Wolfenstein raycaster · ling-3.1-flash

Need write index.html current cwd. Need build complete app. Let's design robust raycaster.

Game:
- canvas 960x600 maybe responsive.
- map 16x16 small maze:
Use grid strings, 1 wall, 0 empty, 2 exit maybe exit door tile? Need reachable exit. Exit unlocked after all enemies. Could represent exit as special tile E at edge, perhaps wall tile with door? Better map includes exit marker at a floor tile? Raycaster walls only; reaching exit if player within radius of exit coordinates. Exit drawn as sprite (green portal) and maybe wall. "reachable exit" means tile. Use exit at (1,1) or (14,14). Start (1.5,1.5) and exit at (14.5,14.5). Maze with walls.

Map:
16x16:
1111111111111111
1000001000000001
1011101011111101
1000101000000101
1110101111101101
1000100000100001
1011111110111101
1000000010000001
1011110111111101
1000010000000101
1011011111110101
1001000000010001
1011111110111101
1000000010000001
1011111011111101
1111111111111111
Need check connectivity start (1,1) to exit (14,14). likely. Let's verify with BFS mentally or script later. Enemies positions at open cells: (5,1), (9,3), (13,7), (3,13), (11,11). Need at least 3. Ensure not in walls. Map row indexing y, col x.
Row0 all walls.
row1 "1000001000000001": x1-5 open, x6 wall, x7-14 open.
row2 "1011101011111101": x1 open, x2-4 walls, x5 open? string indexes: 0 1,1 0,2 1,3 1,4 1,5 0,6 1,7 0,8 1,9 1,10 1,11 1,12 1,13 1,14 0,15 1. Good.
row3 "1000101000000101": x1-3 open, x4 wall, x5 open,x6 wall,x7-12 open,x13 wall,x14 open.
row4 "1110101111101101": x1-2 walls,x3 open,x4 wall,x5 open,x6-10 walls? indexes: 0 1,1 1,2 1,3 0,4 1,5 0,6 1,7 1,8 1,9 1,10 1,11 0,12 1,13 1,14 0,15 1. Good.
row5 "1000100000100001": x1-3 open,x4 wall,x5-9 open,x10 wall,x11-14 open.
row6 "1011111110111101": x1 open, x2-8 walls, x9 open, x10 wall, x11-13 walls? index 11 1,12 1,13 1, x14 open.
row7 "1000000010000001": x1-8 open, x9 wall, x10-14 open.
row8 "1011110111111101": x1 open,x2-5 walls,x6 open,x7-13 walls,x14 open.
row9 "1000010000000101": x1-4 open,x5 wall,x6-12 open,x13 wall,x14 open.
row10 "1011011111110101": x1 open,x2 wall,x3 wall? string: 1 0 1 1 0 1 1 1 1 1 1 0 1 0 1? Let's parse carefully. "1011011111110101": chars 0=1,1=0,2=1,3=1,4=0,5=1,6=1,7=1,8=1,9=1,10=1,11=0,12=1,13=0,14=1,15=1. x1 open, x4 open, x11 open, x13 open, x14 wall.
row11 "1001000000010001": x1-2 open,x3 wall,x4-10 open,x11 wall,x12-14 open.
row12 "1011111110111101": x1 open,x2-8 walls,x9 open,x10 wall,x11-13 walls,x14 open.
row13 "1000000010000001": x1-8 open,x9 wall,x10-14 open.
row14 "1011111011111101": x1 open,x2-6 walls,x7 open,x8-13 walls,x14 open.
row15 walls.

Start at (1.5,1.5), exit (14.5,14.5) row14 x14 open. Enemies:
(5.5,1.5) row1 x5 open
(7.5,3.5) row3 x7 open
(11.5,5.5) row5 x11 open
(1.5,7.5) row7 x1 open
(14.5,9.5) row9 x14 open
(13.5,11.5) row11 x13 open
(1.5,13.5) row13 x1 open
(7.5,14.5) row14 x7 open. 8 enemies.
Need connectivity. Start region row1 x1-5, down via x1 to row7 etc. Exit row14 x14 via row13 x10-14, connected to row11 x12-14? row12 x14 open, row11 x12-14 open, row10 x13 open, row9 x12? row9 x12 open, row8 x14 open? row8 x14 open, row7 x14 open, row6 x14 open, row5 x14 open, row4 x14 open, row3 x14 open, row2 x14 open, row1 x14 open. Yes path along right column. Great.

Raycaster:
- canvas width 960 height 600, use internal resolution maybe 480x300 for perf and upscale via CSS? Need textured walls. Cast one ray per column at canvas width maybe 480 for performance. Use imageData or draw vertical strips with texture canvas patterns. Procedural textures: create 64x64 offscreen canvases for brick, stone, wood, metal, exit? Use drawImage scaled slices. For each column, wall texture based on wall type and side. Compute perpendicular distance, wall height = H / dist, draw texture slice from source x. Use ctx.drawImage(texture, texX,0,1,64, x,y,1,wallHeight). For 480 rays, okay. Add floor/ceiling simple gradient or per-pixel? Could fill ceiling and floor with gradients; maybe textured floor not required. We can draw vertical gradient and maybe floor checker via scanline. Keep simple but stylish.

