigger is lower),
; B the number of cycles (duration). DI while it sounds: the 50 Hz
; interrupt would stretch random half-periods and buzz the tone.
; ----------------------------------------------------------------------------
beep:
di
.bcyc:
ld a, SPEAKER
out ($FE), a
ld a, c
.bd1:
dec a
jr nz, .bd1
xor a
out ($FE), a
ld a, c
.bd2:
dec a
jr nz, .bd2
djnz .bcyc
ei
ret
blip_lit: ; a rising third — the lamp catches
ld b, $17 ; C6
ld c, $67
call beep
ld b, $28 ; E6
ld c, $51
jp beep
chime_dusk: ; two cold tolls, then the motif far off
ld b, $84 ; A4
ld c, $F7
call beep
ld b, 10
call rest
ld b, $84 ; A4
ld c, $F7
call beep
ld b, 13
call rest
ld b, $92 ; E5
ld c, $A4
call beep
ld b, 4
call rest
ld b, $9D ; C5
ld c, $CF
jp beep
; rest — B frames of silence. Musical time rides the heartbeat: the
; gaps between notes are counted in HALTs, not busy-loops.
rest:
halt
djnz rest
ret
fanfare_held: ; THE NIGHT IS HELD — a rising run
ld b, $83 ; C5
ld c, $CF
call beep
ld b, 3
call rest
ld b, $A5 ; E5
ld c, $A4
call beep
ld b, 3
call rest
ld b, $C4 ; G5
ld c, $8A
call beep
ld b, 3
call rest
ld b, $FF ; C6, held — B only counts to 255,
ld c, $67
call beep
ld b, $FF ; so hold it by sounding it twice
ld c, $67
jp beep
sting_nightfall: ; NIGHT FALLS — two steps down, then dark
ld b, $53 ; E5
ld c, $A4
call beep
ld b, 4
call rest
ld b, $49 ; D5
ld c, $B8
call beep
ld b, 4
call rest
ld b, $DC ; A4, long — the night settles on it
ld c, $F7
jp beep
; ----------------------------------------------------------------------------
; Screens.
; ----------------------------------------------------------------------------
; draw_win_screen — lift the lamplighter off the board (restore his
; cell: the eighth lamp, lit, comes out of the buffer), then say it.
; draw_title_screen — sparse and suggestive: a black void, the name,
; the invitation. Everything else is left to the imagination, which
; is both the aesthetic and the budget.
draw_title_screen:
call clear_bitmap
ld hl, $5800
ld de, $5801
ld (hl), %00000000
ld bc, 767
ldir
ld hl, title_text
ld b, TITLE_ROW
ld c, TITLE_COL
call print_string
ld hl, prompt_text
ld b, PROMPT_ROW
ld c, PROMPT_COL
call print_string
; your best night — the lives you kept on your finest win,
; read in lamps (no digits). It survives the loop back to
; the title: the go-again hook.
ld hl, $5800 + 11 * 32 + 14
ld b, LIVES
ld a, (best_lives)
ld c, a
.tpip:
ld a, PIP_UNLIT
inc c
dec c
jr z, .tpcold
ld a, PIP_LIT
dec c
.tpcold:
ld (hl), a
inc hl
djnz .tpip
ret
draw_win_screen:
call restore_under
ld hl, win_text
ld b, MSG_ROW
ld c, WIN_COL
call print_string
ld hl, prompt_text
ld b, CONT_ROW
ld c, PROMPT_COL
call print_string
ret
; draw_lose_screen — the whole attribute table goes black: every lamp,
; every wall, every warm cell, gone in one LDIR. Then the words.
draw_lose_screen:
ld hl, $5800
ld de, $5801
ld (hl), %00000000
ld bc, 767
ldir
ld hl, lose_text
ld b, MSG_ROW
ld c, LOSE_COL
call print_string
ld hl, prompt_text
ld b, CONT_ROW
ld c, PROMPT_COL
call print_string
ret
; ----------------------------------------------------------------------------
; clear_bitmap — zero the pixel layer, $4000-$57FF, with the same
; seed-and-cascade LDIR idiom the cobble wash uses.
; ----------------------------------------------------------------------------
clear_bitmap:
ld hl, $4000
ld de, $4001
ld (hl), 0
ld bc, 6143
ldir
ret
; ----------------------------------------------------------------------------
; player_step — the keys become movement. Each direction key edits a
; TARGET position (tcol, trow) — a proposal, not yet a move — so it
; can be vetoed before it becomes real. Then the move commits: leave
; the old cell, take the new one, draw.
; ----------------------------------------------------------------------------
player_step:
; --- propose: the target starts where he stands ---
ld a, (lamp_col)
ld (tcol), a
ld a, (lamp_row)
ld (trow), a
; The held-key gate: the first press steps at once, then one
; step every PLAYER_REPEAT frames. Releasing every direction
; key re-arms the instant first step, so taps stay crisp.
ld bc, KEYS_OP
in a, (c)
cpl
and %00000011
ld e, a
ld bc, KEYS_Q
in a, (c)
cpl
and %00000001
or e
ld e, a
ld bc, KEYS_A
in a, (c)
cpl
and %00000001
or e
jr nz, .held
xor a
ld (player_timer), a
ret
.held:
ld a, (player_timer)
or a
jr z, .stepnow
dec a
ld (player_timer), a
ret
.stepnow:
ld a, PLAYER_REPEAT
ld (player_timer), a
ld bc, KEYS_OP
in a, (c)
bit 1, a ; O — a zero bit is a pressed key
jr z, .pleft
bit 0, a ; P, same half-row
jr z, .pright
ld bc, KEYS_Q
in a, (c)
bit 0, a ; Q
jr z, .pup
ld bc, KEYS_A
in a, (c)
bit 0, a ; A
jr z, .pdown
ret ; nothing held — nothing to do
.pleft:
ld hl, tcol
dec (hl)
jr .pmove
.pright:
ld hl, tcol
inc (hl)
jr .pmove
.pup:
ld hl, trow
dec (hl)
jr .pmove
.pdown:
ld hl, trow
inc (hl)
.pmove:
; The veto: ask the target cell's attribute whether it's wall.
; NZ means brick — the proposal dies here and he stays put.
ld a, (trow)
ld b, a
ld a, (tcol)
ld c, a
call wall_at
ret nz
; the solid night blocks too — you cannot walk into the dark
ld a, (hl)
cp DARK
ret z
; and the mirror rule: he cannot step onto the wisp either
ld a, (tcol)
ld hl, draught_col
cp (hl)
jr nz, .pcommit
ld a, (trow)
ld hl, draught_row
cp (hl)
jr nz, .pcommit
call lose_life ; walking into the cold costs the same
ret
.pcommit:
; --- commit: restore, step, save, draw — in that order ---
call restore_under
ld a, (tcol)
ld (lamp_col), a
ld a, (trow)
ld (lamp_row), a
call save_under
; light it where it lives: while he covers the lamp, its truth
; is the buffer — rewrite the saved attribute, and restore will
; paint the lamp back lit when he leaves
ld a, (under_lamp + 8)
cp LAMP_UNLIT
jr nz, .pdrawn
ld a, LAMP_LIT
ld (under_lamp + 8), a
; record the lighting order — the night bears its grudges
; oldest-first (lamp_col/lamp_row are the lamplighter's
; position, and he is standing on the lamp)
ld a, (lamp_col)
ld c, a
ld a, (lamp_row)
ld b, a
call lamp_index_at
call lit_push
call light_pip
call blip_lit
call warm_walls
call recompute_pools
.pdrawn:
call draw_lamp
ret
; ----------------------------------------------------------------------------
; fill_ground — the cobble stipple. Not decoration: the stipple is what
; makes ground-state changes visible later, when the game starts
; recolouring these pixels. Rows 1-23 (row 0 is the HUD).
; ----------------------------------------------------------------------------
fill_ground:
ld b, 1 ; rows 1-23 (row 0 is the HUD)
.fgr:
ld c, 0
.fgc:
ld de, cobble_tex
call blit_tex
inc c
ld a, c
cp 32
jr c, .fgc
inc b
ld a, b
cp 24
jr c, .fgr
ret
; fill_walls — brickwork. Driven by the wall attribute bit, so anything
; painted as wall — now or later in the game — gets its brick for free:
; the map itself decides where the brick goes.
fill_walls:
ld b, 1
.fwr:
ld c, 0
.fwc:
push bc
call attr_addr_cr
bit WALL_BIT, (hl)
pop bc
jr z, .fwn
ld de, brick_tex
call blit_tex
.fwn:
inc c
ld a, c
cp 32
jr c, .fwc
inc b
ld a, b
cp 24
jr c, .fwr
ret
; blit_tex — write the 8-byte texture at DE into cell (C, B)'s bitmap.
; scr_addr_cr finds the cell's first pixel row; INC H steps down the
; other seven, 256 bytes apart.
blit_tex:
push bc
call scr_addr_cr
ld b, 8
.bt:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .bt
pop bc
ret
cobble_tex:
defb %10000010
defb %00000000
defb %00001000
defb %00000000
defb %00100001
defb %00000000
defb %00010000
defb %00000000
mist_tex:
; the solid night — dense, swirling, unmistakably *there*
defb %01101100
defb %11011011
defb %00110110
defb %01101101
defb %11011010
defb %10110110
defb %01101011
defb %11010110
brick_tex:
; mortar courses with staggered verticals — dusk-lit stone
defb %00001000
defb %00001000
defb %00001000
defb %11111111
defb %10000000
defb %10000000
defb %10000000
defb %11111111
; ----------------------------------------------------------------------------
; recompute_pools — the lamps cast their light. Every glow cell dies
; back to bare cobble, then every LIT lamp warms its eight neighbours.
; Derived, not tracked: called after any light or snuff, it rebuilds
; the whole layer from lamp truth, so the pools can never drift.
