Both captures below are real iTerm2 sessions running the demo — the same binary renders at pixel resolution where the terminal speaks the kitty graphics protocol, and as ASCII cells everywhere else.
kitty graphics — boids-gfx
A few hundred boids run Reynolds' separation / alignment / cohesion rules; each is an additive glow coloured by heading, drawn into a framebuffer that decays instead of clearing — so the flock trails motion-blur ribbons.
boids — kitty pixel mode
ASCII cells — boids
Each boid becomes a directional arrow glyph coloured by speed.
boids — ASCII cell mode
Controls
Key
Action
space
scatter the flock
mouse click
attractor at the pointer
a
toggle a predator
c
cycle colour scheme
+ / -
flock size
q / Esc
quit
Tuning env vars use the BOIDS_* prefix — e.g. BOIDS_MAXDIM=1024 for sharper frames, BOIDS_CELLS=1 to force cell rendering even on kitty terminals. See the overview for the full tuning table.