- player FOV 60 deg, direction angle. rays angle = dir - FOV/2 + x / width * FOV. DDA.
- Wall collision: check map cell at proposed position with radius 0.2; prevent movement if cell wall. Need robust axis separated.
- Turning arrow keys left/right rotate.
- Shooting: Space. Weapon feedback: muzzle flash, gun sprite drawn on canvas (procedural), recoil, maybe screen shake. Ammo? Not required; perhaps unlimited. Fire rate 350ms. Hitscan ray from player toward crosshair: cast ray to enemy with wall distance. For each enemy, compute angle difference and distance; ray-wall distance along enemy direction; if enemy distance < wall distance and angular alignment within tolerance, damage. Better: on shoot, choose nearest enemy within crosshair tolerance (e.g. 4 degrees) and line-of-sight unobstructed. Use exact raycast to enemy center: distance along ray angle to enemy perpendicular? We can compute projection t = dot(enemy-player, dir); perpendicular distance = cross / t; if abs(perp) < enemy radius (~0.35), t < wallDist along same ray, then hit. Choose smallest t. Damage 34, enemy health 100, 3 shots. Enemy flash/death animation. Kill count.
- Enemies visible: billboards sorted far to near, draw procedural enemy sprite scaled by distance, occluded by walls via depth buffer per column. Need sprite rendering with zbuffer. Create enemy sprite canvas (e.g. 64x64) with humanoid robot/zombie. Draw vertical strip or whole scaled sprite with per-column clipping using zbuffer. Simpler draw sprite as image scaled, but occlusion would not hide behind walls. Implement per-column: for each screen column covered by sprite, if transformY < zbuffer[col], draw 1-pixel slice from source. We can compute sprite screen x, size, then loop columns. Use offscreen sprite canvas 64x64. Need draw with drawImage source slice to dest 1px. For 8 enemies * maybe 100 cols, okay. Enemy sprite can have procedural colors and simple shape. Also enemy health bars maybe above.
- Enemy behavior: clear attack rule. Enemies damage player when within attack range (e.g. <1.5 units) and line of sight? "Enemies can damage the player under a clear attack rule." Use if distance < 1.6 and cooldown 1s, deal 8 damage, show red flash. Maybe enemies move toward player when within 6 units and line-of-sight, simple pathless movement with collision; could get stuck but okay. Need not overcomplicate. Enemies patrol or chase. If they move, ensure no wall collision. Attack when close. Add attack warning.
- Player health 100; zero game over overlay. Defeat all enemies unlocks exit; exit portal sprite maybe initially red/locked, green when unlocked. Reaching within 0.7 units and unlocked => win. If locked, display "Exit locked — eliminate all enemies" when near.
- Restart button resets state. Also R maybe.
- Controls displayed: W/S move, A/D strafe, arrows turn, Space shoot, R restart.
- HUD health bar, enemies remaining, crosshair, message.
- Start screen? Could have title and click to start? Not required; keyboard works immediately. Audio not required; can use WebAudio for shoot/hit? No external assets; optional. Might add simple oscillator sounds but browser requires user gesture; can create on first key. Not necessary. Keep no audio to avoid issues.
- Mouse turning optional; not required. We can implement pointer lock on click maybe but not necessary. Avoid requiring mouse.
- Game states: playing, gameover, win. Overlays with restart button.

Need write file. Then use browser tool to test. We need maybe screenshot. Let's craft code carefully.

Implementation details:

HTML structure:
<div id="wrap">
<canvas id="game" width="960" height="600"></canvas>
<div id="hud">...
But HUD overlay absolutely positioned. Controls below.
Maybe canvas internal 960x600; raycasting at 480 columns but draw at 2px width. Use RAYS=480, COLW=2. zbuffer length 480. Canvas CSS max-width 100%.

Textures:
makeTexture(type): 64x64.
brick: fill #7a4a3a, mortar lines, random noise.
stone: #5a5f6a blocks.
wood: #8a5a2b planks.
metal: #4a5a6a panels.
Use wall types based on cell value? Map uses 1 only; assign texture by (x+y)%? Could use map char types: 1 brick, maybe 2 stone, 3 wood. Add variety by map values. But easier use (cellX+cellY)%4. However DDA map cell value can be 1; texture index = (mapX+mapY)&3. Side darkens.

Procedural texture generation with seeded random for stable. Use deterministic pseudo random function.

Map as array strings. WALL=1. Exit tile not wall.

DDA:
function castRay(angle):
  dirX=cos, dirY=sin
  mapX=floor(px), mapY=floor(py)
  deltaDistX=abs(1/dirX) etc handle zero.
  step/sideDist standard.
  loop max 32: if map wall return dist, side, mapX,mapY,texture.
  perpWallDist = side==0 ? (mapX-px+(1-stepX)/2)/dirX : ...
  Actually DDA returns perp distance directly.
  hit when map[mapY][mapX]===1.
  texture=(mapX+mapY)%4.
  wallX = side==0 ? py+perp*dirY : px+perp*dirX; wallX-=floor; texX=floor(wallX*64); flip based on side/dir.

Render walls:
ceil gradient dark, floor gradient. For each ray i:
cameraX=2*i/RAYS-1; rayAngle=dir+atan(cameraX*tan(FOV/2))? Use angle = dir + atan(cameraX * tan(FOV/2)); but for fisheye correction, perpendicular distance from DDA with direction ray; if using angle rays, DDA perp distance is along ray, need multiply cos(rayAngle-dir) to correct. Standard: dirX=cos(dir)+planeX*cameraX, etc and perp distance already perpendicular if plane scaled. Easier use direction vector + camera plane:
dirX=cos(player.dir), dirY=sin; planeX=-dirY*tan(FOV/2), planeY=dirX*tan(FOV/2);
rayDirX=dirX+planeX*cameraX; rayDirY=dirY+planeY*cameraX.
DDA perp distance is perpendicular to camera plane (because rayDir includes plane), no fisheye. Good.
wallHeight=H/perp.
y0=(H-wallHeight)/2.
draw texture slice with drawImage(tex, texX,0,1,64, i*2, y0, 2, wallHeight). Need source x clamp. If wallHeight > H maybe still okay.
Side shading: draw black overlay alpha 0.25 on side==1? drawImage then fillRect with rgba(0,0,0,0.25). For distance shading maybe globalAlpha based on dist. Use ctx.globalAlpha = min(0.55, dist/12) then fill black. But if draw black after, okay.
Ceiling/floor: fill gradients each frame. Could add floor checker using scanlines? Not required. Maybe draw floor with gradient and subtle grid lines based on perspective? Skip.

Depth buffer zbuffer[i]=perp.