; ----------------------------------------------------------------------------
recompute_pools:
; the discipline: both movers OFF the screen first, so the
; recolour reads and writes true ground — never a sprite,
; and never into a buffer that would restore stale colour
call restore_under
call restore_draught
ld hl, $5820 ; rows 1-23 (row 0 is the HUD)
ld bc, 736
.rp1:
ld a, (hl)
cp GLOW
jr nz, .rp1n
ld (hl), COBBLE
.rp1n:
inc hl
dec bc
ld a, b
or c
jr nz, .rp1
ld hl, lamp_data
.rp2:
ld a, (hl)
cp $FF
jr z, .rpdone
ld c, a
inc hl
ld b, (hl)
inc hl
push hl
push bc
call attr_addr_cr
ld a, (hl)
pop bc
cp LAMP_LIT
jr nz, .rp2n
call glow_ring
.rp2n:
pop hl
jr .rp2
.rpdone:
; ...and back on, their buffers re-photographing ground
; that now includes the glow
call save_under
call save_draught
call draw_lamp
call draw_draught
ret
; glow_ring — warm the eight cells around lamp (C = col, B = row) where
; they are bare cobble. Pools never take walls, posts, or the dark.
glow_ring:
ld hl, ring_offsets
ld e, 8
.gr:
push hl
push de
push bc
ld a, (hl)
add a, c
ld c, a
inc hl
ld a, (hl)
add a, b
ld b, a
call attr_addr_cr
ld a, (hl)
cp COBBLE
jr nz, .grn
ld (hl), GLOW
.grn:
pop bc
pop de
pop hl
inc hl
inc hl
dec e
jr nz, .gr
ret
ring_offsets:
defb -1, -1, 0, -1, 1, -1
defb -1, 0, 1, 0
defb -1, 1, 0, 1, 1, 1
; ----------------------------------------------------------------------------
; lamp_index_at — which lamp_data entry sits at (C = col, B = row)?
; Returns the index in A ($FF if none — callers only ask about cells
; they know hold a lamp).
; ----------------------------------------------------------------------------
lamp_index_at:
ld hl, lamp_data
ld e, 0
.lia:
ld a, (hl)
cp $FF
ret z
cp c
jr nz, .lian
inc hl
ld a, (hl)
dec hl
cp b
jr nz, .lian
ld a, e
ret
.lian:
inc hl
inc hl
inc e
jr .lia
; lit_push — append lamp index (A) to the lit-order queue.
lit_push:
ld e, a
ld a, (lit_qcount)
ld d, a
inc a
ld (lit_qcount), a
ld a, d
ld hl, lit_queue
add a, l
ld l, a
jr nc, .lp
inc h
.lp:
ld (hl), e
ret
; lit_remove — take lamp index (A) out of the lit-order queue,
; closing the gap.
lit_remove:
ld e, a
ld hl, lit_queue
ld a, (lit_qcount)
ld d, a
or a
ret z
.lr:
ld a, (hl)
cp e
jr z, .lrfound
inc hl
dec d
jr nz, .lr
ret
.lrfound:
dec d
jr z, .lrlast
.lrshift:
inc hl
ld a, (hl)
dec hl
ld (hl), a
inc hl
dec d
jr nz, .lrshift
.lrlast:
ld a, (lit_qcount)
dec a
ld (lit_qcount), a
ret
; ----------------------------------------------------------------------------
; draught_step — the hunt bears grudges. The wisp steps toward the
; OLDEST grievance: the head of the lit-order queue, or, with
; nothing lit, the lamplighter's own flame. Still no walls.
; ----------------------------------------------------------------------------
draught_step:
ld a, (draught_timer)
dec a
ld (draught_timer), a
ret nz
ld a, (dusk_speed)
ld (draught_timer), a
; withdrawing? after a snuff the night carries its prize
; home before hunting again — behaviour is a MODE now, and
; the mode decides what this beat means
ld a, (draught_mode)
or a
jr z, .hunt
ld a, (draught_home_col)
ld hl, draught_col
cp (hl)
jr nz, .whome
ld a, (draught_home_row)
ld hl, draught_row
cp (hl)
jr nz, .whome
xor a ; home — rest, then the hunt resumes
ld (draught_mode), a
ld a, WREST
ld (draught_timer), a
ret
.whome:
ld a, (draught_home_col)
ld (seek_col), a
ld a, (draught_home_row)
ld (seek_row), a
jp .chase
.hunt:
; the oldest flame is the night's grievance — it reclaims
; the ground it lost first. With nothing lit, it hunts the
; lamplighter's own flame: light your first lamp and the
; hunt turns away from you.
ld a, (lit_qcount)
or a
jr nz, .oldest
ld a, (lamp_col)
ld (seek_col), a
ld a, (lamp_row)
ld (seek_row), a
jr .chase
.oldest:
ld a, (lit_queue)
add a, a
ld e, a
ld d, 0
ld hl, lamp_data
add hl, de
ld a, (hl)
ld (seek_col), a
inc hl
ld a, (hl)
ld (seek_row), a
.chase:
; step one cell along the axis with the greater distance
; (ties go sideways) — the night is 4-connected, like the
; lamplighter
ld a, (draught_col)
ld (dtcol), a
ld a, (draught_row)
ld (dtrow), a
ld a, (seek_col)
ld hl, draught_col
sub (hl)
jp p, .absc
neg
.absc:
ld d, a ; D = |dc|
ld a, (seek_row)
ld hl, draught_row
sub (hl)
jp p, .absr
neg
.absr:
cp d ; |dr| vs |dc|
jr z, .tie
jr c, .horiz
jr .vert
.tie:
ld a, d
or a
ret z ; already on the light
jr .horiz
.horiz:
ld a, (seek_col)
ld hl, draught_col
cp (hl)
jr c, .hleft
ld a, (hl)
inc a
ld (dtcol), a
jr .contact
.hleft:
ld a, (hl)
dec a
ld (dtcol), a
jr .contact
.vert:
ld a, (seek_row)
ld hl, draught_row
cp (hl)
jr c, .vup
ld a, (hl)
inc a
ld (dtrow), a
jr .contact
.vup:
ld a, (hl)
dec a
ld (dtrow), a
.contact:
; never step ONTO the lamplighter: adjacent is as close as
; the night comes. Two movers, two buffers — and one cell
; can only ever be under one of them.
ld a, (dtcol)
ld hl, lamp_col
cp (hl)
jr nz, .dmove
ld a, (dtrow)
ld hl, lamp_row
cp (hl)
jr nz, .dmove
call lose_life ; the touch, priced
ret
.dmove:
call restore_draught
; the tendril: night pools where the wisp has walked. Ground
; and spilt light are both taken; posts and stone are not.
ld a, (draught_col)
ld c, a
ld a, (draught_row)
ld b, a
push bc
call attr_addr_cr
pop bc
ld a, (hl)
cp DARK
jr z, .retake
cp COBBLE
jr z, .take
cp GLOW
jr nz, .notake
.take:
ld (hl), DARK
ld de, mist_tex
call blit_tex
.retake:
call tendril_push
.notake:
ld a, (dtcol)
ld (draught_col), a
ld a, (dtrow)
ld (draught_row), a
call save_draught
; the snuff: while the wisp covers a lit lamp, the lamp's
; truth is ITS buffer — the same saved-under rule that lights
; lamps beneath the lamplighter, run by the villain. Rewrite
; the saved attribute to cold, and the wisp's own restore
; will leave the lamp out as it moves on.
ld a, (under_draught + 8)
cp LAMP_LIT
jr nz, .nosnuff
ld a, LAMP_UNLIT
ld (under_draught + 8), a
; the grievance is settled — off the lit-order queue
ld a, (draught_col)
ld c, a
ld a, (draught_row)
ld b, a
call lamp_index_at
call lit_remove
call unlight_pip
call warm_walls
call recompute_pools
ld a, 1 ; the prize is taken — withdraw
ld (draught_mode), a
.nosnuff:
call draw_draught
ret
; ----------------------------------------------------------------------------
; tendril_push — record darkened cell (C = col, B = row) in the tendril
; ring. When the ring is full the oldest cell releases back to bare
; cobble first — the night cannot hold ground beyond its reach, so the
; tendril can never permanently wall the square off.
; ----------------------------------------------------------------------------
tendril_push:
ld a, (tendril_len)
ld hl, tendril_max
cp (hl)
jr c, .tgrow
; full: release the oldest cell (the slot head points at)
push bc
ld a, (tendril_head)
add a, a
ld e, a
ld d, 0
ld hl, tendril_buf
add hl, de
ld c, (hl)
inc hl
ld b, (hl)
; a newer ring entry may still claim this cell (the wisp
; re-walks its own trail) — then the night keeps it
call tendril_claimed
jr z, .treld
; if the wisp itself is crossing that cell, mend its saved
; ground instead of the screen
ld a, (draught_col)
cp c
jr nz, .trel
ld a, (draught_row)
cp b
jr nz, .trel
; mend the wisp's saved ground: stipple, and glow if a lit
; lamp still pools this cell — the light heals behind the dark
push bc
ld hl, cobble_tex
ld de, under_draught
ld bc, 8
ldir
pop bc
call pooled_at
ld a, COBBLE
jr nz, .tsetu
ld a, GLOW
.tsetu:
ld (under_draught + 8), a
jr .treld
.trel:
push bc
call attr_addr_cr
pop bc
ld a, (hl)
cp DARK
jr nz, .treld
push hl
call pooled_at
pop hl
ld a, COBBLE
jr nz, .tset
ld a, GLOW
.tset:
ld (hl), a
ld de, cobble_tex
call blit_tex
.treld:
pop bc
jr .tstore
.tgrow:
inc a
ld (tendril_len), a
.tstore:
ld a, (tendril_head)
add a, a
ld e, a
ld d, 0
ld hl, tendril_buf
add hl, de
ld (hl), c
inc hl
ld (hl), b
ld a, (tendril_head)
inc a
ld hl, tendril_max
cp (hl)
jr c, .tadv
xor a
.tadv:
ld (tendril_head), a
ret
; paint_buildings — walk the rectangle table: each entry is col, row,
; width, height; $FF ends the list. Every cell inside a rectangle gets
; the WALL attribute — and because fill_walls textures by the wall bit,
; the brickwork arrives without another line of drawing code.
paint_buildings:
ld hl, bldg_data
.pb:
ld a, (hl)
cp $FF
ret z
ld c, a ; col
inc hl
ld b, (hl) ; row
inc hl
ld d, (hl) ; width
inc hl
ld e, (hl) ; height
inc hl
push hl
.pbrow:
push bc
push de
.pbcol:
push bc
push de
call attr_addr_cr
ld (hl), WALL
pop de
pop bc
inc c
dec d
jr nz, .pbcol
pop de
pop bc
inc b
dec e
jr nz, .pbrow
pop hl
jr .pb
bldg_data:
defb 5, 5, 4, 3
defb 23, 5, 4, 3
defb $FF
corner_tab:
; where the dark enters, per watch (NE, SE, SW, NW)
defb 28, 4
defb 28, 19
defb 3, 19
defb 3, 4
; ----------------------------------------------------------------------------
; tendril_claimed — does any ring slot other than head hold (C, B)?
