Zombie City

A browser-based zombie infection simulation rendered on HTML Canvas. A procedurally generated city fills the screen; citizens wander the streets until a zombie appears and the infection spreads.

Running

ES modules require an HTTP server — opening index.html directly via file:// will not work.

npx serve .
# or
python -m http.server 8000

Then open http://localhost:8000 (or the port shown).

Controls

Action	Input
Select patient zero	Click any citizen (when INITIAL_ZOMBIE = false)
Restart after infection complete	Click or press any key

Settings

All simulation knobs live at the top of simulation.js.

Population

Constant	Default	Description
NUM_CITIZENS	1000	Total number of entities in the simulation
DOT_RADIUS	2	Visual radius of every dot in pixels

Speeds

All speeds are in pixels per frame (target 60 fps).

Constant	Default	Description
CITIZEN_SPEED	1.2	Base walking speed of calm citizens
PANICKED_SPEED_MULTIPLIER	2.0	Speed multiplier applied to citizens who are fleeing
ZOMBIE_SPEED_MULTIPLIER	0.5	Speed multiplier for zombies wandering with no target
ZOMBIE_CHASE_SPEED_MULTIPLIER	2.0	Speed multiplier for zombies actively chasing a citizen

Vision & Infection

Constant	Default	Description
CITIZEN_VISION_DISTANCE	60	Pixels — radius in which a citizen can see a zombie. Line-of-sight occluded by buildings.
ZOMBIE_VISION_DISTANCE	150	Pixels — radius in which a zombie can detect a citizen
INFECTION_DISTANCE	10	Pixels — contact distance at which a zombie infects a citizen

Patient Zero

Constant	Default	Description
INITIAL_ZOMBIE	true	true — one random citizen is auto-infected at start. false — simulation waits; click any citizen to create patient zero.

City Generation

City layout constants live at the top of city.js.

Constant	Default	Description
TARGET_COLS	12	Target number of building columns (varies ±1 each run)
TARGET_ROWS	10	Target number of building rows (varies ±1 each run)
STREET_NARROW	18	Width of narrow side streets in pixels
STREET_NORMAL	28	Width of standard streets in pixels
STREET_BOULEVARD	52	Width of wide boulevards in pixels
ALLEY_WIDTH	14	Width of through-building alleys in pixels
BUILDING_INSET	4	Sidewalk width — gap between street edge and building face
BOULEVARD_CHANCE	0.13	Fraction of interior street dividers that become boulevards
NARROW_CHANCE	0.52	Fraction of remaining dividers that become narrow streets
ALLEY_CHANCE	0.10	Fraction of building blocks split by a through-alley
EMPTY_BLOCK_CHANCE	0.05	Fraction of blocks left empty (open plazas)