Sprites:
Enemy object {x,y,hp,alive,flash,attackCooldown,state,anim}.
Transform:
relX=e.x-px, relY=e.y-py
invDet=1/(planeX*dirY-dirX*planeY)
transformX=invDet*(dirY*relX-dirX*relY)
transformY=invDet*(-planeY*relX+planeX*relY) // depth
if transformY>0.1:
 spriteScreenX=(W/2)*(1+transformX/transformY)
 size=H/transformY
 draw columns from screenX-size/2 to +size/2; for each screen column i (actual canvas col), if transformY<zbuffer[i], draw source column. Need map source x = floor((col - (spriteScreenX-size/2)) / size * 64). Use ctx.drawImage(sprite, srcX,0,1,64, col, yStart, 1, size). Since canvas width 960 and rays 480 with 2px columns, zbuffer indexed by ray column i; screen pixel col corresponds ray floor(col/2). Use for pixel col step 1 maybe expensive but okay (enemies few). Could step 2 matching ray columns: for i ray index covering sprite, x=i*2. Determine source x from i. Better loop ray columns i from floor((screenX-size/2)/2) to ...; if transformY<zbuffer[i], draw 2px wide slice. srcX based on i*2. Good.
 Enemy sprite size maybe 0.8 units, so size=H/transformY*0.8. yStart=(H-size)/2 + bob.
 Draw health bar above sprite if damaged: screen coordinates approximate, only if sprite visible. Could draw after with clipping? Simple draw bar at spriteScreenX, yStart-12, width size, but may draw over wall. Only if any column visible? Could check center column depth. Fine.
 Death animation: when hp<=0, alive=false, deaths maybe draw fading corpse? Simpler remove and increment kills; maybe spawn brief flash. Keep enemy.visible false after death. Could add deathTimer to draw fallen sprite for 1 sec. Not necessary.
 Enemy flash on hit: use alternate sprite with red overlay. Create enemy sprite normal and hurt (draw red tint). Use hurtTimer.

Enemy sprite generation:
64x64. Draw transparent background. Body: dark green/gray humanoid: head circle, torso rectangle, eyes red, etc. Use shapes. Hurt version same plus red overlay globalCompositeOperation source-atop.
Locked exit sprite: portal 64x64 with red/gray; unlocked green glowing. Draw as sprite at exit location. Exit is floor tile; billboard. When unlocked, draw green portal. Also maybe draw exit marker on minimap? Not needed.
Sprite render order: combine enemies and exit, sort by distance desc. Exit only visible. Exit transform same. If locked, red; unlocked green. Draw exit before/after enemies by distance.

Enemy AI:
for each alive:
 dist to player.
 if dist < 7 and hasLineOfSight (cast ray to enemy? use LOS function): move toward player speed 1.2*dt but only if dist>1.2. Use normalized, attempt move with collision radius 0.25. Enemies avoid walls; if blocked, try strafe? Simple axis separated. Could get stuck but okay. Add slight perpendicular if blocked.
 attack if dist<1.5 and cooldown<=0: player.health -= 10; cooldown=1.2; redFlash=0.3; show message "Enemy hits you!"; maybe knockback? no.
 LOS: cast ray from player toward enemy at angle atan2; wallDist along that exact direction; compare to enemy distance. But ray cast returns perpendicular distance for ray direction; if direction exactly to enemy, perp distance equals distance to wall along that ray. Use function rayDistanceToWall(angle). If enemyDist < wallDist-0.1 then visible. For shooting, use angle to enemy and perpendicular offset.
Enemy movement should not move if gameover/win.

Shooting:
if cooldown>0 return; cooldown=0.35; muzzle=0.12; recoil=8; shots++.
Find target:
best=null; for alive enemies:
 dx,dy; dist; if dist>8 continue;
 ang=atan2(dy,dx); diff=angleDiff(ang,player.dir); if abs(diff)>0.12 rad (~7°) continue;
 wallDist=castRay(ang).dist; if dist < wallDist - 0.05: score=dist + abs(perp?) choose nearest.
Could use crosshair exact center. Enemy radius tolerance 0.30/dist? diff threshold maybe 0.14. Use perpendicular = sin(diff)*dist; if abs(perp)<0.35.
Hit: enemy.hp-=34; enemy.flash=0.15; hit marker; if hp<=0 kill, enemiesLeft--, message. If all dead, unlock exit message.
No ammo. Weapon feedback: draw gun at bottom with recoil offset and muzzle flash; crosshair expands; screen flash.
Weapon drawing: procedural on main canvas: gun shape rectangles at bottom center, recoil. Muzzle flash star. Use canvas paths.

Game loop:
requestAnimationFrame, dt clamp 0.05.
keys object. keydown prevent default for arrows/space.
If state playing: update.
Render always (even overlays).
Movement speed 3.2 units/s, strafe. Turn speed 2.6 rad/s.
Collision:
function tryMove(nx,ny): if !isWall(nx + radius sign?) Standard check cell at (nx, py) for x movement and (px, ny) for y. Use radius 0.25: check four corners? function canStand(x,y): check cells at x±r, y±r. For axis separated, newX = px+dx; if canStand(newX,py) px=newX. Similarly y.
isWall cell: map[y] && map[y][x] === '1'.
Exit reach: if unlocked and dist(player, exit)<0.8 -> win. If locked and dist<1.2 maybe message cooldown.

Restart:
reset player {x:1.5,y:1.5,dir:0? Start facing east (0 rad) maybe into corridor. Health 100, enemies deep copy initial, enemiesLeft, unlocked false, state playing, messages.
Initial enemies list from positions. Need ensure not too close.

HUD:
DOM: health bar width, health text, enemies count, status message, crosshair is canvas. Controls div.
Overlays: #overlay with h1 and button, hidden. Game over/win. Restart button. Also a Restart button in HUD.
CSS: dark background, canvas border, scanline overlay maybe via repeating-linear-gradient pointer-events none. CRT vibe.

Message system: status text with timer. Use DOM #message. Update in loop.

Minimap? Not required. Could add small minimap for accessibility but not needed. Maybe helpful to test. But required visible enemies; 3D enough. Add optional minimap top-right? Could be nice but not necessary. Keep focus.

Potential issue: browser tool can interact. Need test movement/turning/collision/fire. We can use browser screenshot and key actions. Need know browser tool usage. functions.browser action with x/y etc. We'll reload, screenshot, key. We can inspect via evaluate? No evaluate action, only inspect returns DOM/console maybe. Use browser inspect after actions. We can use key action. Need maybe click restart.

Let's write file. Ensure no external resources. Use strict.

Code details for textures:
function makeCanvas(w,h){const c=document.createElement('canvas');...}
Deterministic rand: let seed; function rnd(){seed=(seed*1664525+1013904223)>>>0; return seed/4294967296;}
Brick texture:
base fill #6b3f34; for y rows 16 etc, offset; draw bricks 32x16 with slight color variation and mortar. Add noise.
Stone: fill #4c525c; blocks 16x16 with darker borders and highlights.
Wood: vertical planks 16 wide, grain lines.
Metal: fill #3f4a55; panels, rivets, scratches.
Maybe exit wall texture not needed.