; Z set if claimed. Only called with the ring full, so every slot holds
; a real cell.
; ----------------------------------------------------------------------------
tendril_claimed:
ld hl, tendril_buf
ld e, 0
.tc:
ld a, (tendril_head)
cp e
jr z, .tcn ; the slot being released — skip
ld a, (hl)
cp c
jr nz, .tcn
inc hl
ld a, (hl)
dec hl
cp b
jr nz, .tcn
xor a ; Z — a newer claim holds it
ret
.tcn:
inc hl
inc hl
inc e
ld a, (tendril_max)
cp e
jr nz, .tc
or a ; NZ (max is never 0) — free
ret
; ----------------------------------------------------------------------------
; pooled_at — is cell (C, B) within one cell of a LIT lamp? Z if so.
; The light heals: released tendril ground inside a live pool returns
; to glow, not bare cobble.
; ----------------------------------------------------------------------------
pooled_at:
ld hl, lamp_data
.pa:
ld a, (hl)
cp $FF
jr z, .pano
ld e, a ; lamp col
inc hl
ld d, (hl) ; lamp row
inc hl
ld a, e
sub c
jp p, .pac
neg
.pac:
cp 2
jr nc, .pa
ld a, d
sub b
jp p, .par
neg
.par:
cp 2
jr nc, .pa
push hl
push bc
ld c, e
ld b, d
call attr_addr_cr
ld a, (hl)
pop bc
pop hl
cp LAMP_LIT
jr nz, .pa
xor a ; Z — pooled by a lit lamp
ret
.pano:
or 1 ; NZ — bare ground
ret
; ----------------------------------------------------------------------------
; lose_life — the price of the touch: one ember out, and either a
; fresh start or the fall of night.
; ----------------------------------------------------------------------------
lose_life:
ld a, (lives)
dec a
ld (lives), a
ld e, a
ld d, 0
ld hl, LIFE_BASE
add hl, de
ld (hl), COBBLE ; the ember at the new count goes out
ld a, (lives)
or a
jr z, .gone
; a life left: the lamplighter returns to the start cell
call restore_under
ld a, START_COL
ld (lamp_col), a
ld a, START_ROW
ld (lamp_row), a
call save_under
call draw_lamp
; the taking costs the night its reach — the wisp recoils to
; the far corner, so every life buys a whole fresh chase
; (leaving it beside the respawn made a catch strip every
; life in seconds once the draught learnt to hunt)
call restore_draught
ld a, (draught_home_col)
ld (draught_col), a
ld a, (draught_home_row)
ld (draught_row), a
ld a, (dusk_speed)
ld (draught_timer), a
xor a ; already home — hunt on arrival
ld (draught_mode), a
call save_draught
call draw_draught
ret
.gone:
call draw_lose_screen
call sting_nightfall
ld a, LOCK
ld (input_lock), a
ld a, STATE_LOSE
ld (game_state), a
ret
; ----------------------------------------------------------------------------
; print_string / print_char — the machine's own letters. The Spectrum
; keeps its font in ROM: eight bytes per character, and FONT is chosen
; so that ASCII code x 8 + FONT is the glyph's address. Each character
; is drawn like any cell: attribute first, eight rows down the cell.
; ----------------------------------------------------------------------------
print_string:
.ps:
ld a, (hl)
cp $FF
ret z
push hl
push bc
call print_char
pop bc
pop hl
inc hl
inc c
jr .ps
print_char:
ld l, a
ld h, 0
add hl, hl
add hl, hl
add hl, hl
ld de, FONT
add hl, de
ex de, hl
push de
call attr_addr_cr
ld (hl), MSG_ATTR
call scr_addr_cr
pop de
ld b, 8
.pc:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .pc
ret
; ----------------------------------------------------------------------------
; light_pip / unlight_pip / draw_pips / draw_lives.
; ----------------------------------------------------------------------------
; light_pip — warm the next pip along and count the lamp. lit_count is
; the index of the pip to light AND the number of lamps lit so far —
; read it for the address, then step it.
light_pip:
ld a, (lit_count)
ld e, a
ld d, 0
inc a
ld (lit_count), a
ld hl, PIP_BASE
add hl, de
ld (hl), PIP_LIT
ret
; unlight_pip — light_pip's mirror: step the count back and cool the
; pip at the new count. The tally can go DOWN now.
unlight_pip:
ld a, (lit_count)
dec a
ld (lit_count), a
ld e, a
ld d, 0
ld hl, PIP_BASE
add hl, de
ld (hl), PIP_UNLIT
ret
; draw_pips — the tally row: one cell per lamp on the HUD ledge, all
; cold to start. A pip is pure attribute — no glyph, just a block of
; PAPER — so the row costs eight bytes of screen and no bitmap at all.
draw_pips:
ld hl, PIP_BASE
ld b, NUM_LAMPS
ld a, PIP_UNLIT
.dp:
ld (hl), a
inc hl
djnz .dp
ret
; draw_lives — three embers on the ledge's right shoulder.
draw_lives:
ld hl, LIFE_BASE
ld b, LIVES
ld a, LIFE_PIP
.dlv:
ld (hl), a
inc hl
djnz .dlv
ret
; ----------------------------------------------------------------------------
; draw_lamps — walk the position table: col, row pairs, $FF to finish.
; Placement is data; the drawing code neither knows nor cares how many
; lamps the town has tonight.
; ----------------------------------------------------------------------------
draw_lamps:
ld hl, lamp_data
.next:
ld a, (hl)
cp $FF
ret z
ld c, a
inc hl
ld b, (hl)
inc hl
push hl
call draw_lantern
pop hl
jr .next
; draw_lantern — an unlit lamp into cell (C, B): cold cyan attribute,
; then the lantern glyph down the cell like any texture.
draw_lantern:
call attr_addr_cr
ld (hl), LAMP_UNLIT
call scr_addr_cr
ld de, lantern
ld b, 8
.dlt:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .dlt
ret
; ----------------------------------------------------------------------------
; scr_addr_cr — HL = bitmap address of cell (C, B)'s first pixel row.
; The row's top two bits pick the third of the screen (H), its bottom
; three become L's top bits, and the column fills L's low five.
; ----------------------------------------------------------------------------
scr_addr_cr:
ld a, b
and %00011000 ; the third (row bits 4-3) ...
or %01000000 ; ... under the screen base $40xx
ld h, a
ld a, b
and %00000111 ; the char row within the third ...
rrca ; ... rotated into bits 7-5
rrca
rrca
or c ; the column in bits 4-0
ld l, a
ret
; attr_addr_cr — HL = attribute address of cell (C, B):
; $5800 + row*32 + col, the row shifted up five times.
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
; wall_at — is cell (C, B) wall? The answer is already on the screen:
; every wall cell's attribute has WALL_BIT set, so one bit-test of
; attribute memory is the whole collision system. NZ = wall.
wall_at:
call attr_addr_cr
bit WALL_BIT, (hl)
ret
; ----------------------------------------------------------------------------
; The lamplighter's save / restore / draw.
; ----------------------------------------------------------------------------
; pos_bc — the lamplighter's cell into (C, B), read fresh from the data.
pos_bc:
ld a, (lamp_row)
ld b, a
ld a, (lamp_col)
ld c, a
ret
; save_under — copy the nine bytes of his cell into the buffer: eight
; bitmap rows, then the attribute. Runs as he ARRIVES, before the
; draw — so the buffer always holds true ground, never him.
save_under:
call pos_bc
call scr_addr_cr
ld de, under_lamp
ld b, 8
.su:
ld a, (hl)
ld (de), a
inc de
inc h
djnz .su
call pos_bc
call attr_addr_cr
ld a, (hl)
ld (under_lamp + 8), a
ret
; restore_under — the same nine bytes back the other way: the ground
; returns exactly as it was. Runs as he LEAVES, while the position
; still points at the old cell.
restore_under:
call pos_bc
call scr_addr_cr
ld de, under_lamp
ld b, 8
.ru:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .ru
call pos_bc
call attr_addr_cr
ld a, (under_lamp + 8)
ld (hl), a
ret
draw_lamp:
; his colour first: the cell's attribute becomes his own —
; bright white on the black, his own light about him
call pos_bc
call attr_addr_cr
ld (hl), LAMP_ATTR
; then his shape, eight bytes down the cell like any texture
call pos_bc
call scr_addr_cr
ld de, lamplighter
ld b, 8
.dl:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .dl
ret
; ----------------------------------------------------------------------------
; The draught's save / restore / draw — the lamplighter's engine, twice.
; Same loops, same nine-byte contract, its own buffer and its own
; position: two movers can share a world but never a buffer.
; ----------------------------------------------------------------------------
dpos_bc:
ld a, (draught_row)
ld b, a
ld a, (draught_col)
ld c, a
ret
save_draught:
call dpos_bc
call scr_addr_cr
ld de, under_draught
ld b, 8
.sd:
ld a, (hl)
ld (de), a
inc de
inc h
djnz .sd
call dpos_bc
call attr_addr_cr
ld a, (hl)
ld (under_draught + 8), a
ret
restore_draught:
call dpos_bc
call scr_addr_cr
ld de, under_draught
ld b, 8
.rd:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .rd
call dpos_bc
call attr_addr_cr
ld a, (under_draught + 8)
ld (hl), a
ret
draw_draught:
call dpos_bc
call attr_addr_cr
ld (hl), DRAUGHT_ATTR
call dpos_bc
call scr_addr_cr
ld de, draught_glyph
ld b, 8
.dd:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .dd
ret
; ----------------------------------------------------------------------------
; Data.
; ----------------------------------------------------------------------------
game_state:
defb STATE_TITLE
input_lock:
defb 0
dusk_table:
; the wisp's pace per dusk (frames between steps) — the
; night deepens as data, not code. Dusk 1 is gentle on
; purpose: the hunt must be readable before it's a threat.
; The final watch is pace 9, not 8 — playtested: 8 is the
; human wall, 9 is beatable. The last watch should be the
; climax, not the ceiling.
defb 16, 13, 11, 9, 9
dusk_lentab:
; the tendril's reach per watch (cells of night held) —
; the second axis of the deepening. Front-loading reach
; made watch 1 brutal (playtested: a practised player lost
; at watch 2) — the opening teaches the mechanic, the deep
; watches punish with it.
defb 3, 6, 9, 13, 18
wall_ramp:
; The square warms in the game's own vocabulary: the stone
; stays dusk-blue; the lamplight catches the mortar first
; (ink white -> yellow), then the whole face glows BRIGHT.
