Starling Murmuration: 2D Boid Flocking Lab

This 2D companion runs the same three local boid rules as the 3D original — separation, alignment and cohesion — but from directly overhead, on a plain canvas built around a uniform spatial grid so hundreds of birds can be tested neighbour-by-neighbour every frame without a quadratic slowdown. A slow-drifting attraction point keeps the flock swirling rather than settling into a static blob, and a live "order parameter" readout — the length of the flock's mean velocity vector divided by its mean speed — turns the qualitative "does it look like a murmuration" question into a number between 0 (disordered swarm) and 1 (perfectly aligned flock) that visibly rises and falls as you retune the separation, alignment and cohesion weights. Click or tap the canvas to send a scare impulse through the nearest birds and watch the flock scatter and re-cohere.