Enemy sprite:
normal: transparent. Use shapes:
- shadow ellipse at bottom? draw body: torso rounded rect 20-44 x 24-48 color #3d5a3d; head circle 32,20 radius 10 color #6b7f5a; eyes red; arms. Add outline.
Use ctx shadow? no.
Hurt: draw normal then red overlay.
Exit sprite locked: 64x64, draw arch door red/gray; unlocked green glow. Since sprite billboard, okay.

Floor/ceiling: maybe create gradient each frame; add distant fog. Also draw ceiling with dark blue gradient and floor with dark brown gradient. Add subtle horizontal lines? Fine.

Screen shake: shake timer, offset canvas translate random. Apply ctx.save translate before render world, restore before HUD? We can render world with translate. Simpler no shake or small.

Crosshair: canvas center lines, color changes when target? Could compute target each frame for feedback. Use enemy under crosshair within LOS to color green. Nice.

Weapon: draw after world, before HUD DOM. Gun at bottom center: use path. recoil variable decays. muzzle timer. Draw barrel, body, hands. Muzzle flash if muzzle>0.

Messages: DOM update each frame: msgTimer. Use setMessage(text, dur).

Overlays: when gameover/win, show overlay. Restart button both overlay and HUD. Use button click restart. Also Enter/R key.

State: 'playing' | 'over' | 'win'. On win, maybe still render scene. Stop enemy updates.

Enemy count: initialEnemies length. enemiesLeft = alive count. HUD update.

Exit unlocked when enemiesLeft===0. Set message once. unlocked flag.

Win check only if unlocked. If player reaches locked exit, show locked message at most every 1s.

Edge: enemies may damage after death? only alive.

Angle normalize function.

LOS for enemy movement: function lineOfSight(x0,y0,x1,y1): angle=atan2; castRay(angle) dist; return distance(x0,y0,x1,y1) < wallDist - 0.05. But castRay from player position; if enemy exactly behind wall, wallDist < dist. Good. For enemy sprite visibility, raycaster zbuffer handles occlusion. For AI, use LOS.

Shooting through wall: use wallDist along angle to enemy. Good.

Enemy movement collision: canStandEnemy(x,y, self) with radius 0.25 and maybe avoid other enemies. Check walls only; enemies can overlap. Add simple separation from other enemies.

Enemy speed maybe 1.0, player 3.2 so can escape. Attack range 1.4, damage 9, cooldown 1.1. With 8 enemies, could be dangerous but fair. Health 100.

Map connectivity and enemy positions: Need ensure enemies reachable and not isolated. (5.5,1.5) near start. (7.5,3.5) reachable via row1 to x7 then down row3? row2 x7 open, row3 x7 open yes. (11.5,5.5): row5 x11 open, connected via row7? row6 x11 wall, but row5 x11-14 open and x14 column connects down; also row4 x11 open, row3 x11 open. reachable. (1.5,7.5) via x1 column. (14.5,9.5) via right column. (13.5,11.5) row11 x13 open, connected to x14? row11 x12-14 open and row10 x13 open, yes. (1.5,13.5) via x1. (7.5,14.5) row14 x7 open, connected via row13 x7 open and row13 x1-8. Good.

Let's write.

Now browser test. Use browser reload/screenshot/inspect.

No images support? browser screenshot maybe model doesn't support images. We can inspect DOM and maybe use console. Need test movement/turning near start, collision, fire. Browser tool key actions. We can use key. Need perhaps inspect canvas pixel? No evaluate. Could use browser inspect after key. We can maybe use bash with node? No browser automation. Browser tool actions include key, click, inspect. We can simulate keys and inspect DOM. Need verify internal state maybe not exposed. Could add debug? Not necessary but for testing maybe use screenshot not available. We can use browser inspect to see DOM. Movement doesn't change DOM except message maybe. Could expose state to window for testing? We can temporarily or permanently? Not needed. But to verify, perhaps use browser key and inspect console; no console logs. Could add console debug? Better not. We can use browser tool's inspect maybe returns DOM only. Could use canvas data via JS if we add a debug endpoint? Not needed for final. But task asks verify. We can use browser actions and observe maybe screenshot unsupported. Could use `browser` action screenshot returns maybe "model does not support images". We can still use inspect. We can test key events and maybe use console by adding temporary console.log? Could modify file to log state, then remove. Or use browser's inspect after keys to see health/message. For collision, we can move into wall and see position not exposed. Could expose `window.__game` for debug in final? Not harmful but unnecessary. Could add a hidden debug state object to window for testing; no external. But final can include it. Maybe use `window.__maze = { get state(){...}}`. Then browser inspect won't show JS. No evaluate. Could use console.log and inspect console. Let's add temporary console.log on movement? Better use browser tool maybe action "inspect" returns console messages after interactions. We can add console.log in keydown for test, then remove. But we can also use `bash` with a headless browser? Check available tools? Only browser. Could use node with playwright maybe installed? Let's inspect environment.

No python? command chain stopped at python missing maybe. Could use browser tool only. Maybe browser backend supports actions but no evaluate. We can add console.log statements and inspect console. Let's use browser key actions. First screenshot maybe unsupported but try.

Need test. Use key W for 1 sec? browser key action single key maybe press. We can call multiple key actions. Need maybe hold? action key with text? It likely sends key event. Use key "w" maybe. Let's inspect after key.

Single key press moves small. Need verify position. Could expose debug to window and use console log on keydown. Maybe add `console.log` in update every 30 frames? Then inspect console after actions. But final shouldn't spam. Could add a temporary query param? Simpler add `window.__game = {get player(){return player}, get enemies(){...}}` and use browser? No evaluate. Could use `browser` action "inspect" maybe dom only. Could maybe action type with text into canvas? no.

Alternative use Node jsdom? Not for canvas. Could use browser tool's underlying Chrome with remote debugging? Maybe environment has browser process. But not needed. We can add a debug overlay that shows coordinates in DOM, maybe helpful for verification and not harmful. But required display controls/health/enemies; extra debug maybe okay but not desired. Could add small coordinates in HUD for testing? Not necessary. But to verify collision, we can add a status line showing player position; user didn't forbid. However final artifact cleaner without debug. We can temporarily add, test, remove.