; Never magenta — warmth is yellow here, not red-shifted blue.
defb %00001111 ; dusk stone, white mortar
defb %00001111
defb %00001111
defb %00001110 ; the mortar warms — yellow ink
defb %00001110
defb %00001110
defb %01001110 ; the stone catches the glow — BRIGHT
defb %01001110
defb %01110000 ; all eight lit: the square aglow —
; warm yellow stone, only at the win
lamp_data:
defb 4, 3
defb 27, 3
defb 9, 7
defb 22, 7
defb 6, 15
defb 25, 15
defb 13, 20
defb 18, 20
defb $FF
lamp_col:
defb START_COL
lamp_row:
defb START_ROW
tcol:
defb 0
trow:
defb 0
lit_count:
defb 0
lives:
defb LIVES
best_lives:
defb 0 ; lives kept on the finest win — never reset
draught_col:
defb 28
draught_row:
defb 4
draught_home_col:
defb 28
draught_home_row:
defb 4
draught_mode:
defb 0 ; 0 = hunting, 1 = withdrawing home
draught_timer:
defb 16
player_timer:
defb 0
dusk:
defb 0 ; which watch of the night this is
dusk_speed:
defb 16
seek_col:
defb 0
seek_row:
defb 0
lit_queue:
defb 0, 0, 0, 0, 0, 0, 0, 0
lit_qcount:
defb 0
tendril_head:
defb 0
tendril_len:
defb 0
tendril_max:
defb 6 ; the night's reach — six cells of held ground
tendril_buf:
defb 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
defb 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
dtcol:
defb 0
dtrow:
defb 0
under_lamp:
defb 0, 0, 0, 0, 0, 0, 0, 0, 0
under_draught:
defb 0, 0, 0, 0, 0, 0, 0, 0, 0
lamplighter:
defb %00111100
defb %00111100
defb %00011000
defb %01111110
defb %00011000
defb %00011000
defb %00100100
defb %01000010
lantern:
defb %00011000
defb %00100100
defb %01111110
defb %01111110
defb %01011010
defb %01111110
defb %01111110
defb %00111100
draught_glyph:
defb %00000000
defb %00111100
defb %01111110
defb %11111111
defb %11111111
defb %01111110
defb %00111100
defb %00000000
title_text:
defb "GLOAMING"
defb $FF
prompt_text:
defb "PRESS SPACE"
defb $FF
win_text:
defb "THE NIGHT IS HELD"
defb $FF
lose_text:
defb "NIGHT FALLS"
defb $FF
end start
Note the small guard: dusks past the table’s end (there will be one, briefly, next unit) clamp to the last entry rather than reading whatever byte lives after the table. Every table walk in this game bounds its index; the one time you forget will be the one time a counter goes somewhere you didn’t plan.
Milestone 3 — the ledger must not lie
Now go back to that pair of screenshots. Two embers on the held screen; three when watch 2 opens; and (lives) is 2 the whole time. The bug is one line and it’s been in the file since before this module started: draw_lives paints LIVES — the constant, three — and until tonight that was fine, because init_game only ever ran with full lives. The moment lives carry across a re-init, the constant repaint becomes a lie. Worse, it’s a compounding one: lose a life in watch 2 and lose_life erases the pip at index 1, leaving a lit–dark–lit row — two embers shown, one life held.
We didn’t catch this from a screenshot, and neither did fifteen rounds of playtesting the real thing — everyone read the square, and nobody read the ledge across a watch boundary. It was caught when this game was taken apart to build this module, by the boring, wonderful method of trying to photograph the lives carrying and discovering they didn’t, visually, carry. The machine gate proved the game winnable; only reading every row of the screen caught the HUD lying. Both kinds of checking exist because each finds what the other can’t.
Step 3: draw_lives reads the carried count — displays read state, never constants
+8-2
| 1470 | 1470 | djnz .dp | |
| 1471 | 1471 | ret | |
| 1472 | 1472 | | |
| 1473 | - | ; draw_lives — three embers on the ledge's right shoulder. | |
| 1473 | + | ; draw_lives — the embers on the ledge's right shoulder. Read the | |
| 1474 | + | ; CARRIED lives, not the constant: a run's lives survive the watches | |
| 1475 | + | ; now, and the ledge must say so. (The constant version repainted | |
| 1476 | + | ; three every watch — a lie we only caught while taking this game | |
| 1477 | + | ; apart for this module. Playtests read the square; nobody read the | |
| 1478 | + | ; ledger across a watch boundary.) | |
| 1474 | 1479 | draw_lives: | |
| 1475 | 1480 | ld hl, LIFE_BASE | |
| 1476 | - | ld b, LIVES | |
| 1481 | + | ld a, (lives) | |
| 1482 | + | ld b, a | |
| 1477 | 1483 | ld a, LIFE_PIP | |
| 1478 | 1484 | .dlv: | |
| 1479 | 1485 | ld (hl), a |
The complete step 3 program
; The Long Night — Unit 6: The Night Deepens
; Cumulative build; every step runs on its own. Narrative: the unit page.
; Escalation as data — and the held screen becomes an interstitial.
org 32768
COBBLE equ %00000001 ; PAPER black (0), INK blue (1) — dark ground
GLOW equ %00000110 ; pool-warmed cobble: yellow INK on black —
; ground the light holds
DARK equ %01000001 ; the night made solid: blue INK on black,
; BRIGHT — impassable, unmistakably there
WALL equ %00001111 ; PAPER blue (1), INK white (7) — pale stone
WALL_BIT equ 3 ; the attribute bit that says "this is wall"
LAMP_ATTR equ %01000111 ; BRIGHT, PAPER black, INK white — his own light
LAMP_UNLIT equ %00000101 ; cold cyan INK on black PAPER — bit 3
; clear, so a lamp reads as floor
LAMP_LIT equ %01000110 ; BRIGHT yellow INK on black — a held flame
DRAUGHT_ATTR equ %01000101 ; the wisp: BRIGHT cyan on black — cold light
LIVES equ 3
LIFE_PIP equ %01010000 ; a life: BRIGHT red PAPER — a small ember
LIFE_BASE equ $5800 + 28 ; row 0, right of the ledge — three cells
NUM_DUSKS equ 5 ; five watches of night — the tables
; below give each watch its teeth
PIP_UNLIT equ %00101000 ; a cold pip: cyan PAPER, a solid block
PIP_LIT equ %01110000 ; a warm pip: BRIGHT yellow PAPER
PIP_BASE equ $5800 + 12 ; row 0, column 12 — the HUD ledge,
; eight cells, centred over the square
NUM_LAMPS equ 8
MSG_ATTR equ %01000111 ; message text: bright white on black
MSG_ROW equ 11
LOSE_COL equ 10 ; centres the eleven characters
WIN_COL equ 7 ; centres the seventeen characters
FONT equ $3C00 ; the ROM font, addressed so that
; ASCII x 8 lands on the right glyph
STATE_TITLE equ 0
STATE_PLAY equ 1
STATE_WIN equ 2 ; a dusk held — the night deepens
STATE_LOSE equ 3 ; night falls — the game is lost
LOCK equ 25 ; input-lock frames after entering a screen
SPEAKER equ %00010000 ; port $FE bit 4 — the beeper's one bit
TITLE_COL equ 12 ; GLOAMING, centred
PROMPT_COL equ 10 ; PRESS SPACE, centred
TITLE_ROW equ 8
PROMPT_ROW equ 14
CONT_ROW equ 16 ; "PRESS SPACE" under a win/lose line
START_COL equ 15 ; where the lamplighter begins
START_ROW equ 11
PLAYER_REPEAT equ 6 ; frames between steps while a key is held
GATHER equ 120 ; frames the dark gathers before its first step
WREST equ 48 ; frames it rests at home after a withdrawal —
; the snuff window holds even when home is close
KEYS_OP equ $DFFE ; half-row P O I U Y — bits 1 and 0
KEYS_Q equ $FBFE ; half-row Q W E R T — bit 0 is Q
KEYS_A equ $FDFE ; half-row A S D F G — bit 0 is A
KEYS_SPACE equ $7FFE ; half-row SPACE SYM M N B — bit 0
start:
; --- the border goes black — the night beyond the square ---
; Port $FE bits 0-2 set the BORDER colour. A = 0 = black.
ld a, 0
out ($FE), a
ld a, STATE_TITLE
ld (game_state), a
call draw_title_screen
im 1
ei
call chime_dusk ; after EI — the rests need the interrupt
main_loop:
halt
; the dispatch: each state names what a frame means — the
; title listens for a beginning, PLAY beats the game forward,
; WIN and LOSE hold the screen exactly as it stands
ld a, (game_state)
cp STATE_TITLE
jr z, .do_title
cp STATE_PLAY
jr z, .do_play
call end_step ; WIN or LOSE — wait for a key, then title
jr main_loop
.do_title:
call title_step
jr main_loop
.do_play:
call play_step
jr main_loop
; ----------------------------------------------------------------------------
; title_step — SPACE starts a fresh game.
; ----------------------------------------------------------------------------
title_step:
ld a, (input_lock)
or a
jr z, .tready
dec a
ld (input_lock), a
ret
.tready:
ld bc, KEYS_SPACE
in a, (c)
bit 0, a
ret nz
call init_run
ld a, STATE_PLAY
ld (game_state), a
ret
; ----------------------------------------------------------------------------
; end_step — after the lock, SPACE moves on. A held dusk continues
; the run — the night deepens; only NIGHT FALLS returns to the title.