Let's modify to include debug console logs under `?debug` maybe. Use URL param check; browser likely file? We can add `if (new URLSearchParams(location.search).has('debug')) console.log(...)` in loop. Then reload with ?debug maybe browser tool reload doesn't allow URL. Could set location.hash? We can use browser key? No. Could just console.log every second always; not ideal but acceptable? Better not.

We can test logically and use browser key actions for no errors. Need maybe check console after space. Use key Space.

It hit enemy at start? Start (1.5,1.5) facing east, enemy at (5.5,1.5) distance 4, wall at x6? Path x2-5 open, so hit. Good. Enemy count still 8 (hp 66). Message Hit! Good. Fire feedback maybe not visible but code.

Need test movement and collision. Could use repeated key W many times to move into wall at x6? Starting x1.5, facing east, W moves to x6 wall; should stop at ~5.76. Then maybe message? no. We can add debug position to DOM temporarily. Let's modify with a small debug span? Could use existing message to show coordinates when pressing P? Not needed. For verification, maybe use browser inspect after repeated W and see if message changes? no.

Could use canvas pixel sampling via browser? No evaluate. But perhaps browser tool action "inspect" can return canvas? no. We can use `browser` action "type" maybe text into focused canvas triggers keydown? same.

Maybe we can use Node to parse file and simulate logic separately. But actual browser rendering not verified. We can add a tiny debug readout in HUD that updates coordinates; this also helps user? Not required, but could be okay. Yet final should not clutter. Could include coordinates in health panel small? Maybe not.

Let's add temporary `id="debug"`? Then use browser inspect to see position after keys. We can remove after. Use edit to add span in HUD and updateHud. Then test. Or use console.log in updateHud with position; inspect console. Let's do temporary console.log in updateHud? It updates every frame, console huge. Better on keydown after movement? Movement occurs in loop, not immediate. Could set interval log every 500ms when debug. Add `if (location.hash === '#debug') console.log(...)` in loop. Then set location.hash via browser? No action to navigate, but can maybe key? no. Could use reload with URL not supported. We can modify to always log once per second; test then remove. Let's do temporary.

Now reload and inspect console after keys. But console from previous? reload.

Now press W multiple times. Need maybe key action text "w" sends keydown/up. Do 10 times maybe in parallel? Must sequential because state. Use multiple browser calls? Can use multi_tool parallel but order maybe not guaranteed. Better sequential calls, but time. We can use bash? no. Use browser key repeated maybe action supports hold? Not documented. Could use key with text "wwww"? It might type characters, each keydown? Let's try key text "wwwwwwwwww".

Need individual. Use multiple invokes sequential in same message? We can call multiple browser tools in one assistant message; they may execute in order? multi_tool parallel likely simultaneous, not good. Use one call then next. Let's do 10 sequential maybe okay.

Position unchanged because key press too short and movement per frame; keydown/up maybe no frame while pressed? The browser key action simulates press quickly, maybe keyup before next frame, so no movement. Need hold? Browser tool doesn't support hold. Could use keydown via type? Maybe action "key" with delta? no. Could use `drag`? no. We can test by setting keys via console not possible. Could add auto movement for testing? Maybe use keydown sets key true and keyup false; if press duration shorter than frame, no update. Could in onKeyDown also perform a fixed movement step for testing? Not desired. But actual holding in browser works. For verification, we can simulate by adding a test mode? Or use browser action "key" with `delta` maybe hold? Schema has delta for drag/scroll, not key. Could use `action":"type"` with text "w" maybe sends key events with delays? Let's try type.

Type moved a little (0.06). Good. Need test collision by typing many w maybe action type with text "wwwww" might hold? Try type "wwwww" maybe each char keydown and some hold?

Interesting type only first char? Maybe because canvas focused but type sends text as key events? It moved 0.06 only. Maybe keydown for first w sets true, then subsequent chars not recognized due to repeat? Hmm.

Could use browser action "key" with `delta`? Not for key. Maybe use `action":"click"` and drag? no.

Could add a temporary test button that moves player for 1 second when clicked, then use click. But final can remove. Or use keyboard event with `keys.KeyW = true` via console not available. Could use browser action "type" into body maybe not.

Maybe use `browser` action "motion" to simulate? no.

We can test collision logically by code review. But task says verify; we can mention checked via simulated key events and code. Better to actually verify with a temporary automated test hook. Add a hidden function triggered by pressing `T` that runs a scripted simulation of movement/collision/shooting in JS and console.logs results. Then press T via browser. This can verify actual game functions. We can remove or keep? Could keep as a debug shortcut? Not required; remove after testing. Let's add temporary `if (e.code === 'KeyT') runSelfTest();` and function. It can simulate:
- save state, set player pos/dir, set keys.KeyW true, call updatePlayer(0.5) multiple times, check x stops before wall.
- turn with ArrowLeft/Right.
- shoot enemy at (5.5,1.5) from start facing east, check hp decreases and enemiesLeft unchanged until death; shoot through wall? Place player at (2.5,2.5)? Need test shot cannot damage through wall: target enemy maybe (7.5,3.5) from player (2.5,2.5) with wall between? Let's find. But self-test can use castRay and lineOfSight.
- Restart resets.
Could implement temporary and then remove. But easier: use existing functions and console.log. Let's add temporary function at bottom before init? Need access. Use edit. Then press T. Let's do.

Add runSelfTest before onKeyDown.

Now press T.

No SELFTEST log? Maybe key t not recognized? Console shows only debug, maybe runSelfTest threw error? Console would show error. Maybe browser key "t" not sent because canvas focus? It should. Wait output truncated? It shows many debug logs but no selftest. Maybe key event code is "KeyT" only for physical key; action key with text "t" maybe uses keyboard.press("t") which sends key "t" not code? In onKeyDown e.code should be KeyT. It worked for Space earlier? We used text "Space" and it shot, so action key uses special key names. For "t", maybe keyboard.press("t") sends key with code? likely. But no selftest maybe error occurred and console omitted? Let's inspect with action inspect maybe.

Maybe browser console buffer only last 50 lines and selftest earlier pushed out? It should appear at end though. Maybe key "t" not recognized because action expects key name like "t" but sends to focused element? It did for w via type. Let's use action "type" with "t" maybe.

Still no selftest. Maybe browser console output truncated to last 50 and selftest log not shown because debug logs continue after; selftest should be latest before subsequent debug logs? Actually after runSelfTest, it restores and updateHud, then loop continues debug logs, so selftest may be pushed out by 50 debug logs (0.5s = many logs). We need reduce debug log frequency or remove debug before selftest. Let's remove debugLog first, then press T. Also maybe selftest restore old player but oldState etc; okay. Remove debug lines.

Selftest log missing blockedOk/restartOk? Object console maybe truncated? It shows only up to wallDist, perhaps console formatting? It should include all. Maybe runSelfTest threw after wallDist? Let's inspect code: after wallDist, blockedOk, restartOk, console.log object. If error, console error. Not shown. Maybe browser console serialization truncates object? It shows only first few properties due to formatting? Hmm. Need verify restartOk. Could log individually. Modify runSelfTest console.log to string. Also selftest restores old state, but after resetGame inside, it sets message etc. Fine. Let's change to console.log with concatenated string.

Great. Now remove selftest and T shortcut, debug. Also maybe need test rendering stable. We can sample scene? No images. Could use canvas pixel data via selftest? We can add temporary render check: after render, sample some pixels not all black? But rendering happens in loop. Could use requestAnimationFrame and canvas.toDataURL? No external. We can in selftest call render and inspect pixel values via getImageData. But render uses player and zbuffer; okay. Add temporary check in selftest: render(); const data=ctx.getImageData(0,0,W,H).data; count nonblack pixels; check walls. But render already called each frame. We can add to selftest before restore. Need ensure no error. Let's add temporarily maybe already selftest. We can modify runSelfTest to render and sample. Then press T. This verifies stable wall rendering. Add:
render();
const image=ctx.getImageData(0,0,W,H).data; let nonblack=0; for (let i=0;i<image.length;i+=4){ if (image[i]+image[i+1]+image[i+2]>10) nonblack++; } const renderOk=nonblack>5000;
console includes renderOk.
Need maybe render with current state after restart? At point after restartOk, player reset at start, good. Add before restore. Then test.

Great. Now remove selftest entirely and T shortcut. Also maybe check for JS errors after removal. Use edit to remove function. Need exact text. We'll read relevant lines.

Need find runSelfTest lines. Use grep.

Remove lines 1101-1178 and KeyT line. Use edit with exact function block maybe large. We can use edit oldText from "function runSelfTest() {" through "}" before onKeyDown. Need unique. Use edit.

Now check file syntax with node? We can extract script and run node? It uses DOM, but syntax check via `node --check` won't work with HTML. Could use grep. Maybe use browser reload and inspect console for errors.

Good. Need maybe test restart button click. Use browser click at restart button coordinates? Need coordinates. Could use DOM inspect? We know button at right bottom ~ x 900 y 570. Use click. But restart already via R maybe not tested. We can click restart button. Use browser click x=900 y=570. Then inspect.

Click maybe not on button due coordinates? But state already reset. Fine.

Need review code for bugs:
- renderSprite returns undefined if transformY <=0.12; used for enemy health bar only if info. okay.
- Exit sprite scale 0.72, verticalOffset bob. Good.
- Enemy occlusion via zbuffer. However renderSprite loops ray columns and draws slices; if sprite partially behind wall, zbuffer per ray. Good.
- Shooting: castRay uses player position; if enemy exactly same cell, okay.
- Enemy attack rule clear: within 1.45 and cooldown. It doesn't require LOS, but "under a clear attack rule" okay. Maybe should require line of sight? Enemies only chase when LOS but can attack if close even through wall? Since radius small, if within 1.45 but wall between, could damage through wall. Requirement only says shots cannot damage enemy through wall, not enemy attacks. But clear attack rule maybe should include LOS. Add LOS check to attack to be fair: if dist <1.45 && lineOfSight. This prevents through-wall damage. Let's add. Also enemy movement uses lineOfSight. Good.
- Player health zero game over. Restart restores.
- Exit unlock after all enemies. Reaching exit win.
- Enemies occluded by walls. Good.
- Textured grid maze with perspective wall heights. Good.
- Controls displayed.
- Mouse turning optional not required. We didn't implement mouse turning; optional means not required, okay.
- Solid wall collision. Good.
- Procedural textures. Good.
- No external assets. Good.

Potential issue: `castRay` when ray starts inside wall? Player never inside. Selftest placed at 5.5,2.5 open. Good.
Potential issue: `renderWalls` calls castRay(rayAngle) which uses player position and DDA; rayAngle derived from rayDir. Because DDA returns perpendicular distance to camera plane? Let's verify. We compute rayDir = dir + plane*cameraX. Then rayAngle = atan2(rayDir). DDA perp distance along ray direction. For a ray not parallel to camera plane, the perpendicular distance to camera plane is dist * cos(angle between ray and dir). But DDA returns distance along ray, not perpendicular to camera plane. Standard raycasting uses rayDir with plane and DDA formula `perpWallDist = sideDist - deltaDist`, which gives distance along rayDir, but because rayDir includes plane scaled by tan(FOV/2), the resulting perp distance is actually perpendicular to the camera plane? Let's recall: In standard raycasting, dirX,dirY and planeX,planeY perpendicular; rayDir = dir + plane*cameraX. DDA computes distance along rayDir. The wall height is 1/perpWallDist, and this works because rayDir is not normalized; the "perpWallDist" from DDA with non-normalized rayDir yields the distance measured in units of the camera plane? Let's analyze: DDA sideDist computed with deltaDist = abs(1/rayDir), so it's parameterized by rayDir. The returned perp is t such that hit = player + t*rayDir. The distance perpendicular to camera plane is t * (rayDir dot dir) because dir unit and plane perpendicular. Since rayDir dot dir = 1 (plane dot dir=0), t is exactly perpendicular distance. Yes because rayDir has component 1 along dir. Good. So no fisheye. Great.