; ----------------------------------------------------------------------------
end_step:
ld a, (input_lock)
or a
jr z, .eready
dec a
ld (input_lock), a
ret
.eready:
ld bc, KEYS_SPACE
in a, (c)
bit 0, a
ret nz
ld a, (game_state)
cp STATE_WIN
jr z, .deeper
call draw_title_screen
call chime_dusk
ld a, LOCK
ld (input_lock), a
ld a, STATE_TITLE
ld (game_state), a
ret
.deeper:
; the dusk was held — the night is NOT over. Deepen and
; go again: the square relights, and the lives carry.
ld hl, dusk
inc (hl)
call init_game
ld a, STATE_PLAY
ld (game_state), a
ret
; play_step — one beat of the game: ask the keyboard.
play_step:
call player_step
; contact can end the game mid-frame — if it did, stop here
ld a, (game_state)
cp STATE_PLAY
ret nz
call draught_step
ld a, (game_state)
cp STATE_PLAY
ret nz
; the win check, at the only beat the count can have changed
ld a, (lit_count)
cp NUM_LAMPS
ret nz
; the night is held — the lives you kept are the score
ld a, (lives)
ld hl, best_lives
cp (hl)
jr c, .nobest
ld (hl), a
.nobest:
call draw_win_screen
call fanfare_held
ld a, LOCK
ld (input_lock), a
ld a, STATE_WIN
ld (game_state), a
ret
; ----------------------------------------------------------------------------
; init_run / init_game — a run is a NIGHT now: dusk 0, full lives.
; Each held dusk re-enters init_game with dusk bumped — the square
; relights, the lives carry. What resets per RUN and what resets per
; WATCH is the whole design decision, drawn as two entry points.
; ----------------------------------------------------------------------------
init_run:
xor a
ld (dusk), a
ld a, LIVES
ld (lives), a
; fall through into the per-dusk setup
init_game:
xor a
ld (lit_count), a
; --- place the lamplighter ---
; His position is data. Everything that draws him reads it.
ld a, START_COL
ld (lamp_col), a
ld a, START_ROW
ld (lamp_row), a
; the dark probes from a new quarter each watch —
; a lesson the square teaches by ITSELF: watch 2 already
; feels different before anything else has changed
ld a, (dusk)
and 3
add a, a
ld e, a
ld d, 0
ld hl, corner_tab
add hl, de
ld a, (hl)
ld (draught_col), a
ld (draught_home_col), a
inc hl
ld a, (hl)
ld (draught_row), a
ld (draught_home_row), a
; the night deepens: the wisp's pace comes from the dusk
; table, deeper dusks holding the last entry
ld a, (dusk)
cp NUM_DUSKS
jr c, .dpace
ld a, NUM_DUSKS - 1
.dpace:
ld e, a
ld d, 0
ld hl, dusk_table
add hl, de
ld a, (hl)
ld (dusk_speed), a
; ...but it gathers before the first step — a beat to read
; the square before the hunt begins
ld a, GATHER
ld (draught_timer), a
; the tendril reaches further as the night deepens
ld hl, dusk_lentab
add hl, de
ld a, (hl)
ld (tendril_max), a
xor a
ld (player_timer), a
ld (tendril_len), a
ld (tendril_head), a
ld (draught_mode), a
ld (lit_qcount), a
; --- wipe the canvas ---
; The bitmap ($4000-$57FF) is the pixel layer; whatever was on
; screen before us still lives there. Zero it so only our
; attribute colours show.
call clear_bitmap
; --- texture the ground ---
; Blit the cobble stipple into every cell's bitmap, rows 1-23.
; The attributes will colour these pixels in a moment.
call fill_ground
; --- wash in the cobbles ---
; Seed the first attribute cell, point DE one cell ahead, and
; let LDIR cascade the byte through all 768 cells.
ld hl, $5800
ld de, $5801
ld (hl), COBBLE
ld bc, 767
ldir
call warm_walls
call paint_buildings
; --- brick the walls ---
; Now that the wall cells are painted, fill_walls can read the
; map back and lay brick wherever the wall bit is set.
call fill_walls
call draw_pips
call draw_lives
call draw_lamps
; save what he is about to stand on, BEFORE the first draw
call save_under
call draw_lamp
call save_draught
call draw_draught
ret
; ----------------------------------------------------------------------------
; warm_walls — the square's edge, one attribute write per cell; the
; colour is no longer a constant but the wall_ramp entry for how many
; lamps are lit. Same painting loop as ever — only where C comes from
; has changed.
; ----------------------------------------------------------------------------
warm_walls:
ld a, (lit_count)
ld e, a
ld d, 0
ld hl, wall_ramp
add hl, de
ld c, (hl) ; the byte every wall cell gets
; the top wall: row 1 is 32 cells in a row from $5820
; (row 0 is kept back — it becomes the HUD later)
ld hl, $5820
ld b, 32
.wt:
ld (hl), c
inc hl
djnz .wt
; the bottom wall: row 23, 32 cells from $5AE0
ld hl, $5AE0
ld b, 32
.wb:
ld (hl), c
inc hl
djnz .wb
; the side walls: column 0 and column 31 of rows 1-23.
; Write the row's first cell, hop 31 cells to its last,
; then step a full row (32) down — 23 times.
ld hl, $5820
ld b, 23
.ws:
ld (hl), c
push hl
ld de, 31
add hl, de
ld (hl), c
pop hl
ld de, 32
add hl, de
djnz .ws
ret
; ----------------------------------------------------------------------------
; The beeper. One bit on port $FE: set it, wait, clear it, wait — a
; square wave by hand. C is the half-period (pitch: bigger is lower),
; B the number of cycles (duration). DI while it sounds: the 50 Hz
; interrupt would stretch random half-periods and buzz the tone.
; ----------------------------------------------------------------------------
beep:
di
.bcyc:
ld a, SPEAKER
out ($FE), a
ld a, c
.bd1:
dec a
jr nz, .bd1
xor a
out ($FE), a
ld a, c
.bd2:
dec a
jr nz, .bd2
djnz .bcyc
ei
ret
blip_lit: ; a rising third — the lamp catches
ld b, $17 ; C6
ld c, $67
call beep
ld b, $28 ; E6
ld c, $51
jp beep
chime_dusk: ; two cold tolls, then the motif far off
ld b, $84 ; A4
ld c, $F7
call beep
ld b, 10
call rest
ld b, $84 ; A4
ld c, $F7
call beep
ld b, 13
call rest
ld b, $92 ; E5
ld c, $A4
call beep
ld b, 4
call rest
ld b, $9D ; C5
ld c, $CF
jp beep
; rest — B frames of silence. Musical time rides the heartbeat: the
; gaps between notes are counted in HALTs, not busy-loops.
rest:
halt
djnz rest
ret
fanfare_held: ; THE NIGHT IS HELD — a rising run
ld b, $83 ; C5
ld c, $CF
call beep
ld b, 3
call rest
ld b, $A5 ; E5
ld c, $A4
call beep
ld b, 3
call rest
ld b, $C4 ; G5
ld c, $8A
call beep
ld b, 3
call rest
ld b, $FF ; C6, held — B only counts to 255,
ld c, $67
call beep
ld b, $FF ; so hold it by sounding it twice
ld c, $67
jp beep
sting_nightfall: ; NIGHT FALLS — two steps down, then dark
ld b, $53 ; E5
ld c, $A4
call beep
ld b, 4
call rest
ld b, $49 ; D5
ld c, $B8
call beep
ld b, 4
call rest
ld b, $DC ; A4, long — the night settles on it
ld c, $F7
jp beep
; ----------------------------------------------------------------------------
; Screens.
; ----------------------------------------------------------------------------
; draw_win_screen — lift the lamplighter off the board (restore his
; cell: the eighth lamp, lit, comes out of the buffer), then say it.
; draw_title_screen — sparse and suggestive: a black void, the name,
; the invitation. Everything else is left to the imagination, which
; is both the aesthetic and the budget.
draw_title_screen:
call clear_bitmap
ld hl, $5800
ld de, $5801
ld (hl), %00000000
ld bc, 767
ldir
ld hl, title_text
ld b, TITLE_ROW
ld c, TITLE_COL
call print_string
ld hl, prompt_text
ld b, PROMPT_ROW
ld c, PROMPT_COL
call print_string
; your best night — the lives you kept on your finest win,
; read in lamps (no digits). It survives the loop back to
; the title: the go-again hook.
ld hl, $5800 + 11 * 32 + 14
ld b, LIVES
ld a, (best_lives)
ld c, a
.tpip:
ld a, PIP_UNLIT
inc c
dec c
jr z, .tpcold
ld a, PIP_LIT
dec c
.tpcold:
ld (hl), a
inc hl
djnz .tpip
ret
draw_win_screen:
call restore_under
ld hl, win_text
ld b, MSG_ROW
ld c, WIN_COL
call print_string
ld hl, prompt_text
ld b, CONT_ROW
ld c, PROMPT_COL
call print_string
ret
; draw_lose_screen — the whole attribute table goes black: every lamp,
; every wall, every warm cell, gone in one LDIR. Then the words.
draw_lose_screen:
ld hl, $5800
ld de, $5801
ld (hl), %00000000
ld bc, 767
ldir
ld hl, lose_text
ld b, MSG_ROW
ld c, LOSE_COL
call print_string
ld hl, prompt_text
ld b, CONT_ROW
ld c, PROMPT_COL
call print_string
ret
; ----------------------------------------------------------------------------
; clear_bitmap — zero the pixel layer, $4000-$57FF, with the same
; seed-and-cascade LDIR idiom the cobble wash uses.
; ----------------------------------------------------------------------------
clear_bitmap:
ld hl, $4000
ld de, $4001
ld (hl), 0
ld bc, 6143
ldir
ret
; ----------------------------------------------------------------------------
; player_step — the keys become movement. Each direction key edits a
; TARGET position (tcol, trow) — a proposal, not yet a move — so it
; can be vetoed before it becomes real. Then the move commits: leave
; the old cell, take the new one, draw.
; ----------------------------------------------------------------------------
player_step:
; --- propose: the target starts where he stands ---
ld a, (lamp_col)
ld (tcol), a
ld a, (lamp_row)
ld (trow), a
; The held-key gate: the first press steps at once, then one
; step every PLAYER_REPEAT frames. Releasing every direction
; key re-arms the instant first step, so taps stay crisp.
ld bc, KEYS_OP
in a, (c)
cpl
and %00000011
ld e, a
ld bc, KEYS_Q
in a, (c)
cpl
and %00000001
or e
ld e, a
ld bc, KEYS_A
in a, (c)
cpl
and %00000001
or e
jr nz, .held
xor a
ld (player_timer), a
ret
.held:
ld a, (player_timer)
or a
jr z, .stepnow
dec a
ld (player_timer), a
ret
.stepnow:
ld a, PLAYER_REPEAT
ld (player_timer), a
ld bc, KEYS_OP
in a, (c)
bit 1, a ; O — a zero bit is a pressed key
jr z, .pleft
bit 0, a ; P, same half-row
jr z, .pright
ld bc, KEYS_Q
in a, (c)
bit 0, a ; Q
jr z, .pup
ld bc, KEYS_A
in a, (c)
bit 0, a ; A
jr z, .pdown
ret ; nothing held — nothing to do
.pleft:
ld hl, tcol
dec (hl)
jr .pmove
.pright:
ld hl, tcol
inc (hl)
jr .pmove
.pup:
ld hl, trow
dec (hl)
jr .pmove
.pdown:
ld hl, trow
inc (hl)
.pmove:
; The veto: ask the target cell's attribute whether it's wall.