Potential issue: `renderSprite` transform uses same plane; correct.
Potential issue: `renderSprite` source x mapping uses screenCol - left; if left negative, srcX negative for columns from 0; we skip srcX<0, meaning left part of sprite offscreen not drawn, fine. If sprite extends beyond right, lastRay limited, fine.
Potential issue: `renderSprite` uses `ctx.globalAlpha = alpha` then reset. Good.
Potential issue: enemy health bar depth check only center column; may draw bar over wall if center visible but edges occluded; minor.
Potential issue: `updateEnemies` returns after game over, but loop still calls updateEnemies? In update, if state playing then updatePlayer then updateEnemies; updateEnemies may set state over and return. Next frame state not playing so no update. Good.
Potential issue: `updateHud` called every frame, okay.
Potential issue: `resetGame` uses Math.random for bob, fine.
Potential issue: `hud.overlayTitle.style.color` set on win/over; initial no color. okay.
Potential issue: `setMessage("",0)` on win hides message. okay.
Potential issue: `keys` object uses e.code; arrow keys prevent default. Good.
Potential issue: Space keydown repeats when held, shoot cooldown handles. Good.
Potential issue: R restart even in playing. Good.
Potential issue: Enter restart only when not playing. Good.
Potential issue: Restart button and overlay button. Good.
Potential issue: Canvas focus for key events; window keydown anyway. Good.
Potential issue: No mouse turning; optional. Good.
Potential issue: `image-rendering: pixelated` with drawImage slices; fine.
Potential issue: `ctx.drawImage(tex, hit.texX, 0, 1, 64, i * COL, y0, COL + 0.5, wallHeight);` if y0 negative and wallHeight huge, drawImage handles. Good.
Potential issue: texture index `(mapX+mapY)&3` deterministic. Good.
Potential issue: map connectivity. We should verify with BFS maybe using node. Let's run quick script parse map and BFS from start to exit and enemy positions. Use bash node.

Good.

Need maybe add LOS to enemy attack. Let's edit.

Need maybe test game over and win states? Could simulate via code? We removed selftest. Could temporarily add? Not necessary but maybe verify with browser by using code? We can reason. But maybe we should test win/gameover via a temporary hook again? Time okay. Could add hidden test via console? Not needed. But to ensure, we can use browser with keyboard? Hard to move. Could use code injection through browser? no evaluate. Could add a temporary `KeyY` selftest for win/over, then remove. But we already tested core. Maybe not necessary.

However, there may be a bug in win condition: exit at (14.5,14.5), player can stand within 0.75? canStand radius 0.24 allows player up to 14.76? Map cell 14 open, wall at 15. Player can reach x=14.76, y=14.76, distance to exit 0.35, so yes. Good.
Game over overlay restart works.
Enemy damage: lineOfSight uses castRay from player? Wait lineOfSight(x0,y0,x1,y1) calls castRay, which always uses player.x/player.y as origin, not x0,y0. This is a bug! For enemy attack LOS, e.x,e.y as x0,y0 but castRay uses player position. For enemy chasing, lineOfSight(e.x,e.y,player.x,player.y) should cast from enemy to player, but castRay uses player as origin. It effectively checks wall from player to enemy, which is symmetric for distance along same line? castRay from player toward enemy gives wall distance from player; lineOfSight compares dist (enemy-player) < wallDist from player. That's actually correct for LOS between player and enemy, even though x0,y0 ignored. Since one endpoint is always player in our usage (enemy attack and chase), okay. But function generic is misleading. Shooting uses castRay directly from player. Fine. If we wanted generic, not needed. Could rename or implement properly to be robust. Let's implement generic raycast from arbitrary origin to avoid hidden bug if future. But castRay uses global player. Could add `castRayFrom(x,y,angle)` and `castRay` wrapper. This is better. Need update lineOfSight and maybe shooting? Shooting from player okay. Let's refactor carefully.

Current castRay(angle) uses player. We can change signature to castRay(angle, ox=player.x, oy=player.y) and use ox/oy. Then lineOfSight uses castRay(angle,x0,y0). Shooting uses castRay(angle) from player. Selftest removed. This is safe. Need edit all references within castRay. Let's do.

Check other castRay calls: renderWalls castRay(rayAngle) uses player default; crosshair castRay(...) default; shoot castRay(angle) default. Good.

Need maybe test syntax and rendering again. Reload.

Good.

Need maybe inspect file for external URLs. Use grep.

No external. Good.

Need maybe use browser to test fire feedback more. Space already hit. Could press Space multiple times to kill enemy and see enemy count decrease. Use key Space repeated maybe cooldown 0.34; action key press maybe enough time between calls. Let's press Space 4 times and inspect enemy count. Starting enemy hp 100, 34 dmg => 3 shots. But first earlier space already hit once in previous session? After reload, reset. Current session after reload no hit. Use key Space four times.

Health 55? Why? Enemy at (5.5,1.5) attacked? Distance 4, no. Maybe another enemy at (1.5,7.5) or (7.5,3.5) close? Start to (7.5,3.5) distance 6.3, no. Health 55 means took 45 damage, maybe multiple enemies attacked because game ran for a while and enemies chased? Wait enemies within 7 and LOS: enemy at (5.5,1.5) distance 4, LOS yes, chases player. It can reach player and attack during the time between reload and space (maybe seconds). So health 55. That's okay. Enemy count still 8. Message Hit! from shot. Good.

Need maybe press Space more to kill. But enemy may be near and damage. Use space.

Health 19, still 8. The enemy chasing attacked twice maybe. Space hits but not kill yet? Two hits should hp 32, still alive. Health dropped due attacks. Good. Another space should kill maybe but player might die. Let's press Space.

Game over works. But note enemy count still 8 and health 0. Good. Now click restart mission. Need coordinates overlay button center ~480,330. Use click.

Click maybe missed button. Need use R key to restart.

Restart works. Click on overlay maybe coordinates off due scaling? Not important; button works via keyboard and restart button maybe. But user requires provide Restart; we have button. Could test restart button click more accurately. The stage is scaled? Canvas CSS width 100% but internal 960; browser viewport 1200x800, stage maybe ~? The restart button at right bottom within stage, coordinates maybe x ~? Our click at 900,570 maybe perhaps missed because app width maybe 924 and stage starts x~138? Actually body centers app width min(960,100%) with padding 18; viewport 1200, so app width 960, stage x from 222 to 1182? Wait body padding 18, app width 960, centered in 1200 => left margin (1200-960)/2=120, plus padding? Actually body padding included in layout, so app left ~138. Stage width ~954. Restart button right 14 bottom 12 => x ~138+940=1078, y ~? h1 34 + stage top 18+? stage height ~596? button y ~? 18+34+596-30=618. Our click 900,570 missed. Overlay button center x ~138+477=615, y ~18+34+300=352. We clicked 480,330 missed. So not a bug. Could click restart button at 1070,610. Let's test after reset maybe. Use click.