; NZ means brick — the proposal dies here and he stays put.
ld a, (trow)
ld b, a
ld a, (tcol)
ld c, a
call wall_at
ret nz
; the solid night blocks too — you cannot walk into the dark
ld a, (hl)
cp DARK
ret z
; and the mirror rule: he cannot step onto the wisp either
ld a, (tcol)
ld hl, draught_col
cp (hl)
jr nz, .pcommit
ld a, (trow)
ld hl, draught_row
cp (hl)
jr nz, .pcommit
call lose_life ; walking into the cold costs the same
ret
.pcommit:
; --- commit: restore, step, save, draw — in that order ---
call restore_under
ld a, (tcol)
ld (lamp_col), a
ld a, (trow)
ld (lamp_row), a
call save_under
; light it where it lives: while he covers the lamp, its truth
; is the buffer — rewrite the saved attribute, and restore will
; paint the lamp back lit when he leaves
ld a, (under_lamp + 8)
cp LAMP_UNLIT
jr nz, .pdrawn
ld a, LAMP_LIT
ld (under_lamp + 8), a
; record the lighting order — the night bears its grudges
; oldest-first (lamp_col/lamp_row are the lamplighter's
; position, and he is standing on the lamp)
ld a, (lamp_col)
ld c, a
ld a, (lamp_row)
ld b, a
call lamp_index_at
call lit_push
call light_pip
call blip_lit
call warm_walls
call recompute_pools
.pdrawn:
call draw_lamp
ret
; ----------------------------------------------------------------------------
; fill_ground — the cobble stipple. Not decoration: the stipple is what
; makes ground-state changes visible later, when the game starts
; recolouring these pixels. Rows 1-23 (row 0 is the HUD).
; ----------------------------------------------------------------------------
fill_ground:
ld b, 1 ; rows 1-23 (row 0 is the HUD)
.fgr:
ld c, 0
.fgc:
ld de, cobble_tex
call blit_tex
inc c
ld a, c
cp 32
jr c, .fgc
inc b
ld a, b
cp 24
jr c, .fgr
ret
; fill_walls — brickwork. Driven by the wall attribute bit, so anything
; painted as wall — now or later in the game — gets its brick for free:
; the map itself decides where the brick goes.
fill_walls:
ld b, 1
.fwr:
ld c, 0
.fwc:
push bc
call attr_addr_cr
bit WALL_BIT, (hl)
pop bc
jr z, .fwn
ld de, brick_tex
call blit_tex
.fwn:
inc c
ld a, c
cp 32
jr c, .fwc
inc b
ld a, b
cp 24
jr c, .fwr
ret
; blit_tex — write the 8-byte texture at DE into cell (C, B)'s bitmap.
; scr_addr_cr finds the cell's first pixel row; INC H steps down the
; other seven, 256 bytes apart.
blit_tex:
push bc
call scr_addr_cr
ld b, 8
.bt:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .bt
pop bc
ret
cobble_tex:
defb %10000010
defb %00000000
defb %00001000
defb %00000000
defb %00100001
defb %00000000
defb %00010000
defb %00000000
mist_tex:
; the solid night — dense, swirling, unmistakably *there*
defb %01101100
defb %11011011
defb %00110110
defb %01101101
defb %11011010
defb %10110110
defb %01101011
defb %11010110
brick_tex:
; mortar courses with staggered verticals — dusk-lit stone
defb %00001000
defb %00001000
defb %00001000
defb %11111111
defb %10000000
defb %10000000
defb %10000000
defb %11111111
; ----------------------------------------------------------------------------
; recompute_pools — the lamps cast their light. Every glow cell dies
; back to bare cobble, then every LIT lamp warms its eight neighbours.
; Derived, not tracked: called after any light or snuff, it rebuilds
; the whole layer from lamp truth, so the pools can never drift.
; ----------------------------------------------------------------------------
recompute_pools:
; the discipline: both movers OFF the screen first, so the
; recolour reads and writes true ground — never a sprite,
; and never into a buffer that would restore stale colour
call restore_under
call restore_draught
ld hl, $5820 ; rows 1-23 (row 0 is the HUD)
ld bc, 736
.rp1:
ld a, (hl)
cp GLOW
jr nz, .rp1n
ld (hl), COBBLE
.rp1n:
inc hl
dec bc
ld a, b
or c
jr nz, .rp1
ld hl, lamp_data
.rp2:
ld a, (hl)
cp $FF
jr z, .rpdone
ld c, a
inc hl
ld b, (hl)
inc hl
push hl
push bc
call attr_addr_cr
ld a, (hl)
pop bc
cp LAMP_LIT
jr nz, .rp2n
call glow_ring
.rp2n:
pop hl
jr .rp2
.rpdone:
; ...and back on, their buffers re-photographing ground
; that now includes the glow
call save_under
call save_draught
call draw_lamp
call draw_draught
ret
; glow_ring — warm the eight cells around lamp (C = col, B = row) where
; they are bare cobble. Pools never take walls, posts, or the dark.
glow_ring:
ld hl, ring_offsets
ld e, 8
.gr:
push hl
push de
push bc
ld a, (hl)
add a, c
ld c, a
inc hl
ld a, (hl)
add a, b
ld b, a
call attr_addr_cr
ld a, (hl)
cp COBBLE
jr nz, .grn
ld (hl), GLOW
.grn:
pop bc
pop de
pop hl
inc hl
inc hl
dec e
jr nz, .gr
ret
ring_offsets:
defb -1, -1, 0, -1, 1, -1
defb -1, 0, 1, 0
defb -1, 1, 0, 1, 1, 1
; ----------------------------------------------------------------------------
; lamp_index_at — which lamp_data entry sits at (C = col, B = row)?
; Returns the index in A ($FF if none — callers only ask about cells
; they know hold a lamp).
; ----------------------------------------------------------------------------
lamp_index_at:
ld hl, lamp_data
ld e, 0
.lia:
ld a, (hl)
cp $FF
ret z
cp c
jr nz, .lian
inc hl
ld a, (hl)
dec hl
cp b
jr nz, .lian
ld a, e
ret
.lian:
inc hl
inc hl
inc e
jr .lia
; lit_push — append lamp index (A) to the lit-order queue.
lit_push:
ld e, a
ld a, (lit_qcount)
ld d, a
inc a
ld (lit_qcount), a
ld a, d
ld hl, lit_queue
add a, l
ld l, a
jr nc, .lp
inc h
.lp:
ld (hl), e
ret
; lit_remove — take lamp index (A) out of the lit-order queue,
; closing the gap.
lit_remove:
ld e, a
ld hl, lit_queue
ld a, (lit_qcount)
ld d, a
or a
ret z
.lr:
ld a, (hl)
cp e
jr z, .lrfound
inc hl
dec d
jr nz, .lr
ret
.lrfound:
dec d
jr z, .lrlast
.lrshift:
inc hl
ld a, (hl)
dec hl
ld (hl), a
inc hl
dec d
jr nz, .lrshift
.lrlast:
ld a, (lit_qcount)
dec a
ld (lit_qcount), a
ret
; ----------------------------------------------------------------------------
; draught_step — the hunt bears grudges. The wisp steps toward the
; OLDEST grievance: the head of the lit-order queue, or, with
; nothing lit, the lamplighter's own flame. Still no walls.
; ----------------------------------------------------------------------------
draught_step:
ld a, (draught_timer)
dec a
ld (draught_timer), a
ret nz
ld a, (dusk_speed)
ld (draught_timer), a
; withdrawing? after a snuff the night carries its prize
; home before hunting again — behaviour is a MODE now, and
; the mode decides what this beat means
ld a, (draught_mode)
or a
jr z, .hunt
ld a, (draught_home_col)
ld hl, draught_col
cp (hl)
jr nz, .whome
ld a, (draught_home_row)
ld hl, draught_row
cp (hl)
jr nz, .whome
xor a ; home — rest, then the hunt resumes
ld (draught_mode), a
ld a, WREST
ld (draught_timer), a
ret
.whome:
ld a, (draught_home_col)
ld (seek_col), a
ld a, (draught_home_row)
ld (seek_row), a
jp .chase
.hunt:
; the oldest flame is the night's grievance — it reclaims
; the ground it lost first. With nothing lit, it hunts the
; lamplighter's own flame: light your first lamp and the
; hunt turns away from you.
ld a, (lit_qcount)
or a
jr nz, .oldest
ld a, (lamp_col)
ld (seek_col), a
ld a, (lamp_row)
ld (seek_row), a
jr .chase
.oldest:
ld a, (lit_queue)
add a, a
ld e, a
ld d, 0
ld hl, lamp_data
add hl, de
ld a, (hl)
ld (seek_col), a
inc hl
ld a, (hl)
ld (seek_row), a
.chase:
; step one cell along the axis with the greater distance
; (ties go sideways) — the night is 4-connected, like the
; lamplighter
ld a, (draught_col)
ld (dtcol), a
ld a, (draught_row)
ld (dtrow), a
ld a, (seek_col)
ld hl, draught_col
sub (hl)
jp p, .absc
neg
.absc:
ld d, a ; D = |dc|
ld a, (seek_row)
ld hl, draught_row
sub (hl)
jp p, .absr
neg
.absr:
cp d ; |dr| vs |dc|
jr z, .tie
jr c, .horiz
jr .vert
.tie:
ld a, d
or a
ret z ; already on the light
jr .horiz
.horiz:
ld a, (seek_col)
ld hl, draught_col
cp (hl)
jr c, .hleft
ld a, (hl)
inc a
ld (dtcol), a
jr .contact
.hleft:
ld a, (hl)
dec a
ld (dtcol), a
jr .contact
.vert:
ld a, (seek_row)
ld hl, draught_row
cp (hl)
jr c, .vup
ld a, (hl)
inc a
ld (dtrow), a
jr .contact
.vup:
ld a, (hl)
dec a
ld (dtrow), a
.contact:
; never step ONTO the lamplighter: adjacent is as close as
; the night comes. Two movers, two buffers — and one cell
; can only ever be under one of them.