It clicked and restarted? Health 64, message You are hit! Wait after R reset health 100, then time passed and enemy hit before click, health 64. The click may have hit restart button and reset to 100 then enemy hit immediately? Message "You are hit!" and health 64 suggests maybe click did not restart but enemy attacked. Hmm. Actually after R reset, enemies chase; by the time we click, enemy may attack and reduce health to 64. If click restarted, health would be 100. So click missed again. Button position maybe different. Not crucial.

But this reveals enemies can attack very quickly after reset (attackCooldown 0.4+i*0.12; enemy 0 at 0.4s, chases fast). At start, enemy at (5.5,1.5) distance 4, speed ~1.25, reaches in ~2.3s. Attack cooldown 0.4, so after ~2.7s. Our interactions took > that. Fine.

Could balance: enemy speed maybe too fast, attack damage 9, 8 enemies. But game is playable. Maybe reduce speed to 1.0 and attack cooldown 1.3. Not required. Keep.

Need maybe test win state? Could simulate by moving to exit after killing all enemies via code, but no evaluate. Could add temporary key Y to force kill all and teleport? Not necessary. But we can reason. Maybe there is a bug: `exitUnlocked` set when enemiesLeft===0 in shoot. Good. Win check in updatePlayer each frame. If player reaches exit, state win, overlay. Good.

Need maybe ensure enemies remaining count updates when killed. We saw not yet. Could test by making enemy hp low via code? Not without evaluate. Could press space many times but enemy attacks. We can restart then immediately space 3 times quickly; enemy might not reach in <1s. Let's do R then Space x3 with minimal delay. Use key r then space sequential. The browser calls have some delay but maybe <2s. Let's try.

Great. Enemy count 7, health 73 (attacked twice). Works.

Need maybe test exit locked message? Not necessary.

Potential issue: enemy at start chases and attacks too quickly, maybe game difficulty high but okay. Could reduce initial enemy attack cooldown to 1.0 maybe. Not required.

Need maybe remove console warning? It's from iframe sandbox, not our code. Fine.

Need final file present. We should maybe run a final browser reload and inspect no errors. Already. Maybe use `browser` action screenshot to see? unsupported. We can report checked.

But before final, let's review code for any remaining issues. Read some sections.

Looks good. One issue: renderSprite uses `dist` but not used except early return; fine.
One issue: exit sprite is rendered even if behind player? transformY check. Good.
One issue: enemy sprites sorted by Euclidean distance, but renderSprite uses transformY; sorting by distance is fine for painter's algorithm.
One issue: enemy occlusion uses zbuffer from walls only; sprites behind other sprites not occluded by enemies. Not required.
One issue: exit sprite maybe occluded by walls via zbuffer. Good.

Need maybe add floor/ceiling textures? Requirement says textured grid maze; walls textured enough. Floor has grid lines. Good.

Potential issue: `renderWalls` uses `ctx.drawImage(tex, hit.texX, 0, 1, 64, i * COL, y0, COL + 0.5, wallHeight);` For each ray, texture slice 1px wide scaled to 2px; with 480 rays, good. But because `image-rendering: pixelated`, smooth? fine.

Potential issue: `TAN_HALF_FOV` plane magnitude = tan(30°)=0.577, so FOV 60°. Good.

Potential issue: `angleDiff(player.dir, 0)` normalizes to [-π,π]. Good.

Potential issue: movement diagonal speed slightly higher (√2) if W+A; not a big deal. Could normalize but not required.

Potential issue: `canStand` checks corners but not center; radius 0.24, wall thickness 1, safe.

Potential issue: enemy movement `canStand(ex, e.y, 0.25)` but if ex is NaN? dx/dist safe. Good.

Potential issue: enemy separation can push into wall? canStand checks. Good.

Potential issue: attack uses lineOfSight(e.x,e.y,player.x,player.y) now generic with origin. Good.

Potential issue: `lineOfSight` computes `dist` and `castRay` from x0,y0. If x0,y0 inside wall? enemies not. Good.

Potential issue: `castRay` with origin near wall and angle pointing away, loop may break out of bounds and return dist 24. Fine.

Potential issue: `renderCrosshair` uses castRay for each enemy every frame; 8 rays, fine.

Potential issue: `updateHud` every frame sets style width even unchanged; fine.

Potential issue: `hud.damageFlash.style.opacity` set every frame; fine.

Potential issue: `messageTime` and `lockedMessageTime` both; setMessage overrides locked message maybe. Fine.

Potential issue: when exit unlocked, message "EXIT UNLOCKED!" then if player near exit, win overlay. Good.

Potential issue: restart button inside stage has z-index 4, overlay z-index 5, so overlay restart button above. Good.

Potential issue: overlay covers restart button when shown; overlay has own restart. Good.

Potential issue: canvas tabindex and focus. Good.

Potential issue: no mouse turning; optional. Good.

Need maybe final report concise. But before final, perhaps run one last reload and maybe key R to ensure initial. Already. Need maybe check file exists. Use bash.

Need final answer mention what checked and unverified. Since browser screenshots unsupported, mention DOM/console and self-test. But final should be concise. We can say:
- Created index.html with self-contained raycaster.
- Checked in browser: initial HUD, movement/turning and wall collision via scripted key/self-test (stopped at x=5.73 before wall), shot hit and wall block, restart reset, rendered frame sampled 571,491 lit pixels, game over and enemy count decrement observed.
- Unverified: visual screenshot/pixel-perfect texture appearance not inspected due no image support; mouse optional not implemented; actual win state not manually played through (logic present). But we did not keep self-test in final; we used temporary and removed. We can mention temporary verification harness removed. Need be honest: "I used a temporary self-test hook, then removed it." Good.

Need ensure final doesn't overdo. Also mention controls. No need to include code. Final with file path.