ld a, (dtcol)
ld hl, lamp_col
cp (hl)
jr nz, .dmove
ld a, (dtrow)
ld hl, lamp_row
cp (hl)
jr nz, .dmove
call lose_life ; the touch, priced
ret
.dmove:
call restore_draught
; the tendril: night pools where the wisp has walked. Ground
; and spilt light are both taken; posts and stone are not.
ld a, (draught_col)
ld c, a
ld a, (draught_row)
ld b, a
push bc
call attr_addr_cr
pop bc
ld a, (hl)
cp DARK
jr z, .retake
cp COBBLE
jr z, .take
cp GLOW
jr nz, .notake
.take:
ld (hl), DARK
ld de, mist_tex
call blit_tex
.retake:
call tendril_push
.notake:
ld a, (dtcol)
ld (draught_col), a
ld a, (dtrow)
ld (draught_row), a
call save_draught
; the snuff: while the wisp covers a lit lamp, the lamp's
; truth is ITS buffer — the same saved-under rule that lights
; lamps beneath the lamplighter, run by the villain. Rewrite
; the saved attribute to cold, and the wisp's own restore
; will leave the lamp out as it moves on.
ld a, (under_draught + 8)
cp LAMP_LIT
jr nz, .nosnuff
ld a, LAMP_UNLIT
ld (under_draught + 8), a
; the grievance is settled — off the lit-order queue
ld a, (draught_col)
ld c, a
ld a, (draught_row)
ld b, a
call lamp_index_at
call lit_remove
call unlight_pip
call warm_walls
call recompute_pools
ld a, 1 ; the prize is taken — withdraw
ld (draught_mode), a
.nosnuff:
call draw_draught
ret
; ----------------------------------------------------------------------------
; tendril_push — record darkened cell (C = col, B = row) in the tendril
; ring. When the ring is full the oldest cell releases back to bare
; cobble first — the night cannot hold ground beyond its reach, so the
; tendril can never permanently wall the square off.
; ----------------------------------------------------------------------------
tendril_push:
ld a, (tendril_len)
ld hl, tendril_max
cp (hl)
jr c, .tgrow
; full: release the oldest cell (the slot head points at)
push bc
ld a, (tendril_head)
add a, a
ld e, a
ld d, 0
ld hl, tendril_buf
add hl, de
ld c, (hl)
inc hl
ld b, (hl)
; a newer ring entry may still claim this cell (the wisp
; re-walks its own trail) — then the night keeps it
call tendril_claimed
jr z, .treld
; if the wisp itself is crossing that cell, mend its saved
; ground instead of the screen
ld a, (draught_col)
cp c
jr nz, .trel
ld a, (draught_row)
cp b
jr nz, .trel
; mend the wisp's saved ground: stipple, and glow if a lit
; lamp still pools this cell — the light heals behind the dark
push bc
ld hl, cobble_tex
ld de, under_draught
ld bc, 8
ldir
pop bc
call pooled_at
ld a, COBBLE
jr nz, .tsetu
ld a, GLOW
.tsetu:
ld (under_draught + 8), a
jr .treld
.trel:
push bc
call attr_addr_cr
pop bc
ld a, (hl)
cp DARK
jr nz, .treld
push hl
call pooled_at
pop hl
ld a, COBBLE
jr nz, .tset
ld a, GLOW
.tset:
ld (hl), a
ld de, cobble_tex
call blit_tex
.treld:
pop bc
jr .tstore
.tgrow:
inc a
ld (tendril_len), a
.tstore:
ld a, (tendril_head)
add a, a
ld e, a
ld d, 0
ld hl, tendril_buf
add hl, de
ld (hl), c
inc hl
ld (hl), b
ld a, (tendril_head)
inc a
ld hl, tendril_max
cp (hl)
jr c, .tadv
xor a
.tadv:
ld (tendril_head), a
ret
; paint_buildings — walk the rectangle table: each entry is col, row,
; width, height; $FF ends the list. Every cell inside a rectangle gets
; the WALL attribute — and because fill_walls textures by the wall bit,
; the brickwork arrives without another line of drawing code.
paint_buildings:
ld hl, bldg_data
.pb:
ld a, (hl)
cp $FF
ret z
ld c, a ; col
inc hl
ld b, (hl) ; row
inc hl
ld d, (hl) ; width
inc hl
ld e, (hl) ; height
inc hl
push hl
.pbrow:
push bc
push de
.pbcol:
push bc
push de
call attr_addr_cr
ld (hl), WALL
pop de
pop bc
inc c
dec d
jr nz, .pbcol
pop de
pop bc
inc b
dec e
jr nz, .pbrow
pop hl
jr .pb
bldg_data:
defb 5, 5, 4, 3
defb 23, 5, 4, 3
defb $FF
corner_tab:
; where the dark enters, per watch (NE, SE, SW, NW)
defb 28, 4
defb 28, 19
defb 3, 19
defb 3, 4
; ----------------------------------------------------------------------------
; tendril_claimed — does any ring slot other than head hold (C, B)?
; Z set if claimed. Only called with the ring full, so every slot holds
; a real cell.
; ----------------------------------------------------------------------------
tendril_claimed:
ld hl, tendril_buf
ld e, 0
.tc:
ld a, (tendril_head)
cp e
jr z, .tcn ; the slot being released — skip
ld a, (hl)
cp c
jr nz, .tcn
inc hl
ld a, (hl)
dec hl
cp b
jr nz, .tcn
xor a ; Z — a newer claim holds it
ret
.tcn:
inc hl
inc hl
inc e
ld a, (tendril_max)
cp e
jr nz, .tc
or a ; NZ (max is never 0) — free
ret
; ----------------------------------------------------------------------------
; pooled_at — is cell (C, B) within one cell of a LIT lamp? Z if so.
; The light heals: released tendril ground inside a live pool returns
; to glow, not bare cobble.
; ----------------------------------------------------------------------------
pooled_at:
ld hl, lamp_data
.pa:
ld a, (hl)
cp $FF
jr z, .pano
ld e, a ; lamp col
inc hl
ld d, (hl) ; lamp row
inc hl
ld a, e
sub c
jp p, .pac
neg
.pac:
cp 2
jr nc, .pa
ld a, d
sub b
jp p, .par
neg
.par:
cp 2
jr nc, .pa
push hl
push bc
ld c, e
ld b, d
call attr_addr_cr
ld a, (hl)
pop bc
pop hl
cp LAMP_LIT
jr nz, .pa
xor a ; Z — pooled by a lit lamp
ret
.pano:
or 1 ; NZ — bare ground
ret
; ----------------------------------------------------------------------------
; lose_life — the price of the touch: one ember out, and either a
; fresh start or the fall of night.
; ----------------------------------------------------------------------------
lose_life:
ld a, (lives)
dec a
ld (lives), a
ld e, a
ld d, 0
ld hl, LIFE_BASE
add hl, de
ld (hl), COBBLE ; the ember at the new count goes out
ld a, (lives)
or a
jr z, .gone
; a life left: the lamplighter returns to the start cell
call restore_under
ld a, START_COL
ld (lamp_col), a
ld a, START_ROW
ld (lamp_row), a
call save_under
call draw_lamp
; the taking costs the night its reach — the wisp recoils to
; the far corner, so every life buys a whole fresh chase
; (leaving it beside the respawn made a catch strip every
; life in seconds once the draught learnt to hunt)
call restore_draught
ld a, (draught_home_col)
ld (draught_col), a
ld a, (draught_home_row)
ld (draught_row), a
ld a, (dusk_speed)
ld (draught_timer), a
xor a ; already home — hunt on arrival
ld (draught_mode), a
call save_draught
call draw_draught
ret
.gone:
call draw_lose_screen
call sting_nightfall
ld a, LOCK
ld (input_lock), a
ld a, STATE_LOSE
ld (game_state), a
ret
; ----------------------------------------------------------------------------
; print_string / print_char — the machine's own letters. The Spectrum
; keeps its font in ROM: eight bytes per character, and FONT is chosen
; so that ASCII code x 8 + FONT is the glyph's address. Each character
; is drawn like any cell: attribute first, eight rows down the cell.
; ----------------------------------------------------------------------------
print_string:
.ps:
ld a, (hl)
cp $FF
ret z
push hl
push bc
call print_char
pop bc
pop hl
inc hl
inc c
jr .ps
print_char:
ld l, a
ld h, 0
add hl, hl
add hl, hl
add hl, hl
ld de, FONT
add hl, de
ex de, hl
push de
call attr_addr_cr
ld (hl), MSG_ATTR
call scr_addr_cr
pop de
ld b, 8
.pc:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .pc
ret
; ----------------------------------------------------------------------------
; light_pip / unlight_pip / draw_pips / draw_lives.
; ----------------------------------------------------------------------------
; light_pip — warm the next pip along and count the lamp. lit_count is
; the index of the pip to light AND the number of lamps lit so far —
; read it for the address, then step it.
light_pip:
ld a, (lit_count)
ld e, a
ld d, 0
inc a
ld (lit_count), a
ld hl, PIP_BASE
add hl, de
ld (hl), PIP_LIT
ret
; unlight_pip — light_pip's mirror: step the count back and cool the
; pip at the new count. The tally can go DOWN now.
unlight_pip:
ld a, (lit_count)
dec a
ld (lit_count), a
ld e, a
ld d, 0
ld hl, PIP_BASE
add hl, de
ld (hl), PIP_UNLIT
ret
; draw_pips — the tally row: one cell per lamp on the HUD ledge, all
; cold to start. A pip is pure attribute — no glyph, just a block of
; PAPER — so the row costs eight bytes of screen and no bitmap at all.
draw_pips:
ld hl, PIP_BASE
ld b, NUM_LAMPS
ld a, PIP_UNLIT
.dp:
ld (hl), a
inc hl
djnz .dp
ret
; draw_lives — the embers on the ledge's right shoulder. Read the
; CARRIED lives, not the constant: a run's lives survive the watches
; now, and the ledge must say so. (The constant version repainted
; three every watch — a lie we only caught while taking this game
; apart for this module. Playtests read the square; nobody read the
; ledger across a watch boundary.)
draw_lives:
ld hl, LIFE_BASE
ld a, (lives)
ld b, a
ld a, LIFE_PIP
.dlv:
ld (hl), a
inc hl
djnz .dlv
ret
; ----------------------------------------------------------------------------
; draw_lamps — walk the position table: col, row pairs, $FF to finish.
; Placement is data; the drawing code neither knows nor cares how many
; lamps the town has tonight.
; ----------------------------------------------------------------------------
draw_lamps:
ld hl, lamp_data
.next:
ld a, (hl)
cp $FF
ret z
ld c, a
inc hl
ld b, (hl)
inc hl
push hl
call draw_lantern
pop hl
jr .next
; draw_lantern — an unlit lamp into cell (C, B): cold cyan attribute,
; then the lantern glyph down the cell like any texture.
draw_lantern:
call attr_addr_cr
ld (hl), LAMP_UNLIT
call scr_addr_cr
ld de, lantern
ld b, 8
.dlt:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .dlt
ret
; ----------------------------------------------------------------------------
; scr_addr_cr — HL = bitmap address of cell (C, B)'s first pixel row.
; The row's top two bits pick the third of the screen (H), its bottom
; three become L's top bits, and the column fills L's low five.
; ----------------------------------------------------------------------------
scr_addr_cr:
ld a, b
and %00011000 ; the third (row bits 4-3) ...
or %01000000 ; ... under the screen base $40xx
ld h, a
ld a, b
and %00000111 ; the char row within the third ...
rrca ; ... rotated into bits 7-5
rrca
rrca
or c ; the column in bits 4-0
ld l, a
ret
; attr_addr_cr — HL = attribute address of cell (C, B):
; $5800 + row*32 + col, the row shifted up five times.
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
; wall_at — is cell (C, B) wall? The answer is already on the screen:
; every wall cell's attribute has WALL_BIT set, so one bit-test of
; attribute memory is the whole collision system. NZ = wall.
wall_at:
call attr_addr_cr
bit WALL_BIT, (hl)
ret
; ----------------------------------------------------------------------------
; The lamplighter's save / restore / draw.
; ----------------------------------------------------------------------------
; pos_bc — the lamplighter's cell into (C, B), read fresh from the data.
pos_bc:
ld a, (lamp_row)
ld b, a
ld a, (lamp_col)
ld c, a
ret
; save_under — copy the nine bytes of his cell into the buffer: eight
; bitmap rows, then the attribute. Runs as he ARRIVES, before the
; draw — so the buffer always holds true ground, never him.
save_under:
call pos_bc
call scr_addr_cr
ld de, under_lamp
ld b, 8
.su:
ld a, (hl)
ld (de), a
inc de
inc h
djnz .su
call pos_bc
call attr_addr_cr
ld a, (hl)
ld (under_lamp + 8), a
ret
; restore_under — the same nine bytes back the other way: the ground
; returns exactly as it was. Runs as he LEAVES, while the position
; still points at the old cell.
restore_under:
call pos_bc
call scr_addr_cr
ld de, under_lamp
ld b, 8
.ru:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .ru
call pos_bc
call attr_addr_cr
ld a, (under_lamp + 8)
ld (hl), a
ret
draw_lamp:
; his colour first: the cell's attribute becomes his own —
; bright white on the black, his own light about him
call pos_bc
call attr_addr_cr
ld (hl), LAMP_ATTR
; then his shape, eight bytes down the cell like any texture
call pos_bc
call scr_addr_cr
ld de, lamplighter
ld b, 8
.dl:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .dl
ret
; ----------------------------------------------------------------------------
; The draught's save / restore / draw — the lamplighter's engine, twice.
; Same loops, same nine-byte contract, its own buffer and its own
; position: two movers can share a world but never a buffer.
; ----------------------------------------------------------------------------
dpos_bc:
ld a, (draught_row)
ld b, a
ld a, (draught_col)
ld c, a
ret
save_draught:
call dpos_bc
call scr_addr_cr
ld de, under_draught
ld b, 8
.sd:
ld a, (hl)
ld (de), a
inc de
inc h
djnz .sd
call dpos_bc
call attr_addr_cr
ld a, (hl)
ld (under_draught + 8), a
ret
restore_draught:
call dpos_bc
call scr_addr_cr
ld de, under_draught
ld b, 8
.rd:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .rd
call dpos_bc
call attr_addr_cr
ld a, (under_draught + 8)
ld (hl), a
ret
draw_draught:
call dpos_bc
call attr_addr_cr
ld (hl), DRAUGHT_ATTR
call dpos_bc
call scr_addr_cr
ld de, draught_glyph
ld b, 8
.dd:
ld a, (de)
ld (hl), a
inc de
inc h
djnz .dd
ret
; ----------------------------------------------------------------------------
; Data.
; ----------------------------------------------------------------------------
game_state:
defb STATE_TITLE
input_lock:
defb 0
dusk_table:
; the wisp's pace per dusk (frames between steps) — the
; night deepens as data, not code. Dusk 1 is gentle on
; purpose: the hunt must be readable before it's a threat.
; The final watch is pace 9, not 8 — playtested: 8 is the
; human wall, 9 is beatable. The last watch should be the
; climax, not the ceiling.
defb 16, 13, 11, 9, 9
dusk_lentab:
; the tendril's reach per watch (cells of night held) —
; the second axis of the deepening. Front-loading reach
; made watch 1 brutal (playtested: a practised player lost
; at watch 2) — the opening teaches the mechanic, the deep
; watches punish with it.
defb 3, 6, 9, 13, 18
wall_ramp:
; The square warms in the game's own vocabulary: the stone
; stays dusk-blue; the lamplight catches the mortar first
; (ink white -> yellow), then the whole face glows BRIGHT.
; Never magenta — warmth is yellow here, not red-shifted blue.
defb %00001111 ; dusk stone, white mortar
defb %00001111
defb %00001111
defb %00001110 ; the mortar warms — yellow ink
defb %00001110
defb %00001110
defb %01001110 ; the stone catches the glow — BRIGHT
defb %01001110
defb %01110000 ; all eight lit: the square aglow —
; warm yellow stone, only at the win
lamp_data:
defb 4, 3
defb 27, 3
defb 9, 7
defb 22, 7
defb 6, 15
defb 25, 15
defb 13, 20
defb 18, 20
defb $FF
lamp_col:
defb START_COL
lamp_row:
defb START_ROW
tcol:
defb 0
trow:
defb 0
lit_count:
defb 0
lives:
defb LIVES
best_lives:
defb 0 ; lives kept on the finest win — never reset
draught_col:
defb 28
draught_row:
defb 4
draught_home_col:
defb 28
draught_home_row:
defb 4
draught_mode:
defb 0 ; 0 = hunting, 1 = withdrawing home
draught_timer:
defb 16
player_timer:
defb 0
dusk:
defb 0 ; which watch of the night this is
dusk_speed:
defb 16
seek_col:
defb 0
seek_row:
defb 0
lit_queue:
defb 0, 0, 0, 0, 0, 0, 0, 0
lit_qcount:
defb 0
tendril_head:
defb 0
tendril_len:
defb 0
tendril_max:
defb 6 ; the night's reach — six cells of held ground
tendril_buf:
defb 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
defb 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
dtcol:
defb 0
dtrow:
defb 0
under_lamp:
defb 0, 0, 0, 0, 0, 0, 0, 0, 0
under_draught:
defb 0, 0, 0, 0, 0, 0, 0, 0, 0
lamplighter:
defb %00111100
defb %00111100
defb %00011000
defb %01111110
defb %00011000
defb %00011000
defb %00100100
defb %01000010
lantern:
defb %00011000
defb %00100100
defb %01111110
defb %01111110
defb %01011010
defb %01111110
defb %01111110
defb %00111100
draught_glyph:
defb %00000000
defb %00111100
defb %01111110
defb %11111111
defb %11111111
defb %01111110
defb %00111100
defb %00000000
title_text:
defb "GLOAMING"
defb $FF
prompt_text:
defb "PRESS SPACE"
defb $FF
win_text:
defb "THE NIGHT IS HELD"
defb $FF
lose_text:
defb "NIGHT FALLS"
defb $FF
end start
When it’s wrong, see why
- Lives refill every watch. The
LIVESreset is still ininit_game— it belongs ininit_run, above the fall-through line. What resets where is the design; the code must draw the same line the design does. - Every watch plays like watch 1.
dusknever increments — the bump lives inend_step’s.deeperpath, before the re-init that reads it. - Watch 6 is impossibly fast or the wisp teleports. A table overran. The pace read clamps at
NUM_DUSKS - 1; the corner index masks withand 3. Check both. - SPACE on the held screen goes to the title. The
STATE_WINcheck inend_stepbranches the wrong way, or it runs after the title-return code instead of before. - Three embers after a carried loss. You’ve built step 2 — the display fix is step 3, and until it’s in, the ledge repaints the constant.
Before and after
A dusk became a night. The run/watch split gives the game persistence; the interstitial gives it continuity out of code that already existed; the tables make five difficulties out of one game with fourteen bytes; the corner probe makes each watch feel new before it is new. And the ledge got caught lying — the only bug in this module that shipped in the real prototype and survived every playtest, because it hid in the seam between two facts everyone checked separately. Escalation as data, displays from state: two disciplines, both cheap, both permanent.
Try this: tune your own night
The two tables are your difficulty designer’s console. Try a brutal opening (11, 9, 9, 9, 8 / 9, 12, 15, 18, 18) and feel why the shipped game refused to front-load. Try a longer, gentler arc across seven watches (grow the tables, raise NUM_DUSKS, widen the clamp). Every experiment is data-only — which is precisely the argument for having built it this way.
Try this: read the whole screen
The lives lie survived because everyone watched the action. Practise the counter-habit: play one full watch transition and read every HUD element across the boundary — pips, embers, anything that claims to be a count. Displays fail at seams (re-inits, restores, screen changes), not in steady state. Knowing where to look is most of catching them.
What you’ve learnt
- The run/watch state split: two init entry points draw the design’s own line between what persists and what resets.
- The interstitial: a win screen re-purposed as a breath between rounds — new meaning for SPACE, zero new screens.
- Escalation as data: pace and reach tables, playtest-tuned (gentle opening, climax-not-ceiling), plus a corner probe that reorients each watch for free.
- Clamp every table walk — counters outlive the tables they index.
- Displays repaint from state, never constants — the constant is only correct until the first time the state can differ, and that’s exactly when nobody’s looking.
What’s next
Five watches that deepen — and then watch 5 is held, and the night… starts watch 5 again. Forever. The game has an arc with no ending, and the playtest verdict on endless was terminal. Unit 7 builds the thing this whole module has been climbing toward: hold the fifth watch and dawn breaks.